| Message ID | 20191011113047.11089-1-tz.stoyanov@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/3] trace-cmd: Fix segmentation fault in tracecmd_read_at() in specific use case | expand |
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c index 60ee2f7..1ae2ab5 100644 --- a/lib/trace-cmd/trace-input.c +++ b/lib/trace-cmd/trace-input.c @@ -1345,7 +1345,8 @@ tracecmd_read_at(struct tracecmd_input *handle, unsigned long long offset, /* check to see if we have this page already */ for (cpu = 0; cpu < handle->cpus; cpu++) { if (handle->cpu_data[cpu].offset == page_offset && - handle->cpu_data[cpu].file_size) + handle->cpu_data[cpu].file_size && + handle->cpu_data[cpu].page) break; }
There is a segmentation fault in update_page_info() when the requested page is not loaded, handle->cpu_data[cpu].page is NULL. The problematic flow starts from tracecmd_read_at() API, when reading offset in the first page (less than 4K), and this page is still not loaded. The problem can be observed randomly - there is a sporadic KernelShark crash when loading a file, browsing and zooming events. https://bugzilla.kernel.org/show_bug.cgi?id=205165 Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> --- lib/trace-cmd/trace-input.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)