Rework perf hw_breakpoint support #38

mpe · 2016-03-04T08:46:57Z

The powerpc hw_breakpoint support is the only arch that uses the arch_unregister_hw_breakpoint() hook. In there we do:

if (bp->ctx && bp->ctx->task && bp->ctx->task != ((void *)-1L))
    bp->ctx->task->thread.last_hit_ubp = NULL;

Peterz strongly suggests we should not be using bp->ctx in there, and that we should (probably) instead be storing the breakpoint info per-cpu like other arches:

Indeed, but if there's a preemption point in between setting and using
that state, the ctx->task pointer might not actually still point to the
same task. With inherited events the event might get swapped to the next
task if it has the exact same (inherited) event configuration instead of
reprogramming the hardware.

The code needs to be reworked & tested.

The text was updated successfully, but these errors were encountered:

The binary GCD algorithm is based on the following facts: 1. If a and b are all evens, then gcd(a,b) = 2 * gcd(a/2, b/2) 2. If a is even and b is odd, then gcd(a,b) = gcd(a/2, b) 3. If a and b are all odds, then gcd(a,b) = gcd((a-b)/2, b) = gcd((a+b)/2, b) Even on x86 machines with reasonable division hardware, the binary algorithm runs about 25% faster (80% the execution time) than the division-based Euclidian algorithm. On platforms like Alpha and ARMv6 where division is a function call to emulation code, it's even more significant. There are two variants of the code here, depending on whether a fast __ffs (find least significant set bit) instruction is available. This allows the unpredictable branches in the bit-at-a-time shifting loop to be eliminated. If fast __ffs is not available, the "even/odd" GCD variant is used. I use the following code to benchmark: #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <string.h> #include <time.h> #include <unistd.h> #define swap(a, b) \ do { \ a ^= b; \ b ^= a; \ a ^= b; \ } while (0) unsigned long gcd0(unsigned long a, unsigned long b) { unsigned long r; if (a < b) { swap(a, b); } if (b == 0) return a; while ((r = a % b) != 0) { a = b; b = r; } return b; } unsigned long gcd1(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __builtin_ctzl(b); for (;;) { a >>= __builtin_ctzl(a); if (a == b) return a << __builtin_ctzl(r); if (a < b) swap(a, b); a -= b; } } unsigned long gcd2(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; r &= -r; while (!(b & r)) b >>= 1; for (;;) { while (!(a & r)) a >>= 1; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } unsigned long gcd3(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __builtin_ctzl(b); if (b == 1) return r & -r; for (;;) { a >>= __builtin_ctzl(a); if (a == 1) return r & -r; if (a == b) return a << __builtin_ctzl(r); if (a < b) swap(a, b); a -= b; } } unsigned long gcd4(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; r &= -r; while (!(b & r)) b >>= 1; if (b == r) return r; for (;;) { while (!(a & r)) a >>= 1; if (a == r) return r; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } static unsigned long (*gcd_func[])(unsigned long a, unsigned long b) = { gcd0, gcd1, gcd2, gcd3, gcd4, }; #define TEST_ENTRIES (sizeof(gcd_func) / sizeof(gcd_func[0])) #if defined(__x86_64__) #define rdtscll(val) do { \ unsigned long __a,__d; \ __asm__ __volatile__("rdtsc" : "=a" (__a), "=d" (__d)); \ (val) = ((unsigned long long)__a) | (((unsigned long long)__d)<<32); \ } while(0) static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long), unsigned long a, unsigned long b, unsigned long *res) { unsigned long long start, end; unsigned long long ret; unsigned long gcd_res; rdtscll(start); gcd_res = gcd(a, b); rdtscll(end); if (end >= start) ret = end - start; else ret = ~0ULL - start + 1 + end; *res = gcd_res; return ret; } #else static inline struct timespec read_time(void) { struct timespec time; clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time); return time; } static inline unsigned long long diff_time(struct timespec start, struct timespec end) { struct timespec temp; if ((end.tv_nsec - start.tv_nsec) < 0) { temp.tv_sec = end.tv_sec - start.tv_sec - 1; temp.tv_nsec = 1000000000ULL + end.tv_nsec - start.tv_nsec; } else { temp.tv_sec = end.tv_sec - start.tv_sec; temp.tv_nsec = end.tv_nsec - start.tv_nsec; } return temp.tv_sec * 1000000000ULL + temp.tv_nsec; } static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long), unsigned long a, unsigned long b, unsigned long *res) { struct timespec start, end; unsigned long gcd_res; start = read_time(); gcd_res = gcd(a, b); end = read_time(); *res = gcd_res; return diff_time(start, end); } #endif static inline unsigned long get_rand() { if (sizeof(long) == 8) return (unsigned long)rand() << 32 | rand(); else return rand(); } int main(int argc, char **argv) { unsigned int seed = time(0); int loops = 100; int repeats = 1000; unsigned long (*res)[TEST_ENTRIES]; unsigned long long elapsed[TEST_ENTRIES]; int i, j, k; for (;;) { int opt = getopt(argc, argv, "n:r:s:"); /* End condition always first */ if (opt == -1) break; switch (opt) { case 'n': loops = atoi(optarg); break; case 'r': repeats = atoi(optarg); break; case 's': seed = strtoul(optarg, NULL, 10); break; default: /* You won't actually get here. */ break; } } res = malloc(sizeof(unsigned long) * TEST_ENTRIES * loops); memset(elapsed, 0, sizeof(elapsed)); srand(seed); for (j = 0; j < loops; j++) { unsigned long a = get_rand(); /* Do we have args? */ unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand(); unsigned long long min_elapsed[TEST_ENTRIES]; for (k = 0; k < repeats; k++) { for (i = 0; i < TEST_ENTRIES; i++) { unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &res[j][i]); if (k == 0 || min_elapsed[i] > tmp) min_elapsed[i] = tmp; } } for (i = 0; i < TEST_ENTRIES; i++) elapsed[i] += min_elapsed[i]; } for (i = 0; i < TEST_ENTRIES; i++) printf("gcd%d: elapsed %llu\n", i, elapsed[i]); k = 0; srand(seed); for (j = 0; j < loops; j++) { unsigned long a = get_rand(); unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand(); for (i = 1; i < TEST_ENTRIES; i++) { if (res[j][i] != res[j][0]) break; } if (i < TEST_ENTRIES) { if (k == 0) { k = 1; fprintf(stderr, "Error:\n"); } fprintf(stderr, "gcd(%lu, %lu): ", a, b); for (i = 0; i < TEST_ENTRIES; i++) fprintf(stderr, "%ld%s", res[j][i], i < TEST_ENTRIES - 1 ? ", " : "\n"); } } if (k == 0) fprintf(stderr, "PASS\n"); free(res); return 0; } Compiled with "-O2", on "VirtualBox 4.4.0-22-generic torvalds#38-Ubuntu x86_64" got: zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 10174 gcd1: elapsed 2120 gcd2: elapsed 2902 gcd3: elapsed 2039 gcd4: elapsed 2812 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9309 gcd1: elapsed 2280 gcd2: elapsed 2822 gcd3: elapsed 2217 gcd4: elapsed 2710 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9589 gcd1: elapsed 2098 gcd2: elapsed 2815 gcd3: elapsed 2030 gcd4: elapsed 2718 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9914 gcd1: elapsed 2309 gcd2: elapsed 2779 gcd3: elapsed 2228 gcd4: elapsed 2709 PASS [akpm@linux-foundation.org: avoid #defining a CONFIG_ variable] Signed-off-by: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com> Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When locking a GPIO line as IRQ, we go to lengths to double-check that the line is really set as input before marking it as used for IRQ. This is not good on GPIO chips that can sleep, because this function is called in IRQ-safe context. Just skip this if it can't be checked quickly. Currently this happens on sleeping expanders such as STMPE or TC3589x: BUG: scheduling while atomic: swapper/1/0x00000002 Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 4.9.0-rc1+ torvalds#38 Hardware name: Nomadik STn8815 [<c000f2e0>] (unwind_backtrace) from [<c000d244>] (show_stack+0x10/0x14) [<c000d244>] (show_stack) from [<c0037b78>] (__schedule_bug+0x54/0x80) [<c0037b78>] (__schedule_bug) from [<c042df14>] (__schedule+0x3a0/0x460) [<c042df14>] (__schedule) from [<c042e028>] (schedule+0x54/0xb8) (...) This patch fixes that problem and relies on the direction read from the chip when it was added. Cc: stable@vger.kernel.org Fixes: 9c10280 ("gpio: flush direction status in gpiochip_lock_as_irq()") Cc: Patrice Chotard <patrice.chotard@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

