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authorJiri Olsa <jolsa@redhat.com>2011-03-07 21:13:40 +0100
committerArnaldo Carvalho de Melo <acme@redhat.com>2011-03-10 10:54:13 -0300
commitb9a46bba88001504235459c8410f17e6a7e38008 (patch)
tree35687cc87135475ce5be257c878cee6eeaf40f37 /tools
parent2a8247a2600c3e087a568fc68a6ec4eedac27ef1 (diff)
perf top: Fix events overflow in top command
The snprintf function returns number of printed characters even if it cross the size parameter. So passing enough events via '-e' parameter will cause segmentation fault. It's reproduced by following command: perf top -e `perf list | grep Tracepoint | awk -F'[' '\ {gsub(/[[:space:]]+/,"",$1);array[FNR]=$1}END{outputs=array[1];\ for (i=2;i<=FNR;i++){ outputs=outputs "," array[i];};print outputs}'` Attached patch is adding SNPRINTF macro that provides the overflow check and returns actuall number of printed characters. Reported-by: Han Pingtian <phan@redhat.com> Cc: Han Pingtian <phan@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1299528821-17521-2-git-send-email-jolsa@redhat.com> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/top.c30
1 files changed, 18 insertions, 12 deletions
diff --git a/tools/perf/util/top.c b/tools/perf/util/top.c
index 70a9c13f4ad5..4f869da4e9c7 100644
--- a/tools/perf/util/top.c
+++ b/tools/perf/util/top.c
@@ -61,6 +61,12 @@ static void rb_insert_active_sym(struct rb_root *tree, struct sym_entry *se)
rb_insert_color(&se->rb_node, tree);
}
+#define SNPRINTF(buf, size, fmt, args...) \
+({ \
+ size_t r = snprintf(buf, size, fmt, ## args); \
+ r > size ? size : r; \
+})
+
size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size)
{
struct perf_evsel *counter;
@@ -70,7 +76,7 @@ size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size)
size_t ret = 0;
if (!perf_guest) {
- ret = snprintf(bf, size,
+ ret = SNPRINTF(bf, size,
" PerfTop:%8.0f irqs/sec kernel:%4.1f%%"
" exact: %4.1f%% [", samples_per_sec,
100.0 - (100.0 * ((samples_per_sec - ksamples_per_sec) /
@@ -81,7 +87,7 @@ size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size)
float guest_kernel_samples_per_sec = top->guest_kernel_samples / top->delay_secs;
float guest_us_samples_per_sec = top->guest_us_samples / top->delay_secs;
- ret = snprintf(bf, size,
+ ret = SNPRINTF(bf, size,
" PerfTop:%8.0f irqs/sec kernel:%4.1f%% us:%4.1f%%"
" guest kernel:%4.1f%% guest us:%4.1f%%"
" exact: %4.1f%% [", samples_per_sec,
@@ -101,38 +107,38 @@ size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size)
if (top->evlist->nr_entries == 1 || !top->display_weighted) {
struct perf_evsel *first;
first = list_entry(top->evlist->entries.next, struct perf_evsel, node);
- ret += snprintf(bf + ret, size - ret, "%" PRIu64 "%s ",
+ ret += SNPRINTF(bf + ret, size - ret, "%" PRIu64 "%s ",
(uint64_t)first->attr.sample_period,
top->freq ? "Hz" : "");
}
if (!top->display_weighted) {
- ret += snprintf(bf + ret, size - ret, "%s",
+ ret += SNPRINTF(bf + ret, size - ret, "%s",
event_name(top->sym_evsel));
} else list_for_each_entry(counter, &top->evlist->entries, node) {
- ret += snprintf(bf + ret, size - ret, "%s%s",
+ ret += SNPRINTF(bf + ret, size - ret, "%s%s",
counter->idx ? "/" : "", event_name(counter));
}
- ret += snprintf(bf + ret, size - ret, "], ");
+ ret += SNPRINTF(bf + ret, size - ret, "], ");
if (top->target_pid != -1)
- ret += snprintf(bf + ret, size - ret, " (target_pid: %d",
+ ret += SNPRINTF(bf + ret, size - ret, " (target_pid: %d",
top->target_pid);
else if (top->target_tid != -1)
- ret += snprintf(bf + ret, size - ret, " (target_tid: %d",
+ ret += SNPRINTF(bf + ret, size - ret, " (target_tid: %d",
top->target_tid);
else
- ret += snprintf(bf + ret, size - ret, " (all");
+ ret += SNPRINTF(bf + ret, size - ret, " (all");
if (top->cpu_list)
- ret += snprintf(bf + ret, size - ret, ", CPU%s: %s)",
+ ret += SNPRINTF(bf + ret, size - ret, ", CPU%s: %s)",
top->evlist->cpus->nr > 1 ? "s" : "", top->cpu_list);
else {
if (top->target_tid != -1)
- ret += snprintf(bf + ret, size - ret, ")");
+ ret += SNPRINTF(bf + ret, size - ret, ")");
else
- ret += snprintf(bf + ret, size - ret, ", %d CPU%s)",
+ ret += SNPRINTF(bf + ret, size - ret, ", %d CPU%s)",
top->evlist->cpus->nr,
top->evlist->cpus->nr > 1 ? "s" : "");
}

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