Update drivers/staging/bcm/InterfaceInit.h #24

mdminhazulhaque · 2012-10-23T13:16:36Z

Added device ID of ZTE AX326.

This moves ARM over to the asm-generic/unaligned.h header. This has the benefit of better code generated especially for ARMv7 on gcc 4.7+ compilers. As Arnd Bergmann, points out: The asm-generic version uses the "struct" version for native-endian unaligned access and the "byteshift" version for the opposite endianess. The current ARM version however uses the "byteshift" implementation for both. Thanks to Nicolas Pitre for the excellent analysis: Test case: int foo (int *x) { return get_unaligned(x); } long long bar (long long *x) { return get_unaligned(x); } With the current ARM version: foo: ldrb r3, [r0, #2] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D) + 2B], MEM[(const u8 *)x_1(D) + 2B] ldrb r1, [r0, #1] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D) + 1B], MEM[(const u8 *)x_1(D) + 1B] ldrb r2, [r0, #0] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D)], MEM[(const u8 *)x_1(D)] mov r3, r3, asl #16 @ tmp154, MEM[(const u8 *)x_1(D) + 2B], ldrb r0, [r0, #3] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D) + 3B], MEM[(const u8 *)x_1(D) + 3B] orr r3, r3, r1, asl #8 @, tmp155, tmp154, MEM[(const u8 *)x_1(D) + 1B], orr r3, r3, r2 @ tmp157, tmp155, MEM[(const u8 *)x_1(D)] orr r0, r3, r0, asl #24 @,, tmp157, MEM[(const u8 *)x_1(D) + 3B], bx lr @ bar: stmfd sp!, {r4, r5, r6, r7} @, mov r2, #0 @ tmp184, ldrb r5, [r0, #6] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D) + 6B], MEM[(const u8 *)x_1(D) + 6B] ldrb r4, [r0, #5] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D) + 5B], MEM[(const u8 *)x_1(D) + 5B] ldrb ip, [r0, #2] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D) + 2B], MEM[(const u8 *)x_1(D) + 2B] ldrb r1, [r0, #4] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D) + 4B], MEM[(const u8 *)x_1(D) + 4B] mov r5, r5, asl #16 @ tmp175, MEM[(const u8 *)x_1(D) + 6B], ldrb r7, [r0, #1] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D) + 1B], MEM[(const u8 *)x_1(D) + 1B] orr r5, r5, r4, asl #8 @, tmp176, tmp175, MEM[(const u8 *)x_1(D) + 5B], ldrb r6, [r0, #7] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D) + 7B], MEM[(const u8 *)x_1(D) + 7B] orr r5, r5, r1 @ tmp178, tmp176, MEM[(const u8 *)x_1(D) + 4B] ldrb r4, [r0, #0] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D)], MEM[(const u8 *)x_1(D)] mov ip, ip, asl #16 @ tmp188, MEM[(const u8 *)x_1(D) + 2B], ldrb r1, [r0, #3] @ zero_extendqisi2 @ MEM[(const u8 *)x_1(D) + 3B], MEM[(const u8 *)x_1(D) + 3B] orr ip, ip, r7, asl #8 @, tmp189, tmp188, MEM[(const u8 *)x_1(D) + 1B], orr r3, r5, r6, asl #24 @,, tmp178, MEM[(const u8 *)x_1(D) + 7B], orr ip, ip, r4 @ tmp191, tmp189, MEM[(const u8 *)x_1(D)] orr ip, ip, r1, asl #24 @, tmp194, tmp191, MEM[(const u8 *)x_1(D) + 3B], mov r1, r3 @, orr r0, r2, ip @ tmp171, tmp184, tmp194 ldmfd sp!, {r4, r5, r6, r7} bx lr In both cases the code is slightly suboptimal. One may wonder why wasting r2 with the constant 0 in the second case for example. And all the mov's could be folded in subsequent orr's, etc. Now with the asm-generic version: foo: ldr r0, [r0, #0] @ unaligned @,* x bx lr @ bar: mov r3, r0 @ x, x ldr r0, [r0, #0] @ unaligned @,* x ldr r1, [r3, #4] @ unaligned @, bx lr @ This is way better of course, but only because this was compiled for ARMv7. In this case the compiler knows that the hardware can do unaligned word access. This isn't that obvious for foo(), but if we remove the get_unaligned() from bar as follows: long long bar (long long *x) {return *x; } then the resulting code is: bar: ldmia r0, {r0, r1} @ x,, bx lr @ So this proves that the presumed aligned vs unaligned cases does have influence on the instructions the compiler may use and that the above unaligned code results are not just an accident. Still... this isn't fully conclusive without at least looking at the resulting assembly fron a pre ARMv6 compilation. Let's see with an ARMv5 target: foo: ldrb r3, [r0, #0] @ zero_extendqisi2 @ tmp139,* x ldrb r1, [r0, #1] @ zero_extendqisi2 @ tmp140, ldrb r2, [r0, #2] @ zero_extendqisi2 @ tmp143, ldrb r0, [r0, #3] @ zero_extendqisi2 @ tmp146, orr r3, r3, r1, asl #8 @, tmp142, tmp139, tmp140, orr r3, r3, r2, asl #16 @, tmp145, tmp142, tmp143, orr r0, r3, r0, asl #24 @,, tmp145, tmp146, bx lr @ bar: stmfd sp!, {r4, r5, r6, r7} @, ldrb r2, [r0, #0] @ zero_extendqisi2 @ tmp139,* x ldrb r7, [r0, #1] @ zero_extendqisi2 @ tmp140, ldrb r3, [r0, #4] @ zero_extendqisi2 @ tmp149, ldrb r6, [r0, #5] @ zero_extendqisi2 @ tmp150, ldrb r5, [r0, #2] @ zero_extendqisi2 @ tmp143, ldrb r4, [r0, #6] @ zero_extendqisi2 @ tmp153, ldrb r1, [r0, #7] @ zero_extendqisi2 @ tmp156, ldrb ip, [r0, #3] @ zero_extendqisi2 @ tmp146, orr r2, r2, r7, asl #8 @, tmp142, tmp139, tmp140, orr r3, r3, r6, asl #8 @, tmp152, tmp149, tmp150, orr r2, r2, r5, asl #16 @, tmp145, tmp142, tmp143, orr r3, r3, r4, asl #16 @, tmp155, tmp152, tmp153, orr r0, r2, ip, asl #24 @,, tmp145, tmp146, orr r1, r3, r1, asl #24 @,, tmp155, tmp156, ldmfd sp!, {r4, r5, r6, r7} bx lr Compared to the initial results, this is really nicely optimized and I couldn't do much better if I were to hand code it myself. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

…d reasons We've had some reports of a deadlock where rpciod ends up with a stack trace like this: PID: 2507 TASK: ffff88103691ab40 CPU: 14 COMMAND: "rpciod/14" #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9 #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs] #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8 #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs] #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs] torvalds#6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670 torvalds#7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271 torvalds#8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638 torvalds#9 [ffff8810343bf818] shrink_zone at ffffffff8112788f torvalds#10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e torvalds#11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f torvalds#12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad torvalds#13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942 torvalds#14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a torvalds#15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9 torvalds#16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b torvalds#17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808 torvalds#18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c torvalds#19 [ffff8810343bfce8] inet_create at ffffffff81483ba6 torvalds#20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7 torvalds#21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc] torvalds#22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc] torvalds#23 [ffff8810343bfe38] worker_thread at ffffffff810887d0 torvalds#24 [ffff8810343bfee8] kthread at ffffffff8108dd96 torvalds#25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca rpciod is trying to allocate memory for a new socket to talk to the server. The VM ends up calling ->releasepage to get more memory, and it tries to do a blocking commit. That commit can't succeed however without a connected socket, so we deadlock. Fix this by setting PF_FSTRANS on the workqueue task prior to doing the socket allocation, and having nfs_release_page check for that flag when deciding whether to do a commit call. Also, set PF_FSTRANS unconditionally in rpc_async_schedule since that function can also do allocations sometimes. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org

Printing the "start_ip" for every secondary cpu is very noisy on a large system - and doesn't add any value. Drop this message. Console log before: Booting Node 0, Processors #1 smpboot cpu 1: start_ip = 96000 #2 smpboot cpu 2: start_ip = 96000 #3 smpboot cpu 3: start_ip = 96000 #4 smpboot cpu 4: start_ip = 96000 ... torvalds#31 smpboot cpu 31: start_ip = 96000 Brought up 32 CPUs Console log after: Booting Node 0, Processors #1 #2 #3 #4 #5 torvalds#6 torvalds#7 Ok. Booting Node 1, Processors torvalds#8 torvalds#9 torvalds#10 torvalds#11 torvalds#12 torvalds#13 torvalds#14 torvalds#15 Ok. Booting Node 0, Processors torvalds#16 torvalds#17 torvalds#18 torvalds#19 torvalds#20 torvalds#21 torvalds#22 torvalds#23 Ok. Booting Node 1, Processors torvalds#24 torvalds#25 torvalds#26 torvalds#27 torvalds#28 torvalds#29 torvalds#30 torvalds#31 Brought up 32 CPUs Acked-by: Borislav Petkov <bp@amd64.org> Signed-off-by: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/4f452eb42507460426@agluck-desktop.sc.intel.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>

…d reasons commit 5cf02d0 upstream. We've had some reports of a deadlock where rpciod ends up with a stack trace like this: PID: 2507 TASK: ffff88103691ab40 CPU: 14 COMMAND: "rpciod/14" #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9 #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs] #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8 #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs] #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs] #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670 #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271 #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638 #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f torvalds#10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e torvalds#11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f torvalds#12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad torvalds#13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942 torvalds#14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a torvalds#15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9 torvalds#16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b torvalds#17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808 torvalds#18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c torvalds#19 [ffff8810343bfce8] inet_create at ffffffff81483ba6 torvalds#20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7 torvalds#21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc] torvalds#22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc] torvalds#23 [ffff8810343bfe38] worker_thread at ffffffff810887d0 torvalds#24 [ffff8810343bfee8] kthread at ffffffff8108dd96 torvalds#25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca rpciod is trying to allocate memory for a new socket to talk to the server. The VM ends up calling ->releasepage to get more memory, and it tries to do a blocking commit. That commit can't succeed however without a connected socket, so we deadlock. Fix this by setting PF_FSTRANS on the workqueue task prior to doing the socket allocation, and having nfs_release_page check for that flag when deciding whether to do a commit call. Also, set PF_FSTRANS unconditionally in rpc_async_schedule since that function can also do allocations sometimes. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

asamy · 2012-11-03T12:02:55Z

To get your stuff accepted in the tree, you have to notify them on the mailing list, or send an email to Linus...
See: http://www.tux.org/lkml/

This is an fsfuzzer bug. ->s_journal is set at the end of ext3_load_journal() but we try to use it in the error handling from ext3_get_journal() while it's still NULL. [ 337.039041] BUG: unable to handle kernel NULL pointer dereference at 0000000000000024 [ 337.040380] IP: [<ffffffff816e6539>] _raw_spin_lock+0x9/0x30 [ 337.041687] PGD 0 [ 337.043118] Oops: 0002 [#1] SMP [ 337.044483] CPU 3 [ 337.044495] Modules linked in: ecb md4 cifs fuse kvm_intel kvm brcmsmac brcmutil crc8 cordic r8169 [last unloaded: scsi_wait_scan] [ 337.047633] [ 337.049259] Pid: 8308, comm: mount Not tainted 3.2.0-rc2-next-20111121+ torvalds#24 SAMSUNG ELECTRONICS CO., LTD. RV411/RV511/E3511/S3511 /RV411/RV511/E3511/S3511 [ 337.051064] RIP: 0010:[<ffffffff816e6539>] [<ffffffff816e6539>] _raw_spin_lock+0x9/0x30 [ 337.052879] RSP: 0018:ffff8800b1d11ae8 EFLAGS: 00010282 [ 337.054668] RAX: 0000000000000100 RBX: 0000000000000000 RCX: ffff8800b77c2000 [ 337.056400] RDX: ffff8800a97b5c00 RSI: 0000000000000000 RDI: 0000000000000024 [ 337.058099] RBP: ffff8800b1d11ae8 R08: 6000000000000000 R09: e018000000000000 [ 337.059841] R10: ff67366cc2607c03 R11: 00000000110688e6 R12: 0000000000000000 [ 337.061607] R13: 0000000000000000 R14: 0000000000000000 R15: ffff8800a78f06e8 [ 337.063385] FS: 00007f9d95652800(0000) GS:ffff8800b7180000(0000) knlGS:0000000000000000 [ 337.065110] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 337.066801] CR2: 0000000000000024 CR3: 00000000aef2c000 CR4: 00000000000006e0 [ 337.068581] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 337.070321] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 337.072105] Process mount (pid: 8308, threadinfo ffff8800b1d10000, task ffff8800b1d02be0) [ 337.073800] Stack: [ 337.075487] ffff8800b1d11b08 ffffffff811f48cf ffff88007ac9b158 0000000000000000 [ 337.077255] ffff8800b1d11b38 ffffffff8119405d ffff88007ac9b158 ffff88007ac9b250 [ 337.078851] ffffffff8181bda0 ffffffff8181bda0 ffff8800b1d11b68 ffffffff81131e31 [ 337.080284] Call Trace: [ 337.081706] [<ffffffff811f48cf>] log_start_commit+0x1f/0x40 [ 337.083107] [<ffffffff8119405d>] ext3_evict_inode+0x1fd/0x2a0 [ 337.084490] [<ffffffff81131e31>] evict+0xa1/0x1a0 [ 337.085857] [<ffffffff81132031>] iput+0x101/0x210 [ 337.087220] [<ffffffff811339d1>] iget_failed+0x21/0x30 [ 337.088581] [<ffffffff811905fc>] ext3_iget+0x15c/0x450 [ 337.089936] [<ffffffff8118b0c1>] ? ext3_rsv_window_add+0x81/0x100 [ 337.091284] [<ffffffff816df9a4>] ext3_get_journal+0x15/0xde [ 337.092641] [<ffffffff811a2e9b>] ext3_fill_super+0xf2b/0x1c30 [ 337.093991] [<ffffffff810ddf7d>] ? register_shrinker+0x4d/0x60 [ 337.095332] [<ffffffff8111c112>] mount_bdev+0x1a2/0x1e0 [ 337.096680] [<ffffffff811a1f70>] ? ext3_setup_super+0x210/0x210 [ 337.098026] [<ffffffff8119a770>] ext3_mount+0x10/0x20 [ 337.099362] [<ffffffff8111cbee>] mount_fs+0x3e/0x1b0 [ 337.100759] [<ffffffff810eda1b>] ? __alloc_percpu+0xb/0x10 [ 337.102330] [<ffffffff81135385>] vfs_kern_mount+0x65/0xc0 [ 337.103889] [<ffffffff8113611f>] do_kern_mount+0x4f/0x100 [ 337.105442] [<ffffffff811378fc>] do_mount+0x19c/0x890 [ 337.106989] [<ffffffff810e8456>] ? memdup_user+0x46/0x90 [ 337.108572] [<ffffffff810e84f3>] ? strndup_user+0x53/0x70 [ 337.110114] [<ffffffff811383fb>] sys_mount+0x8b/0xe0 [ 337.111617] [<ffffffff816ed93b>] system_call_fastpath+0x16/0x1b [ 337.113133] Code: 38 c2 74 0f 66 0f 1f 44 00 00 f3 90 0f b6 03 38 c2 75 f7 48 83 c4 08 5b 5d c3 0f 1f 84 00 00 00 00 00 55 b8 00 01 00 00 48 89 e5 <f0> 66 0f c1 07 0f b6 d4 38 c2 74 0c 0f 1f 00 f3 90 0f b6 07 38 [ 337.116588] RIP [<ffffffff816e6539>] _raw_spin_lock+0x9/0x30 [ 337.118260] RSP <ffff8800b1d11ae8> [ 337.119998] CR2: 0000000000000024 [ 337.188701] ---[ end trace c36d790becac1615 ]--- Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>

