From e67f1c11e5ea7fa47449a16325ecc997dbbf9bdf Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 11 Jul 2019 13:40:56 +0200 Subject: [PATCH] x86/entry/32: Simplify common_exception Adding one more option to SAVE_ALL can be used in common_exception to simplify things. This also saves duplication later where page_fault will no longer use common_exception. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Andy Lutomirski Cc: bp@alien8.de Cc: torvalds@linux-foundation.org Cc: hpa@zytor.com Cc: dave.hansen@linux.intel.com Cc: jgross@suse.com Cc: zhe.he@windriver.com Cc: joel@joelfernandes.org Cc: devel@etsukata.com Link: https://lkml.kernel.org/r/20190711114335.945136187@infradead.org --- arch/x86/entry/entry_32.S | 36 +++++++++++++----------------------- 1 file changed, 13 insertions(+), 23 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 90b4732..4d4b610 100644 --- 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 UNWIND_ESPFIX_STACK + + /* fixup %gs */ GS_TO_REG %ecx movl PT_GS(%esp), %edi # get the function address - movl PT_ORIG_EAX(%esp), %edx # get the error code - movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart REG_TO_PTGS %ecx SET_KERNEL_GS %ecx + + /* fixup orig %eax */ + movl PT_ORIG_EAX(%esp), %edx # get the error code + movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart + TRACE_IRQS_OFF movl %esp, %eax # pt_regs pointer CALL_NOSPEC %edi -- 2.7.4