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perf report: Add validation of call-chain entries 

Add boundary checks for call-chain events. In case of corrupted
entries we could crash otherwise.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
hifive-unleashed-5.1
Ingo Molnar 2009-06-18 08:00:17 +02:00
parent b25bcf2f13
commit 7522060c95
2 changed files with 56 additions and 38 deletions
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20
include/linux/perf_counter.h
View File

@ -337,6 +337,16 @@ enum perf_event_type {
*/
};
#define MAX_STACK_DEPTH 255
struct perf_callchain_entry {
__u16 nr;
__u16 hv;
__u16 kernel;
__u16 user;
__u64 ip[MAX_STACK_DEPTH];
};
#ifdef __KERNEL__
/*
* Kernel-internal data types and definitions:
@ -652,16 +662,6 @@ extern void perf_counter_fork(struct task_struct *tsk);
extern void perf_counter_task_migration(struct task_struct *task, int cpu);
#define MAX_STACK_DEPTH 255
struct perf_callchain_entry {
u16 nr;
u16 hv;
u16 kernel;
u16 user;
u64 ip[MAX_STACK_DEPTH];
};
extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
extern int sysctl_perf_counter_paranoid;

74
tools/perf/builtin-report.c
View File

@ -39,6 +39,8 @@ static int dump_trace = 0;
#define cdprintf(x...) do { if (dump_trace) color_fprintf(stdout, color, x); } while (0)
static int verbose;
#define eprintf(x...) do { if (verbose) fprintf(stderr, x); } while (0)
static int full_paths;
static unsigned long page_size;
@ -47,14 +49,6 @@ static unsigned long mmap_window = 32;
static char *parent_pattern = "^sys_|^do_page_fault";
static regex_t parent_regex;
struct ip_chain_event {
__u16 nr;
__u16 hv;
__u16 kernel;
__u16 user;
__u64 ips[];
};
struct ip_event {
struct perf_event_header header;
__u64 ip;
@ -131,15 +125,11 @@ static struct dso *dsos__findnew(const char *name)
nr = dso__load(dso, NULL, verbose);
if (nr < 0) {
if (verbose)
fprintf(stderr, "Failed to open: %s\n", name);
eprintf("Failed to open: %s\n", name);
goto out_delete_dso;
}
if (!nr && verbose) {
fprintf(stderr,
"No symbols found in: %s, maybe install a debug package?\n",
name);
}
if (!nr)
eprintf("No symbols found in: %s, maybe install a debug package?\n", name);
dsos__add(dso);
@ -844,7 +834,7 @@ static struct symbol *call__match(struct symbol *sym)
static int
hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
struct symbol *sym, __u64 ip, struct ip_chain_event *chain,
struct symbol *sym, __u64 ip, struct perf_callchain_entry *chain,
char level, __u64 count)
{
struct rb_node **p = &hist.rb_node;
@ -868,7 +858,7 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
__u64 ip;
for (i = 0; i < chain->kernel; i++) {
ip = chain->ips[nr + i];
ip = chain->ip[nr + i];
dso = kernel_dso;
sym = resolve_symbol(thread, NULL, &dso, &ip);
entry.parent = call__match(sym);
@ -878,7 +868,7 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
nr += i;
for (i = 0; i < chain->user; i++) {
ip = chain->ips[nr + i];
ip = chain->ip[nr + i];
sym = resolve_symbol(thread, NULL, NULL, &ip);
entry.parent = call__match(sym);
if (entry.parent)
@ -1080,6 +1070,30 @@ static unsigned long total = 0,
total_fork = 0,
total_unknown = 0;
static int validate_chain(struct perf_callchain_entry *chain, event_t *event)
{
unsigned int chain_size;
if (chain->nr > MAX_STACK_DEPTH)
return -1;
if (chain->hv > MAX_STACK_DEPTH)
return -1;
if (chain->kernel > MAX_STACK_DEPTH)
return -1;
if (chain->user > MAX_STACK_DEPTH)
return -1;
if (chain->hv + chain->kernel + chain->user != chain->nr)
return -1;
chain_size = event->header.size;
chain_size -= (unsigned long)&event->ip.__more_data - (unsigned long)event;
if (chain->nr*sizeof(__u64) > chain_size)
return -1;
return 0;
}
static int
process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
{
@ -1091,7 +1105,7 @@ process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
__u64 period = 1;
struct map *map = NULL;
void *more_data = event->ip.__more_data;
struct ip_chain_event *chain = NULL;
struct perf_callchain_entry *chain = NULL;
if (event->header.type & PERF_SAMPLE_PERIOD) {
period = *(__u64 *)more_data;
@ -1111,21 +1125,26 @@ process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
chain = (void *)more_data;
if (dump_trace) {
dprintf("... chain: u:%d, k:%d, nr:%d\n",
chain->user,
chain->kernel,
chain->nr);
dprintf("... chain: u:%d, k:%d, nr:%d\n",
chain->user,
chain->kernel,
chain->nr);
if (validate_chain(chain, event) < 0) {
eprintf("call-chain problem with event, skipping it.\n");
return 0;
}
if (dump_trace) {
for (i = 0; i < chain->nr; i++)
dprintf("..... %2d: %016Lx\n", i, chain->ips[i]);
dprintf("..... %2d: %016Lx\n", i, chain->ip[i]);
}
}
dprintf(" ... thread: %s:%d\n", thread->comm, thread->pid);
if (thread == NULL) {
fprintf(stderr, "problem processing %d event, skipping it.\n",
eprintf("problem processing %d event, skipping it.\n",
event->header.type);
return -1;
}
@ -1153,8 +1172,7 @@ process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
struct symbol *sym = resolve_symbol(thread, &map, &dso, &ip);
if (hist_entry__add(thread, map, dso, sym, ip, chain, level, period)) {
fprintf(stderr,
"problem incrementing symbol count, skipping event\n");
eprintf("problem incrementing symbol count, skipping event\n");
return -1;
}
}