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Groups > linux.kernel > #1380878
| From | Ben Hutchings <ben@decadent.org.uk> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path |
| Date | 2016-04-18 02:50 +0200 |
| Message-ID | <rp5y1-4CY-9@gated-at.bofh.it> (permalink) |
| References | <rp5y1-4CY-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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We've always masked off the top 32 bits when x32 is enabled, but hopefully no-one relies on that. Now that the slow path is in C, we check all the bits there, regardless of whether x32 is enabled. Let's make the fast path consistent with it. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Andy Lutomirski <luto@kernel.org> --- arch/x86/entry/entry_64.S | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 858b555e274b..17ba2ca9b24d 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -190,12 +190,10 @@ entry_SYSCALL_64_fastpath: */ TRACE_IRQS_ON ENABLE_INTERRUPTS(CLBR_NONE) -#if __SYSCALL_MASK == ~0 - cmpq $__NR_syscall_max, %rax -#else - andl $__SYSCALL_MASK, %eax - cmpl $__NR_syscall_max, %eax +#if __SYSCALL_MASK != ~0 + andq $__SYSCALL_MASK, %rax #endif + cmpq $__NR_syscall_max, %rax ja 1f /* return -ENOSYS (already in pt_regs->ax) */ movq %r10, %rcx
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Re: System call number masking Ben Hutchings <ben@decadent.org.uk> - 2016-04-18 02:50 +0200
[PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path Ben Hutchings <ben@decadent.org.uk> - 2016-04-18 02:50 +0200
Re: [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path "H. Peter Anvin" <hpa@zytor.com> - 2016-04-18 07:00 +0200
Re: [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path Andy Lutomirski <luto@amacapital.net> - 2016-04-18 07:20 +0200
Re: [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path "H. Peter Anvin" <hpa@zytor.com> - 2016-04-18 07:30 +0200
Re: [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path "H. Peter Anvin" <hpa@zytor.com> - 2016-04-18 07:30 +0200
Re: [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path Andy Lutomirski <luto@amacapital.net> - 2016-04-18 07:40 +0200
Re: [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path "H. Peter Anvin" <hpa@zytor.com> - 2016-04-18 07:50 +0200
Re: [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path Andy Lutomirski <luto@amacapital.net> - 2016-04-18 07:50 +0200
Re: [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path "H. Peter Anvin" <hpa@zytor.com> - 2016-04-18 08:10 +0200
Re: [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path "H. Peter Anvin" <hpa@zytor.com> - 2016-04-18 08:20 +0200
Re: [PATCH] x86/entry/x32: Check top 32 bits of syscall number on the fast path Andy Lutomirski <luto@amacapital.net> - 2016-04-18 08:20 +0200
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