…d reasons commit 5cf02d0 upstream. We've had some reports of a deadlock where rpciod ends up with a stack trace like this: PID: 2507 TASK: ffff88103691ab40 CPU: 14 COMMAND: "rpciod/14" #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9 #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs] #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8 #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs] #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs] #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670 #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271 #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638 #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f torvalds#10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e torvalds#11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f torvalds#12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad torvalds#13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942 torvalds#14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a torvalds#15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9 torvalds#16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b torvalds#17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808 torvalds#18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c torvalds#19 [ffff8810343bfce8] inet_create at ffffffff81483ba6 torvalds#20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7 torvalds#21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc] torvalds#22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc] torvalds#23 [ffff8810343bfe38] worker_thread at ffffffff810887d0 torvalds#24 [ffff8810343bfee8] kthread at ffffffff8108dd96 torvalds#25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca rpciod is trying to allocate memory for a new socket to talk to the server. The VM ends up calling ->releasepage to get more memory, and it tries to do a blocking commit. That commit can't succeed however without a connected socket, so we deadlock. Fix this by setting PF_FSTRANS on the workqueue task prior to doing the socket allocation, and having nfs_release_page check for that flag when deciding whether to do a commit call. Also, set PF_FSTRANS unconditionally in rpc_async_schedule since that function can also do allocations sometimes. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

…d reasons BugLink: http://bugs.launchpad.net/bugs/1035435 commit 5cf02d0 upstream. We've had some reports of a deadlock where rpciod ends up with a stack trace like this: PID: 2507 TASK: ffff88103691ab40 CPU: 14 COMMAND: "rpciod/14" #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9 #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs] #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8 #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs] #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs] torvalds#6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670 torvalds#7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271 torvalds#8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638 torvalds#9 [ffff8810343bf818] shrink_zone at ffffffff8112788f torvalds#10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e torvalds#11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f torvalds#12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad torvalds#13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942 torvalds#14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a torvalds#15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9 torvalds#16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b torvalds#17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808 torvalds#18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c torvalds#19 [ffff8810343bfce8] inet_create at ffffffff81483ba6 torvalds#20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7 torvalds#21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc] torvalds#22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc] torvalds#23 [ffff8810343bfe38] worker_thread at ffffffff810887d0 torvalds#24 [ffff8810343bfee8] kthread at ffffffff8108dd96 torvalds#25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca rpciod is trying to allocate memory for a new socket to talk to the server. The VM ends up calling ->releasepage to get more memory, and it tries to do a blocking commit. That commit can't succeed however without a connected socket, so we deadlock. Fix this by setting PF_FSTRANS on the workqueue task prior to doing the socket allocation, and having nfs_release_page check for that flag when deciding whether to do a commit call. Also, set PF_FSTRANS unconditionally in rpc_async_schedule since that function can also do allocations sometimes. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>

…d reasons commit 5cf02d0 upstream. We've had some reports of a deadlock where rpciod ends up with a stack trace like this: PID: 2507 TASK: ffff88103691ab40 CPU: 14 COMMAND: "rpciod/14" #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9 #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs] #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8 #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs] #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs] #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670 #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271 #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638 #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f torvalds#10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e torvalds#11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f torvalds#12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad torvalds#13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942 torvalds#14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a torvalds#15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9 torvalds#16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b torvalds#17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808 torvalds#18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c torvalds#19 [ffff8810343bfce8] inet_create at ffffffff81483ba6 torvalds#20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7 torvalds#21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc] torvalds#22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc] torvalds#23 [ffff8810343bfe38] worker_thread at ffffffff810887d0 torvalds#24 [ffff8810343bfee8] kthread at ffffffff8108dd96 torvalds#25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca rpciod is trying to allocate memory for a new socket to talk to the server. The VM ends up calling ->releasepage to get more memory, and it tries to do a blocking commit. That commit can't succeed however without a connected socket, so we deadlock. Fix this by setting PF_FSTRANS on the workqueue task prior to doing the socket allocation, and having nfs_release_page check for that flag when deciding whether to do a commit call. Also, set PF_FSTRANS unconditionally in rpc_async_schedule since that function can also do allocations sometimes. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

ERROR: do not initialise statics to 0 or NULL torvalds#24: FILE: scripts/pnmtologo.c:77: +static int is_plain_pbm = 0; WARNING: line over 80 characters torvalds#33: FILE: scripts/pnmtologo.c:108: + * between the digits. This is Ok cause we know a PBM can only have a '1' total: 1 errors, 1 warnings, 25 lines checked ./patches/scripts-pnmtologo-fix-for-plain-pbm.patch has style problems, please review. If any of these errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Andreas Bießmann <andreas@biessmann.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

WARNING: line over 80 characters torvalds#24: FILE: fs/binfmt_elf.c:1604: + info->psinfo.data = NULL; /* So we don't free this wrongly */ ERROR: code indent should use tabs where possible torvalds#26: FILE: fs/binfmt_elf.c:1606: + }$ WARNING: please, no spaces at the start of a line torvalds#26: FILE: fs/binfmt_elf.c:1606: + }$ total: 1 errors, 2 warnings, 11 lines checked NOTE: whitespace errors detected, you may wish to use scripts/cleanpatch or scripts/cleanfile ./patches/binfmt_elf-fix-corner-case-kfree-of-uninitialized-data.patch has style problems, please review. If any of these errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

…d reasons commit 5cf02d0 upstream. We've had some reports of a deadlock where rpciod ends up with a stack trace like this: PID: 2507 TASK: ffff88103691ab40 CPU: 14 COMMAND: "rpciod/14" #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9 #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs] #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8 #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs] #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs] torvalds#6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670 torvalds#7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271 torvalds#8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638 torvalds#9 [ffff8810343bf818] shrink_zone at ffffffff8112788f torvalds#10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e torvalds#11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f torvalds#12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad torvalds#13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942 torvalds#14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a torvalds#15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9 torvalds#16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b torvalds#17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808 torvalds#18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c torvalds#19 [ffff8810343bfce8] inet_create at ffffffff81483ba6 torvalds#20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7 torvalds#21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc] torvalds#22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc] torvalds#23 [ffff8810343bfe38] worker_thread at ffffffff810887d0 torvalds#24 [ffff8810343bfee8] kthread at ffffffff8108dd96 torvalds#25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca rpciod is trying to allocate memory for a new socket to talk to the server. The VM ends up calling ->releasepage to get more memory, and it tries to do a blocking commit. That commit can't succeed however without a connected socket, so we deadlock. Fix this by setting PF_FSTRANS on the workqueue task prior to doing the socket allocation, and having nfs_release_page check for that flag when deciding whether to do a commit call. Also, set PF_FSTRANS unconditionally in rpc_async_schedule since that function can also do allocations sometimes. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ERROR: do not initialise statics to 0 or NULL #24: FILE: scripts/pnmtologo.c:77: +static int is_plain_pbm = 0; WARNING: line over 80 characters #33: FILE: scripts/pnmtologo.c:108: + * between the digits. This is Ok cause we know a PBM can only have a '1' total: 1 errors, 1 warnings, 25 lines checked ./patches/scripts-pnmtologo-fix-for-plain-pbm.patch has style problems, please review. If any of these errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Andreas Bießmann <andreas@biessmann.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

WARNING: line over 80 characters #24: FILE: fs/binfmt_elf.c:1604: + info->psinfo.data = NULL; /* So we don't free this wrongly */ ERROR: code indent should use tabs where possible #26: FILE: fs/binfmt_elf.c:1606: + }$ WARNING: please, no spaces at the start of a line #26: FILE: fs/binfmt_elf.c:1606: + }$ total: 1 errors, 2 warnings, 11 lines checked NOTE: whitespace errors detected, you may wish to use scripts/cleanpatch or scripts/cleanfile ./patches/binfmt_elf-fix-corner-case-kfree-of-uninitialized-data.patch has style problems, please review. If any of these errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

ERROR: do not initialise statics to 0 or NULL #24: FILE: scripts/pnmtologo.c:77: +static int is_plain_pbm = 0; WARNING: line over 80 characters #33: FILE: scripts/pnmtologo.c:108: + * between the digits. This is Ok cause we know a PBM can only have a '1' total: 1 errors, 1 warnings, 25 lines checked ./patches/scripts-pnmtologo-fix-for-plain-pbm.patch has style problems, please review. If any of these errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Andreas Bießmann <andreas@biessmann.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Yan Burman reported following lockdep warning : ============================================= [ INFO: possible recursive locking detected ] 3.7.0+ #24 Not tainted --------------------------------------------- swapper/1/0 is trying to acquire lock: (&n->lock){++--..}, at: [<ffffffff8139f56e>] __neigh_event_send +0x2e/0x2f0 but task is already holding lock: (&n->lock){++--..}, at: [<ffffffff813f63f4>] arp_solicit+0x1d4/0x280 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&n->lock); lock(&n->lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by swapper/1/0: #0: (((&n->timer))){+.-...}, at: [<ffffffff8104b350>] call_timer_fn+0x0/0x1c0 #1: (&n->lock){++--..}, at: [<ffffffff813f63f4>] arp_solicit +0x1d4/0x280 #2: (rcu_read_lock_bh){.+....}, at: [<ffffffff81395400>] dev_queue_xmit+0x0/0x5d0 #3: (rcu_read_lock_bh){.+....}, at: [<ffffffff813cb41e>] ip_finish_output+0x13e/0x640 stack backtrace: Pid: 0, comm: swapper/1 Not tainted 3.7.0+ #24 Call Trace: <IRQ> [<ffffffff8108c7ac>] validate_chain+0xdcc/0x11f0 [<ffffffff8108d570>] ? __lock_acquire+0x440/0xc30 [<ffffffff81120565>] ? kmem_cache_free+0xe5/0x1c0 [<ffffffff8108d570>] __lock_acquire+0x440/0xc30 [<ffffffff813c3570>] ? inet_getpeer+0x40/0x600 [<ffffffff8108d570>] ? __lock_acquire+0x440/0xc30 [<ffffffff8139f56e>] ? __neigh_event_send+0x2e/0x2f0 [<ffffffff8108ddf5>] lock_acquire+0x95/0x140 [<ffffffff8139f56e>] ? __neigh_event_send+0x2e/0x2f0 [<ffffffff8108d570>] ? __lock_acquire+0x440/0xc30 [<ffffffff81448d4b>] _raw_write_lock_bh+0x3b/0x50 [<ffffffff8139f56e>] ? __neigh_event_send+0x2e/0x2f0 [<ffffffff8139f56e>] __neigh_event_send+0x2e/0x2f0 [<ffffffff8139f99b>] neigh_resolve_output+0x16b/0x270 [<ffffffff813cb62d>] ip_finish_output+0x34d/0x640 [<ffffffff813cb41e>] ? ip_finish_output+0x13e/0x640 [<ffffffffa046f146>] ? vxlan_xmit+0x556/0xbec [vxlan] [<ffffffff813cb9a0>] ip_output+0x80/0xf0 [<ffffffff813ca368>] ip_local_out+0x28/0x80 [<ffffffffa046f25a>] vxlan_xmit+0x66a/0xbec [vxlan] [<ffffffffa046f146>] ? vxlan_xmit+0x556/0xbec [vxlan] [<ffffffff81394a50>] ? skb_gso_segment+0x2b0/0x2b0 [<ffffffff81449355>] ? _raw_spin_unlock_irqrestore+0x65/0x80 [<ffffffff81394c57>] ? dev_queue_xmit_nit+0x207/0x270 [<ffffffff813950c8>] dev_hard_start_xmit+0x298/0x5d0 [<ffffffff813956f3>] dev_queue_xmit+0x2f3/0x5d0 [<ffffffff81395400>] ? dev_hard_start_xmit+0x5d0/0x5d0 [<ffffffff813f5788>] arp_xmit+0x58/0x60 [<ffffffff813f59db>] arp_send+0x3b/0x40 [<ffffffff813f6424>] arp_solicit+0x204/0x280 [<ffffffff813a1a70>] ? neigh_add+0x310/0x310 [<ffffffff8139f515>] neigh_probe+0x45/0x70 [<ffffffff813a1c10>] neigh_timer_handler+0x1a0/0x2a0 [<ffffffff8104b3cf>] call_timer_fn+0x7f/0x1c0 [<ffffffff8104b350>] ? detach_if_pending+0x120/0x120 [<ffffffff8104b748>] run_timer_softirq+0x238/0x2b0 [<ffffffff813a1a70>] ? neigh_add+0x310/0x310 [<ffffffff81043e51>] __do_softirq+0x101/0x280 [<ffffffff814518cc>] call_softirq+0x1c/0x30 [<ffffffff81003b65>] do_softirq+0x85/0xc0 [<ffffffff81043a7e>] irq_exit+0x9e/0xc0 [<ffffffff810264f8>] smp_apic_timer_interrupt+0x68/0xa0 [<ffffffff8145122f>] apic_timer_interrupt+0x6f/0x80 <EOI> [<ffffffff8100a054>] ? mwait_idle+0xa4/0x1c0 [<ffffffff8100a04b>] ? mwait_idle+0x9b/0x1c0 [<ffffffff8100a6a9>] cpu_idle+0x89/0xe0 [<ffffffff81441127>] start_secondary+0x1b2/0x1b6 Bug is from arp_solicit(), releasing the neigh lock after arp_send() In case of vxlan, we eventually need to write lock a neigh lock later. Its a false positive, but we can get rid of it without lockdep annotations. We can instead use neigh_ha_snapshot() helper. Reported-by: Yan Burman <yanb@mellanox.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

