* WARNING: can't access registers at asm_sysvec_call_function_single @ 2020-09-08 20:16 syzbot 2020-09-13 21:05 ` Thomas Gleixner 0 siblings, 1 reply; 6+ messages in thread From: syzbot @ 2020-09-08 20:16 UTC (permalink / raw) To: alexandre.chartre, bp, hpa, linux-kernel, luto, mingo, peterz, syzkaller-bugs, tglx, x86 Hello, syzbot found the following issue on: HEAD commit: f4d51dff Linux 5.9-rc4 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1455d4f9900000 kernel config: https://syzkaller.appspot.com/x/.config?x=a9075b36a6ae26c9 dashboard link: https://syzkaller.appspot.com/bug?extid=bc9dbf05dcc151e9b972 compiler: gcc (GCC) 10.1.0-syz 20200507 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+bc9dbf05dcc151e9b972@syzkaller.appspotmail.com WARNING: can't access registers at asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:589 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: WARNING: can't access registers at asm_sysvec_call_function_single 2020-09-08 20:16 WARNING: can't access registers at asm_sysvec_call_function_single syzbot @ 2020-09-13 21:05 ` Thomas Gleixner 2020-09-14 16:49 ` Josh Poimboeuf 0 siblings, 1 reply; 6+ messages in thread From: Thomas Gleixner @ 2020-09-13 21:05 UTC (permalink / raw) To: syzbot, alexandre.chartre, bp, hpa, linux-kernel, luto, mingo, peterz, syzkaller-bugs, x86, Josh Poimboeuf On Tue, Sep 08 2020 at 13:16, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: f4d51dff Linux 5.9-rc4 > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1455d4f9900000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a9075b36a6ae26c9 > dashboard link: https://syzkaller.appspot.com/bug?extid=bc9dbf05dcc151e9b972 > compiler: gcc (GCC) 10.1.0-syz 20200507 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+bc9dbf05dcc151e9b972@syzkaller.appspotmail.com > > WARNING: can't access registers at asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:589 That's the ORC unwinder complaining, but I have no idea why... ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: WARNING: can't access registers at asm_sysvec_call_function_single 2020-09-13 21:05 ` Thomas Gleixner @ 2020-09-14 16:49 ` Josh Poimboeuf 2020-09-14 16:51 ` Josh Poimboeuf 0 siblings, 1 reply; 6+ messages in thread From: Josh Poimboeuf @ 2020-09-14 16:49 UTC (permalink / raw) To: Thomas Gleixner Cc: syzbot, alexandre.chartre, bp, hpa, linux-kernel, luto, mingo, peterz, syzkaller-bugs, x86 On Sun, Sep 13, 2020 at 11:05:21PM +0200, Thomas Gleixner wrote: > On Tue, Sep 08 2020 at 13:16, syzbot wrote: > > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: f4d51dff Linux 5.9-rc4 > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=1455d4f9900000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=a9075b36a6ae26c9 > > dashboard link: https://syzkaller.appspot.com/bug?extid=bc9dbf05dcc151e9b972 > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+bc9dbf05dcc151e9b972@syzkaller.appspotmail.com > > > > WARNING: can't access registers at asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:589 > > That's the ORC unwinder complaining, but I have no idea why... 0000000000000cd0 <asm_sysvec_call_function_single>: cd0: 90 nop cd1: 90 nop cd2: 90 nop cd3: 6a ff pushq $0xffffffffffffffff cd5: e8 b6 03 00 00 callq 1090 <error_entry> cda: 48 89 e7 mov %rsp,%rdi cdd: e8 00 00 00 00 callq ce2 <asm_sysvec_call_function_single+0x12> cde: R_X86_64_PLT32 sysvec_call_function_single-0x4 ce2: e9 69 04 00 00 jmpq 1150 <error_return> ce7: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) cee: 00 00 This is a head scratcher. The ORC data looks ok, at least when I build it on my system. It's expecting to find pt_regs at the top of the stack after returning from sysvec_call_function_single(). But it can't dereference the regs for some reason. So either it's a bug in ORC data or unwinder (not likely) or the stack pointer got corrupted somehow (also seems unlikely)... -- Josh ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: WARNING: can't access