Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

-Wconstant-conversion in arch/x86/kvm/mmu.c #95

Closed
tpimh opened this issue Sep 17, 2018 · 9 comments
Closed

-Wconstant-conversion in arch/x86/kvm/mmu.c #95

tpimh opened this issue Sep 17, 2018 · 9 comments
Assignees
@arndb
Labels
-Wconstant-conversion [ARCH] x86_64 This bug impacts ARCH=x86_64 [BUG] linux A bug that should be fixed in the mainline kernel. [FIXED][LINUX] 5.3 This bug was fixed in Linux 5.3

Comments

@tpimh
Copy link

tpimh commented Sep 17, 2018 

arch/x86/kvm/mmu.c:4519:39: warning: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51
      [-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4521:38: warning: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15
      [-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4523:39: warning: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85
      [-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~
3 warnings generated.
@tpimh tpimh added help wanted good first issue Good for newcomers [BUG] linux A bug that should be fixed in the mainline kernel. [ARCH] x86_64 This bug impacts ARCH=x86_64 low priority This bug is not critical and not a priority -Wconstant-conversion labels Sep 17, 2018
@nathanchance
Copy link
Member

nathanchance commented Sep 24, 2018 •
edited
Loading

I thought I remembered seeing this warning somewhere then I remembered that @mkaehlcke sent a fix for this upstream: https://lore.kernel.org/lkml/20180619192504.180479-1-mka@chromium.org/

Seems like nothing came from that thread, Joe Perches suggested turning off the warning: https://lore.kernel.org/lkml/3b61527dd119e0ab1025e9e36f666e74a336b180.camel@perches.com/

Disabled in chromeos-4.14 too: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1137347

@nathanchance
Copy link
Member

Chromium bug: https://bugs.chromium.org/p/chromium/issues/detail?id=849780

nathanchance pushed a commit that referenced this issue Dec 9, 2018
@davem330
rtnetlink: ndo_dflt_fdb_dump() only work for ARPHRD_ETHER devices
6888389 
kmsan was able to trigger a kernel-infoleak using a gre device [1]

nlmsg_populate_fdb_fill() has a hard coded assumption
that dev->addr_len is ETH_ALEN, as normally guaranteed
for ARPHRD_ETHER devices.

A similar issue was fixed recently in commit da71577
("rtnetlink: Disallow FDB configuration for non-Ethernet device")

