Messages in this thread | | | Subject | Re: [PATCH] x86/entry/64/compat: Fix "x86/entry/64/compat: Preserve r8-r11 in int $0x80" | From | Li Zhijian <> | Date | Wed, 27 Jun 2018 16:51:08 +0800 |
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On 6/27/2018 1:45 PM, Andy Lutomirski wrote: > Commit 8bb2610bc496 ("x86/entry/64/compat: Preserve r8-r11 in int > $0x80") was busted. My original patch had a minor conflict with > some of the nospec changes. git apply is very clever and silently > accepted the patch by making the same changes to a different > function in the same file. There was obviously a huge offset, but > git apply for some reason doesn't feel any need to say so. > > Move the changes to the correct function. Now the > test_syscall_vdso_32 selftests passes. > > If anyone cares to observe the original problem, try applying the > patch at > https://lore.kernel.org/lkml/d4c4d9985fbe64f8c9e19291886453914b48caee.1523975710.git.luto@kernel.org/raw > to the kernel at 316d097c4cd4e7f2ef50c40cff2db266593c4ec4. git am and > git apply accept the patch without any complaints at all. patch -p1 > at least prints out a message about the huge offset. > > Reported-by: zhijianx.li@intel.com > Fixes: 8bb2610bc496 ("x86/entry/64/compat: Preserve r8-r11 in int $0x80") > Cc: stable@vger.kernel.org > Signed-off-by: Andy Lutomirski <luto@kernel.org>
Tested-by: Li Zhijian <zhijianx.li@intel.com>
> --- > arch/x86/entry/entry_64_compat.S | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S > index 9de7f1e1dede..7d0df78db727 100644 > --- a/arch/x86/entry/entry_64_compat.S > +++ b/arch/x86/entry/entry_64_compat.S > @@ -84,13 +84,13 @@ ENTRY(entry_SYSENTER_compat) > pushq %rdx /* pt_regs->dx */ > pushq %rcx /* pt_regs->cx */ > pushq $-ENOSYS /* pt_regs->ax */ > - pushq %r8 /* pt_regs->r8 */ > + pushq $0 /* pt_regs->r8 = 0 */ > xorl %r8d, %r8d /* nospec r8 */ > - pushq %r9 /* pt_regs->r9 */ > + pushq $0 /* pt_regs->r9 = 0 */ > xorl %r9d, %r9d /* nospec r9 */ > - pushq %r10 /* pt_regs->r10 */ > + pushq $0 /* pt_regs->r10 = 0 */ > xorl %r10d, %r10d /* nospec r10 */ > - pushq %r11 /* pt_regs->r11 */ > + pushq $0 /* pt_regs->r11 = 0 */ > xorl %r11d, %r11d /* nospec r11 */ > pushq %rbx /* pt_regs->rbx */ > xorl %ebx, %ebx /* nospec rbx */ > @@ -374,13 +374,13 @@ ENTRY(entry_INT80_compat) > pushq %rcx /* pt_regs->cx */ > xorl %ecx, %ecx /* nospec cx */ > pushq $-ENOSYS /* pt_regs->ax */ > - pushq $0 /* pt_regs->r8 = 0 */ > + pushq %r8 /* pt_regs->r8 */ > xorl %r8d, %r8d /* nospec r8 */ > - pushq $0 /* pt_regs->r9 = 0 */ > + pushq %r9 /* pt_regs->r9 */ > xorl %r9d, %r9d /* nospec r9 */ > - pushq $0 /* pt_regs->r10 = 0 */ > + pushq %r10 /* pt_regs->r10*/ > xorl %r10d, %r10d /* nospec r10 */ > - pushq $0 /* pt_regs->r11 = 0 */ > + pushq %r11 /* pt_regs->r11 */ > xorl %r11d, %r11d /* nospec r11 */ > pushq %rbx /* pt_regs->rbx */ > xorl %ebx, %ebx /* nospec rbx */
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