ERROR: do not initialise statics to 0 or NULL torvalds#24: FILE: scripts/pnmtologo.c:77: +static int is_plain_pbm = 0; WARNING: line over 80 characters torvalds#33: FILE: scripts/pnmtologo.c:108: + * between the digits. This is Ok cause we know a PBM can only have a '1' total: 1 errors, 1 warnings, 25 lines checked ./patches/scripts-pnmtologo-fix-for-plain-pbm.patch has style problems, please review. If any of these errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Andreas Bießmann <andreas@biessmann.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

ERROR: do not initialise statics to 0 or NULL #24: FILE: scripts/pnmtologo.c:77: +static int is_plain_pbm = 0; WARNING: line over 80 characters #33: FILE: scripts/pnmtologo.c:108: + * between the digits. This is Ok cause we know a PBM can only have a '1' total: 1 errors, 1 warnings, 25 lines checked ./patches/scripts-pnmtologo-fix-for-plain-pbm.patch has style problems, please review. If any of these errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Andreas Bießmann <andreas@biessmann.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

ERROR: do not initialise statics to 0 or NULL torvalds#24: FILE: scripts/pnmtologo.c:77: +static int is_plain_pbm = 0; WARNING: line over 80 characters torvalds#33: FILE: scripts/pnmtologo.c:108: + * between the digits. This is Ok cause we know a PBM can only have a '1' total: 1 errors, 1 warnings, 25 lines checked ./patches/scripts-pnmtologo-fix-for-plain-pbm.patch has style problems, please review. If any of these errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Andreas Bießmann <andreas@biessmann.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

…d reasons commit 5cf02d0 upstream. We've had some reports of a deadlock where rpciod ends up with a stack trace like this: PID: 2507 TASK: ffff88103691ab40 CPU: 14 COMMAND: "rpciod/14" #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9 #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs] #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8 #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs] #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs] torvalds#6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670 torvalds#7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271 torvalds#8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638 torvalds#9 [ffff8810343bf818] shrink_zone at ffffffff8112788f torvalds#10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e torvalds#11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f torvalds#12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad torvalds#13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942 torvalds#14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a torvalds#15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9 torvalds#16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b torvalds#17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808 torvalds#18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c torvalds#19 [ffff8810343bfce8] inet_create at ffffffff81483ba6 torvalds#20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7 torvalds#21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc] torvalds#22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc] torvalds#23 [ffff8810343bfe38] worker_thread at ffffffff810887d0 torvalds#24 [ffff8810343bfee8] kthread at ffffffff8108dd96 torvalds#25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca rpciod is trying to allocate memory for a new socket to talk to the server. The VM ends up calling ->releasepage to get more memory, and it tries to do a blocking commit. That commit can't succeed however without a connected socket, so we deadlock. Fix this by setting PF_FSTRANS on the workqueue task prior to doing the socket allocation, and having nfs_release_page check for that flag when deciding whether to do a commit call. Also, set PF_FSTRANS unconditionally in rpc_async_schedule since that function can also do allocations sometimes. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

@task

One of the problems that arise when converting dedicated custom threadpool to workqueue is that the shared worker pool used by workqueue anonimizes each worker making it more difficult to identify what the worker was doing on which target from the output of sysrq-t or debug dump from oops, BUG() and friends. For example, after writeback is converted to use workqueue instead of priviate thread pool, there's no easy to tell which backing device a writeback work item was working on at the time of task dump, which, according to our writeback brethren, is important in tracking down issues with a lot of mounted file systems on a lot of different devices. This patchset implements a way for a work function to mark its execution instance so that task dump of the worker task includes information to indicate what the work item was doing. An example WARN dump would look like the following. WARNING: at fs/fs-writeback.c:1015 bdi_writeback_workfn+0x2b4/0x3c0() Modules linked in: CPU: 0 Pid: 28 Comm: kworker/u18:0 Not tainted 3.9.0-rc1-work+ torvalds#24 Hardware name: empty empty/S3992, BIOS 080011 10/26/2007 Workqueue: writeback bdi_writeback_workfn (flush-8:16) ffffffff820a3a98 ffff88015b927cb8 ffffffff81c61855 ffff88015b927cf8 ffffffff8108f500 0000000000000000 ffff88007a171948 ffff88007a1716b0 ffff88015b49df00 ffff88015b8d3940 0000000000000000 ffff88015b927d08 Call Trace: [<ffffffff81c61855>] dump_stack+0x19/0x1b [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0 ... This patch: Implement probe_kthread_data() which returns kthread_data if accessible. The function is equivalent to kthread_data() except that the specified @task may not be a kthread or its vfork_done is already cleared rendering struct kthread inaccessible. In the former case, probe_kthread_data() may return any value. In the latter, NULL. This will be used to safely print debug information without affecting synchronization in the normal paths. Workqueue debug info printing on dump_stack() and friends will make use of it. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Writeback has been recently converted to use workqueue instead of its private thread pool implementation. One negative side effect of this conversion is that there's no easy to tell which backing device a writeback work item was working on at the time of task dump, be it sysrq-t, BUG, WARN or whatever, which, according to our writeback brethren, is important in tracking down issues with a lot of mounted file systems on a lot of different devices. This patch restores that information using the new worker description facility. bdi_writeback_workfn() calls set_work_desc() to identify which bdi it's working on. The description is printed out together with the worqueue name and worker function as in the following example dump. WARNING: at fs/fs-writeback.c:1015 bdi_writeback_workfn+0x2b4/0x3c0() Modules linked in: Pid: 28, comm: kworker/u18:0 Not tainted 3.9.0-rc1-work+ torvalds#24 empty empty/S3992 Workqueue: writeback bdi_writeback_workfn (flush-8:16) ffffffff820a3a98 ffff88015b927cb8 ffffffff81c61855 ffff88015b927cf8 ffffffff8108f500 0000000000000000 ffff88007a171948 ffff88007a1716b0 ffff88015b49df00 ffff88015b8d3940 0000000000000000 ffff88015b927d08 Call Trace: [<ffffffff81c61855>] dump_stack+0x19/0x1b [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0 [<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20 [<ffffffff81200144>] bdi_writeback_workfn+0x2b4/0x3c0 [<ffffffff810b4c87>] process_one_work+0x1d7/0x660 [<ffffffff810b5c72>] worker_thread+0x122/0x380 [<ffffffff810bdfea>] kthread+0xea/0xf0 [<ffffffff81c6cedc>] ret_from_fork+0x7c/0xb0 Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

WARNING: suspect code indent for conditional statements (8, 24) torvalds#24: FILE: mm/migrate.c:199: else + isolated = folio_isolate_movable(folio, total: 0 errors, 1 warnings, 10 lines checked NOTE: For some of the reported defects, checkpatch may be able to mechanically convert to the typical style using --fix or --fix-inplace. ./patches/mm-migrate-convert-to-folio_isolate_movable.patch has style problems, please review. NOTE: If any of the errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The idea behind this patch is to delay the freeing of PT entry objects until the TLB flush is done. This patch: - Adds a tlb_flush_waitlist in amdgpu_vm_update_params which will keep the objects that need to be freed after tlb_flush. - Adds PT entries in this list in amdgpu_vm_ptes_update after finding the PT entry. - Changes functionality of amdgpu_vm_pt_free_dfs from (df_search + free) to simply freeing of the BOs, also renames it to amdgpu_vm_pt_free_list to reflect this same. - Exports function amdgpu_vm_pt_free_list to be called directly. - Calls amdgpu_vm_pt_free_list directly from amdgpu_vm_update_range. V2: rebase V4: Addressed review comments from Christian - add only locked PTEs entries in TLB flush waitlist. - do not create a separate function for list flush. - do not create a new lock for TLB flush. - there is no need to wait on tlb_flush_fence exclusively. V5: Addressed review comments from Christian - change the amdgpu_vm_pt_free_dfs's functionality to simple freeing of the objects and rename it. - add all the PTE objects in params->tlb_flush_waitlist - let amdgpu_vm_pt_free_root handle the freeing of BOs independently - call amdgpu_vm_pt_free_list directly V6: Rebase V7: Rebase V8: Added a NULL check to fix this backtrace issue: [ 415.351447] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 415.359245] #PF: supervisor write access in kernel mode [ 415.365081] #PF: error_code(0x0002) - not-present page [ 415.370817] PGD 101259067 P4D 101259067 PUD 10125a067 PMD 0 [ 415.377140] Oops: 0002 [#1] PREEMPT SMP NOPTI [ 415.382004] CPU: 0 PID: 25481 Comm: test_with_MPI.e Tainted: G OE 5.18.2-mi300-build-140423-ubuntu-22.04+ torvalds#24 [ 415.394437] Hardware name: AMD Corporation Sh51p/Sh51p, BIOS RMO1001AS 02/21/2024 [ 415.402797] RIP: 0010:amdgpu_vm_ptes_update+0x6fd/0xa10 [amdgpu] [ 415.409648] Code: 4c 89 ff 4d 8d 66 30 e8 f1 ed ff ff 48 85 db 74 42 48 39 5d a0 74 40 48 8b 53 20 48 8b 4b 18 48 8d 43 18 48 8d 75 b0 4c 89 ff <48 > 89 51 08 48 89 0a 49 8b 56 30 48 89 42 08 48 89 53 18 4c 89 63 [ 415.430621] RSP: 0018:ffffc9000401f990 EFLAGS: 00010287 [ 415.436456] RAX: ffff888147bb82f0 RBX: ffff888147bb82d8 RCX: 0000000000000000 [ 415.444426] RDX: 0000000000000000 RSI: ffffc9000401fa30 RDI: ffff888161f80000 [ 415.452397] RBP: ffffc9000401fa80 R08: 0000000000000000 R09: ffffc9000401fa00 [ 415.460368] R10: 00000007f0cc0000 R11: 00000007f0c85000 R12: ffffc9000401fb20 [ 415.468340] R13: 00000007f0d00000 R14: ffffc9000401faf0 R15: ffff888161f80000 [ 415.476312] FS: 00007f132ff89840(0000) GS:ffff889f87c00000(0000) knlGS:0000000000000000 [ 415.485350] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 415.491767] CR2: 0000000000000008 CR3: 0000000161d46003 CR4: 0000000000770ef0 [ 415.499738] PKRU: 55555554 [ 415.502750] Call Trace: [ 415.505482] <TASK> [ 415.507825] amdgpu_vm_update_range+0x32a/0x880 [amdgpu] [ 415.513869] amdgpu_vm_clear_freed+0x117/0x250 [amdgpu] [ 415.519814] amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu+0x18c/0x250 [amdgpu] [ 415.527729] kfd_ioctl_unmap_memory_from_gpu+0xed/0x340 [amdgpu] [ 415.534551] kfd_ioctl+0x3b6/0x510 [amdgpu] V9: Addressed review comments from Christian - No NULL check reqd for root PT freeing - Free PT list regardless of needs_flush - Move adding BOs in list in a separate function V10: Added Christian's RB V11: squash in list fix Cc: Christian König <Christian.Koenig@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Felix Kuehling <felix.kuehling@amd.com> Cc: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com> Acked-by: Felix Kuehling <felix.kuehling@amd.com> Acked-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com> Reviewed-by: Christian König <Christian.Koenig@amd.com> Tested-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com> Signed-off-by: Shashank Sharma <shashank.sharma@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

[ Upstream commit 3dd3841 ] profile->parent->dents[AAFS_PROF_DIR] could be NULL only if its parent is made from __create_missing_ancestors(..) and 'ent->old' is NULL in aa_replace_profiles(..). In that case, it must return an error code and the code, -ENOENT represents its state that the path of its parent is not existed yet. BUG: kernel NULL pointer dereference, address: 0000000000000030 PGD 0 P4D 0 PREEMPT SMP PTI CPU: 4 PID: 3362 Comm: apparmor_parser Not tainted 6.8.0-24-generic torvalds#24 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 RIP: 0010:aafs_create.constprop.0+0x7f/0x130 Code: 4c 63 e0 48 83 c4 18 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 c3 cc cc cc cc <4d> 8b 55 30 4d 8d ba a0 00 00 00 4c 89 55 c0 4c 89 ff e8 7a 6a ae RSP: 0018:ffffc9000b2c7c98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00000000000041ed RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000b2c7cd8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82baac10 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007be9f22cf740(0000) GS:ffff88817bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000030 CR3: 0000000134b08000 CR4: 00000000000006f0 Call Trace: <TASK> ? show_regs+0x6d/0x80 ? __die+0x24/0x80 ? page_fault_oops+0x99/0x1b0 ? kernelmode_fixup_or_oops+0xb2/0x140 ? __bad_area_nosemaphore+0x1a5/0x2c0 ? find_vma+0x34/0x60 ? bad_area_nosemaphore+0x16/0x30 ? do_user_addr_fault+0x2a2/0x6b0 ? exc_page_fault+0x83/0x1b0 ? asm_exc_page_fault+0x27/0x30 ? aafs_create.constprop.0+0x7f/0x130 ? aafs_create.constprop.0+0x51/0x130 __aafs_profile_mkdir+0x3d6/0x480 aa_replace_profiles+0x83f/0x1270 policy_update+0xe3/0x180 profile_load+0xbc/0x150 ? rw_verify_area+0x47/0x140 vfs_write+0x100/0x480 ? __x64_sys_openat+0x55/0xa0 ? syscall_exit_to_user_mode+0x86/0x260 ksys_write+0x73/0x100 __x64_sys_write+0x19/0x30 x64_sys_call+0x7e/0x25c0 do_syscall_64+0x7f/0x180 entry_SYSCALL_64_after_hwframe+0x78/0x80 RIP: 0033:0x7be9f211c574 Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89 RSP: 002b:00007ffd26f2b8c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00005d504415e200 RCX: 00007be9f211c574 RDX: 0000000000001fc1 RSI: 00005d504418bc80 RDI: 0000000000000004 RBP: 0000000000001fc1 R08: 0000000000001fc1 R09: 0000000080000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005d504418bc80 R13: 0000000000000004 R14: 00007ffd26f2b9b0 R15: 00007ffd26f2ba30 </TASK> Modules linked in: snd_seq_dummy snd_hrtimer qrtr snd_hda_codec_generic snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device i2c_i801 snd_timer i2c_smbus qxl snd soundcore drm_ttm_helper lpc_ich ttm joydev input_leds serio_raw mac_hid binfmt_misc msr parport_pc ppdev lp parport efi_pstore nfnetlink dmi_sysfs qemu_fw_cfg ip_tables x_tables autofs4 hid_generic usbhid hid ahci libahci psmouse virtio_rng xhci_pci xhci_pci_renesas CR2: 0000000000000030 ---[ end trace 0000000000000000 ]--- RIP: 0010:aafs_create.constprop.0+0x7f/0x130 Code: 4c 63 e0 48 83 c4 18 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 c3 cc cc cc cc <4d> 8b 55 30 4d 8d ba a0 00 00 00 4c 89 55 c0 4c 89 ff e8 7a 6a ae RSP: 0018:ffffc9000b2c7c98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00000000000041ed RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000b2c7cd8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82baac10 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007be9f22cf740(0000) GS:ffff88817bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000030 CR3: 0000000134b08000 CR4: 00000000000006f0 Signed-off-by: Leesoo Ahn <lsahn@ooseel.net> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

