diff options
| author | Abhishek Sagar <sagar.abhishek@gmail.com> | 2008-06-21 23:47:27 +0530 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-06-23 22:10:56 +0200 |
| commit | 395a59d0f8e86bb39cd700c3d185d30c670bb958 (patch) | |
| tree | 1558e635efcede901c5dbe9acd625d475db5b369 /arch/x86/kernel/ftrace.c | |
| parent | f34bfb1beef8a17ba3d46b60f8fa19ffedc1ed8d (diff) | |
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/x86/kernel/ftrace.c')
| -rw-r--r-- | arch/x86/kernel/ftrace.c | 26 |
1 files changed, 9 insertions, 17 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 55828149e01..ab115cd15fd 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -17,20 +17,21 @@ #include <linux/list.h> #include <asm/alternative.h> +#include <asm/ftrace.h> -#define CALL_BACK 5 /* Long is fine, even if it is only 4 bytes ;-) */ static long *ftrace_nop; union ftrace_code_union { - char code[5]; + char code[MCOUNT_INSN_SIZE]; struct { char e8; int offset; } __attribute__((packed)); }; + static int notrace ftrace_calc_offset(long ip, long addr) { return (int)(addr - ip); @@ -46,7 +47,7 @@ notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) static union ftrace_code_union calc; calc.e8 = 0xe8; - calc.offset = ftrace_calc_offset(ip, addr); + calc.offset = ftrace_calc_offset(ip + MCOUNT_INSN_SIZE, addr); /* * No locking needed, this must be called via kstop_machine @@ -65,9 +66,6 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned char newch = new_code[4]; 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 @@ -102,12 +100,10 @@ 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[5], *new; + unsigned char old[MCOUNT_INSN_SIZE], *new; int ret; - ip += CALL_BACK; - - memcpy(old, &ftrace_call, 5); + memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(ip, (unsigned long)func); ret = ftrace_modify_code(ip, old, new); @@ -118,16 +114,13 @@ notrace int ftrace_mcount_set(unsigned long *data) { unsigned long ip = (long)(&mcount_call); unsigned long *addr = data; - unsigned char old[5], *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, 5); + memcpy(old, &mcount_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(ip, *addr); *addr = ftrace_modify_code(ip, old, new); @@ -142,8 +135,7 @@ int __init ftrace_dyn_arch_init(void *data) ftrace_mcount_set(data); - ftrace_nop = (unsigned long *)noptable[CALL_BACK]; + ftrace_nop = (unsigned long *)noptable[MCOUNT_INSN_SIZE]; return 0; } - |