AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

x86/traps: Don't clear segment high bits in early_idt_handler_common()

Browse Source 
Now that pt_regs defines the segment fields as 16-bit, there's no
need to sanitize the values.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andy Lutomirski 2017-07-28 06:00:31 -07:00 committed by Ingo Molnar
parent 385eca8f27
commit 630c1863bc
1 changed files with 8 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
arch/x86/kernel/head_32.S
View File

@ -457,12 +457,9 @@ early_idt_handler_common:
/* The vector number is in pt_regs->gs */
cld
pushl %fs /* pt_regs->fs */
movw $0, 2(%esp) /* clear high bits (some CPUs leave garbage) */
pushl %es /* pt_regs->es */
movw $0, 2(%esp) /* clear high bits (some CPUs leave garbage) */
pushl %ds /* pt_regs->ds */
movw $0, 2(%esp) /* clear high bits (some CPUs leave garbage) */
pushl %fs /* pt_regs->fs (__fsh varies by model) */
pushl %es /* pt_regs->es (__esh varies by model) */
pushl %ds /* pt_regs->ds (__dsh varies by model) */
pushl %eax /* pt_regs->ax */
pushl %ebp /* pt_regs->bp */
pushl %edi /* pt_regs->di */
@ -479,9 +476,8 @@ early_idt_handler_common:
/* Load the vector number into EDX */
movl PT_GS(%esp), %edx
/* Load GS into pt_regs->gs and clear high bits */
/* Load GS into pt_regs->gs (and maybe clobber __gsh) */
movw %gs, PT_GS(%esp)
movw $0, PT_GS+2(%esp)
movl %esp, %eax /* args are pt_regs (EAX), trapnr (EDX) */
call early_fixup_exception
@ -493,10 +489,10 @@ early_idt_handler_common:
popl %edi /* pt_regs->di */
popl %ebp /* pt_regs->bp */
popl %eax /* pt_regs->ax */
popl %ds /* pt_regs->ds */
popl %es /* pt_regs->es */
popl %fs /* pt_regs->fs */
popl %gs /* pt_regs->gs */
popl %ds /* pt_regs->ds (always ignores __dsh) */
popl %es /* pt_regs->es (always ignores __esh) */
popl %fs /* pt_regs->fs (always ignores __fsh) */
popl %gs /* pt_regs->gs (always ignores __gsh) */
decl %ss:early_recursion_flag
addl $4, %esp /* pop pt_regs->orig_ax */
iret