qxl_release_map will enter an atomic context, but since we still need to alloc memory for BOs, we better delay that until we have everything we need, in case we need to sleep inside the allocation. This avoids the Sleep in atomic state below, which was reported by Mike. [ 43.910362] BUG: sleeping function called from invalid context at mm/slab.h:432 [ 43.910955] in_atomic(): 1, irqs_disabled(): 0, pid: 2077, name: Xorg [ 43.911472] Preemption disabled at: [ 43.911478] [<ffffffffa02b1c45>] qxl_bo_kmap_atomic_page+0xa5/0x100 [qxl] [ 43.912103] CPU: 0 PID: 2077 Comm: Xorg Tainted: G E 4.12.0-master torvalds#38 [ 43.912550] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20161202_174313-build11a 04/01/2014 [ 43.913202] Call Trace: [ 43.913371] dump_stack+0x65/0x89 [ 43.913581] ? qxl_bo_kmap_atomic_page+0xa5/0x100 [qxl] [ 43.913876] ___might_sleep+0x11a/0x190 [ 43.914095] __might_sleep+0x4a/0x80 [ 43.914319] ? qxl_bo_create+0x50/0x190 [qxl] [ 43.914565] kmem_cache_alloc_trace+0x46/0x180 [ 43.914836] qxl_bo_create+0x50/0x190 [qxl] [ 43.915082] ? refcount_dec_and_test+0x11/0x20 [ 43.915332] ? ttm_mem_io_reserve+0x41/0xe0 [ttm] [ 43.915595] qxl_alloc_bo_reserved+0x37/0xb0 [qxl] [ 43.915884] qxl_cursor_atomic_update+0x8f/0x260 [qxl] [ 43.916172] ? drm_atomic_helper_update_legacy_modeset_state+0x1d6/0x210 [drm_kms_helper] [ 43.916623] drm_atomic_helper_commit_planes+0xec/0x230 [drm_kms_helper] [ 43.916995] drm_atomic_helper_commit_tail+0x2b/0x60 [drm_kms_helper] [ 43.917398] commit_tail+0x65/0x70 [drm_kms_helper] [ 43.917693] drm_atomic_helper_commit+0xa9/0x100 [drm_kms_helper] [ 43.918039] drm_atomic_commit+0x4b/0x50 [drm] [ 43.918334] drm_atomic_helper_update_plane+0xf1/0x110 [drm_kms_helper] [ 43.918902] __setplane_internal+0x19f/0x280 [drm] [ 43.919240] drm_mode_cursor_universal+0x101/0x1c0 [drm] [ 43.919541] drm_mode_cursor_common+0x15b/0x1d0 [drm] [ 43.919858] drm_mode_cursor2_ioctl+0xe/0x10 [drm] [ 43.920157] drm_ioctl+0x211/0x460 [drm] [ 43.920383] ? drm_mode_cursor_ioctl+0x50/0x50 [drm] [ 43.920664] ? handle_mm_fault+0x93/0x160 [ 43.920893] do_vfs_ioctl+0x96/0x6e0 [ 43.921117] ? __fget+0x73/0xa0 [ 43.921322] SyS_ioctl+0x41/0x70 [ 43.921545] entry_SYSCALL_64_fastpath+0x1a/0xa5 [ 43.922188] RIP: 0033:0x7f1145804bc7 [ 43.922526] RSP: 002b:00007ffcd3e50508 EFLAGS: 00003246 ORIG_RAX: 0000000000000010 [ 43.923367] RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 00007f1145804bc7 [ 43.923852] RDX: 00007ffcd3e50540 RSI: 00000000c02464bb RDI: 000000000000000b [ 43.924299] RBP: 0000000000000040 R08: 0000000000000040 R09: 000000000000000c [ 43.924694] R10: 00007ffcd3e50340 R11: 0000000000003246 R12: 0000000000000018 [ 43.925128] R13: 00000000022bc390 R14: 0000000000000040 R15: 00007ffcd3e5062c Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk> Link: http://patchwork.freedesktop.org/patch/msgid/20170519175819.15682-1-krisman@collabora.co.uk Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Correct these checkpatch.pl errors: |ERROR: space required before that '-' (ctx:OxO) |torvalds#37: FILE: include/linux/bug.h:37: |+#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) |ERROR: space required before that '-' (ctx:OxO) |torvalds#38: FILE: include/linux/bug.h:38: |+#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) I decided to wrap the bitfield expressions that begin with minus signs in parentheses rather than insert spaces before the minus signs. Link: http://lkml.kernel.org/r/20170525120316.24473-5-abbotti@mev.co.uk Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Kees Cook <keescook@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

