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authorSeiji Aguchi <seiji.aguchi@hds.com>2013-10-30 16:39:03 -0400
committerH. Peter Anvin <hpa@linux.intel.com>2013-11-08 14:15:49 -0800
commitd34603b07c4255b2b00a546d34f297ccd50ae4c6 (patch)
tree133e7788eb885d11cecc0590184f8825f4c0836f /arch/x86/mm
parentac7956e2699380b8b10146ec2ba8cbe43a03ff7a (diff)
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x86, trace: Add page fault tracepoints
This patch introduces page fault tracepoints to x86 architecture by switching IDT. Two events, for user and kernel spaces, are introduced at the beginning of page fault handler for tracing. - User space event There is a request of page fault event for user space as below. https://lkml.kernel.org/r/1368079520-11015-2-git-send-email-fdeslaur+()+gmail+!+com https://lkml.kernel.org/r/1368079520-11015-1-git-send-email-fdeslaur+()+gmail+!+com - Kernel space event: When we measure an overhead in kernel space for investigating performance issues, we can check if it comes from the page fault events. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/52716E67.6090705@hds.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/mm')
-rw-r--r--arch/x86/mm/Makefile2
-rw-r--r--arch/x86/mm/fault.c13
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 23d8e5fecf76..6a19ad9f370d 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -6,6 +6,8 @@ nostackp := $(call cc-option, -fno-stack-protector)
CFLAGS_physaddr.o := $(nostackp)
CFLAGS_setup_nx.o := $(nostackp)
+CFLAGS_fault.o := -I$(src)/../include/asm/trace
+
obj-$(CONFIG_X86_PAT) += pat_rbtree.o
obj-$(CONFIG_SMP) += tlb.o
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index fd3e281fbc70..f2730cbce0b5 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -20,6 +20,9 @@
#include <asm/kmemcheck.h> /* kmemcheck_*(), ... */
#include <asm/fixmap.h> /* VSYSCALL_START */
+#define CREATE_TRACE_POINTS
+#include <asm/trace/exceptions.h>
+
/*
* Page fault error code bits:
*
@@ -1232,12 +1235,22 @@ do_page_fault(struct pt_regs *regs, unsigned long error_code)
exception_exit(prev_state);
}
+static void trace_page_fault_entries(struct pt_regs *regs,
+ unsigned long error_code)
+{
+ if (user_mode(regs))
+ trace_user_page_fault(read_cr2(), regs, error_code);
+ else
+ trace_kernel_page_fault(read_cr2(), regs, error_code);
+}
+
dotraplinkage void __kprobes
trace_do_page_fault(struct pt_regs *regs, unsigned long error_code)
{
enum ctx_state prev_state;
prev_state = exception_enter();
+ trace_page_fault_entries(regs, error_code);
__do_page_fault(regs, error_code);
exception_exit(prev_state);
}