[GIT PULL] perf fixes

From: Ingo Molnar
Date: Wed Jan 18 2017 - 04:27:22 EST


Linus,

Please pull the latest perf-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-for-linus

# HEAD: 31f5260a7653e6042ac28578db1c61e84f2d7898 Merge tag 'perf-urgent-for-mingo-4.10-20170117' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

An Intel PMU driver hotplug fix and three 'perf probe' tooling fixes.

Thanks,

Ingo

------------------>
Masami Hiramatsu (3):
perf probe: Fix to show correct locations for events on modules
perf probe: Add error checks to offline probe post-processing
perf probe: Fix to probe on gcc generated functions in modules

Zhou Chengming (1):
perf/x86/intel: Handle exclusive threadid correctly on CPU hotplug


arch/x86/events/intel/core.c | 7 +++-
tools/perf/util/probe-event.c | 95 +++++++++++++++++++++++++++---------------
tools/perf/util/probe-finder.c | 15 ++++---
tools/perf/util/probe-finder.h | 3 ++
4 files changed, 77 insertions(+), 43 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index d611cab214a6..eb1484c86bb4 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3176,13 +3176,16 @@ static void intel_pmu_cpu_starting(int cpu)

if (x86_pmu.flags & PMU_FL_EXCL_CNTRS) {
for_each_cpu(i, topology_sibling_cpumask(cpu)) {
+ struct cpu_hw_events *sibling;
struct intel_excl_cntrs *c;

- c = per_cpu(cpu_hw_events, i).excl_cntrs;
+ sibling = &per_cpu(cpu_hw_events, i);
+ c = sibling->excl_cntrs;
if (c && c->core_id == core_id) {
cpuc->kfree_on_online[1] = cpuc->excl_cntrs;
cpuc->excl_cntrs = c;
- cpuc->excl_thread_id = 1;
+ if (!sibling->excl_thread_id)
+ cpuc->excl_thread_id = 1;
break;
}
}
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 4a57c8a60bd9..6a6f44dd594b 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -610,6 +610,33 @@ static int find_perf_probe_point_from_dwarf(struct probe_trace_point *tp,
return ret ? : -ENOENT;
}

+/* Adjust symbol name and address */
+static int post_process_probe_trace_point(struct probe_trace_point *tp,
+ struct map *map, unsigned long offs)
+{
+ struct symbol *sym;
+ u64 addr = tp->address + tp->offset - offs;
+
+ sym = map__find_symbol(map, addr);
+ if (!sym)
+ return -ENOENT;
+
+ if (strcmp(sym->name, tp->symbol)) {
+ /* If we have no realname, use symbol for it */
+ if (!tp->realname)
+ tp->realname = tp->symbol;
+ else
+ free(tp->symbol);
+ tp->symbol = strdup(sym->name);
+ if (!tp->symbol)
+ return -ENOMEM;
+ }
+ tp->offset = addr - sym->start;
+ tp->address -= offs;
+
+ return 0;
+}
+
/*
* Rename DWARF symbols to ELF symbols -- gcc sometimes optimizes functions
* and generate new symbols with suffixes such as .constprop.N or .isra.N
@@ -622,11 +649,9 @@ static int
post_process_offline_probe_trace_events(struct probe_trace_event *tevs,
int ntevs, const char *pathname)
{
- struct symbol *sym;
struct map *map;
unsigned long stext = 0;
- u64 addr;
- int i;
+ int i, ret = 0;

/* Prepare a map for offline binary */
map = dso__new_map(pathname);
@@ -636,23 +661,14 @@ post_process_offline_probe_trace_events(struct probe_trace_event *tevs,
}

for (i = 0; i < ntevs; i++) {
- addr = tevs[i].point.address + tevs[i].point.offset - stext;
- sym = map__find_symbol(map, addr);
- if (!sym)
- continue;
- if (!strcmp(sym->name, tevs[i].point.symbol))
- continue;
- /* If we have no realname, use symbol for it */
- if (!tevs[i].point.realname)
- tevs[i].point.realname = tevs[i].point.symbol;
- else
- free(tevs[i].point.symbol);
- tevs[i].point.symbol = strdup(sym->name);
- tevs[i].point.offset = addr - sym->start;
+ ret = post_process_probe_trace_point(&tevs[i].point,
+ map, stext);
+ if (ret < 0)
+ break;
}
map__put(map);

- return 0;
+ return ret;
}

static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
@@ -682,18 +698,31 @@ static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
return ret;
}

-static int add_module_to_probe_trace_events(struct probe_trace_event *tevs,
- int ntevs, const char *module)
+static int
+post_process_module_probe_trace_events(struct probe_trace_event *tevs,
+ int ntevs, const char *module,
+ struct debuginfo *dinfo)
{
+ Dwarf_Addr text_offs = 0;
int i, ret = 0;
char *mod_name = NULL;
+ struct map *map;

if (!module)
return 0;

