[PATCH 0/2] perf kvm/sched: Use strstarts instead of strncmp to match subcommands

[PATCH 0/2] perf kvm/sched: Use strstarts instead of strncmp to match subcommands

[Yang Jihong]

Yang Jihong (2):
  perf kvm: Fix subcommand matching error
  perf sched latency: Fix subcommand matching error

 tools/perf/builtin-kvm.c   | 8 ++++----
 tools/perf/builtin-sched.c | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

-- 
2.30.GIT

[PATCH 1/2] perf kvm: Fix subcommand matching error

[Yang Jihong]

Currently, diff, top, buildid-list and stat use strncmp to match subcommands.
As a result, matching does not meet expectation.

For example:
  # perf kvm diff1234
  # Event 'cycles'
  #
  # Baseline  Delta Abs  Shared Object  Symbol
  # ........  .........  .............  ......
  #

  # Event 'dummy:HG'
  #
  # Baseline  Delta Abs  Shared Object  Symbol
  # ........  .........  .............  ......
  #
  # echo $?
  0
  #

Invalid information should be returned, but success is actually returned.

Solution: Use strstarts to match subcommands.

After:
  # perf kvm diff1234

   Usage: perf kvm [<options>] {top|record|report|diff|buildid-list|stat}

      -i, --input <file>    Input file name
      -o, --output <file>   Output file name
      -v, --verbose         be more verbose (show counter open errors, etc)
          --guest           Collect guest os data
          --guest-code      Guest code can be found in hypervisor process
          --guestkallsyms <file>
                            file saving guest os /proc/kallsyms
          --guestmodules <file>
                            file saving guest os /proc/modules
          --guestmount <directory>
                            guest mount directory under which every guest os instance has a subdir
          --guestvmlinux <file>
                            file saving guest os vmlinux
          --host            Collect host os data

  # echo $?
  129
  #

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
---
 tools/perf/builtin-kvm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 3696ae97f149..7d9ec1bac1a2 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -1638,14 +1638,14 @@ int cmd_kvm(int argc, const char **argv)
 		return __cmd_record(file_name, argc, argv);
 	else if (strlen(argv[0]) > 2 && strstarts("report", argv[0]))
 		return __cmd_report(file_name, argc, argv);
-	else if (!strncmp(argv[0], "diff", 4))
+	else if (strlen(argv[0]) > 2 && strstarts("diff", argv[0]))
 		return cmd_diff(argc, argv);
-	else if (!strncmp(argv[0], "top", 3))
+	else if (!strcmp(argv[0], "top"))
 		return cmd_top(argc, argv);
-	else if (!strncmp(argv[0], "buildid-list", 12))
+	else if (strlen(argv[0]) > 2 && strstarts("buildid-list", argv[0]))
 		return __cmd_buildid_list(file_name, argc, argv);
 #ifdef HAVE_KVM_STAT_SUPPORT
-	else if (!strncmp(argv[0], "stat", 4))
+	else if (strlen(argv[0]) > 2 && strstarts("stat", argv[0]))
 		return kvm_cmd_stat(file_name, argc, argv);
 #endif
 	else
-- 
2.30.GIT

[PATCH 2/2] perf sched latency: Fix subcommand matching error

[Yang Jihong]

perf sched latency use strncmp to match subcommands which matching does not
meet expectation.

Before:

  # perf sched lat1234 >/dev/null
  # echo $?
  0
  #

Solution: Use strstarts to match subcommand.

After:

   # perf sched lat1234

   Usage: perf sched [<options>] {record|latency|map|replay|script|timehist}

      -D, --dump-raw-trace  dump raw trace in ASCII
      -f, --force           don't complain, do it
      -i, --input <file>    input file name
      -v, --verbose         be more verbose (show symbol address, etc)

  # echo $?
  129
  #
  # perf sched lat >/dev/null
  # echo $?
  0
  #

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
---
 tools/perf/builtin-sched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 646bd938927a..2f6cd1b8b662 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -3563,7 +3563,7 @@ int cmd_sched(int argc, const char **argv)
 
 	if (strlen(argv[0]) > 2 && strstarts("record", argv[0])) {
 		return __cmd_record(argc, argv);
-	} else if (!strncmp(argv[0], "lat", 3)) {
+	} else if (strlen(argv[0]) > 2 && strstarts("latency", argv[0])) {
 		sched.tp_handler = &lat_ops;
 		if (argc > 1) {
 			argc = parse_options(argc, argv, latency_options, latency_usage, 0);
-- 
2.30.GIT

Re: [PATCH 0/2] perf kvm/sched: Use strstarts instead of strncmp to match subcommands

[Namhyung Kim]

Hello,

On Mon, Aug 8, 2022 at 2:27 AM Yang Jihong <yangjihong1@huawei.com> wrote:
>
> Yang Jihong (2):
>   perf kvm: Fix subcommand matching error
>   perf sched latency: Fix subcommand matching error

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung


>
>  tools/perf/builtin-kvm.c   | 8 ++++----
>  tools/perf/builtin-sched.c | 2 +-
>  2 files changed, 5 insertions(+), 5 deletions(-)
>
> --
> 2.30.GIT
>

Re: [PATCH 0/2] perf kvm/sched: Use strstarts instead of strncmp to match subcommands

[Arnaldo Carvalho de Melo]

Em Mon, Aug 08, 2022 at 02:22:22PM -0700, Namhyung Kim escreveu:
> Hello,
> 
> On Mon, Aug 8, 2022 at 2:27 AM Yang Jihong <yangjihong1@huawei.com> wrote:
> >
> > Yang Jihong (2):
> >   perf kvm: Fix subcommand matching error
> >   perf sched latency: Fix subcommand matching error
> 
> Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks, applied.

- Arnaldo