[1]
BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:143 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x4c0/0x2700 lib/iov_iter.c:576
CPU: 0 PID: 6697 Comm: syz-executor310 Not tainted 4.20.0-rc3+ #95
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+0x32d/0x480 lib/dump_stack.c:113
 kmsan_report+0x12c/0x290 mm/kmsan/kmsan.c:683
 kmsan_internal_check_memory+0x32a/0xa50 mm/kmsan/kmsan.c:743
 kmsan_copy_to_user+0x78/0xd0 mm/kmsan/kmsan_hooks.c:634
 copyout lib/iov_iter.c:143 [inline]
 _copy_to_iter+0x4c0/0x2700 lib/iov_iter.c:576
 copy_to_iter include/linux/uio.h:143 [inline]
 skb_copy_datagram_iter+0x4e2/0x1070 net/core/datagram.c:431
 skb_copy_datagram_msg include/linux/skbuff.h:3316 [inline]
 netlink_recvmsg+0x6f9/0x19d0 net/netlink/af_netlink.c:1975
 sock_recvmsg_nosec net/socket.c:794 [inline]
 sock_recvmsg+0x1d1/0x230 net/socket.c:801
 ___sys_recvmsg+0x444/0xae0 net/socket.c:2278
 __sys_recvmsg net/socket.c:2327 [inline]
 __do_sys_recvmsg net/socket.c:2337 [inline]
 __se_sys_recvmsg+0x2fa/0x450 net/socket.c:2334
 __x64_sys_recvmsg+0x4a/0x70 net/socket.c:2334
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x441119
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffc7f008a8 EFLAGS: 00000207 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000441119
RDX: 0000000000000040 RSI: 00000000200005c0 RDI: 0000000000000003
RBP: 00000000006cc018 R08: 0000000000000100 R09: 0000000000000100
R10: 0000000000000100 R11: 0000000000000207 R12: 0000000000402080
R13: 0000000000402110 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:246 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:261 [inline]
 kmsan_internal_chain_origin+0x13d/0x240 mm/kmsan/kmsan.c:469
 kmsan_memcpy_memmove_metadata+0x1a9/0xf70 mm/kmsan/kmsan.c:344
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:362
 __msan_memcpy+0x61/0x70 mm/kmsan/kmsan_instr.c:162
 __nla_put lib/nlattr.c:744 [inline]
 nla_put+0x20a/0x2d0 lib/nlattr.c:802
 nlmsg_populate_fdb_fill+0x444/0x810 net/core/rtnetlink.c:3466
 nlmsg_populate_fdb net/core/rtnetlink.c:3775 [inline]
 ndo_dflt_fdb_dump+0x73a/0x960 net/core/rtnetlink.c:3807
 rtnl_fdb_dump+0x1318/0x1cb0 net/core/rtnetlink.c:3979
 netlink_dump+0xc79/0x1c90 net/netlink/af_netlink.c:2244
 __netlink_dump_start+0x10c4/0x11d0 net/netlink/af_netlink.c:2352
 netlink_dump_start include/linux/netlink.h:216 [inline]
 rtnetlink_rcv_msg+0x141b/0x1540 net/core/rtnetlink.c:4910
 netlink_rcv_skb+0x394/0x640 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4965
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x1699/0x1740 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x13c7/0x1440 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xe3b/0x1240 net/socket.c:2116
 __sys_sendmsg net/socket.c:2154 [inline]
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2161
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:246 [inline]
 kmsan_internal_poison_shadow+0x6d/0x130 mm/kmsan/kmsan.c:170
 kmsan_kmalloc+0xa1/0x100 mm/kmsan/kmsan_hooks.c:186
 __kmalloc+0x14c/0x4d0 mm/slub.c:3825
 kmalloc include/linux/slab.h:551 [inline]
 __hw_addr_create_ex net/core/dev_addr_lists.c:34 [inline]
 __hw_addr_add_ex net/core/dev_addr_lists.c:80 [inline]
 __dev_mc_add+0x357/0x8a0 net/core/dev_addr_lists.c:670
 dev_mc_add+0x6d/0x80 net/core/dev_addr_lists.c:687
 ip_mc_filter_add net/ipv4/igmp.c:1128 [inline]
 igmp_group_added+0x4d4/0xb80 net/ipv4/igmp.c:1311
 __ip_mc_inc_group+0xea9/0xf70 net/ipv4/igmp.c:1444
 ip_mc_inc_group net/ipv4/igmp.c:1453 [inline]
 ip_mc_up+0x1c3/0x400 net/ipv4/igmp.c:1775
 inetdev_event+0x1d03/0x1d80 net/ipv4/devinet.c:1522
 notifier_call_chain kernel/notifier.c:93 [inline]
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x13d/0x240 kernel/notifier.c:401
 __dev_notify_flags+0x3da/0x860 net/core/dev.c:1733
 dev_change_flags+0x1ac/0x230 net/core/dev.c:7569
 do_setlink+0x165f/0x5ea0 net/core/rtnetlink.c:2492
 rtnl_newlink+0x2ad7/0x35a0 net/core/rtnetlink.c:3111
 rtnetlink_rcv_msg+0x1148/0x1540 net/core/rtnetlink.c:4947
 netlink_rcv_skb+0x394/0x640 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4965
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x1699/0x1740 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x13c7/0x1440 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xe3b/0x1240 net/socket.c:2116
 __sys_sendmsg net/socket.c:2154 [inline]
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2161
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Bytes 36-37 of 105 are uninitialized
Memory access of size 105 starts at ffff88819686c000
Data copied to user address 0000000020000380

Fixes: d83b060 ("net: add fdb generic dump routine")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Ido Schimmel <idosch@mellanox.com>
Cc: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
nathanchance pushed a commit that referenced this issue Dec 20, 2018
@lxin @davem330
sctp: initialize sin6_flowinfo for ipv6 addrs in sctp_inet6addr_event
4a2eb0c 
syzbot reported a kernel-infoleak, which is caused by an uninitialized
field(sin6_flowinfo) of addr->a.v6 in sctp_inet6addr_event().
The call trace is as below:

