From: Tao Ma Date: Thu, 26 May 2011 19:11:07 +0000 (+0200) Subject: blkparse: Avoid segfault for wrong cpu number. X-Git-Tag: blktrace-1.0.3~2^2~1 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=13d4859277102703a7ba1d64c2f5f8560eea5568;p=blktrace.git blkparse: Avoid segfault for wrong cpu number. Currently we only check the magic number to see whether a blktrace is valid or not, but Bill Broadley did meet with a case that the cpu info is wrong with a number of 1725552676. So in resize_cpu_info, we meet with a overflow when calculating size = new_count * sizeof(struct per_cpu_info); And the program will be either segfault or has the error of out of memory. Although this is more likely a kernel problem, the blkparse shoudn't segfault for it. So this patch just check whether the cpu stored in the trace is the same as the file, if not, just warn it out and skip it. Cc: Jens Axboe Reported-by: Bill Broadley Signed-off-by: Tao Ma Signed-off-by: Jens Axboe --- diff --git a/blkparse.c b/blkparse.c index 7ee9f9d..817cb31 100644 --- a/blkparse.c +++ b/blkparse.c @@ -2354,6 +2354,12 @@ static int ms_prime(struct ms_stream *msp) if (verify_trace(bit)) goto err; + if (bit->cpu != pci->cpu) { + fprintf(stderr, "cpu %d trace info has error cpu %d\n", + pci->cpu, bit->cpu); + continue; + } + if (bit->action & BLK_TC_ACT(BLK_TC_NOTIFY) && bit->action != BLK_TN_MESSAGE) { handle_notify(bit); output_binary(bit, sizeof(*bit) + bit->pdu_len);