Otherwise another CPU's flushing vp request may intervene the list_add(). It leads to following kernel oops during guest destruction. general protection fault, probably for non-canonical address 0xdeacffffffffe248: 0000 [#1] SMP NOPTI CPU: 36 PID: 0 Comm: swapper/36 Tainted: G S W 5.12.0-rc2-chao+ torvalds#24 Hardware name: Intel Corporation ArcherCity/ArcherCity, BIOS EGSDCRB1.86B.0057.D03.2104150329 04/15/2021 RIP: 0010:vt_hardware_disable+0x132/0x1a0 [kvm_intel] Code: 48 8b 93 b8 1e 00 00 48 8b 83 c0 1e 00 00 48 89 42 08 48 89 10 4c 89 b3 b8 1e 00 00 4c 89 ab c0 1e 00 00 c7 43 20 ff ff ff 0 RSP: 0018:ff7c1d9340c6cf50 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ff314db1480d2780 RCX: 0000000000000027 RDX: 0000000000000027 RSI: ff314dcfbd2183b0 RDI: ff314dcfbd2183b8 RBP: ff7c1d9340c6cf78 R08: 0000000000000000 R09: c0000000ffffbfff R10: 0000000000000001 R11: ff7c1d9340c6ccf8 R12: deacffffffffe248 R13: dead000000000122 R14: dead000000000100 R15: ff314dcfbd22f020 FS: 0000000000000000(0000) GS:ff314dcfbd200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d086915f44 CR3: 000000015ea28006 CR4: 0000000000773ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <IRQ> kvm_arch_hardware_disable+0xe/0x40 [kvm] hardware_disable_nolock+0x32/0x40 [kvm] flush_smp_call_function_queue+0x125/0x1b0 generic_smp_call_function_single_interrupt+0x13/0x20 __sysvec_call_function+0x30/0xa0 sysvec_call_function+0x73/0xa0 </IRQ> asm_sysvec_call_function+0x12/0x20 Fixes: e68c216b9069 ("KVM: TDX: Add "basic" support for building and running Trust Domains") Signed-off-by: Chao Gao <chao.gao@intel.com>

[ Upstream commit 3dd3841 ] profile->parent->dents[AAFS_PROF_DIR] could be NULL only if its parent is made from __create_missing_ancestors(..) and 'ent->old' is NULL in aa_replace_profiles(..). In that case, it must return an error code and the code, -ENOENT represents its state that the path of its parent is not existed yet. BUG: kernel NULL pointer dereference, address: 0000000000000030 PGD 0 P4D 0 PREEMPT SMP PTI CPU: 4 PID: 3362 Comm: apparmor_parser Not tainted 6.8.0-24-generic torvalds#24 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 RIP: 0010:aafs_create.constprop.0+0x7f/0x130 Code: 4c 63 e0 48 83 c4 18 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 c3 cc cc cc cc <4d> 8b 55 30 4d 8d ba a0 00 00 00 4c 89 55 c0 4c 89 ff e8 7a 6a ae RSP: 0018:ffffc9000b2c7c98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00000000000041ed RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000b2c7cd8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82baac10 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007be9f22cf740(0000) GS:ffff88817bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000030 CR3: 0000000134b08000 CR4: 00000000000006f0 Call Trace: <TASK> ? show_regs+0x6d/0x80 ? __die+0x24/0x80 ? page_fault_oops+0x99/0x1b0 ? kernelmode_fixup_or_oops+0xb2/0x140 ? __bad_area_nosemaphore+0x1a5/0x2c0 ? find_vma+0x34/0x60 ? bad_area_nosemaphore+0x16/0x30 ? do_user_addr_fault+0x2a2/0x6b0 ? exc_page_fault+0x83/0x1b0 ? asm_exc_page_fault+0x27/0x30 ? aafs_create.constprop.0+0x7f/0x130 ? aafs_create.constprop.0+0x51/0x130 __aafs_profile_mkdir+0x3d6/0x480 aa_replace_profiles+0x83f/0x1270 policy_update+0xe3/0x180 profile_load+0xbc/0x150 ? rw_verify_area+0x47/0x140 vfs_write+0x100/0x480 ? __x64_sys_openat+0x55/0xa0 ? syscall_exit_to_user_mode+0x86/0x260 ksys_write+0x73/0x100 __x64_sys_write+0x19/0x30 x64_sys_call+0x7e/0x25c0 do_syscall_64+0x7f/0x180 entry_SYSCALL_64_after_hwframe+0x78/0x80 RIP: 0033:0x7be9f211c574 Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89 RSP: 002b:00007ffd26f2b8c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00005d504415e200 RCX: 00007be9f211c574 RDX: 0000000000001fc1 RSI: 00005d504418bc80 RDI: 0000000000000004 RBP: 0000000000001fc1 R08: 0000000000001fc1 R09: 0000000080000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005d504418bc80 R13: 0000000000000004 R14: 00007ffd26f2b9b0 R15: 00007ffd26f2ba30 </TASK> Modules linked in: snd_seq_dummy snd_hrtimer qrtr snd_hda_codec_generic snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device i2c_i801 snd_timer i2c_smbus qxl snd soundcore drm_ttm_helper lpc_ich ttm joydev input_leds serio_raw mac_hid binfmt_misc msr parport_pc ppdev lp parport efi_pstore nfnetlink dmi_sysfs qemu_fw_cfg ip_tables x_tables autofs4 hid_generic usbhid hid ahci libahci psmouse virtio_rng xhci_pci xhci_pci_renesas CR2: 0000000000000030 ---[ end trace 0000000000000000 ]--- RIP: 0010:aafs_create.constprop.0+0x7f/0x130 Code: 4c 63 e0 48 83 c4 18 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 c3 cc cc cc cc <4d> 8b 55 30 4d 8d ba a0 00 00 00 4c 89 55 c0 4c 89 ff e8 7a 6a ae RSP: 0018:ffffc9000b2c7c98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00000000000041ed RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000b2c7cd8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82baac10 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007be9f22cf740(0000) GS:ffff88817bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000030 CR3: 0000000134b08000 CR4: 00000000000006f0 Signed-off-by: Leesoo Ahn <lsahn@ooseel.net> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

KASAN reported a null-ptr-deref issue when executing the following command: # echo ts2020 0x20 > /sys/bus/i2c/devices/i2c-0/new_device KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 53 UID: 0 PID: 970 Comm: systemd-udevd Not tainted 6.12.0-rc2+ torvalds#24 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009) RIP: 0010:ts2020_probe+0xad/0xe10 [ts2020] RSP: 0018:ffffc9000abbf598 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffffc0714809 RDX: 0000000000000002 RSI: ffff88811550be00 RDI: 0000000000000010 RBP: ffff888109868800 R08: 0000000000000001 R09: fffff52001577eb6 R10: 0000000000000000 R11: ffffc9000abbff50 R12: ffffffffc0714790 R13: 1ffff92001577eb8 R14: ffffffffc07190d0 R15: 0000000000000001 FS: 00007f95f13b98c0(0000) GS:ffff888149280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555d2634b000 CR3: 0000000152236000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ts2020_probe+0xad/0xe10 [ts2020] i2c_device_probe+0x421/0xb40 really_probe+0x266/0x850 ... The cause of the problem is that when using sysfs to dynamically register an i2c device, there is no platform data, but the probe process of ts2020 needs to use platform data, resulting in a null pointer being accessed. Solve this problem by adding checks to platform data. Fixes: dc245a5 ("[media] ts2020: implement I2C client bindings") Signed-off-by: Li Zetao <lizetao1@huawei.com>