- mod_name = find_module_name(module);
+ map = get_target_map(module, false);
+ if (!map || debuginfo__get_text_offset(dinfo, &text_offs, true) < 0) {
+ pr_warning("Failed to get ELF symbols for %s\n", module);
+ return -EINVAL;
+ }

+ mod_name = find_module_name(module);
for (i = 0; i < ntevs; i++) {
+ ret = post_process_probe_trace_point(&tevs[i].point,
+ map, (unsigned long)text_offs);
+ if (ret < 0)
+ break;
tevs[i].point.module =
strdup(mod_name ? mod_name : module);
if (!tevs[i].point.module) {
@@ -703,6 +732,8 @@ static int add_module_to_probe_trace_events(struct probe_trace_event *tevs,
}

free(mod_name);
+ map__put(map);
+
return ret;
}

@@ -760,7 +791,7 @@ arch__post_process_probe_trace_events(struct perf_probe_event *pev __maybe_unuse
static int post_process_probe_trace_events(struct perf_probe_event *pev,
struct probe_trace_event *tevs,
int ntevs, const char *module,
- bool uprobe)
+ bool uprobe, struct debuginfo *dinfo)
{
int ret;

@@ -768,7 +799,8 @@ static int post_process_probe_trace_events(struct perf_probe_event *pev,
ret = add_exec_to_probe_trace_events(tevs, ntevs, module);
else if (module)
/* Currently ref_reloc_sym based probe is not for drivers */
- ret = add_module_to_probe_trace_events(tevs, ntevs, module);
+ ret = post_process_module_probe_trace_events(tevs, ntevs,
+ module, dinfo);
else
ret = post_process_kernel_probe_trace_events(tevs, ntevs);

@@ -812,30 +844,27 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
}
}

- debuginfo__delete(dinfo);
-
if (ntevs > 0) { /* Succeeded to find trace events */
pr_debug("Found %d probe_trace_events.\n", ntevs);
ret = post_process_probe_trace_events(pev, *tevs, ntevs,
- pev->target, pev->uprobes);
+ pev->target, pev->uprobes, dinfo);
if (ret < 0 || ret == ntevs) {
+ pr_debug("Post processing failed or all events are skipped. (%d)\n", ret);
clear_probe_trace_events(*tevs, ntevs);
zfree(tevs);
+ ntevs = 0;
}
- if (ret != ntevs)
- return ret < 0 ? ret : ntevs;
- ntevs = 0;
- /* Fall through */
}

+ debuginfo__delete(dinfo);
+
if (ntevs == 0) { /* No error but failed to find probe point. */
pr_warning("Probe point '%s' not found.\n",
synthesize_perf_probe_point(&pev->point));
return -ENOENT;
- }
- /* Error path : ntevs < 0 */
- pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs);
- if (ntevs < 0) {
+ } else if (ntevs < 0) {
+ /* Error path : ntevs < 0 */
+ pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs);
if (ntevs == -EBADF)
pr_warning("Warning: No dwarf info found in the vmlinux - "
"please rebuild kernel with CONFIG_DEBUG_INFO=y.\n");
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index df4debe564da..0d9d6e0803b8 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -1501,7 +1501,8 @@ int debuginfo__find_available_vars_at(struct debuginfo *dbg,
}

/* For the kernel module, we need a special code to get a DIE */
-static int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs)
+int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,
+ bool adjust_offset)
{
int n, i;
Elf32_Word shndx;
@@ -1530,6 +1531,8 @@ static int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs)
if (!shdr)
return -ENOENT;
*offs = shdr->sh_addr;
+ if (adjust_offset)
+ *offs -= shdr->sh_offset;
}
}
return 0;
@@ -1543,16 +1546,12 @@ int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
Dwarf_Addr _addr = 0, baseaddr = 0;
const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
int baseline = 0, lineno = 0, ret = 0;
- bool reloc = false;

-retry:
+ /* We always need to relocate the address for aranges */
+ if (debuginfo__get_text_offset(dbg, &baseaddr, false) == 0)
+ addr += baseaddr;
/* Find cu die */
if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {
- if (!reloc && debuginfo__get_text_offset(dbg, &baseaddr) == 0) {
- addr += baseaddr;
- reloc = true;
- goto retry;
- }
pr_warning("Failed to find debug information for address %lx\n",
addr);
ret = -EINVAL;
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index f1d8558f498e..2956c5198652 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -46,6 +46,9 @@ int debuginfo__find_trace_events(struct debuginfo *dbg,
int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
struct perf_probe_point *ppt);

+int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,
+ bool adjust_offset);
+
/* Find a line range */
int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr);