Re: [PATCH] selftests/memfd:Fix a resource leak

From: Shuah Khan
Date: Wed Jul 10 2024 - 12:08:45 EST


On 7/10/24 01:33, Zhu Jun wrote:
From a good programming practice perspective, especially in more
complex programs, explicitly freeing allocated memory is a good habit.


The change looks good to me, however can you elaborate more on what
kind of leak your fixing here?

Signed-off-by: Zhu Jun <zhujun2@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/memfd/memfd_test.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c
index 95af2d78fd31..f842a4aeb47d 100644
--- a/tools/testing/selftests/memfd/memfd_test.c
+++ b/tools/testing/selftests/memfd/memfd_test.c
@@ -661,9 +661,11 @@ static void mfd_assert_grow_write(int fd)
l = pwrite(fd, buf, mfd_def_size * 8, 0);
if (l != (mfd_def_size * 8)) {
printf("pwrite() failed: %m\n");
+ free(buf);
abort();
}
+ free(buf);
mfd_assert_size(fd, mfd_def_size * 8);
}
@@ -685,8 +687,11 @@ static void mfd_fail_grow_write(int fd)
l = pwrite(fd, buf, mfd_def_size * 8, 0);
if (l == (mfd_def_size * 8)) {
printf("pwrite() didn't fail as expected\n");
+ free(buf);
abort();
}
+
+ free(buf);
}
static void mfd_assert_mode(int fd, int mode)
@@ -771,9 +776,11 @@ static pid_t spawn_thread(unsigned int flags, int (*fn)(void *), void *arg)
pid = clone(fn, stack + STACK_SIZE, SIGCHLD | flags, arg);
if (pid < 0) {
printf("clone() failed: %m\n");
+ free(stack);
abort();
}
+ free(stack);
return pid;
}

thanks,
-- Shuah