When firmware crashes on startup, the htt logic may be stopped twice, leading to use-after free and/or double-free problems. This is from my 4.16 tree, which has my own changes as well as some patches cherry-picked from upstream. Firmware is modified 10.4 on 9984, but no firmware should cause the driver to crash, so firmware is mostly of no concern. I added a WARN_ON in the ath10k_htt_rx_free and a bit of printk debugging to help understand how this happens. Here is the log of the call path. The WARN_ON is the first rx_free, the BUG is the second one. With this patch, it has survived multiple crashes of the firmware on startup without trouble. [ 132.560515] ath10k_pci 0000:04:00.0: htt-rx-alloc, htt rx ring size 2048 fill_level 1023 netbufs_ring: 000000007e01aa60 [ 132.570374] ath10k_pci 0000:04:00.0: boot hif start [ 132.576061] ath10k_pci 0000:04:00.0: boot htc service HTT Data does not allocate target credits [ 132.576160] ath10k_pci 0000:04:00.0: boot htc service 'HTT Data' ul pipe 4 dl pipe 5 eid 1 ready [ 132.576163] ath10k_pci 0000:04:00.0: boot htc service 'HTT Data' eid 1 TX flow control disabled [ 132.576869] ath10k_pci 0000:04:00.0: boot htc service 'WMI' ul pipe 3 dl pipe 2 eid 2 ready [ 132.577693] ath10k_pci 0000:04:00.0: firmware 10.4-ct-9984-xtH-004-cf82bd4 booted [ 132.577716] ath10k_pci 0000:04:00.0: 10.4 wmi init: vdevs: 4 peers: 64 tid: 156 [ 132.577719] ath10k_pci 0000:04:00.0: using rx swcrypt [ 132.577722] ath10k_pci 0000:04:00.0: using 7 firmware rate-ctrl objects [ 132.577725] ath10k_pci 0000:04:00.0: msdu-desc: 2200 skid: 60 [ 132.582645] e1000e: eth5 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx [ 132.652834] ath10k_pci 0000:04:00.0: wmi print 'P 64 V 4 T 238' [ 132.652871] ath10k_pci 0000:04:00.0: wmi print 'msdu-desc: 2200 sw-crypt: 1' [ 132.653499] ath10k_pci 0000:04:00.0: wmi print 'free: 65288 iram: 5108 sram: 19380' [ 132.654306] ath10k_pci 0000:04:00.0: htt target version 2.2 [ 132.981802] ath10k_pci 0000:04:00.0: firmware crashed! (guid 90d614c4-915e-4d23-9929-e5fb1da30789) [ 132.989839] ath10k_pci 0000:04:00.0: qca9984/qca9994 hw1.0 target 0x01000000 chip_id 0x00000000 sub 168c:cafe [ 132.989845] ath10k_pci 0000:04:00.0: kconfig debug 1 debugfs 1 tracing 1 dfs 1 testmode 1 [ 132.990776] ath10k_pci 0000:04:00.0: firmware ver 10.4-ct-9984-xtH-004-cf82bd4 api 5 features peer-flow-ctrl,txstatus-noack,wmi-10.x-CT,rxswcrypt-CT8 [ 132.991007] ath10k_pci 0000:04:00.0: board_file api 2 bmi_id 0:31 crc32 e807b522 [ 132.991011] ath10k_pci 0000:04:00.0: htt-ver 2.2 wmi-op 6 htt-op 4 cal otp max-sta 64 raw 0 hwcrypto 1 [ 132.993057] ath10k_pci 0000:04:00.0: firmware register dump: *** snip *** [ 133.546095] igb 0000:01:00.3 eth3: igb: eth3 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX [ 133.546343] ath10k_pci 0000:04:00.0: failed to update channel list: -108 [ 133.546375] ath10k_pci 0000:04:00.0: failed to set pdev regdomain: -108 [ 133.546401] ath10k_pci 0000:04:00.0: failed to set quiet mode period 100 duarion 0 enabled 0 ret -108 [ 133.546475] ath10k_pci 0000:04:00.0: failed to create WMI vdev 0: -108 [ 133.553696] ath10k_pci 0000:04:00.0: boot hif stop [ 133.553756] ath10k_pci 0000:04:00.0: boot qca99x0 chip reset [ 133.553759] ath10k_pci 0000:04:00.0: boot cold reset [ 133.597554] ath10k_pci 0000:04:00.0: boot cold reset complete [ 133.597559] ath10k_pci 0000:04:00.0: boot waiting target to initialise [ 133.597564] ath10k_pci 0000:04:00.0: boot target indicator 2 [ 133.597570] ath10k_pci 0000:04:00.0: boot target initialised [ 133.597572] ath10k_pci 0000:04:00.0: boot qca99x0 chip reset complete (cold) [ 133.606567] htt-rx-free, ring-sz: 16384 vaddr: 00000000731130b3 base_paddr: 4275339264 [ 133.615109] htt-rx-free, sizeof vaddr: 4 vaddr: 0000000095a6e617 paddr: 4280053760 netbufs_ring: 000000007e01aa60 [ 133.625808] WARNING: CPU: 3 PID: 289 at /home/greearb/git/linux-4.16.dev.y/drivers/net/wireless/ath/ath10k/htt_rx.c:304 ath10k_htt_rx_free+0x33e/0x7] [ 133.625810] Modules linked in: bonding veth vrf 8021q garp mrp stp llc fuse macvlan pktgen nfsv3 nfs fscache snd_hda_codec_hdmi iTCO_wdt iTCO_vendort [ 133.625914] CPU: 3 PID: 289 Comm: kworker/u8:3 Tainted: G W 4.16.18+ torvalds#24 [ 133.625915] Hardware name: _ _/, BIOS 5.11 08/26/2016 [ 133.625927] Workqueue: ath10k_wq ath10k_core_restart [ath10k_core] [ 133.625939] RIP: 0010:ath10k_htt_rx_free+0x33e/0x740 [ath10k_core] [ 133.625941] RSP: 0018:ffff880143dcfc98 EFLAGS: 00010286 [ 133.625945] RAX: 0000000000000067 RBX: ffff880140b84fe8 RCX: 0000000000000000 [ 133.625947] RDX: 0000000000000067 RSI: ffff88014df9f718 RDI: ffffed00287b9f89 [ 133.625949] RBP: ffff880140b85110 R08: 0000000000000001 R09: 0000000000000000 [ 133.625950] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880140b85118 [ 133.625953] R13: ffff880140b85060 R14: ffff880171d9c000 R15: ffff880171d9c000 [ 133.625955] FS: 0000000000000000(0000) GS:ffff88014df80000(0000) knlGS:0000000000000000 [ 133.625957] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 133.625959] CR2: 0000556f59a470f8 CR3: 0000000003a14005 CR4: 00000000003606e0 [ 133.625961] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 133.625963] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 133.625964] Call Trace: [ 133.625980] ath10k_core_stop+0x127/0x180 [ath10k_core] [ 133.625990] ath10k_halt+0x3d0/0x630 [ath10k_core] [ 133.626003] ath10k_core_restart+0x166/0x230 [ath10k_core] [ 133.626024] process_one_work+0x5f7/0x14d0 [ 133.626033] ? pwq_dec_nr_in_flight+0x2b0/0x2b0 [ 133.626039] ? _raw_spin_unlock_irq+0x24/0x40 [ 133.626046] worker_thread+0xdc/0x12d0 [ 133.626059] ? rescuer_thread+0x12b0/0x12b0 [ 133.626062] kthread+0x2cf/0x3c0 [ 133.626065] ? kthread_delayed_work_timer_fn+0x1e0/0x1e0 [ 133.626070] ret_from_fork+0x24/0x30 [ 133.626081] Code: 00 00 48 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 5d 02 00 00 48 8b 93 28 01 00 00 be 04 00 00 00 48 c7 c7 60 57 7f a1 e8 e7 31 bf df < [ 133.626170] ---[ end trace 1183b41e13eec444 ]--- [ 133.626186] ath10k_pci 0000:04:00.0: boot hif power down [ 133.626192] ieee80211 wiphy1: Hardware restart was requested [ 133.638827] ath10k_pci 0000:04:00.0: failed to read hi_board_data address: -16 [ 133.638861] ath10k_pci 0000:04:00.0: boot hif stop [ 133.638955] ath10k_pci 0000:04:00.0: boot qca99x0 chip reset [ 133.638957] ath10k_pci 0000:04:00.0: boot cold reset [ 133.682411] ath10k_pci 0000:04:00.0: boot cold reset complete [ 133.682416] ath10k_pci 0000:04:00.0: boot waiting target to initialise [ 133.682421] ath10k_pci 0000:04:00.0: boot target indicator 2 [ 133.682427] ath10k_pci 0000:04:00.0: boot target initialised [ 133.682430] ath10k_pci 0000:04:00.0: boot qca99x0 chip reset complete (cold) [ 133.682589] htt-rx-free, ring-sz: 0 vaddr: 00000000731130b3 base_paddr: 4275339264 [ 133.690694] ------------[ cut here ]------------ [ 133.690697] kernel BUG at /home/greearb/git/linux-4.16.dev.y/drivers/iommu/intel-iommu.c:1260! [ 133.699699] invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI [ 133.705511] Modules linked in: bonding veth vrf 8021q garp mrp stp llc fuse macvlan pktgen nfsv3 nfs fscache snd_hda_codec_hdmi iTCO_wdt iTCO_vendort [ 133.763582] CPU: 3 PID: 3288 Comm: hostapd Tainted: G W 4.16.18+ torvalds#24 [ 133.771573] Hardware name: _ _/, BIOS 5.11 08/26/2016 [ 133.777051] RIP: 0010:domain_unmap+0x1cf/0x230 [ 133.782026] RSP: 0018:ffff8801390d7588 EFLAGS: 00010202 [ 133.787769] RAX: 0000000000000000 RBX: ffff880145b98d00 RCX: 0000000000000024 [ 133.795390] RDX: 0000000000000000 RSI: 00000000000fed48 RDI: ffff880145b998dc [ 133.803015] RBP: 00000000000fed48 R08: 0000000000000000 R09: 0000000000000000 [ 133.810642] R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000fed47 [ 133.818854] R13: ffff88014d819b80 R14: 0000000000000002 R15: 00000000000fed48 [ 133.826490] FS: 00007f72c2cde800(0000) GS:ffff88014df80000(0000) knlGS:0000000000000000 [ 133.835109] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 133.841414] CR2: 0000556f59a470f8 CR3: 000000013ad6c004 CR4: 00000000003606e0 [ 133.849118] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 133.856840] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 133.864528] Call Trace: [ 133.867533] intel_unmap+0xbb/0x1d0 [ 133.871618] intel_free_coherent+0x92/0x120 [ 133.876281] ath10k_htt_rx_free+0x2b8/0x740 [ath10k_core] [ 133.882282] ath10k_core_stop+0x127/0x180 [ath10k_core] [ 133.888040] ath10k_halt+0x3d0/0x630 [ath10k_core] [ 133.893316] ath10k_stop+0xa9/0xf0 [ath10k_core] [ 133.898493] drv_stop+0xc8/0x5a0 [mac80211] [ 133.903174] ieee80211_do_open+0x1137/0x1b60 [mac80211] [ 133.908912] __dev_open+0x185/0x2c0 [ 133.912893] ? dev_set_rx_mode+0x30/0x30 [ 133.917250] ? trace_hardirqs_on_caller+0x3ea/0x560 [ 133.922640] ? __dev_change_flags+0x14b/0x4c0 [ 133.927478] __dev_change_flags+0x39b/0x4c0 [ 133.932147] ? dev_set_allmulti+0x10/0x10 [ 133.936604] ? lock_downgrade+0x580/0x580 [ 133.941071] dev_change_flags+0x75/0x150 [ 133.945426] devinet_ioctl+0xf6f/0x1600 [ 133.949678] ? inet_ioctl+0x171/0x2d0 [ 133.953725] inet_ioctl+0x171/0x2d0 [ 133.957562] ? inet_getname+0x3d0/0x3d0 [ 133.961764] ? dev_load+0x66/0x150 [ 133.965519] ? __might_fault+0xea/0x1a0 [ 133.969677] ? lock_downgrade+0x580/0x580 [ 133.973961] ? sock_do_ioctl+0xef/0x250 [ 133.978068] sock_do_ioctl+0xef/0x250 [ 133.982050] ? compat_ifr_data_ioctl+0x130/0x130 [ 133.986919] ? __lock_acquire_lockdep+0xb4d/0x3de0 [ 133.991930] ? ___sys_sendmsg+0x8f0/0x8f0 [ 133.996171] ? debug_check_no_locks_freed+0x290/0x290 [ 134.001468] ? sock_ioctl+0x407/0x500 [ 134.005317] sock_ioctl+0x407/0x500 [ 134.008969] ? dlci_ioctl_set+0x30/0x30 [ 134.013675] ? __audit_syscall_entry+0x2f5/0x5f0 [ 134.018978] ? lock_downgrade+0x580/0x580 [ 134.023639] ? lock_acquire+0x114/0x330 [ 134.027621] ? do_vfs_ioctl+0x16e/0xe70 [ 134.031593] do_vfs_ioctl+0x16e/0xe70 [ 134.035314] ? trace_hardirqs_on_caller+0x3ea/0x560 [ 134.040260] ? ioctl_preallocate+0x170/0x170 [ 134.044640] ? __audit_syscall_entry+0x2f5/0x5f0 [ 134.049311] ? syscall_trace_enter+0x51a/0xbf0 [ 134.053776] ? kfree+0x299/0x300 [ 134.056983] ? trace_raw_output_sys_exit+0xe0/0xe0 [ 134.061753] ? __audit_syscall_exit+0x722/0xa00 [ 134.066235] SyS_ioctl+0x6f/0x80 [ 134.069416] ? do_vfs_ioctl+0xe70/0xe70 [ 134.073129] do_syscall_64+0x193/0x5e0 [ 134.076712] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 134.081501] RIP: 0033:0x7f72c163ccc7 [ 134.084828] RSP: 002b:00007ffd098bf558 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 134.092124] RAX: ffffffffffffffda RBX: 0000000002071e10 RCX: 00007f72c163ccc7 [ 134.099044] RDX: 00007ffd098bf570 RSI: 0000000000008914 RDI: 0000000000000009 [ 134.105983] RBP: 00007ffd098bf5a0 R08: 0000000002075100 R09: 0000000000000000 [ 134.112885] R10: 0000000000019630 R11: 0000000000000206 R12: 0000000000408320 [ 134.119781] R13: 00007ffd098bfa70 R14: 0000000000000000 R15: 0000000000000000 [ 134.126684] Code: 89 fe 48 c1 ee 03 80 3c 0e 00 75 2b 48 89 45 10 48 c7 83 d0 0b 00 00 00 00 00 00 48 83 c4 08 5b 48 89 e8 5d 41 5c 41 5d 41 5e c3 < [ 134.146604] RIP: domain_unmap+0x1cf/0x230 RSP: ffff8801390d7588 [ 134.152466] ---[ end trace 1183b41e13eec445 ]--- Signed-off-by: Ben Greear <greearb@candelatech.com>

KASAN reported a null-ptr-deref issue when executing the following command: # echo ts2020 0x20 > /sys/bus/i2c/devices/i2c-0/new_device KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 53 UID: 0 PID: 970 Comm: systemd-udevd Not tainted 6.12.0-rc2+ torvalds#24 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009) RIP: 0010:ts2020_probe+0xad/0xe10 [ts2020] RSP: 0018:ffffc9000abbf598 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffffc0714809 RDX: 0000000000000002 RSI: ffff88811550be00 RDI: 0000000000000010 RBP: ffff888109868800 R08: 0000000000000001 R09: fffff52001577eb6 R10: 0000000000000000 R11: ffffc9000abbff50 R12: ffffffffc0714790 R13: 1ffff92001577eb8 R14: ffffffffc07190d0 R15: 0000000000000001 FS: 00007f95f13b98c0(0000) GS:ffff888149280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555d2634b000 CR3: 0000000152236000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ts2020_probe+0xad/0xe10 [ts2020] i2c_device_probe+0x421/0xb40 really_probe+0x266/0x850 ... The cause of the problem is that when using sysfs to dynamically register an i2c device, there is no platform data, but the probe process of ts2020 needs to use platform data, resulting in a null pointer being accessed. Solve this problem by adding checks to platform data. Fixes: dc245a5 ("[media] ts2020: implement I2C client bindings") Cc: <stable@vger.kernel.org> Signed-off-by: Li Zetao <lizetao1@huawei.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

scx_ops_bypass() can currently race on the ops enable / disable path as follows: 1. scx_ops_bypass(true) called on enable path, bypass depth is set to 1 2. An op on the init path exits, which schedules scx_ops_disable_workfn() 3. scx_ops_bypass(false) is called on the disable path, and bypass depth is decremented to 0 4. kthread is scheduled to execute scx_ops_disable_workfn() 5. scx_ops_bypass(true) called, bypass depth set to 1 6. scx_ops_bypass() races when iterating over CPUs Fixing this is difficult because we can't take any locks when enabling bypass due to us not being able to trust the BPF scheduler. This is problematic, because what we really need to do is coordinate between possible concurrent calls of scx_ops_bypass(true) and scx_ops_bypass(false), but the whole point of that code is that we can't use any locks to coordinate. Instead of taking a lock, however, we can instead just serialize the calls to enable and disable bypass by executing the calls on the scx_ops_helper kthread that's currently responsible for disabling a BPF scheduler. This patch therefore adds a new schedule_scx_bypass_delta() function which schedules changes to scx_ops_bypass() to occur on the scx_ops_helper kthread (where necessary). Without this change, we observe the following warnings when running the 'exit' sched_ext selftest (sometimes requires a couple of runs): .[root@virtme-ng sched_ext]# ./runner -t exit ===== START ===== TEST: exit ... [ 14.935078] WARNING: CPU: 2 PID: 360 at kernel/sched/ext.c:4332 scx_ops_bypass+0x1ca/0x280 [ 14.935126] Modules linked in: [ 14.935150] CPU: 2 UID: 0 PID: 360 Comm: sched_ext_ops_h Not tainted 6.11.0-virtme torvalds#24 [ 14.935192] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 14.935242] Sched_ext: exit (enabling+all) [ 14.935244] RIP: 0010:scx_ops_bypass+0x1ca/0x280 [ 14.935300] Code: ff ff ff e8 48 96 10 00 fb e9 08 ff ff ff c6 05 7b 34 e8 01 01 90 48 c7 c7 89 86 88 87 e8 be 1d f8 ff 90 0f 0b 90 90 eb 95 90 <0f> 0b 90 41 8b 84 24 24 0a 00 00 eb 97 90 0f 0b 90 41 8b 84 24 24 [ 14.935394] RSP: 0018:ffffb706c0957ce0 EFLAGS: 00010002 [ 14.935424] RAX: 0000000000000009 RBX: 0000000000000001 RCX: 00000000e3fb8b2a [ 14.935465] RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff88a4c080 [ 14.935512] RBP: 0000000000009b56 R08: 0000000000000004 R09: 00000003f12e520a [ 14.935555] R10: ffffffff863a9795 R11: 0000000000000000 R12: ffff8fc5fec31300 [ 14.935598] R13: ffff8fc5fec31318 R14: 0000000000000286 R15: 0000000000000018 [ 14.935642] FS: 0000000000000000(0000) GS:ffff8fc5fe680000(0000) knlGS:0000000000000000 [ 14.935684] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 14.935721] CR2: 0000557d92890b88 CR3: 000000002464a000 CR4: 0000000000750ef0 [ 14.935765] PKRU: 55555554 [ 14.935782] Call Trace: [ 14.935802] <TASK> [ 14.935823] ? __warn+0xce/0x220 [ 14.935850] ? scx_ops_bypass+0x1ca/0x280 [ 14.935881] ? report_bug+0xc1/0x160 [ 14.935909] ? handle_bug+0x61/0x90 [ 14.935934] ? exc_invalid_op+0x1a/0x50 [ 14.935959] ? asm_exc_invalid_op+0x1a/0x20 [ 14.935984] ? raw_spin_rq_lock_nested+0x15/0x30 [ 14.936019] ? scx_ops_bypass+0x1ca/0x280 [ 14.936046] ? srso_alias_return_thunk+0x5/0xfbef5 [ 14.936081] ? __pfx_scx_ops_disable_workfn+0x10/0x10 [ 14.936111] scx_ops_disable_workfn+0x146/0xac0 [ 14.936142] ? finish_task_switch+0xa9/0x2c0 [ 14.936172] ? srso_alias_return_thunk+0x5/0xfbef5 [ 14.936211] ? __pfx_scx_ops_disable_workfn+0x10/0x10 [ 14.936244] kthread_worker_fn+0x101/0x2c0 [ 14.936268] ? __pfx_kthread_worker_fn+0x10/0x10 [ 14.936299] kthread+0xec/0x110 [ 14.936327] ? __pfx_kthread+0x10/0x10 [ 14.936351] ret_from_fork+0x37/0x50 [ 14.936374] ? __pfx_kthread+0x10/0x10 [ 14.936400] ret_from_fork_asm+0x1a/0x30 [ 14.936427] </TASK> [ 14.936443] irq event stamp: 21002 [ 14.936467] hardirqs last enabled at (21001): [<ffffffff863aa35f>] resched_cpu+0x9f/0xd0 [ 14.936521] hardirqs last disabled at (21002): [<ffffffff863dd0ba>] scx_ops_bypass+0x11a/0x280 [ 14.936571] softirqs last enabled at (20642): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.936622] softirqs last disabled at (20637): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.936672] ---[ end trace 0000000000000000 ]--- [ 14.953282] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 14.953352] ------------[ cut here ]------------ [ 14.953383] WARNING: CPU: 2 PID: 360 at kernel/sched/ext.c:4335 scx_ops_bypass+0x1d8/0x280 [ 14.953428] Modules linked in: [ 14.953453] CPU: 2 UID: 0 PID: 360 Comm: sched_ext_ops_h Tainted: G W 6.11.0-virtme torvalds#24 [ 14.953505] Tainted: [W]=WARN [ 14.953527] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 14.953574] RIP: 0010:scx_ops_bypass+0x1d8/0x280 [ 14.953603] Code: c6 05 7b 34 e8 01 01 90 48 c7 c7 89 86 88 87 e8 be 1d f8 ff 90 0f 0b 90 90 eb 95 90 0f 0b 90 41 8b 84 24 24 0a 00 00 eb 97 90 <0f> 0b 90 41 8b 84 24 24 0a 00 00 eb 92 f3 0f 1e fa 49 8d 84 24 f0 [ 14.953693] RSP: 0018:ffffb706c0957ce0 EFLAGS: 00010046 [ 14.953722] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001 [ 14.953763] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8fc5fec31318 [ 14.953804] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 14.953845] R10: ffffffff863a9795 R11: 0000000000000000 R12: ffff8fc5fec31300 [ 14.953888] R13: ffff8fc5fec31318 R14: 0000000000000286 R15: 0000000000000018 [ 14.953934] FS: 0000000000000000(0000) GS:ffff8fc5fe680000(0000) knlGS:0000000000000000 [ 14.953974] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 14.954009] CR2: 0000557d92890b88 CR3: 000000002464a000 CR4: 0000000000750ef0 [ 14.954052] PKRU: 55555554 [ 14.954068] Call Trace: [ 14.954085] <TASK> [ 14.954102] ? __warn+0xce/0x220 [ 14.954126] ? scx_ops_bypass+0x1d8/0x280 [ 14.954150] ? report_bug+0xc1/0x160 [ 14.954178] ? handle_bug+0x61/0x90 [ 14.954203] ? exc_invalid_op+0x1a/0x50 [ 14.954226] ? asm_exc_invalid_op+0x1a/0x20 [ 14.954250] ? raw_spin_rq_lock_nested+0x15/0x30 [ 14.954285] ? scx_ops_bypass+0x1d8/0x280 [ 14.954311] ? __mutex_unlock_slowpath+0x3a/0x260 [ 14.954343] scx_ops_disable_workfn+0xa3e/0xac0 [ 14.954381] ? __pfx_scx_ops_disable_workfn+0x10/0x10 [ 14.954413] kthread_worker_fn+0x101/0x2c0 [ 14.954442] ? __pfx_kthread_worker_fn+0x10/0x10 [ 14.954479] kthread+0xec/0x110 [ 14.954507] ? __pfx_kthread+0x10/0x10 [ 14.954530] ret_from_fork+0x37/0x50 [ 14.954553] ? __pfx_kthread+0x10/0x10 [ 14.954576] ret_from_fork_asm+0x1a/0x30 [ 14.954603] </TASK> [ 14.954621] irq event stamp: 21002 [ 14.954644] hardirqs last enabled at (21001): [<ffffffff863aa35f>] resched_cpu+0x9f/0xd0 [ 14.954686] hardirqs last disabled at (21002): [<ffffffff863dd0ba>] scx_ops_bypass+0x11a/0x280 [ 14.954735] softirqs last enabled at (20642): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.954782] softirqs last disabled at (20637): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.954829] ---[ end trace 0000000000000000 ]--- [ 15.022283] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 15.092282] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 15.149282] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) ok 1 exit # ===== END ===== And with it, the test passes without issue after 100 runs: .[root@virtme-ng sched_ext]# ./runner -t exit ===== START ===== TEST: exit DESCRIPTION: Verify we can cleanly exit a scheduler in multiple places OUTPUT: [ 7.412856] sched_ext: BPF scheduler "exit" enabled [ 7.427924] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.466677] sched_ext: BPF scheduler "exit" enabled [ 7.475923] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.512803] sched_ext: BPF scheduler "exit" enabled [ 7.532924] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.586809] sched_ext: BPF scheduler "exit" enabled [ 7.595926] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.661923] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.723923] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) ok 1 exit # ===== END ===== ============================= RESULTS: PASSED: 1 SKIPPED: 0 FAILED: 0 Fixes: f0e1a06 ("sched_ext: Implement BPF extensible scheduler class") Signed-off-by: David Vernet <void@manifault.com>