  BUG: KMSAN: kernel-infoleak in _copy_to_user+0x19a/0x230 lib/usercopy.c:33
  CPU: 1 PID: 8164 Comm: syz-executor2 Not tainted 4.20.0-rc3+ #95
  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+0x32d/0x480 lib/dump_stack.c:113
    kmsan_report+0x12c/0x290 mm/kmsan/kmsan.c:683
    kmsan_internal_check_memory+0x32a/0xa50 mm/kmsan/kmsan.c:743
    kmsan_copy_to_user+0x78/0xd0 mm/kmsan/kmsan_hooks.c:634
    _copy_to_user+0x19a/0x230 lib/usercopy.c:33
    copy_to_user include/linux/uaccess.h:183 [inline]
    sctp_getsockopt_local_addrs net/sctp/socket.c:5998 [inline]
    sctp_getsockopt+0x15248/0x186f0 net/sctp/socket.c:7477
    sock_common_getsockopt+0x13f/0x180 net/core/sock.c:2937
    __sys_getsockopt+0x489/0x550 net/socket.c:1939
    __do_sys_getsockopt net/socket.c:1950 [inline]
    __se_sys_getsockopt+0xe1/0x100 net/socket.c:1947
    __x64_sys_getsockopt+0x62/0x80 net/socket.c:1947
    do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
    entry_SYSCALL_64_after_hwframe+0x63/0xe7

sin6_flowinfo is not really used by SCTP, so it will be fixed by simply
setting it to 0.

The issue exists since very beginning.
Thanks Alexander for the reproducer provided.

Reported-by: syzbot+ad5d327e6936a2e284be@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
@nickdesaulniers nickdesaulniers removed the good first issue Good for newcomers label Jan 8, 2019
@nickdesaulniers nickdesaulniers added the [PATCH] Rejected The submitted patch was rejected label Mar 9, 2019
nathanchance pushed a commit that referenced this issue Mar 11, 2019
@borkmann
xsk: fix potential crash in xsk_diag_put_umem()
915905f 
Fixes two typos in xsk_diag_put_umem()

syzbot reported the following crash :

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 7641 Comm: syz-executor946 Not tainted 5.0.0-rc7+ #95
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:xsk_diag_put_umem net/xdp/xsk_diag.c:71 [inline]
RIP: 0010:xsk_diag_fill net/xdp/xsk_diag.c:113 [inline]
RIP: 0010:xsk_diag_dump+0xdcb/0x13a0 net/xdp/xsk_diag.c:143
Code: 8d be c0 04 00 00 48 89 f8 48 c1 e8 03 42 80 3c 20 00 0f 85 39 04 00 00 49 8b 96 c0 04 00 00 48 8d 7a 14 48 89 f8 48 c1 e8 03 <42> 0f b6 0c 20 48 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85
RSP: 0018:ffff888090bcf2d8 EFLAGS: 00010203
RAX: 0000000000000002 RBX: ffff8880a0aacbc0 RCX: ffffffff86ffdc3c
RDX: 0000000000000000 RSI: ffffffff86ffdc70 RDI: 0000000000000014
RBP: ffff888090bcf438 R08: ffff88808e04a700 R09: ffffed1011c74174
R10: ffffed1011c74173 R11: ffff88808e3a0b9f R12: dffffc0000000000
R13: ffff888093a6d818 R14: ffff88808e365240 R15: ffff88808e3a0b40
FS:  00000000011ea880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 000000008fa13000 CR4: 00000000001406e0
Call Trace:
 netlink_dump+0x55d/0xfb0 net/netlink/af_netlink.c:2252
 __netlink_dump_start+0x5b4/0x7e0 net/netlink/af_netlink.c:2360
 netlink_dump_start include/linux/netlink.h:226 [inline]
 xsk_diag_handler_dump+0x1b2/0x250 net/xdp/xsk_diag.c:170
 __sock_diag_cmd net/core/sock_diag.c:232 [inline]
 sock_diag_rcv_msg+0x322/0x410 net/core/sock_diag.c:263
 netlink_rcv_skb+0x17a/0x460 net/netlink/af_netlink.c:2485
 sock_diag_rcv+0x2b/0x40 net/core/sock_diag.c:274
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x536/0x720 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1925
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:632
 sock_write_iter+0x27c/0x3e0 net/socket.c:923
 call_write_iter include/linux/fs.h:1863 [inline]
 do_iter_readv_writev+0x5e0/0x8e0 fs/read_write.c:680
 do_iter_write fs/read_write.c:956 [inline]
 do_iter_write+0x184/0x610 fs/read_write.c:937
 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1001
 do_writev+0xf6/0x290 fs/read_write.c:1036
 __do_sys_writev fs/read_write.c:1109 [inline]
 __se_sys_writev fs/read_write.c:1106 [inline]
 __x64_sys_writev+0x75/0xb0 fs/read_write.c:1106
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440139
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcc966cc18 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440139
RDX: 0000000000000001 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000000000004 R11: 0000000000000246 R12: 00000000004019c0
R13: 0000000000401a50 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 460a3c24d0a656c9 ]---
RIP: 0010:xsk_diag_put_umem net/xdp/xsk_diag.c:71 [inline]
RIP: 0010:xsk_diag_fill net/xdp/xsk_diag.c:113 [inline]
RIP: 0010:xsk_diag_dump+0xdcb/0x13a0 net/xdp/xsk_diag.c:143
Code: 8d be c0 04 00 00 48 89 f8 48 c1 e8 03 42 80 3c 20 00 0f 85 39 04 00 00 49 8b 96 c0 04 00 00 48 8d 7a 14 48 89 f8 48 c1 e8 03 <42> 0f b6 0c 20 48 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85
RSP: 0018:ffff888090bcf2d8 EFLAGS: 00010203
RAX: 0000000000000002 RBX: ffff8880a0aacbc0 RCX: ffffffff86ffdc3c
RDX: 0000000000000000 RSI: ffffffff86ffdc70 RDI: 0000000000000014
RBP: ffff888090bcf438 R08: ffff88808e04a700 R09: ffffed1011c74174
R10: ffffed1011c74173 R11: ffff88808e3a0b9f R12: dffffc0000000000
R13: ffff888093a6d818 R14: ffff88808e365240 R15: ffff88808e3a0b40
FS:  00000000011ea880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001d22000 CR3: 000000008fa13000 CR4: 00000000001406f0

