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-rw-r--r--arch/mips/kernel/ftrace.c52
1 files changed, 25 insertions, 27 deletions
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c
index 5970286131dd..40ef34ccb76b 100644
--- a/arch/mips/kernel/ftrace.c
+++ b/arch/mips/kernel/ftrace.c
@@ -190,21 +190,19 @@ int ftrace_disable_ftrace_graph_caller(void)
#define S_R_SP (0xafb0 << 16) /* s{d,w} R, offset(sp) */
#define OFFSET_MASK 0xffff /* stack offset range: 0 ~ PT_SIZE */
-unsigned long ftrace_get_parent_addr(unsigned long self_addr,
- unsigned long parent,
- unsigned long parent_addr,
- unsigned long fp)
+unsigned long ftrace_get_parent_ra_addr(unsigned long self_ra, unsigned long
+ old_parent_ra, unsigned long parent_ra_addr, unsigned long fp)
{
- unsigned long sp, ip, ra;
+ unsigned long sp, ip, tmp;
unsigned int code;
int faulted;
/*
- * For module, move the ip from calling site of mcount after the
+ * For module, move the ip from the return address after the
* instruction "lui v1, hi_16bit_of_mcount"(offset is 24), but for
* kernel, move after the instruction "move ra, at"(offset is 16)
*/
- ip = self_addr - (in_kernel_space(self_addr) ? 16 : 24);
+ ip = self_ra - (in_kernel_space(self_ra) ? 16 : 24);
/*
* search the text until finding the non-store instruction or "s{d,w}
@@ -222,7 +220,7 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr,
* store the ra on the stack
*/
if ((code & S_R_SP) != S_R_SP)
- return parent_addr;
+ return parent_ra_addr;
/* Move to the next instruction */
ip -= 4;
@@ -230,12 +228,12 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr,
sp = fp + (code & OFFSET_MASK);
- /* ra = *(unsigned long *)sp; */
- safe_load_stack(ra, sp, faulted);
+ /* tmp = *(unsigned long *)sp; */
+ safe_load_stack(tmp, sp, faulted);
if (unlikely(faulted))
return 0;
- if (ra == parent)
+ if (tmp == old_parent_ra)
return sp;
return 0;
}
@@ -246,10 +244,10 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr,
* Hook the return address and push it in the stack of return addrs
* in current thread info.
*/
-void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
unsigned long fp)
{
- unsigned long old;
+ unsigned long old_parent_ra;
struct ftrace_graph_ent trace;
unsigned long return_hooker = (unsigned long)
&return_to_handler;
@@ -259,8 +257,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
return;
/*
- * "parent" is the stack address saved the return address of the caller
- * of _mcount.
+ * "parent_ra_addr" is the stack address saved the return address of
+ * the caller of _mcount.
*
* if the gcc < 4.5, a leaf function does not save the return address
* in the stack address, so, we "emulate" one in _mcount's stack space,
@@ -275,37 +273,37 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
* do it in ftrace_graph_caller of mcount.S.
*/
- /* old = *parent; */
- safe_load_stack(old, parent, faulted);
+ /* old_parent_ra = *parent_ra_addr; */
+ safe_load_stack(old_parent_ra, parent_ra_addr, faulted);
if (unlikely(faulted))
goto out;
#ifndef KBUILD_MCOUNT_RA_ADDRESS
- parent = (unsigned long *)ftrace_get_parent_addr(self_addr, old,
- (unsigned long)parent, fp);
+ parent_ra_addr = (unsigned long *)ftrace_get_parent_ra_addr(self_ra,
+ old_parent_ra, (unsigned long)parent_ra_addr, fp);
/*
* If fails when getting the stack address of the non-leaf function's
* ra, stop function graph tracer and return
*/
- if (parent == 0)
+ if (parent_ra_addr == 0)
goto out;
#endif
- /* *parent = return_hooker; */
- safe_store_stack(return_hooker, parent, faulted);
+ /* *parent_ra_addr = return_hooker; */
+ safe_store_stack(return_hooker, parent_ra_addr, faulted);
if (unlikely(faulted))
goto out;
- if (ftrace_push_return_trace(old, self_addr, &trace.depth, fp) ==
- -EBUSY) {
- *parent = old;
+ if (ftrace_push_return_trace(old_parent_ra, self_ra, &trace.depth, fp)
+ == -EBUSY) {
+ *parent_ra_addr = old_parent_ra;
return;
}
- trace.func = self_addr;
+ trace.func = self_ra;
/* Only trace if the calling function expects to */
if (!ftrace_graph_entry(&trace)) {
current->curr_ret_stack--;
- *parent = old;
+ *parent_ra_addr = old_parent_ra;
}
return;
out: