hi, Al Viro, On Wed, Apr 28, 2021 at 04:32:44AM +0000, Al Viro wrote: > On Wed, Apr 28, 2021 at 10:37:47AM +0800, kernel test robot wrote: > > > > > > Greeting, > > > > FYI, we noticed the following commit (built with gcc-9): > > > > commit: 2418c34937c42a30ef4bccd923ad664a89e1fbd4 ("iov_iter: optimize iov_iter_advance() for iovec and kvec") > > https://git.kernel.org/cgit/linux/kernel/git/viro/vfs.git untested.iov_iter > > > > > > in testcase: boot > > > > on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G > > > > caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): > > Could you try https://git.kernel.org/cgit/linux/kernel/git/viro/vfs.git for-lkp > on the same test and see what (if anything) gets spewed into dmesg? please check attached dmesg.xz for detail [ 18.549991] ------------[ cut here ]------------ [ 18.550798] WARNING: CPU: 0 PID: 124 at lib/iov_iter.c:1117 iov_iter_advance.cold+0x13/0x7b [ 18.552115] Modules linked in: [ 18.552693] CPU: 0 PID: 124 Comm: kmodloader Not tainted 5.12.0-rc2-00004-g039686f7e8a0 #1 [ 18.554221] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 [ 18.555733] EIP: iov_iter_advance.cold+0x13/0x7b [ 18.556616] Code: 00 00 b8 90 78 2f b2 31 c9 e8 cd 9e 79 ff 58 31 c0 5a e9 cc 4b a8 ff 6a 01 31 c9 ba 01 00 00 00 b8 c8 6d 2f b2 e8 b1 9e 79 ff <0f> 0 b 6a 01 31 c9 ba 01 00 00 00 b8 b0 6d 2f b2 31 db e8 9a 9e 79 [ 18.559751] EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: 00000001 [ 18.560818] ESI: 00000000 EDI: ddf89ee4 EBP: ddf89eac ESP: ddf89e5c [ 18.561894] DS: 007b ES: 007b FS: 0000 GS: 00e0 SS: 0068 EFLAGS: 00010206 [ 18.563020] CR0: 80050033 CR2: a7f30844 CR3: 2deee000 CR4: 000406d0 [ 18.564011] Call Trace: [ 18.564483] do_iter_read+0x138/0x1c0 [ 18.565159] vfs_readv+0x47/0x80 [ 18.565771] ? lock_acquire+0xa8/0x2e0 [ 18.566463] ? __fget_light+0x4d/0x90 [ 18.567152] do_readv+0x5f/0xe0 [ 18.567723] __ia32_sys_readv+0x12/0x20 [ 18.568451] __do_fast_syscall_32+0x74/0xb0 [ 18.569223] do_fast_syscall_32+0x28/0x60 [ 18.569977] do_SYSENTER_32+0x15/0x20 [ 18.570676] entry_SYSENTER_32+0x9f/0xf1 [ 18.571419] EIP: 0xa7f44549 [ 18.571962] Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5 a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 [ 18.575391] EAX: ffffffda EBX: 00000004 ECX: af810710 EDX: 00000002 [ 18.576611] ESI: 00000001 EDI: 00003061 EBP: af810738 ESP: af8106e4 [ 18.577748] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00000282 [ 18.578970] irq event stamp: 2455 [ 18.579587] hardirqs last enabled at (2463): [<b10bd9b5>] console_unlock+0x455/0x610 [ 18.580951] hardirqs last disabled at (2470): [<b10bd9a5>] console_unlock+0x445/0x610 [ 18.582269] softirqs last enabled at (2322): [<b19d6aad>] __do_softirq+0x29d/0x434 [ 18.583483] softirqs last disabled at (2313): [<b1024220>] call_on_stack+0x40/0x50 [ 18.585165] ---[ end trace 6e5f78d431f11767 ]---
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dmesg.xz
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