Fixes: a36b38a ("xsk: add sock_diag interface for AF_XDP")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
@dileks
Copy link
Collaborator

dileks commented Mar 18, 2019

Looks like good compromise to me - rathan than brutally turning it off (added a missing comma to the cc-option check):

diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index 8d5357053f86..9b1d0d59e8d0 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -46,6 +46,7 @@ warning-2 += $(call cc-option, -Wunused-macros)
 warning-3 := -Wbad-function-cast
 warning-3 += -Wcast-qual
 warning-3 += -Wconversion
+warning-3 += $(call cc-option, -Wconstant-conversion)
 warning-3 += -Wpacked
 warning-3 += -Wpadded
 warning-3 += -Wpointer-arith

[1] https://lore.kernel.org/lkml/3b61527dd119e0ab1025e9e36f666e74a336b180.camel@perches.com/

@nathanchance
Copy link
Member

I've fixed all constant conversion warnings in arm{32,64} and x86 {def,allyes}config builds, this is the only one that is still around: https://github.com/ClangBuiltLinux/linux/issues?q=label%3A-Wconstant-conversion

I'd rather not see this warning disabled personally.

@dileks
Copy link
Collaborator

dileks commented Mar 18, 2019

This is the last warning I see with clang, the rest are objtool warnings.

@dileks
Copy link
Collaborator

dileks commented Mar 20, 2019

As an alternative...

x86-kvm-clang-Disable-Wconstant-conversion-warning_patch.txt

@nickdesaulniers
Copy link
Member

@arndb sent a patch that's been accepted but not pushed yet: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg2048148.html

@nickdesaulniers nickdesaulniers added [PATCH] Submitted A patch has been submitted for review and removed [PATCH] Rejected The submitted patch was rejected labels Jul 12, 2019
@nathanchance
Copy link
Member

Arnd’s patch is now in -next: https://git.kernel.org/next/linux-next/c/a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff

@nathanchance nathanchance added [PATCH] Accepted A submitted patch has been accepted upstream and removed [PATCH] Submitted A patch has been submitted for review low priority This bug is not critical and not a priority labels Jul 17, 2019
avagin pushed a commit to avagin/linux that referenced this issue Jul 17, 2019
@arndb @bonzini
x86: kvm: avoid constant-conversion warning
a6a6d3b 
clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
@nathanchance
Copy link
Member

Merged into mainline: https://git.kernel.org/linus/a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff

