diff mbox series

[v6,03/45] trace-cmd: Check if file version is supported

Message ID 20210614075029.598048-4-tz.stoyanov@gmail.com (mailing list archive)
State Accepted
Headers show
Series Add trace file compression | expand

Commit Message

Tzvetomir Stoyanov (VMware) June 14, 2021, 7:49 a.m. UTC 
When reading a trace file, version of the file is ignored. This could
case problems when bumping the version number because of changes in
in the structure of the file. The old code should detect unsupported
file version and should not try to read it.
A new trace-cmd library API is added to check if version is supported:
 tracecmd_is_version_supported()
Checks are added in the code to ensure not trying to read trace file
from unsupported version.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 lib/trace-cmd/include/private/trace-cmd-private.h |  2 ++
 lib/trace-cmd/trace-input.c                       | 10 ++++++++++
 lib/trace-cmd/trace-util.c                        |  7 +++++++
 tracecmd/trace-dump.c                             |  7 +++++++
 4 files changed, 26 insertions(+)

Comments

Steven Rostedt June 21, 2021, 10:27 p.m. UTC | #1 
On Mon, 14 Jun 2021 10:49:47 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:

> When reading a trace file, version of the file is ignored. This could
> case problems when bumping the version number because of changes in
> in the structure of the file. The old code should detect unsupported
> file version and should not try to read it.
> A new trace-cmd library API is added to check if version is supported:
>  tracecmd_is_version_supported()
> Checks are added in the code to ensure not trying to read trace file
> from unsupported version.

After applying this patch, I get:

$ ./tracecmd/trace-cmd report 
  error reading header for trace.dat

-- Steve
Steven Rostedt June 21, 2021, 10:36 p.m. UTC | #2 
On Mon, 21 Jun 2021 18:27:46 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> After applying this patch, I get:
> 
> $ ./tracecmd/trace-cmd report 
>   error reading header for trace.dat

Never mind, I tested on a leftover trace.dat that had version 7 already set!
So the patch did work :-)

-- Steve
diff mbox series

Patch

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index 49539432..6fc18938 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -42,6 +42,8 @@  void tracecmd_record_ref(struct tep_record *record);
 void tracecmd_set_debug(bool set_debug);
 bool tracecmd_get_debug(void);
 
+bool tracecmd_is_version_supported(unsigned int version);
+
 struct tracecmd_output;
 struct tracecmd_recorder;
 struct hook_list;
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 5ee69b14..97ad0a5d 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -131,6 +131,7 @@  struct tracecmd_input {
 	bool			use_trace_clock;
 	bool			read_page;
 	bool			use_pipe;
+	int			file_version;
 	struct cpu_data 	*cpu_data;
 	long long		ts_offset;
 	struct tsc2nsec		tsc_calc;
@@ -3269,6 +3270,7 @@  struct tracecmd_input *tracecmd_alloc_fd(int fd, int flags)
 	unsigned int page_size;
 	char *version;
 	char buf[BUFSIZ];
+	unsigned long ver;
 
 	handle = malloc(sizeof(*handle));
 	if (!handle)
@@ -3293,6 +3295,14 @@  struct tracecmd_input *tracecmd_alloc_fd(int fd, int flags)
 	if (!version)
 		goto failed_read;
 	tracecmd_info("version = %s\n", version);
+	ver = strtol(version, NULL, 10);
+	if (!ver && errno)
+		goto failed_read;
+	if (!tracecmd_is_version_supported(ver)) {
+		tracecmd_warning("Unsupported file version %lu", ver);
+		goto failed_read;
+	}
+	handle->file_version = ver;
 	free(version);
 
 	if (do_read_check(handle, buf, 1))
diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c
index b65f9dec..b0c98c72 100644
--- a/lib/trace-cmd/trace-util.c
+++ b/lib/trace-cmd/trace-util.c
@@ -617,3 +617,10 @@  unsigned long long tracecmd_generate_traceid(void)
 	free(str);
 	return hash;
 }
+
+bool tracecmd_is_version_supported(unsigned int version)
+{
+	if (version <= FILE_VERSION)
+		return true;
+	return false;
+}
diff --git a/tracecmd/trace-dump.c b/tracecmd/trace-dump.c
index 98425b98..03cc82b4 100644
--- a/tracecmd/trace-dump.c
+++ b/tracecmd/trace-dump.c
@@ -10,6 +10,7 @@ 
 #include <getopt.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <errno.h>
 
 #include "trace-local.h"
 
@@ -145,6 +146,7 @@  static void dump_initial_format(int fd)
 	char magic[] = TRACECMD_MAGIC;
 	char buf[DUMP_SIZE];
 	int val4;
+	unsigned long ver;
 
 	do_print(SUMMARY, "\t[Initial format]\n");
 
@@ -166,6 +168,11 @@  static void dump_initial_format(int fd)
 		die("no version string");
 
 	do_print(SUMMARY, "\t\t%s\t[Version]\n", buf);
+	ver = strtol(buf, NULL, 10);
+	if (!ver && errno)
+		die("Invalid file version string %s", buf);
+	if (!tracecmd_is_version_supported(ver))
+		die("Unsupported file version %lu", ver);
 
 	/* get file endianness*/
 	if (read_file_bytes(fd, buf, 1))