scx_ops_bypass() can currently race on the ops enable / disable path as follows: 1. scx_ops_bypass(true) called on enable path, bypass depth is set to 1 2. An op on the init path exits, which schedules scx_ops_disable_workfn() 3. scx_ops_bypass(false) is called on the disable path, and bypass depth is decremented to 0 4. kthread is scheduled to execute scx_ops_disable_workfn() 5. scx_ops_bypass(true) called, bypass depth set to 1 6. scx_ops_bypass() races when iterating over CPUs While it's not safe to take any blocking locks on the bypass path, it is safe to take a raw spinlock which cannot be preempted. This patch therefore updates scx_ops_bypass() to use a raw spinlock to synchronize, and changes scx_ops_bypass_depth to be a regular int. Without this change, we observe the following warnings when running the 'exit' sched_ext selftest (sometimes requires a couple of runs): .[root@virtme-ng sched_ext]# ./runner -t exit ===== START ===== TEST: exit ... [ 14.935078] WARNING: CPU: 2 PID: 360 at kernel/sched/ext.c:4332 scx_ops_bypass+0x1ca/0x280 [ 14.935126] Modules linked in: [ 14.935150] CPU: 2 UID: 0 PID: 360 Comm: sched_ext_ops_h Not tainted 6.11.0-virtme torvalds#24 [ 14.935192] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 14.935242] Sched_ext: exit (enabling+all) [ 14.935244] RIP: 0010:scx_ops_bypass+0x1ca/0x280 [ 14.935300] Code: ff ff ff e8 48 96 10 00 fb e9 08 ff ff ff c6 05 7b 34 e8 01 01 90 48 c7 c7 89 86 88 87 e8 be 1d f8 ff 90 0f 0b 90 90 eb 95 90 <0f> 0b 90 41 8b 84 24 24 0a 00 00 eb 97 90 0f 0b 90 41 8b 84 24 24 [ 14.935394] RSP: 0018:ffffb706c0957ce0 EFLAGS: 00010002 [ 14.935424] RAX: 0000000000000009 RBX: 0000000000000001 RCX: 00000000e3fb8b2a [ 14.935465] RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff88a4c080 [ 14.935512] RBP: 0000000000009b56 R08: 0000000000000004 R09: 00000003f12e520a [ 14.935555] R10: ffffffff863a9795 R11: 0000000000000000 R12: ffff8fc5fec31300 [ 14.935598] R13: ffff8fc5fec31318 R14: 0000000000000286 R15: 0000000000000018 [ 14.935642] FS: 0000000000000000(0000) GS:ffff8fc5fe680000(0000) knlGS:0000000000000000 [ 14.935684] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 14.935721] CR2: 0000557d92890b88 CR3: 000000002464a000 CR4: 0000000000750ef0 [ 14.935765] PKRU: 55555554 [ 14.935782] Call Trace: [ 14.935802] <TASK> [ 14.935823] ? __warn+0xce/0x220 [ 14.935850] ? scx_ops_bypass+0x1ca/0x280 [ 14.935881] ? report_bug+0xc1/0x160 [ 14.935909] ? handle_bug+0x61/0x90 [ 14.935934] ? exc_invalid_op+0x1a/0x50 [ 14.935959] ? asm_exc_invalid_op+0x1a/0x20 [ 14.935984] ? raw_spin_rq_lock_nested+0x15/0x30 [ 14.936019] ? scx_ops_bypass+0x1ca/0x280 [ 14.936046] ? srso_alias_return_thunk+0x5/0xfbef5 [ 14.936081] ? __pfx_scx_ops_disable_workfn+0x10/0x10 [ 14.936111] scx_ops_disable_workfn+0x146/0xac0 [ 14.936142] ? finish_task_switch+0xa9/0x2c0 [ 14.936172] ? srso_alias_return_thunk+0x5/0xfbef5 [ 14.936211] ? __pfx_scx_ops_disable_workfn+0x10/0x10 [ 14.936244] kthread_worker_fn+0x101/0x2c0 [ 14.936268] ? __pfx_kthread_worker_fn+0x10/0x10 [ 14.936299] kthread+0xec/0x110 [ 14.936327] ? __pfx_kthread+0x10/0x10 [ 14.936351] ret_from_fork+0x37/0x50 [ 14.936374] ? __pfx_kthread+0x10/0x10 [ 14.936400] ret_from_fork_asm+0x1a/0x30 [ 14.936427] </TASK> [ 14.936443] irq event stamp: 21002 [ 14.936467] hardirqs last enabled at (21001): [<ffffffff863aa35f>] resched_cpu+0x9f/0xd0 [ 14.936521] hardirqs last disabled at (21002): [<ffffffff863dd0ba>] scx_ops_bypass+0x11a/0x280 [ 14.936571] softirqs last enabled at (20642): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.936622] softirqs last disabled at (20637): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.936672] ---[ end trace 0000000000000000 ]--- [ 14.953282] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 14.953352] ------------[ cut here ]------------ [ 14.953383] WARNING: CPU: 2 PID: 360 at kernel/sched/ext.c:4335 scx_ops_bypass+0x1d8/0x280 [ 14.953428] Modules linked in: [ 14.953453] CPU: 2 UID: 0 PID: 360 Comm: sched_ext_ops_h Tainted: G W 6.11.0-virtme torvalds#24 [ 14.953505] Tainted: [W]=WARN [ 14.953527] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 14.953574] RIP: 0010:scx_ops_bypass+0x1d8/0x280 [ 14.953603] Code: c6 05 7b 34 e8 01 01 90 48 c7 c7 89 86 88 87 e8 be 1d f8 ff 90 0f 0b 90 90 eb 95 90 0f 0b 90 41 8b 84 24 24 0a 00 00 eb 97 90 <0f> 0b 90 41 8b 84 24 24 0a 00 00 eb 92 f3 0f 1e fa 49 8d 84 24 f0 [ 14.953693] RSP: 0018:ffffb706c0957ce0 EFLAGS: 00010046 [ 14.953722] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001 [ 14.953763] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8fc5fec31318 [ 14.953804] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 14.953845] R10: ffffffff863a9795 R11: 0000000000000000 R12: ffff8fc5fec31300 [ 14.953888] R13: ffff8fc5fec31318 R14: 0000000000000286 R15: 0000000000000018 [ 14.953934] FS: 0000000000000000(0000) GS:ffff8fc5fe680000(0000) knlGS:0000000000000000 [ 14.953974] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 14.954009] CR2: 0000557d92890b88 CR3: 000000002464a000 CR4: 0000000000750ef0 [ 14.954052] PKRU: 55555554 [ 14.954068] Call Trace: [ 14.954085] <TASK> [ 14.954102] ? __warn+0xce/0x220 [ 14.954126] ? scx_ops_bypass+0x1d8/0x280 [ 14.954150] ? report_bug+0xc1/0x160 [ 14.954178] ? handle_bug+0x61/0x90 [ 14.954203] ? exc_invalid_op+0x1a/0x50 [ 14.954226] ? asm_exc_invalid_op+0x1a/0x20 [ 14.954250] ? raw_spin_rq_lock_nested+0x15/0x30 [ 14.954285] ? scx_ops_bypass+0x1d8/0x280 [ 14.954311] ? __mutex_unlock_slowpath+0x3a/0x260 [ 14.954343] scx_ops_disable_workfn+0xa3e/0xac0 [ 14.954381] ? __pfx_scx_ops_disable_workfn+0x10/0x10 [ 14.954413] kthread_worker_fn+0x101/0x2c0 [ 14.954442] ? __pfx_kthread_worker_fn+0x10/0x10 [ 14.954479] kthread+0xec/0x110 [ 14.954507] ? __pfx_kthread+0x10/0x10 [ 14.954530] ret_from_fork+0x37/0x50 [ 14.954553] ? __pfx_kthread+0x10/0x10 [ 14.954576] ret_from_fork_asm+0x1a/0x30 [ 14.954603] </TASK> [ 14.954621] irq event stamp: 21002 [ 14.954644] hardirqs last enabled at (21001): [<ffffffff863aa35f>] resched_cpu+0x9f/0xd0 [ 14.954686] hardirqs last disabled at (21002): [<ffffffff863dd0ba>] scx_ops_bypass+0x11a/0x280 [ 14.954735] softirqs last enabled at (20642): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.954782] softirqs last disabled at (20637): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.954829] ---[ end trace 0000000000000000 ]--- [ 15.022283] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 15.092282] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 15.149282] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) ok 1 exit # ===== END ===== And with it, the test passes without issue after 1000s of runs: .[root@virtme-ng sched_ext]# ./runner -t exit ===== START ===== TEST: exit DESCRIPTION: Verify we can cleanly exit a scheduler in multiple places OUTPUT: [ 7.412856] sched_ext: BPF scheduler "exit" enabled [ 7.427924] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.466677] sched_ext: BPF scheduler "exit" enabled [ 7.475923] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.512803] sched_ext: BPF scheduler "exit" enabled [ 7.532924] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.586809] sched_ext: BPF scheduler "exit" enabled [ 7.595926] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.661923] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.723923] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) ok 1 exit # ===== END ===== ============================= RESULTS: PASSED: 1 SKIPPED: 0 FAILED: 0 Fixes: f0e1a06 ("sched_ext: Implement BPF extensible scheduler class") Signed-off-by: David Vernet <void@manifault.com>