@nathanchance nathanchance removed the [PATCH] Accepted A submitted patch has been accepted upstream label Jul 21, 2019
freeza-inc pushed a commit to freeza-inc/bm-galaxy-note10-sd855-pie that referenced this issue Dec 28, 2019
@arndb @freeza-inc
x86: kvm: avoid constant-conversion warning
6a2a0bb 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Flatty11 pushed a commit to Flatty11/Kernel_S10p_q that referenced this issue Jan 6, 2020
@arndb @Flatty11
x86: kvm: avoid constant-conversion warning
8698743 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
freeza-inc pushed a commit to freeza-inc/bm-galaxy-note10-sd855-Q that referenced this issue Jan 23, 2020
@arndb @freeza-inc
x86: kvm: avoid constant-conversion warning
f22c2f7 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
kartikbhalla12 pushed a commit to kartikbhalla12/HyperX-X2 that referenced this issue Apr 3, 2020
@arndb @kartikbhalla12
x86: kvm: avoid constant-conversion warning
ce55e4f 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
nathanchance pushed a commit that referenced this issue May 7, 2020
@davem330
mptcp: move option parsing into mptcp_incoming_options()
cfde141 
The mptcp_options_received structure carries several per
packet flags (mp_capable, mp_join, etc.). Such fields must
be cleared on each packet, even on dropped ones or packet
not carrying any MPTCP options, but the current mptcp
code clears them only on TCP option reset.

On several races/corner cases we end-up with stray bits in
incoming options, leading to WARN_ON splats. e.g.:

[  171.164906] Bad mapping: ssn=32714 map_seq=1 map_data_len=32713
[  171.165006] WARNING: CPU: 1 PID: 5026 at net/mptcp/subflow.c:533 warn_bad_map (linux-mptcp/net/mptcp/subflow.c:533 linux-mptcp/net/mptcp/subflow.c:531)
[  171.167632] Modules linked in: ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel geneve ip6_udp_tunnel udp_tunnel macsec macvtap tap ipvlan macvlan 8021q garp mrp xfrm_interface veth netdevsim nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun binfmt_misc intel_rapl_msr intel_rapl_common rfkill kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel joydev virtio_balloon pcspkr i2c_piix4 sunrpc ip_tables xfs libcrc32c crc32c_intel serio_raw virtio_console ata_generic virtio_blk virtio_net net_failover failover ata_piix libata
[  171.199464] CPU: 1 PID: 5026 Comm: repro Not tainted 5.7.0-rc1.mptcp_f227fdf5d388+ #95
[  171.200886] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
[  171.202546] RIP: 0010:warn_bad_map (linux-mptcp/net/mptcp/subflow.c:533 linux-mptcp/net/mptcp/subflow.c:531)
[  171.206537] Code: c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1d 8b 55 3c 44 89 e6 48 c7 c7 20 51 13 95 e8 37 8b 22 fe <0f> 0b 48 83 c4 08 5b 5d 41 5c c3 89 4c 24 04 e8 db d6 94 fe 8b 4c
[  171.220473] RSP: 0018:ffffc90000150560 EFLAGS: 00010282
[  171.221639] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  171.223108] RDX: 0000000000000000 RSI: 0000000000000008 RDI: fffff5200002a09e
[  171.224388] RBP: ffff8880aa6e3c00 R08: 0000000000000001 R09: fffffbfff2ec9955
[  171.225706] R10: ffffffff9764caa7 R11: fffffbfff2ec9954 R12: 0000000000007fca
[  171.227211] R13: ffff8881066f4a7f R14: ffff8880aa6e3c00 R15: 0000000000000020
[  171.228460] FS:  00007f8623719740(0000) GS:ffff88810be00000(0000) knlGS:0000000000000000
[  171.230065] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  171.231303] CR2: 00007ffdab190a50 CR3: 00000001038ea006 CR4: 0000000000160ee0
[  171.232586] Call Trace:
[  171.233109]  <IRQ>
[  171.233531] get_mapping_status (linux-mptcp/net/mptcp/subflow.c:691)
[  171.234371] mptcp_subflow_data_available (linux-mptcp/net/mptcp/subflow.c:736 linux-mptcp/net/mptcp/subflow.c:832)
[  171.238181] subflow_state_change (linux-mptcp/net/mptcp/subflow.c:1085 (discriminator 1))
[  171.239066] tcp_fin (linux-mptcp/net/ipv4/tcp_input.c:4217)
[  171.240123] tcp_data_queue (linux-mptcp/./include/linux/compiler.h:199 linux-mptcp/net/ipv4/tcp_input.c:4822)
[  171.245083] tcp_rcv_established (linux-mptcp/./include/linux/skbuff.h:1785 linux-mptcp/./include/net/tcp.h:1774 linux-mptcp/./include/net/tcp.h:1847 linux-mptcp/net/ipv4/tcp_input.c:5238 linux-mptcp/net/ipv4/tcp_input.c:5730)
[  171.254089] tcp_v4_rcv (linux-mptcp/./include/linux/spinlock.h:393 linux-mptcp/net/ipv4/tcp_ipv4.c:2009)
[  171.258969] ip_protocol_deliver_rcu (linux-mptcp/net/ipv4/ip_input.c:204 (discriminator 1))
[  171.260214] ip_local_deliver_finish (linux-mptcp/./include/linux/rcupdate.h:651 linux-mptcp/net/ipv4/ip_input.c:232)
[  171.261389] ip_local_deliver (linux-mptcp/./include/linux/netfilter.h:307 linux-mptcp/./include/linux/netfilter.h:301 linux-mptcp/net/ipv4/ip_input.c:252)
[  171.265884] ip_rcv (linux-mptcp/./include/linux/netfilter.h:307 linux-mptcp/./include/linux/netfilter.h:301 linux-mptcp/net/ipv4/ip_input.c:539)
[  171.273666] process_backlog (linux-mptcp/./include/linux/rcupdate.h:651 linux-mptcp/net/core/dev.c:6135)
[  171.275328] net_rx_action (linux-mptcp/net/core/dev.c:6572 linux-mptcp/net/core/dev.c:6640)
[  171.280472] __do_softirq (linux-mptcp/./arch/x86/include/asm/jump_label.h:25 linux-mptcp/./include/linux/jump_label.h:200 linux-mptcp/./include/trace/events/irq.h:142 linux-mptcp/kernel/softirq.c:293)
[  171.281379] do_softirq_own_stack (linux-mptcp/arch/x86/entry/entry_64.S:1083)
[  171.282358]  </IRQ>