registers at asm_sysvec_call_function_single 2020-09-14 16:49 ` Josh Poimboeuf @ 2020-09-14 16:51 ` Josh Poimboeuf 2020-09-15 4:27 ` Dmitry Vyukov 0 siblings, 1 reply; 6+ messages in thread From: Josh Poimboeuf @ 2020-09-14 16:51 UTC (permalink / raw) To: Thomas Gleixner Cc: syzbot, alexandre.chartre, bp, hpa, linux-kernel, luto, mingo, peterz, syzkaller-bugs, x86 On Mon, Sep 14, 2020 at 11:49:30AM -0500, Josh Poimboeuf wrote: > On Sun, Sep 13, 2020 at 11:05:21PM +0200, Thomas Gleixner wrote: > > On Tue, Sep 08 2020 at 13:16, syzbot wrote: > > > > > Hello, > > > > > > syzbot found the following issue on: > > > > > > HEAD commit: f4d51dff Linux 5.9-rc4 > > > git tree: upstream > > > console output: https://syzkaller.appspot.com/x/log.txt?x=1455d4f9900000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=a9075b36a6ae26c9 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=bc9dbf05dcc151e9b972 > > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > > Reported-by: syzbot+bc9dbf05dcc151e9b972@syzkaller.appspotmail.com > > > > > > WARNING: can't access registers at asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:589 > > > > That's the ORC unwinder complaining, but I have no idea why... > > 0000000000000cd0 <asm_sysvec_call_function_single>: > cd0: 90 nop > cd1: 90 nop > cd2: 90 nop > cd3: 6a ff pushq $0xffffffffffffffff > cd5: e8 b6 03 00 00 callq 1090 <error_entry> > cda: 48 89 e7 mov %rsp,%rdi > cdd: e8 00 00 00 00 callq ce2 <asm_sysvec_call_function_single+0x12> > cde: R_X86_64_PLT32 sysvec_call_function_single-0x4 > ce2: e9 69 04 00 00 jmpq 1150 <error_return> > ce7: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) > cee: 00 00 > > This is a head scratcher. The ORC data looks ok, at least when I build > it on my system. It's expecting to find pt_regs at the top of the stack > after returning from sysvec_call_function_single(). But it can't > dereference the regs for some reason. > > So either it's a bug in ORC data or unwinder (not likely) or the stack > pointer got corrupted somehow (also seems unlikely)... The true bug may be revealed elsewhere on the stack... I probably need to start enabling ORC stack dumps like I did for FP. -- Josh ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: WARNING: can't access registers at asm_sysvec_call_function_single 2020-09-14 16:51 ` Josh Poimboeuf @ 2020-09-15 4:27 ` Dmitry Vyukov 2020-09-15 14:19 ` Josh Poimboeuf 0 siblings, 1 reply; 6+ messages in thread From: Dmitry Vyukov @ 2020-09-15 4:27 UTC (permalink / raw) To: Josh Poimboeuf Cc: Thomas Gleixner, syzbot, alexandre.chartre, Borislav Petkov, H. Peter Anvin, LKML, Andy Lutomirski, Ingo Molnar, Peter Zijlstra, syzkaller-bugs, the arch/x86 maintainers On Mon, Sep 14, 2020 at 6:51 PM Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > > On Tue, Sep 08 2020 at 13:16, syzbot wrote: > > > > > > > Hello, > > > > > > > > syzbot found the following issue on: > > > > > > > > HEAD commit: f4d51dff Linux 5.9-rc4 > > > > git tree: upstream > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=1455d4f9900000 > > > > kernel config: https://syzkaller.appspot.com/x/.config?x=a9075b36a6ae26c9 > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=bc9dbf05dcc151e9b972 > > > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > > > > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > > > Reported-by: syzbot+bc9dbf05dcc151e9b972@syzkaller.appspotmail.com > > > > > > > > WARNING: can't access registers at asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:589 > > > > > > That's the ORC unwinder complaining, but I have no idea why... > > > > 0000000000000cd0 <asm_sysvec_call_function_single>: > > cd0: 90 nop > > cd1: 90 nop > > cd2: 90 nop > > cd3: 6a ff pushq $0xffffffffffffffff > > cd5: e8 b6 03 00 00 callq 1090 <error_entry> > > cda: 48 89 e7 mov %rsp,%rdi > > cdd: e8 00 00 00 00 callq ce2 <asm_sysvec_call_function_single+0x12> > > cde: R_X86_64_PLT32 sysvec_call_function_single-0x4 > > ce2: e9 69 04 00 00 jmpq 1150 <error_return> > > ce7: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) > > cee: 00 00 > > > > This is a head scratcher. The ORC data looks ok, at least when I build > > it on my system. It's expecting to find pt_regs at the top of the stack > > after returning from sysvec_call_function_single(). But it can't > > dereference the regs for some reason. > > > > So either it's a bug in ORC data or unwinder (not likely) or the stack > > pointer got corrupted somehow (also seems unlikely)... > > The true bug may be revealed elsewhere on the stack... I probably need > to start enabling ORC stack dumps like I did for FP. Hi Josh, Is there a config for this? We could enable it on syzbot. More informative kernel diagnostics are always better. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: WARNING: can't access registers at asm_sysvec_call_function_single 2020-09-15 4:27 ` Dmitry Vyukov @ 2020-09-15 14:19 ` Josh Poimboeuf 0 siblings, 0 replies; 6+ messages in thread From: Josh Poimboeuf @ 2020-09-15 14:19 UTC (permalink / raw) To: Dmitry Vyukov Cc: Thomas Gleixner, syzbot, alexandre.chartre, Borislav Petkov, H. Peter Anvin, LKML, Andy Lutomirski, Ingo Molnar, Peter Zijlstra, syzkaller-bugs, the arch/x86 maintainers On Tue, Sep 15, 2020 at 06:27:25AM +0200, Dmitry Vyukov wrote: > On Mon, Sep 14, 2020 at 6:51 PM Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > > > On Tue, Sep 08 2020 at 13:16, syzbot wrote: > > > > > > > > > Hello, > > > > > > > > > > syzbot found the following issue on: > > > > > > > > > > HEAD commit: f4d51dff Linux 5.9-rc4 > > > > > git tree: upstream > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=1455d4f9900000 > > > > > kernel config: https://syzkaller.appspot.com/x/.config?x=a9075b36a6ae26c9 > > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=bc9dbf05dcc151e9b972 > > > > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > > > > > > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > > > > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > > > > Reported-by: syzbot+bc9dbf05dcc151e9b972@syzkaller.appspotmail.com > > > > > > > > > > WARNING: can't access registers at asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:589 > > > > > > > > That's the ORC unwinder complaining, but I have no idea why... > > > > > > 0000000000000cd0 <asm_sysvec_call_function_single>: > > > cd0: 90 nop > > > cd1: 90 nop > > > cd2: 90 nop > > > cd3: 6a ff pushq $0xffffffffffffffff > > > cd5: e8 b6 03 00 00 callq 1090 <error_entry> > > > cda: 48 89 e7 mov %rsp,%rdi > > > cdd: e8 00 00 00 00 callq ce2 <asm_sysvec_call_function_single+0x12> > > > cde: R_X86_64_PLT32 sysvec_call_function_single-0x4 > > > ce2: e9 69 04 00 00 jmpq 1150 <error_return> > > > ce7: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) > > > cee: 00 00 > > > > > > This is a head scratcher. The ORC data looks ok, at least when I build > > > it on my system. It's expecting to find pt_regs at the top of the stack > > > after returning from sysvec_call_function_single(). But it can't > > > dereference the regs for some reason. > > > > > > So either it's a bug in ORC data or unwinder (not likely) or the stack > > > pointer got corrupted somehow (also seems unlikely)... > > > > The true bug may be revealed elsewhere on the stack... I probably need > > to start enabling ORC stack dumps like I did for FP. > > Hi Josh, > > Is there a config for this? We could enable it on syzbot. More > informative kernel diagnostics are always better. Unfortunately the ORC dump code doesn't exist upstream yet. I need to dust the patches off and post. -- Josh ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-09-16 0:17 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-09-08 20:16 WARNING: can't access registers at asm_sysvec_call_function_single syzbot 2020-09-13 21:05 ` Thomas Gleixner 2020-09-14 16:49 ` Josh Poimboeuf 2020-09-14 16:51 ` Josh Poimboeuf 2020-09-15 4:27 ` Dmitry Vyukov 2020-09-15 14:19 ` Josh Poimboeuf
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