scx_ops_bypass() can currently race on the ops enable / disable path as follows: 1. scx_ops_bypass(true) called on enable path, bypass depth is set to 1 2. An op on the init path exits, which schedules scx_ops_disable_workfn() 3. scx_ops_bypass(false) is called on the disable path, and bypass depth is decremented to 0 4. kthread is scheduled to execute scx_ops_disable_workfn() 5. scx_ops_bypass(true) called, bypass depth set to 1 6. scx_ops_bypass() races when iterating over CPUs While it's not safe to take any blocking locks on the bypass path, it is safe to take a raw spinlock which cannot be preempted. This patch therefore updates scx_ops_bypass() to use a raw spinlock to synchronize, and changes scx_ops_bypass_depth to be a regular int. Without this change, we observe the following warnings when running the 'exit' sched_ext selftest (sometimes requires a couple of runs): .[root@virtme-ng sched_ext]# ./runner -t exit ===== START ===== TEST: exit ... [ 14.935078] WARNING: CPU: 2 PID: 360 at kernel/sched/ext.c:4332 scx_ops_bypass+0x1ca/0x280 [ 14.935126] Modules linked in: [ 14.935150] CPU: 2 UID: 0 PID: 360 Comm: sched_ext_ops_h Not tainted 6.11.0-virtme torvalds#24 [ 14.935192] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 14.935242] Sched_ext: exit (enabling+all) [ 14.935244] RIP: 0010:scx_ops_bypass+0x1ca/0x280 [ 14.935300] Code: ff ff ff e8 48 96 10 00 fb e9 08 ff ff ff c6 05 7b 34 e8 01 01 90 48 c7 c7 89 86 88 87 e8 be 1d f8 ff 90 0f 0b 90 90 eb 95 90 <0f> 0b 90 41 8b 84 24 24 0a 00 00 eb 97 90 0f 0b 90 41 8b 84 24 24 [ 14.935394] RSP: 0018:ffffb706c0957ce0 EFLAGS: 00010002 [ 14.935424] RAX: 0000000000000009 RBX: 0000000000000001 RCX: 00000000e3fb8b2a [ 14.935465] RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff88a4c080 [ 14.935512] RBP: 0000000000009b56 R08: 0000000000000004 R09: 00000003f12e520a [ 14.935555] R10: ffffffff863a9795 R11: 0000000000000000 R12: ffff8fc5fec31300 [ 14.935598] R13: ffff8fc5fec31318 R14: 0000000000000286 R15: 0000000000000018 [ 14.935642] FS: 0000000000000000(0000) GS:ffff8fc5fe680000(0000) knlGS:0000000000000000 [ 14.935684] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 14.935721] CR2: 0000557d92890b88 CR3: 000000002464a000 CR4: 0000000000750ef0 [ 14.935765] PKRU: 55555554 [ 14.935782] Call Trace: [ 14.935802] <TASK> [ 14.935823] ? __warn+0xce/0x220 [ 14.935850] ? scx_ops_bypass+0x1ca/0x280 [ 14.935881] ? report_bug+0xc1/0x160 [ 14.935909] ? handle_bug+0x61/0x90 [ 14.935934] ? exc_invalid_op+0x1a/0x50 [ 14.935959] ? asm_exc_invalid_op+0x1a/0x20 [ 14.935984] ? raw_spin_rq_lock_nested+0x15/0x30 [ 14.936019] ? scx_ops_bypass+0x1ca/0x280 [ 14.936046] ? srso_alias_return_thunk+0x5/0xfbef5 [ 14.936081] ? __pfx_scx_ops_disable_workfn+0x10/0x10 [ 14.936111] scx_ops_disable_workfn+0x146/0xac0 [ 14.936142] ? finish_task_switch+0xa9/0x2c0 [ 14.936172] ? srso_alias_return_thunk+0x5/0xfbef5 [ 14.936211] ? __pfx_scx_ops_disable_workfn+0x10/0x10 [ 14.936244] kthread_worker_fn+0x101/0x2c0 [ 14.936268] ? __pfx_kthread_worker_fn+0x10/0x10 [ 14.936299] kthread+0xec/0x110 [ 14.936327] ? __pfx_kthread+0x10/0x10 [ 14.936351] ret_from_fork+0x37/0x50 [ 14.936374] ? __pfx_kthread+0x10/0x10 [ 14.936400] ret_from_fork_asm+0x1a/0x30 [ 14.936427] </TASK> [ 14.936443] irq event stamp: 21002 [ 14.936467] hardirqs last enabled at (21001): [<ffffffff863aa35f>] resched_cpu+0x9f/0xd0 [ 14.936521] hardirqs last disabled at (21002): [<ffffffff863dd0ba>] scx_ops_bypass+0x11a/0x280 [ 14.936571] softirqs last enabled at (20642): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.936622] softirqs last disabled at (20637): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.936672] ---[ end trace 0000000000000000 ]--- [ 14.953282] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 14.953352] ------------[ cut here ]------------ [ 14.953383] WARNING: CPU: 2 PID: 360 at kernel/sched/ext.c:4335 scx_ops_bypass+0x1d8/0x280 [ 14.953428] Modules linked in: [ 14.953453] CPU: 2 UID: 0 PID: 360 Comm: sched_ext_ops_h Tainted: G W 6.11.0-virtme torvalds#24 [ 14.953505] Tainted: [W]=WARN [ 14.953527] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 14.953574] RIP: 0010:scx_ops_bypass+0x1d8/0x280 [ 14.953603] Code: c6 05 7b 34 e8 01 01 90 48 c7 c7 89 86 88 87 e8 be 1d f8 ff 90 0f 0b 90 90 eb 95 90 0f 0b 90 41 8b 84 24 24 0a 00 00 eb 97 90 <0f> 0b 90 41 8b 84 24 24 0a 00 00 eb 92 f3 0f 1e fa 49 8d 84 24 f0 [ 14.953693] RSP: 0018:ffffb706c0957ce0 EFLAGS: 00010046 [ 14.953722] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001 [ 14.953763] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8fc5fec31318 [ 14.953804] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 14.953845] R10: ffffffff863a9795 R11: 0000000000000000 R12: ffff8fc5fec31300 [ 14.953888] R13: ffff8fc5fec31318 R14: 0000000000000286 R15: 0000000000000018 [ 14.953934] FS: 0000000000000000(0000) GS:ffff8fc5fe680000(0000) knlGS:0000000000000000 [ 14.953974] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 14.954009] CR2: 0000557d92890b88 CR3: 000000002464a000 CR4: 0000000000750ef0 [ 14.954052] PKRU: 55555554 [ 14.954068] Call Trace: [ 14.954085] <TASK> [ 14.954102] ? __warn+0xce/0x220 [ 14.954126] ? scx_ops_bypass+0x1d8/0x280 [ 14.954150] ? report_bug+0xc1/0x160 [ 14.954178] ? handle_bug+0x61/0x90 [ 14.954203] ? exc_invalid_op+0x1a/0x50 [ 14.954226] ? asm_exc_invalid_op+0x1a/0x20 [ 14.954250] ? raw_spin_rq_lock_nested+0x15/0x30 [ 14.954285] ? scx_ops_bypass+0x1d8/0x280 [ 14.954311] ? __mutex_unlock_slowpath+0x3a/0x260 [ 14.954343] scx_ops_disable_workfn+0xa3e/0xac0 [ 14.954381] ? __pfx_scx_ops_disable_workfn+0x10/0x10 [ 14.954413] kthread_worker_fn+0x101/0x2c0 [ 14.954442] ? __pfx_kthread_worker_fn+0x10/0x10 [ 14.954479] kthread+0xec/0x110 [ 14.954507] ? __pfx_kthread+0x10/0x10 [ 14.954530] ret_from_fork+0x37/0x50 [ 14.954553] ? __pfx_kthread+0x10/0x10 [ 14.954576] ret_from_fork_asm+0x1a/0x30 [ 14.954603] </TASK> [ 14.954621] irq event stamp: 21002 [ 14.954644] hardirqs last enabled at (21001): [<ffffffff863aa35f>] resched_cpu+0x9f/0xd0 [ 14.954686] hardirqs last disabled at (21002): [<ffffffff863dd0ba>] scx_ops_bypass+0x11a/0x280 [ 14.954735] softirqs last enabled at (20642): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.954782] softirqs last disabled at (20637): [<ffffffff863683d7>] __irq_exit_rcu+0x67/0xd0 [ 14.954829] ---[ end trace 0000000000000000 ]--- [ 15.022283] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 15.092282] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 15.149282] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) ok 1 exit # ===== END ===== And with it, the test passes without issue after 1000s of runs: .[root@virtme-ng sched_ext]# ./runner -t exit ===== START ===== TEST: exit DESCRIPTION: Verify we can cleanly exit a scheduler in multiple places OUTPUT: [ 7.412856] sched_ext: BPF scheduler "exit" enabled [ 7.427924] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.466677] sched_ext: BPF scheduler "exit" enabled [ 7.475923] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.512803] sched_ext: BPF scheduler "exit" enabled [ 7.532924] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.586809] sched_ext: BPF scheduler "exit" enabled [ 7.595926] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.661923] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 7.723923] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) ok 1 exit # ===== END ===== ============================= RESULTS: PASSED: 1 SKIPPED: 0 FAILED: 0 Fixes: f0e1a06 ("sched_ext: Implement BPF extensible scheduler class") Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Tejun Heo <tj@kernel.org>

I found an issue with the line number display in perf probe -l: # perf probe -l probe:schedule (on schedule:-6751@kernel/sched/core.c) I founded that in debuginfo__find_probe_point(), the fname obtained by cu_find_lineinfo() is different from the result returned by die_get_decl_file(). The 'baseline' and 'lineno' do not correspond to the same file, resulting in an incorrect calculation of the line number (lineno - baseline). The DWARF dump information shows that the probed address 0xffff800080e55bc4 (i.e., schedule+20) has two source file information: # readelf --debug-dump=decodedline vmlinux | grep ffff800080e55bc4 -C 2 ./arch/arm64/include/asm/current.h: current.h 19 0xffff800080e55bc0 current.h 21 0xffff800080e55bc4 x current.h 21 0xffff800080e55bc4 1 kernel/sched/core.c: core.c 6777 0xffff800080e55bc4 2 x core.c 6777 0xffff800080e55bc4 3 x core.c 6777 0xffff800080e55bc4 4 x core.c 6780 0xffff800080e55bc4 5 x The first location corresponds to the inline function get_current(), and cu_find_lineinfo() should have found this entry. However, the probed instruction is actually in the schedule() function, which is disassembled as follows: crash> disassemble/s schedule Dump of assembler code for function schedule: ./arch/arm64/include/asm/current.h: 15 static __always_inline struct task_struct *get_current(void) 16 { 17 unsigned long sp_el0; 18 19 asm ("mrs %0, sp_el0" : "=r" (sp_el0)); 0xffff800080e55bb0 <+0>: paciasp Dump of assembler code for function schedule: ./arch/arm64/include/asm/current.h: 15 static __always_inline struct task_struct *get_current(void) 16 { 17 unsigned long sp_el0; 18 19 asm ("mrs %0, sp_el0" : "=r" (sp_el0)); 0xffff800080e55bb0 <+0>: paciasp 0xffff800080e55bb4 <+4>: stp x29, x30, [sp, #-32]! 0xffff800080e55bb8 <+8>: mov x29, sp 0xffff800080e55bbc <+12>: stp x19, x20, [sp, torvalds#16] 0xffff800080e55bc0 <+16>: mrs x19, sp_el0 kernel/sched/core.c: 6780 if (!task_is_running(tsk)) 0xffff800080e55bc4 <+20>: ldr w0, [x19, torvalds#24] 0xffff800080e55bc8 <+24>: cbnz w0, 0xffff800080e55bf8 <schedule+72> And the DWARF function dump information: <1><11eae66>: Abbrev Number: 88 (DW_TAG_subprogram) <11eae67> DW_AT_external : 1 <11eae67> DW_AT_name : (indirect string, offset: 0x233efb): schedule <11eae6b> DW_AT_decl_file : 18 <11eae6c> DW_AT_decl_line : 6772 <11eae6e> DW_AT_decl_column : 35 <11eae6f> DW_AT_prototyped : 1 <11eae6f> DW_AT_low_pc : 0xffff800080e55bb0 <11eae77> DW_AT_high_pc : 0xb8 <11eae7f> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa) <11eae81> DW_AT_GNU_all_call_sites: 1 <11eae81> DW_AT_sibling : <0x11eb12d> <2><11eae85>: Abbrev Number: 50 (DW_TAG_variable) <11eae86> DW_AT_name : tsk <11eae8a> DW_AT_decl_file : 18 <11eae8b> DW_AT_decl_line : 6774 <11eae8d> DW_AT_decl_column : 22 <11eae8e> DW_AT_type : <0x11b2b34> <11eae92> DW_AT_location : 0x5be6f0 (location list) <11eae96> DW_AT_GNU_locviews: 0x5be6ec <2><11eae9a>: Abbrev Number: 78 (DW_TAG_lexical_block) <11eae9b> DW_AT_low_pc : 0xffff800080e55bc4 <11eaea3> DW_AT_high_pc : 0x0 <11eaeab> DW_AT_sibling : <0x11eaeb9> Therefore, here we should use the result of die_find_realfunc() + die_get_decl_file(). However, regardless, we should verify if the fname obtained from both is the same. If they are different, we should use the latter to avoid inconsistencies between lineno, fname, and basefunc. After the modification, the output is as follows: # perf probe -l probe:schedule (on schedule+20@kernel/sched/core.c) Fixes: 57f95bf ("perf probe: Show correct statement line number by perf probe -l") Signed-off-by: Li Huafei <lihuafei1@huawei.com>

@strlen

Under certain kernel configurations when building with Clang/LLVM, the compiler does not generate a return or jump as the terminator instruction for ip_vs_protocol_init(), triggering the following objtool warning during build time: vmlinux.o: warning: objtool: ip_vs_protocol_init() falls through to next function __initstub__kmod_ip_vs_rr__935_123_ip_vs_rr_init6() At runtime, this either causes an oops when trying to load the ipvs module or a boot-time panic if ipvs is built-in. This same issue has been reported by the Intel kernel test robot previously. Digging deeper into both LLVM and the kernel code reveals this to be a undefined behavior problem. ip_vs_protocol_init() uses a on-stack buffer of 64 chars to store the registered protocol names and leaves it uninitialized after definition. The function calls strnlen() when concatenating protocol names into the buffer. With CONFIG_FORTIFY_SOURCE strnlen() performs an extra step to check whether the last byte of the input char buffer is a null character (commit 3009f89 ("fortify: Allow strlen() and strnlen() to pass compile-time known lengths")). This, together with possibly other configurations, cause the following IR to be generated: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #5 section ".init.text" align 16 !kcfi_type !29 { %1 = alloca [64 x i8], align 16 ... 14: ; preds = %11 %15 = getelementptr inbounds i8, ptr %1, i64 63 %16 = load i8, ptr %15, align 1 %17 = tail call i1 @llvm.is.constant.i8(i8 %16) %18 = icmp eq i8 %16, 0 %19 = select i1 %17, i1 %18, i1 false br i1 %19, label %20, label %23 20: ; preds = %14 %21 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) torvalds#23 ... 23: ; preds = %14, %11, %20 %24 = call i64 @strnlen(ptr noundef nonnull dereferenceable(1) %1, i64 noundef 64) torvalds#24 ... } The above code calculates the address of the last char in the buffer (value %15) and then loads from it (value %16). Because the buffer is never initialized, the LLVM GVN pass marks value %16 as undefined: %13 = getelementptr inbounds i8, ptr %1, i64 63 br i1 undef, label %14, label %17 This gives later passes (SCCP, in particular) to more DCE opportunities by propagating the undef value further, and eventually removes everything after the load on the uninitialized stack location: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #0 section ".init.text" align 16 !kcfi_type !11 { %1 = alloca [64 x i8], align 16 ... 12: ; preds = %11 %13 = getelementptr inbounds i8, ptr %1, i64 63 unreachable } In this way, the generated native code will just fall through to the next function, as LLVM does not generate any code for the unreachable IR instruction and leaves the function without a terminator. Zero the on-stack buffer to avoid this possible UB. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402100205.PWXIz1ZK-lkp@intel.com/ Co-developed-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Jinghao Jia <jinghao7@illinois.edu>