We could address the issue clearing explicitly the relevant fields
in several places - tcp_parse_option, tcp_fast_parse_options,
possibly others.

Instead we move the MPTCP option parsing into the already existing
mptcp ingress hook, so that we need to clear the fields in a single
place.

This allows us dropping an MPTCP hook from the TCP code and
removing the quite large mptcp_options_received from the tcp_sock
struct. On the flip side, the MPTCP sockets will traverse the
option space twice (in tcp_parse_option() and in
mptcp_incoming_options(). That looks acceptable: we already
do that for syn and 3rd ack packets, plain TCP socket will
benefit from it, and even MPTCP sockets will experience better
code locality, reducing the jumps between TCP and MPTCP code.

v1 -> v2:
 - rebased on current '-net' tree

Fixes: 648ef4b ("mptcp: Implement MPTCP receive path")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Claymore1297 pushed a commit to Claymore1297/kernel_oneplus_sm8150 that referenced this issue Aug 15, 2020
@arndb @Claymore1297
x86: kvm: avoid constant-conversion warning
8babee9 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
nathanchance pushed a commit that referenced this issue Nov 10, 2020
@josefbacik @kdave
btrfs: fix min reserved size calculation in merge_reloc_root
fca3a45 
The minimum reserve size was adjusted to take into account the height of
the tree we are merging, however we can have a root with a level == 0.
What we want is root_level + 1 to get the number of nodes we may have to
cow.  This fixes the enospc_debug warning pops with btrfs/101.

Nikolay: this fixes failures on btrfs/060 btrfs/062 btrfs/063 and
btrfs/195 That I was seeing, the call trace was:

