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perf tools: Fix buffer overflow error when specifying all tracepoints 

I found when specifying all tracepoints with -e to one of subcommand,
such as 'stat', the program will trigger a buffer overflow error, like
this:

*** buffer overflow detected ***: ./perf terminated
======= Backtrace: =========
/lib64/libc.so.6(__fortify_fail+0x37)[0x382cefb2c7]
....

The tracepoints are separated by comma, something like this:

$ perf stat -a -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}'`

The root reason of this problem is that store_event_type() is called for all
events, and will overflow the 'filename' at:

    strncat(filename, orgname, strlen(orgname));

This patch fixes it by calling store_event_type() only when the event name has
been found.

LKML-Reference: <20110106093922.GB6713@hpt.nay.redhat.com>
Signed-off-by: Han Pingtian <phan@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Han Pingtian 2011-01-06 17:39:22 +08:00 committed by Arnaldo Carvalho de Melo
parent 4b95f135f6
commit f006d25a15
1 changed files with 30 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
tools/perf/util/parse-events.c
View File

@ -490,6 +490,31 @@ parse_multiple_tracepoint_event(char *sys_name, const char *evt_exp,
return EVT_HANDLED_ALL;
}
static int store_event_type(const char *orgname)
{
char filename[PATH_MAX], *c;
FILE *file;
int id, n;
sprintf(filename, "%s/", debugfs_path);
strncat(filename, orgname, strlen(orgname));
strcat(filename, "/id");
c = strchr(filename, ':');
if (c)
*c = '/';
file = fopen(filename, "r");
if (!file)
return 0;
n = fscanf(file, "%i", &id);
fclose(file);
if (n < 1) {
pr_err("cannot store event ID\n");
return -EINVAL;
}
return perf_header__push_event(id, orgname);
}
static enum event_result parse_tracepoint_event(const char **strp,
struct perf_event_attr *attr)
@ -533,9 +558,13 @@ static enum event_result parse_tracepoint_event(const char **strp,
*strp += strlen(sys_name) + evt_length;
return parse_multiple_tracepoint_event(sys_name, evt_name,
flags);
} else
} else {
if (store_event_type(evt_name) < 0)
return EVT_FAILED;
return parse_single_tracepoint_event(sys_name, evt_name,
evt_length, attr, strp);
}
}
static enum event_result
@ -778,41 +807,11 @@ modifier:
return ret;
}
static int store_event_type(const char *orgname)
{
char filename[PATH_MAX], *c;
FILE *file;
int id, n;
sprintf(filename, "%s/", debugfs_path);
strncat(filename, orgname, strlen(orgname));
strcat(filename, "/id");
c = strchr(filename, ':');
if (c)
*c = '/';
file = fopen(filename, "r");
if (!file)
return 0;
n = fscanf(file, "%i", &id);
fclose(file);
if (n < 1) {
pr_err("cannot store event ID\n");
return -EINVAL;
}
return perf_header__push_event(id, orgname);
}
int parse_events(const struct option *opt __used, const char *str, int unset __used)
{
struct perf_event_attr attr;
enum event_result ret;
if (strchr(str, ':'))
if (store_event_type(str) < 0)
return -1;
for (;;) {
memset(&attr, 0, sizeof(attr));
ret = parse_event_symbols(&str, &attr);