On Fri, Apr 4, 2025 at 9:22 PM Andrii Nakryiko andrii.nakryiko@gmail.com wrote:

On Sun, Mar 23, 2025 at 11:43 PM Malaya Kumar Rout malayarout91@gmail.com wrote:

...

Static Analyis for bench_htab_mem.c with cppcheck:error tools/testing/selftests/bpf/benchs/bench_htab_mem.c:284:3: error: Resource leak: fd [resourceLeak] tools/testing/selftests/bpf/prog_tests/sk_assign.c:41:3: error: Resource leak: tc [resourceLeak]

fix the issue by closing the file descriptor (fd & tc) when read & fgets operation fails.

Signed-off-by: Malaya Kumar Rout malayarout91@gmail.com

tools/testing/selftests/bpf/benchs/bench_htab_mem.c | 1 + tools/testing/selftests/bpf/prog_tests/sk_assign.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c index 926ee822143e..59746fd2c23a 100644 --- a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c +++ b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c @@ -281,6 +281,7 @@ static void htab_mem_read_mem_cgrp_file(const char *name, unsigned long *value) got = read(fd, buf, sizeof(buf) - 1);

It could be a bit cleaner to add close(fd) here and drop the one we have at the end of the function.

Here, close(fd) is now positioned within the error handling block, guaranteeing that the file descriptor will be closed prior to returning from the function in the event of a read error. Meanwhile, the final close(fd) at the end of the function is retained for successful execution, thereby avoiding any potential resource leaks. Hence, It is essential to add the close(fd) in both locations to prevent resource leakage.

pw-bot: cr

...

    if (got <= 0) {
            *value = 0;

•           close(fd);
            return;
    }
    buf[got] = 0;
  

diff --git a/tools/testing/selftests/bpf/prog_tests/sk_assign.c b/tools/testing/selftests/bpf/prog_tests/sk_assign.c index 0b9bd1d6f7cc..10a0ab954b8a 100644 --- a/tools/testing/selftests/bpf/prog_tests/sk_assign.c +++ b/tools/testing/selftests/bpf/prog_tests/sk_assign.c @@ -37,8 +37,10 @@ configure_stack(void) tc = popen("tc -V", "r"); if (CHECK_FAIL(!tc)) return false;

•   if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc)))
  

•   if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc))) {
  

•           pclose(tc);
  

this one looks good

...

            return false;

•   }
    if (strstr(tc_version, ", libbpf "))
            prog = "test_sk_assign_libbpf.bpf.o";
    else
  

-- 2.43.0

On Mon, Apr 7, 2025 at 7:07 AM Hou Tao houtao@huaweicloud.com wrote:

Hi,

On 4/5/2025 1:59 PM, malaya kumar rout wrote:

...

On Fri, Apr 4, 2025 at 9:22 PM Andrii Nakryiko andrii.nakryiko@gmail.com wrote:

...

On Sun, Mar 23, 2025 at 11:43 PM Malaya Kumar Rout malayarout91@gmail.com wrote:

...

Static Analyis for bench_htab_mem.c with cppcheck:error tools/testing/selftests/bpf/benchs/bench_htab_mem.c:284:3: error: Resource leak: fd [resourceLeak] tools/testing/selftests/bpf/prog_tests/sk_assign.c:41:3: error: Resource leak: tc [resourceLeak]

fix the issue by closing the file descriptor (fd & tc) when read & fgets operation fails.

Signed-off-by: Malaya Kumar Rout malayarout91@gmail.com

tools/testing/selftests/bpf/benchs/bench_htab_mem.c | 1 + tools/testing/selftests/bpf/prog_tests/sk_assign.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c index 926ee822143e..59746fd2c23a 100644 --- a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c +++ b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c @@ -281,6 +281,7 @@ static void htab_mem_read_mem_cgrp_file(const char *name, unsigned long *value) got = read(fd, buf, sizeof(buf) - 1);

It could be a bit cleaner to add close(fd) here and drop the one we have at the end of the function.

Here, close(fd) is now positioned within the error handling block, guaranteeing that the file descriptor will be closed prior to returning from the function in the event of a read error. Meanwhile, the final close(fd) at the end of the function is retained for successful execution, thereby avoiding any potential resource leaks. Hence, It is essential to add the close(fd) in both locations to prevent resource leakage.

I think Andrii was proposing the following solution:

{ /* ...... */ got = read(fd, buf, sizeof(buf) - 1); close(fd); if (got <= 0) { *value = 0; return; } buf[got] = 0;

    *value = strtoull(buf, NULL, 0);

}

It only invokes close(fd) once to handle both the failed case and the successful case.

...

I greatly appreciate your insightful feedback on the review. I will proceed to share the updated patch that includes the modifications.

...

...

pw-bot: cr

...

    if (got <= 0) {
            *value = 0;

•           close(fd);
            return;
    }
    buf[got] = 0;
  

diff --git a/tools/testing/selftests/bpf/prog_tests/sk_assign.c b/tools/testing/selftests/bpf/prog_tests/sk_assign.c index 0b9bd1d6f7cc..10a0ab954b8a 100644 --- a/tools/testing/selftests/bpf/prog_tests/sk_assign.c +++ b/tools/testing/selftests/bpf/prog_tests/sk_assign.c @@ -37,8 +37,10 @@ configure_stack(void) tc = popen("tc -V", "r"); if (CHECK_FAIL(!tc)) return false;

•   if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc)))
  

•   if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc))) {
  

•           pclose(tc);
  

this one looks good

...

            return false;

•   }
    if (strstr(tc_version, ", libbpf "))
            prog = "test_sk_assign_libbpf.bpf.o";
    else
  

-- 2.43.0

.

On 4/7/2025 6:01 PM, Malaya Kumar Rout wrote:

Static Analyis for bench_htab_mem.c with cppcheck:error tools/testing/selftests/bpf/benchs/bench_htab_mem.c:284:3: error: Resource leak: fd [resourceLeak] tools/testing/selftests/bpf/prog_tests/sk_assign.c:41:3: error: Resource leak: tc [resourceLeak]

fix the issue by closing the file descriptor (fd & tc) when read & fgets operation fails.

Signed-off-by: Malaya Kumar Rout malayarout91@gmail.com

Acked-by: Hou Tao houtao1@huawei.com

It will be better to resend the patch and change the subject prefix to "[PATCH RESEND bpf-next v2]" instead of "[PATCH v2]".

---

tools/testing/selftests/bpf/benchs/bench_htab_mem.c | 3 +-- tools/testing/selftests/bpf/prog_tests/sk_assign.c | 4 +++- 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c index 926ee822143e..297e32390cd1 100644 --- a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c +++ b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c @@ -279,6 +279,7 @@ static void htab_mem_read_mem_cgrp_file(const char *name, unsigned long *value) } got = read(fd, buf, sizeof(buf) - 1);

• close(fd); if (got <= 0) { *value = 0; return;

@@ -286,8 +287,6 @@ static void htab_mem_read_mem_cgrp_file(const char *name, unsigned long *value) buf[got] = 0; *value = strtoull(buf, NULL, 0);

• close(fd);

} static void htab_mem_measure(struct bench_res *res) diff --git a/tools/testing/selftests/bpf/prog_tests/sk_assign.c b/tools/testing/selftests/bpf/prog_tests/sk_assign.c index 0b9bd1d6f7cc..10a0ab954b8a 100644 --- a/tools/testing/selftests/bpf/prog_tests/sk_assign.c +++ b/tools/testing/selftests/bpf/prog_tests/sk_assign.c @@ -37,8 +37,10 @@ configure_stack(void) tc = popen("tc -V", "r"); if (CHECK_FAIL(!tc)) return false;

• if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc)))

• if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc))) {

• pclose(tc);
  

  return false;
• } if (strstr(tc_version, ", libbpf ")) prog = "test_sk_assign_libbpf.bpf.o"; else