commit 80526491c2ca6abc028c0f0dbb0707a1f35fb18a upstream.

Fix to check kprobe blacklist address correctly with relocated address by adjusting debuginfo address.

Since the address in the debuginfo is same as objdump, it is different from relocated kernel address with KASLR. Thus, 'perf probe' always misses to catch the blacklisted addresses.

Without this patch, 'perf probe' can not detect the blacklist addresses on a KASLR enabled kernel.

# perf probe kprobe_dispatcher Failed to write event: Invalid argument Error: Failed to add events. #

With this patch, it correctly shows the error message.

# perf probe kprobe_dispatcher kprobe_dispatcher is blacklisted function, skip it. Probe point 'kprobe_dispatcher' not found. Error: Failed to add events. #

Fixes: 9aaf5a5f479b ("perf probe: Check kprobes blacklist when adding new events") Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Tested-by: Arnaldo Carvalho de Melo acme@redhat.com Cc: Jiri Olsa jolsa@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: stable@vger.kernel.org Link: http://lore.kernel.org/lkml/158763966411.30755.5882376357738273695.stgit@dev... Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com --- tools/perf/util/probe-event.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index a7452fd3b6ee..0551a02ee17c 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -118,7 +118,7 @@ static struct symbol *__find_kernel_function(u64 addr, struct map **mapp) return machine__find_kernel_function(host_machine, addr, mapp); }

-static struct ref_reloc_sym *kernel_get_ref_reloc_sym(void) +static struct ref_reloc_sym *kernel_get_ref_reloc_sym(struct map **pmap) { /* kmap->ref_reloc_sym should be set if host_machine is initialized */ struct kmap *kmap; @@ -130,6 +130,10 @@ static struct ref_reloc_sym *kernel_get_ref_reloc_sym(void) kmap = map__kmap(map); if (!kmap) return NULL; + + if (pmap) + *pmap = map; + return kmap->ref_reloc_sym; }

@@ -141,7 +145,7 @@ static int kernel_get_symbol_address_by_name(const char *name, u64 *addr, struct map *map;

/* ref_reloc_sym is just a label. Need a special fix*/ - reloc_sym = kernel_get_ref_reloc_sym(); + reloc_sym = kernel_get_ref_reloc_sym(NULL); if (reloc_sym && strcmp(name, reloc_sym->name) == 0) *addr = (reloc) ? reloc_sym->addr : reloc_sym->unrelocated_addr; else { @@ -742,6 +746,7 @@ post_process_kernel_probe_trace_events(struct probe_trace_event *tevs, int ntevs) { struct ref_reloc_sym *reloc_sym; + struct map *map; char *tmp; int i, skipped = 0;

@@ -750,7 +755,7 @@ post_process_kernel_probe_trace_events(struct probe_trace_event *tevs, return post_process_offline_probe_trace_events(tevs, ntevs, symbol_conf.vmlinux_name);

- reloc_sym = kernel_get_ref_reloc_sym(); + reloc_sym = kernel_get_ref_reloc_sym(&map); if (!reloc_sym) { pr_warning("Relocated base symbol is not found!\n"); return -EINVAL; @@ -759,9 +764,13 @@ post_process_kernel_probe_trace_events(struct probe_trace_event *tevs, for (i = 0; i < ntevs; i++) { if (!tevs[i].point.address || tevs[i].point.retprobe) continue; - /* If we found a wrong one, mark it by NULL symbol */ + /* + * If we found a wrong one, mark it by NULL symbol. + * Since addresses in debuginfo is same as objdump, we need + * to convert it to addresses on memory. + */ if (kprobe_warn_out_range(tevs[i].point.symbol, - tevs[i].point.address)) { + map__objdump_2mem(map, tevs[i].point.address))) { tmp = NULL; skipped++; } else { @@ -2850,7 +2859,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev,

/* Note that the symbols in the kmodule are not relocated */ if (!pev->uprobes && !pp->retprobe && !pev->target) { - reloc_sym = kernel_get_ref_reloc_sym(); + reloc_sym = kernel_get_ref_reloc_sym(NULL); if (!reloc_sym) { pr_warning("Relocated base symbol is not found!\n"); ret = -EINVAL;

From: Jiri Olsa jolsa@kernel.org

commit 77f18153c080855e1c3fb520ca31a4e61530121d upstream.

[Add an additional sprintf replacement in tools/perf/builtin-script.c]

With gcc 8 we get new set of snprintf() warnings that breaks the compilation, one example:

tests/mem.c: In function ‘check’: tests/mem.c:19:48: error: ‘%s’ directive output may be truncated writing \ up to 99 bytes into a region of size 89 [-Werror=format-truncation=] snprintf(failure, sizeof failure, "unexpected %s", out);

The gcc docs says:

To avoid the warning either use a bigger buffer or handle the function's return value which indicates whether or not its output has been truncated.

Given that all these warnings are harmless, because the code either properly fails due to uncomplete file path or we don't care for truncated output at all, I'm changing all those snprintf() calls to scnprintf(), which actually 'checks' for the snprint return value so the gcc stays silent.