pppol2tp_release uses call_rcu to put the final ref on its socket. But the session object doesn't hold a ref on the session socket so may be freed while the pppol2tp_put_sk RCU callback is scheduled. Fix this by having the session hold a ref on its socket until the session is destroyed. It is this ref that is dropped via call_rcu. Sessions are also deleted via l2tp_tunnel_closeall. This must now also put the final ref via call_rcu. So move the call_rcu call site into pppol2tp_session_close so that this happens in both destroy paths. A common destroy path should really be implemented, perhaps with l2tp_tunnel_closeall calling l2tp_session_delete like pppol2tp_release does, but this will be looked at later. ODEBUG: activate active (active state 1) object type: rcu_head hint: (null) WARNING: CPU: 3 PID: 13407 at lib/debugobjects.c:291 debug_print_object+0x166/0x220 Modules linked in: CPU: 3 PID: 13407 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ torvalds#38 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:debug_print_object+0x166/0x220 RSP: 0018:ffff880013647a00 EFLAGS: 00010082 RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff814d3333 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88001a59f6d0 RBP: ffff880013647a40 R08: 0000000000000000 R09: 0000000000000001 R10: ffff8800136479a8 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff86161420 R14: ffffffff85648b60 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020e77000 CR3: 0000000006022000 CR4: 00000000000006e0 Call Trace: debug_object_activate+0x38b/0x530 ? debug_object_assert_init+0x3b0/0x3b0 ? __mutex_unlock_slowpath+0x85/0x8b0 ? pppol2tp_session_destruct+0x110/0x110 __call_rcu.constprop.66+0x39/0x890 ? __call_rcu.constprop.66+0x39/0x890 call_rcu_sched+0x17/0x20 pppol2tp_release+0x2c7/0x440 ? fcntl_setlk+0xca0/0xca0 ? sock_alloc_file+0x340/0x340 sock_release+0x92/0x1e0 sock_close+0x1b/0x20 __fput+0x296/0x6e0 ____fput+0x1a/0x20 task_work_run+0x127/0x1a0 do_exit+0x7f9/0x2ce0 ? SYSC_connect+0x212/0x310 ? mm_update_next_owner+0x690/0x690 ? up_read+0x1f/0x40 ? __do_page_fault+0x3c8/0xca0 do_group_exit+0x10d/0x330 ? do_group_exit+0x330/0x330 SyS_exit_group+0x22/0x30 do_syscall_64+0x1e0/0x730 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f362e471259 RSP: 002b:00007ffe389abe08 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f362e471259 RDX: 00007f362e471259 RSI: 000000000000002e RDI: 0000000000000000 RBP: 00007ffe389abe30 R08: 0000000000000000 R09: 00007f362e944270 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60 R13: 00007ffe389abf50 R14: 0000000000000000 R15: 0000000000000000 Code: 8d 3c dd a0 8f 64 85 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7b 48 8b 14 dd a0 8f 64 85 4c 89 f6 48 c7 c7 20 85 64 85 e 8 2a 55 14 ff <0f> 0b 83 05 ad 2a 68 04 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 Fixes: ee40fb2 ("l2tp: protect sock pointer of struct pppol2tp_session with RCU") Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>

syzbot caught an infinite recursion in nsh_gso_segment(). Problem here is that we need to make sure the NSH header is of reasonable length. BUG: MAX_LOCK_DEPTH too low! turning off the locking correctness validator. depth: 48 max: 48! 48 locks held by syz-executor0/10189: #0: (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517 #1: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] #1: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 #2: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] #2: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 #3: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] #3: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 #4: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] #4: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 #5: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] #5: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#6: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#6: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#7: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#7: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#8: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#8: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#9: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#9: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#10: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#10: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#11: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#11: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#12: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#12: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#13: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#13: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#14: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#14: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#15: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#15: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#16: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#16: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#17: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#17: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#18: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#18: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#19: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#19: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#20: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#20: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#21: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#21: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#22: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#22: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#23: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#23: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#24: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#24: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#25: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#25: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#26: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#26: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#27: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#27: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#28: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#28: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#29: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#29: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#30: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#30: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#31: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#31: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 dccp_close: ABORT with 65423 bytes unread torvalds#32: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#32: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#33: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#33: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#34: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#34: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#35: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#35: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#36: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#36: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#37: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#37: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#38: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#38: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#39: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#39: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#40: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#40: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#41: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#41: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#42: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#42: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#43: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#43: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#44: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#44: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#45: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#45: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#46: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#46: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 torvalds#47: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] torvalds#47: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 INFO: lockdep is turned off. CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ torvalds#26 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920 rcu_lock_acquire include/linux/rcupdate.h:246 [inline] rcu_read_lock include/linux/rcupdate.h:632 [inline] skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865 skb_gso_segment include/linux/netdevice.h:4025 [inline] validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312 qdisc_restart net/sched/sch_generic.c:399 [inline] __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410 __dev_xmit_skb net/core/dev.c:3243 [inline] __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616 packet_snd net/packet/af_packet.c:2951 [inline] packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 __sys_sendto+0x3d7/0x670 net/socket.c:1789 __do_sys_sendto net/socket.c:1801 [inline] __se_sys_sendto net/socket.c:1797 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: c411ed8 ("nsh: add GSO support") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jiri Benc <jbenc@redhat.com> Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Increase kasan instrumented kernel stack size from 32k to 64k. Other architectures seems to get away with just doubling kernel stack size under kasan, but on s390 this appears to be not enough due to bigger frame size. The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting stack overflow is fs sync on xfs filesystem: #0 [9a0681e8] 704 bytes check_usage at 34b1fc #1 [9a0684a8] 432 bytes check_usage at 34c710 #2 [9a068658] 1048 bytes validate_chain at 35044a #3 [9a068a70] 312 bytes __lock_acquire at 3559fe #4 [9a068ba8] 440 bytes lock_acquire at 3576ee #5 [9a068d60] 104 bytes _raw_spin_lock at 21b44e0 torvalds#6 [9a068dc8] 1992 bytes enqueue_entity at 2dbf72 torvalds#7 [9a069590] 1496 bytes enqueue_task_fair at 2df5f0 torvalds#8 [9a069b68] 64 bytes ttwu_do_activate at 28f438 torvalds#9 [9a069ba8] 552 bytes try_to_wake_up at 298c4c torvalds#10 [9a069dd0] 168 bytes wake_up_worker at 23f97c torvalds#11 [9a069e78] 200 bytes insert_work at 23fc2e torvalds#12 [9a069f40] 648 bytes __queue_work at 2487c0 torvalds#13 [9a06a1c8] 200 bytes __queue_delayed_work at 24db28 torvalds#14 [9a06a290] 248 bytes mod_delayed_work_on at 24de84 torvalds#15 [9a06a388] 24 bytes kblockd_mod_delayed_work_on at 153e2a0 torvalds#16 [9a06a3a0] 288 bytes __blk_mq_delay_run_hw_queue at 158168c torvalds#17 [9a06a4c0] 192 bytes blk_mq_run_hw_queue at 1581a3c torvalds#18 [9a06a580] 184 bytes blk_mq_sched_insert_requests at 15a2192 torvalds#19 [9a06a638] 1024 bytes blk_mq_flush_plug_list at 1590f3a torvalds#20 [9a06aa38] 704 bytes blk_flush_plug_list at 1555028 torvalds#21 [9a06acf8] 320 bytes schedule at 219e476 torvalds#22 [9a06ae38] 760 bytes schedule_timeout at 21b0aac torvalds#23 [9a06b130] 408 bytes wait_for_common at 21a1706 torvalds#24 [9a06b2c8] 360 bytes xfs_buf_iowait at fa1540 torvalds#25 [9a06b430] 256 bytes __xfs_buf_submit at fadae6 torvalds#26 [9a06b530] 264 bytes xfs_buf_read_map at fae3f6 torvalds#27 [9a06b638] 656 bytes xfs_trans_read_buf_map at 10ac9a8 torvalds#28 [9a06b8c8] 304 bytes xfs_btree_kill_root at e72426 torvalds#29 [9a06b9f8] 288 bytes xfs_btree_lookup_get_block at e7bc5e torvalds#30 [9a06bb18] 624 bytes xfs_btree_lookup at e7e1a6 torvalds#31 [9a06bd88] 2664 bytes xfs_alloc_ag_vextent_near at dfa070 torvalds#32 [9a06c7f0] 144 bytes xfs_alloc_ag_vextent at dff3ca torvalds#33 [9a06c880] 1128 bytes xfs_alloc_vextent at e05fce torvalds#34 [9a06cce8] 584 bytes xfs_bmap_btalloc at e58342 torvalds#35 [9a06cf30] 1336 bytes xfs_bmapi_write at e618de torvalds#36 [9a06d468] 776 bytes xfs_iomap_write_allocate at ff678e torvalds#37 [9a06d770] 720 bytes xfs_map_blocks at f82af8 torvalds#38 [9a06da40] 928 bytes xfs_writepage_map at f83cd6 torvalds#39 [9a06dde0] 320 bytes xfs_do_writepage at f85872 torvalds#40 [9a06df20] 1320 bytes write_cache_pages at 73dfe8 torvalds#41 [9a06e448] 208 bytes xfs_vm_writepages at f7f892 torvalds#42 [9a06e518] 88 bytes do_writepages at 73fe6a torvalds#43 [9a06e570] 872 bytes __writeback_single_inode at a20cb6 torvalds#44 [9a06e8d8] 664 bytes writeback_sb_inodes at a23be2 torvalds#45 [9a06eb70] 296 bytes __writeback_inodes_wb at a242e0 torvalds#46 [9a06ec98] 928 bytes wb_writeback at a2500e torvalds#47 [9a06f038] 848 bytes wb_do_writeback at a260ae torvalds#48 [9a06f388] 536 bytes wb_workfn at a28228 torvalds#49 [9a06f5a0] 1088 bytes process_one_work at 24a234 torvalds#50 [9a06f9e0] 1120 bytes worker_thread at 24ba26 torvalds#51 [9a06fe40] 104 bytes kthread at 26545a #52 [9a06fea8] kernel_thread_starter at 21b6b62 To be able to increase the stack size to 64k reuse LLILL instruction in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE (65192) value as unsigned. Reported-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

deece · 2018-11-28T04:51:20Z

Still relevant, see arch/powerpc/kernel/hw_breakpoint.c:arch_unregister_hw_breakpoint()

mpe · 2023-08-02T12:01:17Z

Possible solution from @BenjaminGrayNp1 : https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=366657

mpe · 2024-05-06T13:05:55Z

Fixed by @BenjaminGrayNp1 in torvalds/linux@53834a0

mpe transferred this issue from linuxppc/linux Jan 7, 2019

mpe added bug It's a bug medium Possibly not too difficult labels Jan 7, 2019

mpe added this to the v6.6 milestone Aug 24, 2023

mpe closed this as completed May 6, 2024

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Rework perf hw_breakpoint support #38

Rework perf hw_breakpoint support #38

mpe commented Mar 4, 2016

deece commented Nov 28, 2018

mpe commented Aug 2, 2023

mpe commented May 6, 2024

Rework perf hw_breakpoint support #38

Rework perf hw_breakpoint support #38

Comments

mpe commented Mar 4, 2016

deece commented Nov 28, 2018

mpe commented Aug 2, 2023

mpe commented May 6, 2024