@strlen

Under certain kernel configurations when building with Clang/LLVM, the compiler does not generate a return or jump as the terminator instruction for ip_vs_protocol_init(), triggering the following objtool warning during build time: vmlinux.o: warning: objtool: ip_vs_protocol_init() falls through to next function __initstub__kmod_ip_vs_rr__935_123_ip_vs_rr_init6() At runtime, this either causes an oops when trying to load the ipvs module or a boot-time panic if ipvs is built-in. This same issue has been reported by the Intel kernel test robot previously. Digging deeper into both LLVM and the kernel code reveals this to be a undefined behavior problem. ip_vs_protocol_init() uses a on-stack buffer of 64 chars to store the registered protocol names and leaves it uninitialized after definition. The function calls strnlen() when concatenating protocol names into the buffer. With CONFIG_FORTIFY_SOURCE strnlen() performs an extra step to check whether the last byte of the input char buffer is a null character (commit 3009f89 ("fortify: Allow strlen() and strnlen() to pass compile-time known lengths")). This, together with possibly other configurations, cause the following IR to be generated: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #5 section ".init.text" align 16 !kcfi_type !29 { %1 = alloca [64 x i8], align 16 ... 14: ; preds = %11 %15 = getelementptr inbounds i8, ptr %1, i64 63 %16 = load i8, ptr %15, align 1 %17 = tail call i1 @llvm.is.constant.i8(i8 %16) %18 = icmp eq i8 %16, 0 %19 = select i1 %17, i1 %18, i1 false br i1 %19, label %20, label %23 20: ; preds = %14 %21 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) torvalds#23 ... 23: ; preds = %14, %11, %20 %24 = call i64 @strnlen(ptr noundef nonnull dereferenceable(1) %1, i64 noundef 64) torvalds#24 ... } The above code calculates the address of the last char in the buffer (value %15) and then loads from it (value %16). Because the buffer is never initialized, the LLVM GVN pass marks value %16 as undefined: %13 = getelementptr inbounds i8, ptr %1, i64 63 br i1 undef, label %14, label %17 This gives later passes (SCCP, in particular) to more DCE opportunities by propagating the undef value further, and eventually removes everything after the load on the uninitialized stack location: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #0 section ".init.text" align 16 !kcfi_type !11 { %1 = alloca [64 x i8], align 16 ... 12: ; preds = %11 %13 = getelementptr inbounds i8, ptr %1, i64 63 unreachable } In this way, the generated native code will just fall through to the next function, as LLVM does not generate any code for the unreachable IR instruction and leaves the function without a terminator. Zero the on-stack buffer to avoid this possible UB. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402100205.PWXIz1ZK-lkp@intel.com/ Co-developed-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Jinghao Jia <jinghao7@illinois.edu> Signed-off-by: NipaLocal <nipa@local>

@strlen

Under certain kernel configurations when building with Clang/LLVM, the compiler does not generate a return or jump as the terminator instruction for ip_vs_protocol_init(), triggering the following objtool warning during build time: vmlinux.o: warning: objtool: ip_vs_protocol_init() falls through to next function __initstub__kmod_ip_vs_rr__935_123_ip_vs_rr_init6() At runtime, this either causes an oops when trying to load the ipvs module or a boot-time panic if ipvs is built-in. This same issue has been reported by the Intel kernel test robot previously. Digging deeper into both LLVM and the kernel code reveals this to be a undefined behavior problem. ip_vs_protocol_init() uses a on-stack buffer of 64 chars to store the registered protocol names and leaves it uninitialized after definition. The function calls strnlen() when concatenating protocol names into the buffer. With CONFIG_FORTIFY_SOURCE strnlen() performs an extra step to check whether the last byte of the input char buffer is a null character (commit 3009f89 ("fortify: Allow strlen() and strnlen() to pass compile-time known lengths")). This, together with possibly other configurations, cause the following IR to be generated: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #5 section ".init.text" align 16 !kcfi_type !29 { %1 = alloca [64 x i8], align 16 ... 14: ; preds = %11 %15 = getelementptr inbounds i8, ptr %1, i64 63 %16 = load i8, ptr %15, align 1 %17 = tail call i1 @llvm.is.constant.i8(i8 %16) %18 = icmp eq i8 %16, 0 %19 = select i1 %17, i1 %18, i1 false br i1 %19, label %20, label %23 20: ; preds = %14 %21 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) torvalds#23 ... 23: ; preds = %14, %11, %20 %24 = call i64 @strnlen(ptr noundef nonnull dereferenceable(1) %1, i64 noundef 64) torvalds#24 ... } The above code calculates the address of the last char in the buffer (value %15) and then loads from it (value %16). Because the buffer is never initialized, the LLVM GVN pass marks value %16 as undefined: %13 = getelementptr inbounds i8, ptr %1, i64 63 br i1 undef, label %14, label %17 This gives later passes (SCCP, in particular) to more DCE opportunities by propagating the undef value further, and eventually removes everything after the load on the uninitialized stack location: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #0 section ".init.text" align 16 !kcfi_type !11 { %1 = alloca [64 x i8], align 16 ... 12: ; preds = %11 %13 = getelementptr inbounds i8, ptr %1, i64 63 unreachable } In this way, the generated native code will just fall through to the next function, as LLVM does not generate any code for the unreachable IR instruction and leaves the function without a terminator. Zero the on-stack buffer to avoid this possible UB. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402100205.PWXIz1ZK-lkp@intel.com/ Co-developed-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Jinghao Jia <jinghao7@illinois.edu> Signed-off-by: NipaLocal <nipa@local>

@strlen

Under certain kernel configurations when building with Clang/LLVM, the compiler does not generate a return or jump as the terminator instruction for ip_vs_protocol_init(), triggering the following objtool warning during build time: vmlinux.o: warning: objtool: ip_vs_protocol_init() falls through to next function __initstub__kmod_ip_vs_rr__935_123_ip_vs_rr_init6() At runtime, this either causes an oops when trying to load the ipvs module or a boot-time panic if ipvs is built-in. This same issue has been reported by the Intel kernel test robot previously. Digging deeper into both LLVM and the kernel code reveals this to be a undefined behavior problem. ip_vs_protocol_init() uses a on-stack buffer of 64 chars to store the registered protocol names and leaves it uninitialized after definition. The function calls strnlen() when concatenating protocol names into the buffer. With CONFIG_FORTIFY_SOURCE strnlen() performs an extra step to check whether the last byte of the input char buffer is a null character (commit 3009f89 ("fortify: Allow strlen() and strnlen() to pass compile-time known lengths")). This, together with possibly other configurations, cause the following IR to be generated: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #5 section ".init.text" align 16 !kcfi_type !29 { %1 = alloca [64 x i8], align 16 ... 14: ; preds = %11 %15 = getelementptr inbounds i8, ptr %1, i64 63 %16 = load i8, ptr %15, align 1 %17 = tail call i1 @llvm.is.constant.i8(i8 %16) %18 = icmp eq i8 %16, 0 %19 = select i1 %17, i1 %18, i1 false br i1 %19, label %20, label %23 20: ; preds = %14 %21 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) torvalds#23 ... 23: ; preds = %14, %11, %20 %24 = call i64 @strnlen(ptr noundef nonnull dereferenceable(1) %1, i64 noundef 64) torvalds#24 ... } The above code calculates the address of the last char in the buffer (value %15) and then loads from it (value %16). Because the buffer is never initialized, the LLVM GVN pass marks value %16 as undefined: %13 = getelementptr inbounds i8, ptr %1, i64 63 br i1 undef, label %14, label %17 This gives later passes (SCCP, in particular) to more DCE opportunities by propagating the undef value further, and eventually removes everything after the load on the uninitialized stack location: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #0 section ".init.text" align 16 !kcfi_type !11 { %1 = alloca [64 x i8], align 16 ... 12: ; preds = %11 %13 = getelementptr inbounds i8, ptr %1, i64 63 unreachable } In this way, the generated native code will just fall through to the next function, as LLVM does not generate any code for the unreachable IR instruction and leaves the function without a terminator. Zero the on-stack buffer to avoid this possible UB. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402100205.PWXIz1ZK-lkp@intel.com/ Co-developed-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Jinghao Jia <jinghao7@illinois.edu> Signed-off-by: NipaLocal <nipa@local>

@strlen

Under certain kernel configurations when building with Clang/LLVM, the compiler does not generate a return or jump as the terminator instruction for ip_vs_protocol_init(), triggering the following objtool warning during build time: vmlinux.o: warning: objtool: ip_vs_protocol_init() falls through to next function __initstub__kmod_ip_vs_rr__935_123_ip_vs_rr_init6() At runtime, this either causes an oops when trying to load the ipvs module or a boot-time panic if ipvs is built-in. This same issue has been reported by the Intel kernel test robot previously. Digging deeper into both LLVM and the kernel code reveals this to be a undefined behavior problem. ip_vs_protocol_init() uses a on-stack buffer of 64 chars to store the registered protocol names and leaves it uninitialized after definition. The function calls strnlen() when concatenating protocol names into the buffer. With CONFIG_FORTIFY_SOURCE strnlen() performs an extra step to check whether the last byte of the input char buffer is a null character (commit 3009f89 ("fortify: Allow strlen() and strnlen() to pass compile-time known lengths")). This, together with possibly other configurations, cause the following IR to be generated: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #5 section ".init.text" align 16 !kcfi_type !29 { %1 = alloca [64 x i8], align 16 ... 14: ; preds = %11 %15 = getelementptr inbounds i8, ptr %1, i64 63 %16 = load i8, ptr %15, align 1 %17 = tail call i1 @llvm.is.constant.i8(i8 %16) %18 = icmp eq i8 %16, 0 %19 = select i1 %17, i1 %18, i1 false br i1 %19, label %20, label %23 20: ; preds = %14 %21 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) torvalds#23 ... 23: ; preds = %14, %11, %20 %24 = call i64 @strnlen(ptr noundef nonnull dereferenceable(1) %1, i64 noundef 64) torvalds#24 ... } The above code calculates the address of the last char in the buffer (value %15) and then loads from it (value %16). Because the buffer is never initialized, the LLVM GVN pass marks value %16 as undefined: %13 = getelementptr inbounds i8, ptr %1, i64 63 br i1 undef, label %14, label %17 This gives later passes (SCCP, in particular) to more DCE opportunities by propagating the undef value further, and eventually removes everything after the load on the uninitialized stack location: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #0 section ".init.text" align 16 !kcfi_type !11 { %1 = alloca [64 x i8], align 16 ... 12: ; preds = %11 %13 = getelementptr inbounds i8, ptr %1, i64 63 unreachable } In this way, the generated native code will just fall through to the next function, as LLVM does not generate any code for the unreachable IR instruction and leaves the function without a terminator. Zero the on-stack buffer to avoid this possible UB. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402100205.PWXIz1ZK-lkp@intel.com/ Co-developed-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Jinghao Jia <jinghao7@illinois.edu> Signed-off-by: NipaLocal <nipa@local>

@strlen

Under certain kernel configurations when building with Clang/LLVM, the compiler does not generate a return or jump as the terminator instruction for ip_vs_protocol_init(), triggering the following objtool warning during build time: vmlinux.o: warning: objtool: ip_vs_protocol_init() falls through to next function __initstub__kmod_ip_vs_rr__935_123_ip_vs_rr_init6() At runtime, this either causes an oops when trying to load the ipvs module or a boot-time panic if ipvs is built-in. This same issue has been reported by the Intel kernel test robot previously. Digging deeper into both LLVM and the kernel code reveals this to be a undefined behavior problem. ip_vs_protocol_init() uses a on-stack buffer of 64 chars to store the registered protocol names and leaves it uninitialized after definition. The function calls strnlen() when concatenating protocol names into the buffer. With CONFIG_FORTIFY_SOURCE strnlen() performs an extra step to check whether the last byte of the input char buffer is a null character (commit 3009f89 ("fortify: Allow strlen() and strnlen() to pass compile-time known lengths")). This, together with possibly other configurations, cause the following IR to be generated: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #5 section ".init.text" align 16 !kcfi_type !29 { %1 = alloca [64 x i8], align 16 ... 14: ; preds = %11 %15 = getelementptr inbounds i8, ptr %1, i64 63 %16 = load i8, ptr %15, align 1 %17 = tail call i1 @llvm.is.constant.i8(i8 %16) %18 = icmp eq i8 %16, 0 %19 = select i1 %17, i1 %18, i1 false br i1 %19, label %20, label %23 20: ; preds = %14 %21 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) torvalds#23 ... 23: ; preds = %14, %11, %20 %24 = call i64 @strnlen(ptr noundef nonnull dereferenceable(1) %1, i64 noundef 64) torvalds#24 ... } The above code calculates the address of the last char in the buffer (value %15) and then loads from it (value %16). Because the buffer is never initialized, the LLVM GVN pass marks value %16 as undefined: %13 = getelementptr inbounds i8, ptr %1, i64 63 br i1 undef, label %14, label %17 This gives later passes (SCCP, in particular) to more DCE opportunities by propagating the undef value further, and eventually removes everything after the load on the uninitialized stack location: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #0 section ".init.text" align 16 !kcfi_type !11 { %1 = alloca [64 x i8], align 16 ... 12: ; preds = %11 %13 = getelementptr inbounds i8, ptr %1, i64 63 unreachable } In this way, the generated native code will just fall through to the next function, as LLVM does not generate any code for the unreachable IR instruction and leaves the function without a terminator. Zero the on-stack buffer to avoid this possible UB. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402100205.PWXIz1ZK-lkp@intel.com/ Co-developed-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Ruowen Qin <ruqin@redhat.com> Signed-off-by: Jinghao Jia <jinghao7@illinois.edu> Signed-off-by: NipaLocal <nipa@local>

Update drivers/staging/bcm/InterfaceInit.h

94e6860

Added device ID of ZTE AX326.

vineetgarc referenced this pull request in foss-for-synopsys-dwc-arc-processors/linux Oct 31, 2012

ARC: SMP resurrect #24: Makefile fix for relo errors

805b0d4

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

vineetgarc referenced this pull request in foss-for-synopsys-dwc-arc-processors/linux Dec 31, 2012

ARC: SMP resurrect #24: Makefile fix for relo errors

a68d78f

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

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Update drivers/staging/bcm/InterfaceInit.h #24

Update drivers/staging/bcm/InterfaceInit.h #24

mdminhazulhaque commented Oct 23, 2012

asamy commented Nov 3, 2012

Update drivers/staging/bcm/InterfaceInit.h #24

Update drivers/staging/bcm/InterfaceInit.h #24

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mdminhazulhaque commented Oct 23, 2012

asamy commented Nov 3, 2012