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authorMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>2010-10-21 19:13:41 +0900
committerArnaldo Carvalho de Melo <acme@redhat.com>2010-10-21 16:11:44 -0200
commit469b9b88488e89114bb3e9ac5ee7906b7b96123f (patch)
tree9f002195a8b1167eddbe560ac834e6ba2dedb19f /tools/perf/util/probe-finder.c
parentfb8c5a56c7ddbc2b0d2ee7a8da60fe1355f75141 (diff)
perf probe: Add basic module support
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>
Diffstat (limited to 'tools/perf/util/probe-finder.c')
-rw-r--r--tools/perf/util/probe-finder.c142
1 files changed, 126 insertions, 16 deletions
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index a274fd0c143e..c20bd52833aa 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -116,6 +116,101 @@ static void line_list__free(struct list_head *head)
}
}
+/* Dwarf FL wrappers */
+
+static int __linux_kernel_find_elf(Dwfl_Module *mod,
+ void **userdata,
+ const char *module_name,
+ Dwarf_Addr base,
+ char **file_name, Elf **elfp)
+{
+ int fd;
+ const char *path = kernel_get_module_path(module_name);
+
+ if (path) {
+ fd = open(path, O_RDONLY);
+ if (fd >= 0) {
+ *file_name = strdup(path);
+ return fd;
+ }
+ }
+ /* If failed, try to call standard method */
+ return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
+ file_name, elfp);
+}
+
+static char *debuginfo_path; /* Currently dummy */
+
+static const Dwfl_Callbacks offline_callbacks = {
+ .find_debuginfo = dwfl_standard_find_debuginfo,
+ .debuginfo_path = &debuginfo_path,
+
+ .section_address = dwfl_offline_section_address,
+
+ /* We use this table for core files too. */
+ .find_elf = dwfl_build_id_find_elf,
+};
+
+static const Dwfl_Callbacks kernel_callbacks = {
+ .find_debuginfo = dwfl_standard_find_debuginfo,
+ .debuginfo_path = &debuginfo_path,
+
+ .find_elf = __linux_kernel_find_elf,
+ .section_address = dwfl_linux_kernel_module_section_address,
+};
+
+/* Get a Dwarf from offline image */
+static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias)
+{
+ Dwfl_Module *mod;
+ Dwarf *dbg = NULL;
+
+ if (!dwflp)
+ return NULL;
+
+ *dwflp = dwfl_begin(&offline_callbacks);
+ if (!*dwflp)
+ return NULL;
+
+ mod = dwfl_report_offline(*dwflp, "", "", fd);
+ if (!mod)
+ goto error;
+
+ dbg = dwfl_module_getdwarf(mod, bias);
+ if (!dbg) {
+error:
+ dwfl_end(*dwflp);
+ *dwflp = NULL;
+ }
+ return dbg;
+}
+
+/* Get a Dwarf from live kernel image */
+static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp,
+ Dwarf_Addr *bias)
+{
+ Dwarf *dbg;
+
+ if (!dwflp)
+ return NULL;
+
+ *dwflp = dwfl_begin(&kernel_callbacks);
+ if (!*dwflp)
+ return NULL;
+
+ /* Load the kernel dwarves: Don't care the result here */
+ dwfl_linux_kernel_report_kernel(*dwflp);
+ dwfl_linux_kernel_report_modules(*dwflp);
+
+ dbg = dwfl_addrdwarf(*dwflp, addr, bias);
+ /* Here, check whether we could get a real dwarf */
+ if (!dbg) {
+ dwfl_end(*dwflp);
+ *dwflp = NULL;
+ }
+ return dbg;
+}
+
/* Dwarf wrappers */
/* Find the realpath of the target file. */
@@ -1177,10 +1272,12 @@ static int find_probes(int fd, struct probe_finder *pf)
Dwarf_Off off, noff;
size_t cuhl;
Dwarf_Die *diep;
- Dwarf *dbg;
+ Dwarf *dbg = NULL;
+ Dwfl *dwfl;
+ Dwarf_Addr bias; /* Currently ignored */
int ret = 0;
- dbg = dwarf_begin(fd, DWARF_C_READ);
+ dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
if (!dbg) {
pr_warning("No dwarf info found in the vmlinux - "
"please rebuild with CONFIG_DEBUG_INFO=y.\n");
@@ -1221,7 +1318,8 @@ static int find_probes(int fd, struct probe_finder *pf)
off = noff;
}
line_list__free(&pf->lcache);
- dwarf_end(dbg);
+ if (dwfl)
+ dwfl_end(dwfl);
return ret;
}
@@ -1412,23 +1510,31 @@ int find_available_vars_at(int fd, struct perf_probe_event *pev,
}
/* Reverse search */
-int find_perf_probe_point(int fd, unsigned long addr,
- struct perf_probe_point *ppt)
+int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
{
Dwarf_Die cudie, spdie, indie;
- Dwarf *dbg;
+ Dwarf *dbg = NULL;
+ Dwfl *dwfl = NULL;
Dwarf_Line *line;
- Dwarf_Addr laddr, eaddr;
+ Dwarf_Addr laddr, eaddr, bias = 0;
const char *tmp;
int lineno, ret = 0;
bool found = false;
- dbg = dwarf_begin(fd, DWARF_C_READ);
- if (!dbg)
- return -EBADF;
+ /* Open the live linux kernel */
+ dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
+ if (!dbg) {
+ pr_warning("No dwarf info found in the vmlinux - "
+ "please rebuild with CONFIG_DEBUG_INFO=y.\n");
+ ret = -EINVAL;
+ goto end;
+ }
+ /* Adjust address with bias */
+ addr += bias;
/* Find cu die */
- if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
+ if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
+ pr_warning("No CU DIE is found at %lx\n", addr);
ret = -EINVAL;
goto end;
}
@@ -1491,7 +1597,8 @@ found:
}
end:
- dwarf_end(dbg);
+ if (dwfl)
+ dwfl_end(dwfl);
if (ret >= 0)
ret = found ? 1 : 0;
return ret;
@@ -1624,6 +1731,8 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
struct line_finder *lf = param->data;
struct line_range *lr = lf->lr;
+ pr_debug("find (%lx) %s\n", dwarf_dieoffset(sp_die),
+ dwarf_diename(sp_die));
if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
die_compare_name(sp_die, lr->function)) {
lf->fname = dwarf_decl_file(sp_die);
@@ -1667,10 +1776,12 @@ int find_line_range(int fd, struct line_range *lr)
Dwarf_Off off = 0, noff;
size_t cuhl;
Dwarf_Die *diep;
- Dwarf *dbg;
+ Dwarf *dbg = NULL;
+ Dwfl *dwfl;
+ Dwarf_Addr bias; /* Currently ignored */
const char *comp_dir;
- dbg = dwarf_begin(fd, DWARF_C_READ);
+ dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
if (!dbg) {
pr_warning("No dwarf info found in the vmlinux - "
"please rebuild with CONFIG_DEBUG_INFO=y.\n");
@@ -1716,8 +1827,7 @@ int find_line_range(int fd, struct line_range *lr)
}
pr_debug("path: %s\n", lr->path);
- dwarf_end(dbg);
-
+ dwfl_end(dwfl);
return (ret < 0) ? ret : lf.found;
}