lkml.org 
[lkml]   [2019]   [Jul]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH v2 2/7] x86/entry/32: Simplify common_exception
By adding one more option to SAVE_ALL we can make use of it in
common_exception and simplify things. This saves duplication later
where page_fault will no longer use common_exception.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/entry/entry_32.S | 36 +++++++++++++-----------------------
1 file changed, 13 insertions(+), 23 deletions(-)

--- 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

\
 
 \ /
  Last update: 2019-07-04 22:04    [W:0.233 / U:0.564 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site