  [ 3680.515564] ------------[ cut here ]------------
  [ 3680.515566] BTRFS: block rsv returned -28
  [ 3680.515585] WARNING: CPU: 2 PID: 8339 at fs/btrfs/block-rsv.c:521 btrfs_use_block_rsv+0x162/0x180
  [ 3680.515587] Modules linked in:
  [ 3680.515591] CPU: 2 PID: 8339 Comm: btrfs Tainted: G        W         5.9.0-rc8-default #95
  [ 3680.515593] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
  [ 3680.515595] RIP: 0010:btrfs_use_block_rsv+0x162/0x180
  [ 3680.515600] RSP: 0018:ffffa01ac9753910 EFLAGS: 00010282
  [ 3680.515602] RAX: 0000000000000000 RBX: ffff984b34200000 RCX: 0000000000000027
  [ 3680.515604] RDX: 0000000000000027 RSI: 0000000000000000 RDI: ffff984b3bd19e28
  [ 3680.515606] RBP: 0000000000004000 R08: ffff984b3bd19e20 R09: 0000000000000001
  [ 3680.515608] R10: 0000000000000004 R11: 0000000000000046 R12: ffff984b264fdc00
  [ 3680.515609] R13: ffff984b13149000 R14: 00000000ffffffe4 R15: ffff984b34200000
  [ 3680.515613] FS:  00007f4e2912b8c0(0000) GS:ffff984b3bd00000(0000) knlGS:0000000000000000
  [ 3680.515615] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 3680.515617] CR2: 00007fab87122150 CR3: 0000000118e42000 CR4: 00000000000006e0
  [ 3680.515620] Call Trace:
  [ 3680.515627]  btrfs_alloc_tree_block+0x8b/0x340
  [ 3680.515633]  ? __lock_acquire+0x51a/0xac0
  [ 3680.515646]  alloc_tree_block_no_bg_flush+0x4f/0x60
  [ 3680.515651]  __btrfs_cow_block+0x14e/0x7e0
  [ 3680.515662]  btrfs_cow_block+0x144/0x2c0
  [ 3680.515670]  merge_reloc_root+0x4d4/0x610
  [ 3680.515675]  ? btrfs_lookup_fs_root+0x78/0x90
  [ 3680.515686]  merge_reloc_roots+0xee/0x280
  [ 3680.515695]  relocate_block_group+0x2ce/0x5e0
  [ 3680.515704]  btrfs_relocate_block_group+0x16e/0x310
  [ 3680.515711]  btrfs_relocate_chunk+0x38/0xf0
  [ 3680.515716]  btrfs_shrink_device+0x200/0x560
  [ 3680.515728]  btrfs_rm_device+0x1ae/0x6a6
  [ 3680.515744]  ? _copy_from_user+0x6e/0xb0
  [ 3680.515750]  btrfs_ioctl+0x1afe/0x28c0
  [ 3680.515755]  ? find_held_lock+0x2b/0x80
  [ 3680.515760]  ? do_user_addr_fault+0x1f8/0x418
  [ 3680.515773]  ? __x64_sys_ioctl+0x77/0xb0
  [ 3680.515775]  __x64_sys_ioctl+0x77/0xb0
  [ 3680.515781]  do_syscall_64+0x31/0x70
  [ 3680.515785]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported-by: Nikolay Borisov <nborisov@suse.com>
Fixes: 44d354a ("btrfs: relocation: review the call sites which can be interrupted by signal")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
nazunamoe pushed a commit to nazunamoe/Nanahira_Kernel that referenced this issue Dec 4, 2020
@arndb @nazunamoe
x86: kvm: avoid constant-conversion warning
d061d29 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
kimocoder pushed a commit to kimocoder/android_kernel_oneplus_sm8150_draco that referenced this issue Dec 28, 2020
@arndb @kimocoder
x86: kvm: avoid constant-conversion warning
282ba60 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ThunderStorms21th pushed a commit to ThunderStorms21th/Galaxy-S10 that referenced this issue Mar 20, 2021
@arndb @ThunderStorms21th
x86: kvm: avoid constant-conversion warning
fba4fdb 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
TenSeventy7 pushed a commit to FreshROMs/android_kernel_samsung_exynos9610_mint that referenced this issue Apr 22, 2021
@arndb @TenSeventy7
x86: kvm: avoid constant-conversion warning
8b44d81 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
soulr344 pushed a commit to TotsukaINC/android_kernel_universal_my1nsxx that referenced this issue May 3, 2021
@arndb @soulr344
x86: kvm: avoid constant-conversion warning
9866be1 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gamer13433 pushed a commit to gamer13433/Universal9611_M21_devel that referenced this issue May 5, 2021
@arndb @gamer13433
x86: kvm: avoid constant-conversion warning
fafdf57 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
topser9 pushed a commit to topser9/kernel_samsung_universal9610 that referenced this issue Jul 19, 2021
@arndb @topser9
x86: kvm: avoid constant-conversion warning
7bc0da7 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Dark-Matter7232 pushed a commit to Dark-Matter7232/The-Cosmic-Staff that referenced this issue Jul 23, 2021
@arndb @Dark-Matter7232
x86: kvm: avoid constant-conversion warning
05d49e8 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bode327 pushed a commit to bode327/kernel_samsung_a50 that referenced this issue Jul 31, 2021
@arndb
x86: kvm: avoid constant-conversion warning
