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ftrace: store mcount address in rec->ip

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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>
This commit is contained in:
Abhishek Sagar
2008-06-21 23:47:27 +05:30
committed by Ingo Molnar
parent f34bfb1bee
commit 395a59d0f8
19 changed files with 111 additions and 57 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
arch/powerpc/kernel/entry_32.S
View File

@@ -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)

5
arch/powerpc/kernel/entry_64.S
View File

@@ -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)

21
arch/powerpc/kernel/ftrace.c
View File

@@ -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);