On Thu, 04 Jul 2019 21:55:57 +0200 Peter Zijlstra <[email protected]> wrote:
> --- a/arch/x86/entry/entry_32.S > +++ b/arch/x86/entry/entry_32.S > @@ -294,9 +294,11 @@ > .Lfinished_frame_\@: > .endm > > -.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0 > +.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0 skip_gs=0 > cld > +.if \skip_gs == 0 > PUSH_GS > +.endif > FIXUP_FRAME > pushl %fs > pushl %es > @@ -313,13 +315,13 @@ > movl %edx, %es > movl $(__KERNEL_PERCPU), %edx > movl %edx, %fs > +.if \skip_gs == 0 > SET_KERNEL_GS %edx > - > +.endif > /* Switch to kernel stack if necessary */ > .if \switch_stacks > 0 > SWITCH_TO_KERNEL_STACK > .endif > - > .endm > > .macro SAVE_ALL_NMI cr3_reg:req > @@ -1448,32 +1450,20 @@ END(page_fault) > > common_exception: > /* the function address is in %gs's slot on the stack */ > - FIXUP_FRAME > - pushl %fs > - pushl %es > - pushl %ds > - pushl %eax > - movl $(__USER_DS), %eax > - movl %eax, %ds > - movl %eax, %es > - movl $(__KERNEL_PERCPU), %eax > - movl %eax, %fs > - pushl %ebp > - pushl %edi > - pushl %esi > - pushl %edx > - pushl %ecx > - pushl %ebx > - SWITCH_TO_KERNEL_STACK > + SAVE_ALL switch_stacks=1 skip_gs=1 > ENCODE_FRAME_POINTER > - cld The only code change of this is that cld moved from the end to the beginning. As this appears to match other SAVE_ALL users with respect to ENCODE_FRAME_POINTER, this shouldn't be an issue. Reviewed-by: Steven Rostedt (VMware) <[email protected]> -- Steve > UNWIND_ESPFIX_STACK > +
