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authorPeter Zijlstra <peterz@infradead.org>2019-07-11 13:40:56 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-07-17 23:17:37 +0200
commite67f1c11e5ea7fa47449a16325ecc997dbbf9bdf (patch)
tree381f948737b9f0a1c616b3b99b230d47ce33513f
parent55aedddb6149ab71bec9f050846855113977b033 (diff)
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) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Andy Lutomirski <luto@kernel.org> 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
-rw-r--r--arch/x86/entry/entry_32.S36
1 files changed, 13 insertions, 23 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 90b473297299..4d4b6100f0e8 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