Signed-off-by: Jiri Olsa jolsa@kernel.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: David Ahern dsahern@gmail.com Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Sergey Senozhatsky sergey.senozhatsky.work@gmail.com Link: http://lkml.kernel.org/r/20180319082902.4518-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com --- tools/perf/builtin-script.c | 24 ++++++++++++------------ tools/perf/tests/attr.c | 4 ++-- tools/perf/tests/pmu.c | 2 +- tools/perf/util/cgroup.c | 2 +- tools/perf/util/parse-events.c | 4 ++-- tools/perf/util/pmu.c | 2 +- 6 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index 7228d141a789..676568286eef 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -1516,7 +1516,7 @@ static int is_directory(const char *base_path, const struct dirent *dent) char path[PATH_MAX]; struct stat st;

- sprintf(path, "%s/%s", base_path, dent->d_name); + scnprintf(path, PATH_MAX, "%s/%s", base_path, dent->d_name); if (stat(path, &st)) return 0;

@@ -1702,8 +1702,8 @@ static int list_available_scripts(const struct option *opt __maybe_unused, }

for_each_lang(scripts_path, scripts_dir, lang_dirent) { - snprintf(lang_path, MAXPATHLEN, "%s/%s/bin", scripts_path, - lang_dirent->d_name); + scnprintf(lang_path, MAXPATHLEN, "%s/%s/bin", scripts_path, + lang_dirent->d_name); lang_dir = opendir(lang_path); if (!lang_dir) continue; @@ -1712,8 +1712,8 @@ static int list_available_scripts(const struct option *opt __maybe_unused, script_root = get_script_root(script_dirent, REPORT_SUFFIX); if (script_root) { desc = script_desc__findnew(script_root); - snprintf(script_path, MAXPATHLEN, "%s/%s", - lang_path, script_dirent->d_name); + scnprintf(script_path, MAXPATHLEN, "%s/%s", + lang_path, script_dirent->d_name); read_script_info(desc, script_path); free(script_root); } @@ -1749,7 +1749,7 @@ static int check_ev_match(char *dir_name, char *scriptname, int match, len; FILE *fp;

- sprintf(filename, "%s/bin/%s-record", dir_name, scriptname); + scnprintf(filename, MAXPATHLEN, "%s/bin/%s-record", dir_name, scriptname);

fp = fopen(filename, "r"); if (!fp) @@ -1825,8 +1825,8 @@ int find_scripts(char **scripts_array, char **scripts_path_array) }

for_each_lang(scripts_path, scripts_dir, lang_dirent) { - snprintf(lang_path, MAXPATHLEN, "%s/%s", scripts_path, - lang_dirent->d_name); + scnprintf(lang_path, MAXPATHLEN, "%s/%s", scripts_path, + lang_dirent->d_name); #ifdef NO_LIBPERL if (strstr(lang_path, "perl")) continue; @@ -1881,8 +1881,8 @@ static char *get_script_path(const char *script_root, const char *suffix) return NULL;

for_each_lang(scripts_path, scripts_dir, lang_dirent) { - snprintf(lang_path, MAXPATHLEN, "%s/%s/bin", scripts_path, - lang_dirent->d_name); + scnprintf(lang_path, MAXPATHLEN, "%s/%s/bin", scripts_path, + lang_dirent->d_name); lang_dir = opendir(lang_path); if (!lang_dir) continue; @@ -1893,8 +1893,8 @@ static char *get_script_path(const char *script_root, const char *suffix) free(__script_root); closedir(lang_dir); closedir(scripts_dir); - snprintf(script_path, MAXPATHLEN, "%s/%s", - lang_path, script_dirent->d_name); + scnprintf(script_path, MAXPATHLEN, "%s/%s", + lang_path, script_dirent->d_name); return strdup(script_path); } free(__script_root); diff --git a/tools/perf/tests/attr.c b/tools/perf/tests/attr.c index b60a6fd66517..a607d2a851ef 100644 --- a/tools/perf/tests/attr.c +++ b/tools/perf/tests/attr.c @@ -147,8 +147,8 @@ static int run_dir(const char *d, const char *perf) if (verbose) vcnt++;

- snprintf(cmd, 3*PATH_MAX, PYTHON " %s/attr.py -d %s/attr/ -p %s %.*s", - d, d, perf, vcnt, v); + scnprintf(cmd, 3*PATH_MAX, PYTHON " %s/attr.py -d %s/attr/ -p %s %.*s", + d, d, perf, vcnt, v);

return system(cmd) ? TEST_FAIL : TEST_OK; } diff --git a/tools/perf/tests/pmu.c b/tools/perf/tests/pmu.c index 1e2ba2602930..1802ad3f45b6 100644 --- a/tools/perf/tests/pmu.c +++ b/tools/perf/tests/pmu.c @@ -95,7 +95,7 @@ static char *test_format_dir_get(void) struct test_format *format = &test_formats[i]; FILE *file;

- snprintf(name, PATH_MAX, "%s/%s", dir, format->name); + scnprintf(name, PATH_MAX, "%s/%s", dir, format->name);

file = fopen(name, "w"); if (!file) diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c index 8fdee24725a7..5bc2b92ace6d 100644 --- a/tools/perf/util/cgroup.c +++ b/tools/perf/util/cgroup.c @@ -64,7 +64,7 @@ static int open_cgroup(char *name) if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1)) return -1;

- snprintf(path, PATH_MAX, "%s/%s", mnt, name); + scnprintf(path, PATH_MAX, "%s/%s", mnt, name);

fd = open(path, O_RDONLY); if (fd == -1) diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index 6193be6d7639..f9f7e35f47a7 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -195,8 +195,8 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)

for_each_event(sys_dirent, evt_dir, evt_dirent) {

- snprintf(evt_path, MAXPATHLEN, "%s/%s/id", dir_path, - evt_dirent->d_name); + scnprintf(evt_path, MAXPATHLEN, "%s/%s/id", dir_path, + evt_dirent->d_name); fd = open(evt_path, O_RDONLY); if (fd < 0) continue; diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index c86c1d5ea65c..39abbf827646 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -325,7 +325,7 @@ static int pmu_aliases_parse(char *dir, struct list_head *head) if (pmu_alias_info_file(name)) continue;

- snprintf(path, PATH_MAX, "%s/%s", dir, name); + scnprintf(path, PATH_MAX, "%s/%s", dir, name);

file = fopen(path, "r"); if (!file) {