lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ftrace: store mcount address in rec->ip

Browse Source 
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

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);