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perf_counter tools: fix infinite loop in perf-report on zeroed event records

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Bail out early if a record has zero size - we have no chance to make
reliable progress in that case. Print out the offset where this happens,
and print the number of bytes we missed out on.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar 2009-04-30 14:14:37 +02:00
parent 66cf782996
commit bad760089c
1 changed files with 16 additions and 2 deletions
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18
Documentation/perf_counter/perf-report.cc
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@ -13,6 +13,7 @@
#include <ctype.h>
#include <time.h>
#include <getopt.h>
#include <assert.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
@ -226,7 +227,7 @@ void load_kallsyms(void)
while (!feof(file)) {
uint64_t start;
char c;
char sym[1024];
char sym[1024000];
if (getline(&line, &n, file) < 0)
break;
@ -416,12 +417,23 @@ more:
if (head + event->header.size >= page_size * mmap_window) {
unsigned long shift = page_size * (head / page_size);
int ret;
ret = munmap(buf, page_size * mmap_window);
assert(ret == 0);
munmap(buf, page_size * mmap_window);
offset += shift;
head -= shift;
goto remap;
}
if (!event->header.size) {
fprintf(stderr, "zero-sized event at file offset %ld\n", offset + head);
fprintf(stderr, "skipping %ld bytes of events.\n", stat.st_size - offset - head);
goto done;
}
head += event->header.size;
if (event->header.misc & PERF_EVENT_MISC_OVERFLOW) {
@ -458,6 +470,8 @@ more:
if (offset + head < stat.st_size)
goto more;
done:
close(input);
std::map<std::string, int>::iterator hi = hist.begin();