c677d28 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
TenSeventy7 pushed a commit to FreshROMs/android_kernel_samsung_exynos9610_mint that referenced this issue Aug 23, 2021
@arndb @TenSeventy7
x86: kvm: avoid constant-conversion warning
510f0e1 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Dark-Matter7232 pushed a commit to Dark-Matter7232/The-Cosmic-Staff that referenced this issue Aug 25, 2021
@arndb @Dark-Matter7232
x86: kvm: avoid constant-conversion warning
18ee29c 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
sergoops pushed a commit to sergoops/kernel_realme_sm6150 that referenced this issue Aug 29, 2021
@arndb @sergoops
x86: kvm: avoid constant-conversion warning
a5b6ec6 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
krazey pushed a commit to krazey/android_kernel_motorola_exynos9610 that referenced this issue Apr 27, 2022
@arndb @krazey
x86: kvm: avoid constant-conversion warning
561e17b 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
krazey pushed a commit to krazey/android_kernel_motorola_exynos9610 that referenced this issue Apr 27, 2022
@arndb @krazey
x86: kvm: avoid constant-conversion warning
069a135 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
krazey pushed a commit to krazey/android_kernel_motorola_exynos9610 that referenced this issue Apr 27, 2022
@arndb @krazey
x86: kvm: avoid constant-conversion warning
2a135bc 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Royna2544 pushed a commit to Roynas-Android-Playground/kernel_samsung_universal9611 that referenced this issue Jan 25, 2023
@arndb @Royna2544
x86: kvm: avoid constant-conversion warning
b8c014d 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Meghthedev pushed a commit to SamsungM30s/android_kernel_samsung_m30s that referenced this issue May 9, 2023
@arndb @Meghthedev
x86: kvm: avoid constant-conversion warning
d10077c 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Meghthedev pushed a commit to Meghthedev/kernel_samsung_m30s that referenced this issue Jul 19, 2023
@arndb @Meghthedev
x86: kvm: avoid constant-conversion warning
3091553 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Meghthedev pushed a commit to Meghthedev/kernel_samsung_m30s that referenced this issue Jul 19, 2023
@arndb @Meghthedev
x86: kvm: avoid constant-conversion warning
e696f36 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Meghthedev pushed a commit to Meghthedev/kernel_samsung_m30s that referenced this issue Jul 19, 2023
@arndb @Meghthedev
x86: kvm: avoid constant-conversion warning
4bf8bd0 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Meghthedev pushed a commit to Meghthedev/kernel_samsung_m30s that referenced this issue Aug 25, 2023
@arndb @Meghthedev
x86: kvm: avoid constant-conversion warning
b3854c2 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
LMAO-armv8 pushed a commit to LMAO-armv8/kernel_samsung_m31 that referenced this issue Oct 9, 2023
@arndb @LMAO-armv8
x86: kvm: avoid constant-conversion warning
e4c80bc 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
LMAO-armv8 pushed a commit to LMAO-armv8/kernel_samsung_m31 that referenced this issue Nov 17, 2023
@arndb @LMAO-armv8
x86: kvm: avoid constant-conversion warning
2bbaa8e 
[ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ]

clang finds a contruct suspicious that converts an unsigned
character to a signed integer and back, causing an overflow:

arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion]
                u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
                   ~~                               ^~
arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion]
                u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
                   ~~                              ^~
arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion]
                u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
                   ~~                               ^~

Add an explicit cast to tell clang that everything works as
intended here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: ClangBuiltLinux/linux#95
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees

@arndb arndb

Labels
-Wconstant-conversion [ARCH] x86_64 This bug impacts ARCH=x86_64 [BUG] linux A bug that should be fixed in the mainline kernel. [FIXED][LINUX] 5.3 This bug was fixed in Linux 5.3
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
5 participants
@dileks @tpimh @arndb @nickdesaulniers @nathanchance