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authorAlexei Starovoitov <ast@fb.com>2016-02-17 19:58:57 -0800
committerDavid S. Miller <davem@davemloft.net>2016-02-20 00:21:44 -0500
commit568b329a02f75ed3aaae5eb2cca384cb9e09cb29 (patch)
treeae50fa4f98c1c7ad07ad834677be3304a282499e /arch
parent6b83d28a55a891a9d70fc61ccb1c138e47dcbe74 (diff)
downloadlinux-568b329a02f75ed3aaae5eb2cca384cb9e09cb29.tar.bz2
perf: generalize perf_callchain
. avoid walking the stack when there is no room left in the buffer . generalize get_perf_callchain() to be called from bpf helper Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/stacktrace.h2
-rw-r--r--arch/x86/kernel/cpu/perf_event.c4
-rw-r--r--arch/x86/kernel/dumpstack.c6
-rw-r--r--arch/x86/kernel/stacktrace.c18
-rw-r--r--arch/x86/oprofile/backtrace.c3
5 files changed, 20 insertions, 13 deletions
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h
index 70bbe39043a9..7c247e7404be 100644
--- a/arch/x86/include/asm/stacktrace.h
+++ b/arch/x86/include/asm/stacktrace.h
@@ -37,7 +37,7 @@ print_context_stack_bp(struct thread_info *tinfo,
/* Generic stack tracer with callbacks */
struct stacktrace_ops {
- void (*address)(void *data, unsigned long address, int reliable);
+ int (*address)(void *data, unsigned long address, int reliable);
/* On negative return stop dumping */
int (*stack)(void *data, char *name);
walk_stack_t walk_stack;
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 1b443db2db50..d276b31ca473 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -2180,11 +2180,11 @@ static int backtrace_stack(void *data, char *name)
return 0;
}
-static void backtrace_address(void *data, unsigned long addr, int reliable)
+static int backtrace_address(void *data, unsigned long addr, int reliable)
{
struct perf_callchain_entry *entry = data;
- perf_callchain_store(entry, addr);
+ return perf_callchain_store(entry, addr);
}
static const struct stacktrace_ops backtrace_ops = {
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 9c30acfadae2..0d1ff4b407d4 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -135,7 +135,8 @@ print_context_stack_bp(struct thread_info *tinfo,
if (!__kernel_text_address(addr))
break;
- ops->address(data, addr, 1);
+ if (ops->address(data, addr, 1))
+ break;
frame = frame->next_frame;
ret_addr = &frame->return_address;
print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
@@ -154,10 +155,11 @@ static int print_trace_stack(void *data, char *name)
/*
* Print one address/symbol entries per line.
*/
-static void print_trace_address(void *data, unsigned long addr, int reliable)
+static int print_trace_address(void *data, unsigned long addr, int reliable)
{
touch_nmi_watchdog();
printk_stack_address(addr, reliable, data);
+ return 0;
}
static const struct stacktrace_ops print_trace_ops = {
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index fdd0c6430e5a..9ee98eefc44d 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -14,30 +14,34 @@ static int save_stack_stack(void *data, char *name)
return 0;
}
-static void
+static int
__save_stack_address(void *data, unsigned long addr, bool reliable, bool nosched)
{
struct stack_trace *trace = data;
#ifdef CONFIG_FRAME_POINTER
if (!reliable)
- return;
+ return 0;
#endif
if (nosched && in_sched_functions(addr))
- return;
+ return 0;
if (trace->skip > 0) {
trace->skip--;
- return;
+ return 0;
}
- if (trace->nr_entries < trace->max_entries)
+ if (trace->nr_entries < trace->max_entries) {
trace->entries[trace->nr_entries++] = addr;
+ return 0;
+ } else {
+ return -1; /* no more room, stop walking the stack */
+ }
}
-static void save_stack_address(void *data, unsigned long addr, int reliable)
+static int save_stack_address(void *data, unsigned long addr, int reliable)
{
return __save_stack_address(data, addr, reliable, false);
}
-static void
+static int
save_stack_address_nosched(void *data, unsigned long addr, int reliable)
{
return __save_stack_address(data, addr, reliable, true);
diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index 4e664bdb535a..cb31a4440e58 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -23,12 +23,13 @@ static int backtrace_stack(void *data, char *name)
return 0;
}
-static void backtrace_address(void *data, unsigned long addr, int reliable)
+static int backtrace_address(void *data, unsigned long addr, int reliable)
{
unsigned int *depth = data;
if ((*depth)--)
oprofile_add_trace(addr);
+ return 0;
}
static struct stacktrace_ops backtrace_ops = {