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MIPS: Tracing: Make ftrace for MIPS work without -fno-omit-frame-pointer 

When remove the -fno-omit-frame-pointer, gcc will not save the frame
pointer for us, we need to save one ourselves.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: zhangfx@lemote.com
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/679/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Wu Zhangjin 2009-11-20 20:34:36 +08:00 committed by Ralf Baechle
parent e17ff5fec6
commit 046199cae7
3 changed files with 106 additions and 15 deletions
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57
arch/mips/include/asm/ftrace.h
View File

@ -19,6 +19,62 @@
extern void _mcount(void);
#define mcount _mcount
#define safe_load(load, src, dst, error) \
do { \
asm volatile ( \
"1: " load " %[" STR(dst) "], 0(%[" STR(src) "])\n"\
" li %[" STR(error) "], 0\n" \
"2:\n" \
\
".section .fixup, \"ax\"\n" \
"3: li %[" STR(error) "], 1\n" \
" j 2b\n" \
".previous\n" \
\
".section\t__ex_table,\"a\"\n\t" \
STR(PTR) "\t1b, 3b\n\t" \
".previous\n" \
\
: [dst] "=&r" (dst), [error] "=r" (error)\
: [src] "r" (src) \
: "memory" \
); \
} while (0)
#define safe_store(store, src, dst, error) \
do { \
asm volatile ( \
"1: " store " %[" STR(src) "], 0(%[" STR(dst) "])\n"\
" li %[" STR(error) "], 0\n" \
"2:\n" \
\
".section .fixup, \"ax\"\n" \
"3: li %[" STR(error) "], 1\n" \
" j 2b\n" \
".previous\n" \
\
".section\t__ex_table,\"a\"\n\t"\
STR(PTR) "\t1b, 3b\n\t" \
".previous\n" \
\
: [error] "=r" (error) \
: [dst] "r" (dst), [src] "r" (src)\
: "memory" \
); \
} while (0)
#define safe_load_code(dst, src, error) \
safe_load(STR(lw), src, dst, error)
#define safe_store_code(src, dst, error) \
safe_store(STR(sw), src, dst, error)
#define safe_load_stack(dst, src, error) \
safe_load(STR(PTR_L), src, dst, error)
#define safe_store_stack(src, dst, error) \
safe_store(STR(PTR_S), src, dst, error)
#ifdef CONFIG_DYNAMIC_FTRACE
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
@ -27,6 +83,7 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
struct dyn_arch_ftrace {
};
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_FUNCTION_TRACER */

56
arch/mips/kernel/ftrace.c
View File

@ -27,7 +27,13 @@ static unsigned int ftrace_nop = 0x00000000;
static int ftrace_modify_code(unsigned long ip, unsigned int new_code)
{
*(unsigned int *)ip = new_code;
int faulted;
/* *(unsigned int *)ip = new_code; */
safe_store_code(new_code, ip, faulted);
if (unlikely(faulted))
return -EFAULT;
flush_icache_range(ip, ip + 8);
@ -41,14 +47,20 @@ int ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr)
{
unsigned int new;
int faulted;
unsigned long ip = rec->ip;
/* We have compiled module with -mlong-calls, but compiled the kernel
* without it, we need to cope with them respectively. */
if (ip & 0x40000000) {
/* record it for ftrace_make_call */
if (lui_v1 == 0)
lui_v1 = *(unsigned int *)ip;
if (lui_v1 == 0) {
/* lui_v1 = *(unsigned int *)ip; */
safe_load_code(lui_v1, ip, faulted);
if (unlikely(faulted))
return -EFAULT;
}
/* lui v1, hi_16bit_of_mcount --> b 1f (0x10000004)
* addiu v1, v1, low_16bit_of_mcount
@ -147,6 +159,7 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr,
{
unsigned long sp, ip, ra;
unsigned int code;
int faulted;
/* in module or kernel? */
if (self_addr & 0x40000000) {
@ -162,8 +175,11 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr,
do {
ip -= 4;
/* get the code at "ip" */
code = *(unsigned int *)ip;
/* get the code at "ip": code = *(unsigned int *)ip; */
safe_load_code(code, ip, faulted);
if (unlikely(faulted))
return 0;
/* If we hit the non-store instruction before finding where the
* ra is stored, then this is a leaf function and it does not
@ -174,11 +190,14 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr,
} while (((code & S_RA_SP) != S_RA_SP));
sp = fp + (code & OFFSET_MASK);
ra = *(unsigned long *)sp;
/* ra = *(unsigned long *)sp; */
safe_load_stack(ra, sp, faulted);
if (unlikely(faulted))
return 0;
if (ra == parent)
return sp;
return 0;
}
@ -193,6 +212,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
struct ftrace_graph_ent trace;
unsigned long return_hooker = (unsigned long)
&return_to_handler;
int faulted;
if (unlikely(atomic_read(&current->tracing_graph_pause)))
return;
@ -206,21 +226,23 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
* ftrace_get_parent_addr() does it!
*/
old = *parent;
/* old = *parent; */
safe_load_stack(old, parent, faulted);
if (unlikely(faulted))
goto out;
parent = (unsigned long *)ftrace_get_parent_addr(self_addr, old,
(unsigned long)parent,
fp);
/* If fails when getting the stack address of the non-leaf function's
* ra, stop function graph tracer and return */
if (parent == 0) {
ftrace_graph_stop();
WARN_ON(1);
return;
}
if (parent == 0)
goto out;
*parent = return_hooker;
/* *parent = return_hooker; */
safe_store_stack(return_hooker, parent, faulted);
if (unlikely(faulted))
goto out;
if (ftrace_push_return_trace(old, self_addr, &trace.depth, fp) ==
-EBUSY) {
@ -235,5 +257,9 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
current->curr_ret_stack--;
*parent = old;
}
return;
out:
ftrace_graph_stop();
WARN_ON(1);
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

8
arch/mips/kernel/mcount.S
View File

@ -139,7 +139,15 @@ NESTED(ftrace_graph_caller, PT_SIZE, ra)
#endif
PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */
jal prepare_ftrace_return
#ifdef CONFIG_FRAME_POINTER
move a2, fp /* arg3: frame pointer */
#else
#ifdef CONFIG_64BIT
PTR_LA a2, PT_SIZE(sp)
#else
PTR_LA a2, (PT_SIZE+8)(sp)
#endif
#endif
MCOUNT_RESTORE_REGS
RETURN_BACK