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From: Peter Zijlstra <peterz@infradead.org>
To: tglx@linutronix.de, bp@alien8.de, mingo@kernel.org,
	rostedt@goodmis.org, luto@kernel.org,
	torvalds@linux-foundation.org
Cc: hpa@zytor.com, dave.hansen@linux.intel.com, jgross@suse.com,
	linux-kernel@vger.kernel.org, zhe.he@windriver.com,
	joel@joelfernandes.org, devel@etsukata.com, peterz@infradead.org
Subject: [PATCH v3 2/6] x86/entry/32: Simplify common_exception
Date: Thu, 11 Jul 2019 13:40:56 +0200	[thread overview]
Message-ID: <20190711114335.945136187@infradead.org> (raw)
In-Reply-To: 20190711114054.406765395@infradead.org

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.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
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



  parent reply	other threads:[~2019-07-11 11:52 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-11 11:40 [PATCH v3 0/6] Tracing vs CR2 Peter Zijlstra
2019-07-11 11:40 ` [PATCH v3 1/6] x86/paravirt: Make read_cr2() CALLEE_SAVE Peter Zijlstra
2019-07-17 21:22   ` [tip:x86/urgent] " tip-bot for Peter Zijlstra
2019-07-11 11:40 ` Peter Zijlstra [this message]
2019-07-17 21:23   ` [tip:x86/urgent] x86/entry/32: Simplify common_exception tip-bot for Peter Zijlstra
2019-07-11 11:40 ` [PATCH v3 3/6] x86/entry/64: Simplify idtentry a little Peter Zijlstra
2019-07-17 21:24   ` [tip:x86/urgent] " tip-bot for Peter Zijlstra
2019-07-11 11:40 ` [PATCH v3 4/6] x86/entry/64: Update comments and sanity tests for create_gap Peter Zijlstra
2019-07-17 21:25   ` [tip:x86/urgent] " tip-bot for Peter Zijlstra
2019-07-11 11:40 ` [PATCH v3 5/6] x86/mm, tracing: Fix CR2 corruption Peter Zijlstra
2019-07-17 21:25   ` [tip:x86/urgent] " tip-bot for Peter Zijlstra
2019-07-11 11:41 ` [PATCH v3 6/6] x86/entry/64: Remove TRACE_IRQS_*_DEBUG Peter Zijlstra
2019-07-11 14:45   ` Andy Lutomirski
2019-07-11 18:28     ` Peter Zijlstra
2019-07-16 19:33 ` [PATCH v3 0/6] Tracing vs CR2 Vegard Nossum
2019-07-16 21:51   ` Vegard Nossum
2019-07-17  1:02     ` Andy Lutomirski
2019-07-17  7:46       ` Vegard Nossum
2019-07-17  7:47       ` Peter Zijlstra
2019-07-17  9:37     ` Eiichi Tsukata
2019-07-18 20:27       ` Andy Lutomirski
2019-07-20  3:59         ` Eiichi Tsukata
2019-07-20 12:49           ` Andy Lutomirski
2019-07-20 14:23             ` Eiichi Tsukata
2019-07-17  8:07   ` Peter Zijlstra
2019-07-17  8:09     ` Vegard Nossum
2019-07-18  8:57       ` [PATCH] stacktrace: Force USER_DS for stack_trace_save_user() Peter Zijlstra
2019-07-18 13:21         ` Joel Fernandes
2019-07-18 14:52         ` [tip:core/urgent] " tip-bot for Peter Zijlstra

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