[PATCH] lockdep: irqtrace subsystem, x86_64 support

Add irqflags-tracing support to x86_64.

[akpm@osdl.org: build fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/x86_64/Kconfig.debug

@@ -1,5 +1,9 @@
 menu "Kernel hacking"
 
+config TRACE_IRQFLAGS_SUPPORT
+	bool
+	default y
+
 source "lib/Kconfig.debug"
 
 config DEBUG_RODATA

arch/x86_64/ia32/ia32entry.S

@@ -13,6 +13,7 @@
 #include <asm/thread_info.h>	
 #include <asm/segment.h>
 #include <asm/vsyscall32.h>
+#include <asm/irqflags.h>
 #include <linux/linkage.h>
 
 #define IA32_NR_syscalls ((ia32_syscall_end - ia32_sys_call_table)/8)
@@ -75,6 +76,10 @@ ENTRY(ia32_sysenter_target)
 	swapgs
 	movq	%gs:pda_kernelstack, %rsp
 	addq	$(PDA_STACKOFFSET),%rsp	
+	/*
+	 * No need to follow this irqs on/off section: the syscall
+	 * disabled irqs, here we enable it straight after entry:
+	 */
 	sti	
  	movl	%ebp,%ebp		/* zero extension */
 	pushq	$__USER32_DS
@@ -118,6 +123,7 @@ sysenter_do_call:
 	movq	%rax,RAX-ARGOFFSET(%rsp)
 	GET_THREAD_INFO(%r10)
 	cli
+	TRACE_IRQS_OFF
 	testl	$_TIF_ALLWORK_MASK,threadinfo_flags(%r10)
 	jnz	int_ret_from_sys_call
 	andl    $~TS_COMPAT,threadinfo_status(%r10)
@@ -132,6 +138,7 @@ sysenter_do_call:
 	CFI_REGISTER rsp,rcx
 	movl	$VSYSCALL32_SYSEXIT,%edx	/* User %eip */
 	CFI_REGISTER rip,rdx
+	TRACE_IRQS_ON
 	swapgs
 	sti		/* sti only takes effect after the next instruction */
 	/* sysexit */
@@ -186,6 +193,10 @@ ENTRY(ia32_cstar_target)
 	movl	%esp,%r8d
 	CFI_REGISTER	rsp,r8
 	movq	%gs:pda_kernelstack,%rsp
+	/*
+	 * No need to follow this irqs on/off section: the syscall
+	 * disabled irqs and here we enable it straight after entry:
+	 */
 	sti
 	SAVE_ARGS 8,1,1
 	movl 	%eax,%eax	/* zero extension */
@@ -220,6 +231,7 @@ cstar_do_call:
 	movq %rax,RAX-ARGOFFSET(%rsp)
 	GET_THREAD_INFO(%r10)
 	cli
+	TRACE_IRQS_OFF
 	testl $_TIF_ALLWORK_MASK,threadinfo_flags(%r10)
 	jnz  int_ret_from_sys_call
 	andl $~TS_COMPAT,threadinfo_status(%r10)
@@ -228,6 +240,7 @@ cstar_do_call:
 	CFI_REGISTER rip,rcx
 	movl EFLAGS-ARGOFFSET(%rsp),%r11d	
 	/*CFI_REGISTER rflags,r11*/
+	TRACE_IRQS_ON
 	movl RSP-ARGOFFSET(%rsp),%esp
 	CFI_RESTORE rsp
 	swapgs
@@ -286,7 +299,11 @@ ENTRY(ia32_syscall)
 	/*CFI_REL_OFFSET	rflags,EFLAGS-RIP*/
 	/*CFI_REL_OFFSET	cs,CS-RIP*/
 	CFI_REL_OFFSET	rip,RIP-RIP
-	swapgs	
+	swapgs
+	/*
+	 * No need to follow this irqs on/off section: the syscall
+	 * disabled irqs and here we enable it straight after entry:
+	 */
 	sti
 	movl %eax,%eax
 	pushq %rax