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perf probe: Add basic module support

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Add basic module probe support on perf probe. This introduces "--module
<MODNAME>" option to perf probe for putting probes and showing lines and
variables in the given module.

Currently, this supports only probing on running modules.  Supporting off-line
module probing is the next step.

e.g.)
[show lines]
 # ./perf probe --module drm -L drm_vblank_info
<drm_vblank_info:0>
      0  int drm_vblank_info(struct seq_file *m, void *data)
      1  {
                struct drm_info_node *node = (struct drm_info_node *) m->private
      3         struct drm_device *dev = node->minor->dev;
 ...
[show vars]
 # ./perf probe --module drm -V drm_vblank_info:3
Available variables at drm_vblank_info:3
        @<drm_vblank_info+20>
                (unknown_type)  data
                struct drm_info_node*   node
                struct seq_file*        m
[put a probe]
 # ./perf probe --module drm drm_vblank_info:3 node m
Add new event:
  probe:drm_vblank_info (on drm_vblank_info:3 with node m)

You can now use it on all perf tools, such as:

        perf record -e probe:drm_vblank_info -aR sleep 1
[list probes]
 # ./perf probe -l
probe:drm_vblank_info (on drm_vblank_info:3@drivers/gpu/drm/drm_info.c with ...

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101021101341.3542.71638.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu
2010-10-21 19:13:41 +09:00
committed by Arnaldo Carvalho de Melo
parent fb8c5a56c7
commit 469b9b8848
7 changed files with 240 additions and 70 deletions
Download Patch File Download Diff File Expand all files Collapse all files

125
tools/perf/util/probe-event.c
View File

@@ -74,10 +74,9 @@ static int e_snprintf(char *str, size_t size, const char *format, ...)
static char *synthesize_perf_probe_point(struct perf_probe_point *pp);
static struct machine machine;
/* Initialize symbol maps and path of vmlinux */
/* Initialize symbol maps and path of vmlinux/modules */
static int init_vmlinux(void)
{
struct dso *kernel;
int ret;
symbol_conf.sort_by_name = true;
@@ -91,33 +90,61 @@ static int init_vmlinux(void)
goto out;
}
ret = machine__init(&machine, "/", 0);
ret = machine__init(&machine, "", HOST_KERNEL_ID);
if (ret < 0)
goto out;
kernel = dso__new_kernel(symbol_conf.vmlinux_name);
if (kernel == NULL)
die("Failed to create kernel dso.");
ret = __machine__create_kernel_maps(&machine, kernel);
if (ret < 0)
pr_debug("Failed to create kernel maps.\n");
if (machine__create_kernel_maps(&machine) < 0) {
pr_debug("machine__create_kernel_maps ");
goto out;
}
out:
if (ret < 0)
pr_warning("Failed to init vmlinux path.\n");
return ret;
}
#ifdef DWARF_SUPPORT
static int open_vmlinux(void)
static struct symbol *__find_kernel_function_by_name(const char *name,
struct map **mapp)
{
if (map__load(machine.vmlinux_maps[MAP__FUNCTION], NULL) < 0) {
pr_debug("Failed to load kernel map.\n");
return -EINVAL;
return machine__find_kernel_function_by_name(&machine, name, mapp,
NULL);
}
const char *kernel_get_module_path(const char *module)
{
struct dso *dso;
if (module) {
list_for_each_entry(dso, &machine.kernel_dsos, node) {
if (strncmp(dso->short_name + 1, module,
dso->short_name_len - 2) == 0)
goto found;
}
pr_debug("Failed to find module %s.\n", module);
return NULL;
} else {
dso = machine.vmlinux_maps[MAP__FUNCTION]->dso;
if (dso__load_vmlinux_path(dso,
machine.vmlinux_maps[MAP__FUNCTION], NULL) < 0) {
pr_debug("Failed to load kernel map.\n");
return NULL;
}
}
pr_debug("Try to open %s\n", machine.vmlinux_maps[MAP__FUNCTION]->dso->long_name);
return open(machine.vmlinux_maps[MAP__FUNCTION]->dso->long_name, O_RDONLY);
found:
return dso->long_name;
}
#ifdef DWARF_SUPPORT
static int open_vmlinux(const char *module)
{
const char *path = kernel_get_module_path(module);
if (!path) {
pr_err("Failed to find path of %s module", module ?: "kernel");
return -ENOENT;
}
pr_debug("Try to open %s\n", path);
return open(path, O_RDONLY);
}
/*
@@ -125,20 +152,19 @@ static int open_vmlinux(void)
* Currently only handles kprobes.
*/
static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp,
struct perf_probe_point *pp)
struct perf_probe_point *pp)
{
struct symbol *sym;
int fd, ret = -ENOENT;
struct map *map;
u64 addr;
int ret = -ENOENT;
sym = map__find_symbol_by_name(machine.vmlinux_maps[MAP__FUNCTION],
tp->symbol, NULL);
sym = __find_kernel_function_by_name(tp->symbol, &map);
if (sym) {
fd = open_vmlinux();
if (fd >= 0) {
ret = find_perf_probe_point(fd,
sym->start + tp->offset, pp);
close(fd);
}
addr = map->unmap_ip(map, sym->start + tp->offset);
pr_debug("try to find %s+%ld@%llx\n", tp->symbol,
tp->offset, addr);
ret = find_perf_probe_point((unsigned long)addr, pp);
}
if (ret <= 0) {
pr_debug("Failed to find corresponding probes from "
@@ -156,12 +182,12 @@ static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp,
/* Try to find perf_probe_event with debuginfo */
static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
struct probe_trace_event **tevs,
int max_tevs)
int max_tevs, const char *module)
{
bool need_dwarf = perf_probe_event_need_dwarf(pev);
int fd, ntevs;
fd = open_vmlinux();
fd = open_vmlinux(module);
if (fd < 0) {
if (need_dwarf) {
pr_warning("Failed to open debuginfo file.\n");
@@ -300,7 +326,7 @@ error:
* Show line-range always requires debuginfo to find source file and
* line number.
*/
int show_line_range(struct line_range *lr)
int show_line_range(struct line_range *lr, const char *module)
{
int l = 1;
struct line_node *ln;
@@ -313,7 +339,7 @@ int show_line_range(struct line_range *lr)
if (ret < 0)
return ret;
fd = open_vmlinux();
fd = open_vmlinux(module);
if (fd < 0) {
pr_warning("Failed to open debuginfo file.\n");
return fd;
@@ -421,7 +447,7 @@ static int show_available_vars_at(int fd, struct perf_probe_event *pev,
/* Show available variables on given probe point */
int show_available_vars(struct perf_probe_event *pevs, int npevs,
int max_vls, bool externs)
int max_vls, const char *module, bool externs)
{
int i, fd, ret = 0;
@@ -429,7 +455,7 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs,
if (ret < 0)
return ret;
fd = open_vmlinux();
fd = open_vmlinux(module);
if (fd < 0) {
pr_warning("Failed to open debuginfo file.\n");
return fd;
@@ -447,8 +473,15 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs,
#else /* !DWARF_SUPPORT */
static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp,
struct perf_probe_point *pp)
struct perf_probe_point *pp)
{
struct symbol *sym;
sym = __find_kernel_function_by_name(tp->symbol, NULL);
if (!sym) {
pr_err("Failed to find symbol %s in kernel.\n", tp->symbol);
return -ENOENT;
}
pp->function = strdup(tp->symbol);
if (pp->function == NULL)
return -ENOMEM;
@@ -460,7 +493,7 @@ static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp,
static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
struct probe_trace_event **tevs __unused,
int max_tevs __unused)
int max_tevs __unused, const char *mod __unused)
{
if (perf_probe_event_need_dwarf(pev)) {
pr_warning("Debuginfo-analysis is not supported.\n");
@@ -469,14 +502,15 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
return 0;
}
int show_line_range(struct line_range *lr __unused)
int show_line_range(struct line_range *lr __unused, const char *module __unused)
{
pr_warning("Debuginfo-analysis is not supported.\n");
return -ENOSYS;
}
int show_available_vars(struct perf_probe_event *pevs __unused,
int npevs __unused, int max_probe_points __unused)
int npevs __unused, int max_vls __unused,
const char *module __unused, bool externs __unused)
{
pr_warning("Debuginfo-analysis is not supported.\n");
return -ENOSYS;
@@ -1159,7 +1193,7 @@ error:
}
static int convert_to_perf_probe_event(struct probe_trace_event *tev,
struct perf_probe_event *pev)
struct perf_probe_event *pev)
{
char buf[64] = "";
int i, ret;
@@ -1588,14 +1622,14 @@ static int __add_probe_trace_events(struct perf_probe_event *pev,
static int convert_to_probe_trace_events(struct perf_probe_event *pev,
struct probe_trace_event **tevs,
int max_tevs)
int max_tevs, const char *module)
{
struct symbol *sym;
int ret = 0, i;
struct probe_trace_event *tev;
/* Convert perf_probe_event with debuginfo */
ret = try_to_find_probe_trace_events(pev, tevs, max_tevs);
ret = try_to_find_probe_trace_events(pev, tevs, max_tevs, module);
if (ret != 0)
return ret;
@@ -1644,8 +1678,7 @@ static int convert_to_probe_trace_events(struct perf_probe_event *pev,
}
/* Currently just checking function name from symbol map */
sym = map__find_symbol_by_name(machine.vmlinux_maps[MAP__FUNCTION],
tev->point.symbol, NULL);
sym = __find_kernel_function_by_name(tev->point.symbol, NULL);
if (!sym) {
pr_warning("Kernel symbol \'%s\' not found.\n",
tev->point.symbol);
@@ -1668,7 +1701,7 @@ struct __event_package {
};
int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,
int max_tevs, bool force_add)
int max_tevs, const char *module, bool force_add)
{
int i, j, ret;
struct __event_package *pkgs;
@@ -1689,7 +1722,9 @@ int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,
pkgs[i].pev = &pevs[i];
/* Convert with or without debuginfo */
ret = convert_to_probe_trace_events(pkgs[i].pev,
&pkgs[i].tevs, max_tevs);
&pkgs[i].tevs,
max_tevs,
module);
if (ret < 0)
goto end;
pkgs[i].ntevs = ret;