Re: [Intel-gfx] [PATCH i-g-t] intel_gpu_top: Fix cleanup on old kernels / unsupported GPU

[Das, Nirmoy]

On 1/19/2023 4:54 PM, Tvrtko Ursulin wrote:

From: Tvrtko Ursulin <tvrtko.ursu...@intel.com>

Avoid trying to dereference null engines on exit when there are either
none which are supported, or kernel does not have i915 PMU support.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursu...@intel.com>

Acked-by: Nirmoy Das <nirmoy....@intel.com>

---
  tools/intel_gpu_top.c | 10 +++++++---
  1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/intel_gpu_top.c b/tools/intel_gpu_top.c
index 7aa233570463..517dc2995d26 100644
--- a/tools/intel_gpu_top.c
+++ b/tools/intel_gpu_top.c
@@ -448,6 +448,9 @@ static void free_engines(struct engines *engines)
        };
        unsigned int i;

+ if (!engines)

+               return;
+
        for (pmu = &free_list[0]; *pmu; pmu++) {
                if ((*pmu)->present)
                        free((char *)(*pmu)->units);
@@ -2568,7 +2571,7 @@ int main(int argc, char **argv)
                        "Failed to detect engines! (%s)\n(Kernel 4.16 or newer is 
required for i915 PMU support.)\n",
                        strerror(errno));
                ret = EXIT_FAILURE;
-               goto err;
+               goto err_engines;
        }

ret = pmu_init(engines);

@@ -2585,7 +2588,7 @@ int main(int argc, char **argv)
  "More information can be found at 'Perf events and tool security' document:\n"
  "https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html\n";);
                ret = EXIT_FAILURE;
-               goto err;
+               goto err_pmu;
        }

ret = EXIT_SUCCESS;

@@ -2699,8 +2702,9 @@ int main(int argc, char **argv)
                free_clients(clients);

free(codename);

-err:
+err_pmu:
        free_engines(engines);
+err_engines:
        free(pmu_device);
  exit:
        igt_devices_free();