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powerpc64, tracing: add function graph tracer with dynamic tracing

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This is the port of the function graph tracer to PowerPC with
dynamic tracing.

Geoff Lavand tested on PS3.

Tested-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Steven Rostedt
2009-02-10 22:19:54 -08:00
committed by Benjamin Herrenschmidt
parent 6794c78243
commit 4654288847
3 changed files with 49 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

47
arch/powerpc/kernel/ftrace.c
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@@ -43,7 +43,8 @@ static unsigned char *ftrace_nop_replace(void)
return (char *)&ftrace_nop;
}
static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
static unsigned char *
ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
{
static unsigned int op;
@@ -55,8 +56,9 @@ static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
*/
addr = GET_ADDR(addr);
/* Set to "bl addr" */
op = 0x48000001 | (ftrace_calc_offset(ip, addr) & 0x03fffffc);
/* if (link) set op to 'bl' else 'b' */
op = 0x48000000 | (link ? 1 : 0);
op |= (ftrace_calc_offset(ip, addr) & 0x03fffffc);
/*
* No locking needed, this must be called via kstop_machine
@@ -344,7 +346,7 @@ int ftrace_make_nop(struct module *mod,
*/
if (test_24bit_addr(ip, addr)) {
/* within range */
old = ftrace_call_replace(ip, addr);
old = ftrace_call_replace(ip, addr, 1);
new = ftrace_nop_replace();
return ftrace_modify_code(ip, old, new);
}
@@ -484,7 +486,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
if (test_24bit_addr(ip, addr)) {
/* within range */
old = ftrace_nop_replace();
new = ftrace_call_replace(ip, addr);
new = ftrace_call_replace(ip, addr, 1);
return ftrace_modify_code(ip, old, new);
}
@@ -513,7 +515,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
int ret;
memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, (unsigned long)func);
new = ftrace_call_replace(ip, (unsigned long)func, 1);
ret = ftrace_modify_code(ip, old, new);
return ret;
@@ -532,6 +534,39 @@ int __init ftrace_dyn_arch_init(void *data)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
extern void ftrace_graph_call(void);
extern void ftrace_graph_stub(void);
int ftrace_enable_ftrace_graph_caller(void)
{
unsigned long ip = (unsigned long)(&ftrace_graph_call);
unsigned long addr = (unsigned long)(&ftrace_graph_caller);
unsigned long stub = (unsigned long)(&ftrace_graph_stub);
unsigned char old[MCOUNT_INSN_SIZE], *new;
new = ftrace_call_replace(ip, stub, 0);
memcpy(old, new, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, addr, 0);
return ftrace_modify_code(ip, old, new);
}
int ftrace_disable_ftrace_graph_caller(void)
{
unsigned long ip = (unsigned long)(&ftrace_graph_call);
unsigned long addr = (unsigned long)(&ftrace_graph_caller);
unsigned long stub = (unsigned long)(&ftrace_graph_stub);
unsigned char old[MCOUNT_INSN_SIZE], *new;
new = ftrace_call_replace(ip, addr, 0);
memcpy(old, new, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, stub, 0);
return ftrace_modify_code(ip, old, new);
}
#endif /* CONFIG_DYNAMIC_FTRACE */
/*
* Hook the return address and push it in the stack of return addrs
* in current thread info.