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authorAbhishek Sagar <sagar.abhishek@gmail.com>2008-06-21 23:47:27 +0530
committerIngo Molnar <mingo@elte.hu>2008-06-23 22:10:56 +0200
commit395a59d0f8e86bb39cd700c3d185d30c670bb958 (patch)
tree1558e635efcede901c5dbe9acd625d475db5b369 /arch/powerpc
parentf34bfb1beef8a17ba3d46b60f8fa19ffedc1ed8d (diff)
downloadop-kernel-dev-395a59d0f8e86bb39cd700c3d185d30c670bb958.zip
op-kernel-dev-395a59d0f8e86bb39cd700c3d185d30c670bb958.tar.gz
ftrace: store mcount address in rec->ip
Record the address of the mcount call-site. Currently all archs except sparc64 record the address of the instruction following the mcount call-site. Some general cleanups are entailed. Storing mcount addresses in rec->ip enables looking them up in the kprobe hash table later on to check if they're kprobe'd. Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: davem@davemloft.net Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/entry_32.S4
-rw-r--r--arch/powerpc/kernel/entry_64.S5
-rw-r--r--arch/powerpc/kernel/ftrace.c21
3 files changed, 15 insertions, 15 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 3b1dd29..7231a70 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -30,6 +30,7 @@
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
+#include <asm/ftrace.h>
#undef SHOW_SYSCALLS
#undef SHOW_SYSCALLS_TASK
@@ -1053,6 +1054,7 @@ _GLOBAL(_mcount)
stw r10,40(r1)
stw r3, 44(r1)
stw r5, 8(r1)
+ subi r3, r3, MCOUNT_INSN_SIZE
.globl mcount_call
mcount_call:
bl ftrace_stub
@@ -1090,6 +1092,7 @@ _GLOBAL(ftrace_caller)
stw r10,40(r1)
stw r3, 44(r1)
stw r5, 8(r1)
+ subi r3, r3, MCOUNT_INSN_SIZE
.globl ftrace_call
ftrace_call:
bl ftrace_stub
@@ -1128,6 +1131,7 @@ _GLOBAL(_mcount)
stw r3, 44(r1)
stw r5, 8(r1)
+ subi r3, r3, MCOUNT_INSN_SIZE
LOAD_REG_ADDR(r5, ftrace_trace_function)
lwz r5,0(r5)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 2c4d9e0..2f511a9 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -31,6 +31,7 @@
#include <asm/bug.h>
#include <asm/ptrace.h>
#include <asm/irqflags.h>
+#include <asm/ftrace.h>
/*
* System calls.
@@ -879,6 +880,7 @@ _GLOBAL(_mcount)
mflr r3
stdu r1, -112(r1)
std r3, 128(r1)
+ subi r3, r3, MCOUNT_INSN_SIZE
.globl mcount_call
mcount_call:
bl ftrace_stub
@@ -895,6 +897,7 @@ _GLOBAL(ftrace_caller)
stdu r1, -112(r1)
std r3, 128(r1)
ld r4, 16(r11)
+ subi r3, r3, MCOUNT_INSN_SIZE
.globl ftrace_call
ftrace_call:
bl ftrace_stub
@@ -916,7 +919,7 @@ _GLOBAL(_mcount)
std r3, 128(r1)
ld r4, 16(r11)
-
+ subi r3, r3, MCOUNT_INSN_SIZE
LOAD_REG_ADDR(r5,ftrace_trace_function)
ld r5,0(r5)
ld r5,0(r5)
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index e12c593..3855ceb 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -15,8 +15,8 @@
#include <linux/list.h>
#include <asm/cacheflush.h>
+#include <asm/ftrace.h>
-#define CALL_BACK 4
static unsigned int ftrace_nop = 0x60000000;
@@ -27,9 +27,10 @@ static unsigned int ftrace_nop = 0x60000000;
# define GET_ADDR(addr) *(unsigned long *)addr
#endif
+
static unsigned int notrace ftrace_calc_offset(long ip, long addr)
{
- return (int)((addr + CALL_BACK) - ip);
+ return (int)(addr - ip);
}
notrace unsigned char *ftrace_nop_replace(void)
@@ -76,9 +77,6 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
unsigned new = *(unsigned *)new_code;
int faulted = 0;
- /* move the IP back to the start of the call */
- ip -= CALL_BACK;
-
/*
* Note: Due to modules and __init, code can
* disappear and change, we need to protect against faulting
@@ -118,12 +116,10 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
notrace int ftrace_update_ftrace_func(ftrace_func_t func)
{
unsigned long ip = (unsigned long)(&ftrace_call);
- unsigned char old[4], *new;
+ unsigned char old[MCOUNT_INSN_SIZE], *new;
int ret;
- ip += CALL_BACK;
-
- memcpy(old, &ftrace_call, 4);
+ memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, (unsigned long)func);
ret = ftrace_modify_code(ip, old, new);
@@ -134,16 +130,13 @@ notrace int ftrace_mcount_set(unsigned long *data)
{
unsigned long ip = (long)(&mcount_call);
unsigned long *addr = data;
- unsigned char old[4], *new;
-
- /* ip is at the location, but modify code will subtact this */
- ip += CALL_BACK;
+ unsigned char old[MCOUNT_INSN_SIZE], *new;
/*
* Replace the mcount stub with a pointer to the
* ip recorder function.
*/
- memcpy(old, &mcount_call, 4);
+ memcpy(old, &mcount_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, *addr);
*addr = ftrace_modify_code(ip, old, new);
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