[libgpiod][PATCH 1/2] gpiosim: get the process name using prctl()

[Bartosz Golaszewski <brgl@bgdev.pl>]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

program_invocation_short_name is set once at the program's start. If we
change the process name using prctl(), we need to retrieve it using the
same system call as program_invocation_short_name will not be updated.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 configure.ac            |  2 ++
 tests/gpiosim/gpiosim.c | 10 +++++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index dc945ef..07706f0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -85,10 +85,12 @@ AC_CHECK_FUNC([scandir], [], [FUNC_NOT_FOUND_LIB([scandir])])
 AC_CHECK_FUNC([alphasort], [], [FUNC_NOT_FOUND_LIB([alphasort])])
 AC_CHECK_FUNC([ppoll], [], [FUNC_NOT_FOUND_LIB([ppoll])])
 AC_CHECK_FUNC([realpath], [], [FUNC_NOT_FOUND_LIB([realpath])])
+AC_CHECK_FUNC([prctl], [], [FUNC_NOT_FOUND_LIB([prctl])])
 AC_CHECK_HEADERS([getopt.h], [], [HEADER_NOT_FOUND_LIB([getopt.h])])
 AC_CHECK_HEADERS([dirent.h], [], [HEADER_NOT_FOUND_LIB([dirent.h])])
 AC_CHECK_HEADERS([sys/poll.h], [], [HEADER_NOT_FOUND_LIB([sys/poll.h])])
 AC_CHECK_HEADERS([sys/sysmacros.h], [], [HEADER_NOT_FOUND_LIB([sys/sysmacros.h])])
+AC_CHECK_HEADERS([sys/prctl.h], [], [HEADER_NOT_FOUND_LIB([sys/prctl.h])])
 AC_CHECK_HEADERS([linux/version.h], [], [HEADER_NOT_FOUND_LIB([linux/version.h])])
 AC_CHECK_HEADERS([linux/const.h], [], [HEADER_NOT_FOUND_LIB([linux/const.h])])
 AC_CHECK_HEADERS([linux/ioctl.h], [], [HEADER_NOT_FOUND_LIB([linux/ioctl.h])])
diff --git a/tests/gpiosim/gpiosim.c b/tests/gpiosim/gpiosim.c
index 881ecc8..e2a97fa 100644
--- a/tests/gpiosim/gpiosim.c
+++ b/tests/gpiosim/gpiosim.c
@@ -12,6 +12,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mount.h>
+#include <sys/prctl.h>
 #include <sys/random.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -365,11 +366,14 @@ out_unref_kmod:
 
 static char *configfs_make_item(int at, int id)
 {
-	char *item_name;
+	char *item_name, prname[17];
 	int ret;
 
-	ret = asprintf(&item_name, "%s.%u.%d",
-		       program_invocation_short_name, getpid(), id);
+	ret = prctl(PR_GET_NAME, prname);
+	if (ret)
+		return NULL;
+
+	ret = asprintf(&item_name, "%s.%u.%d", prname, getpid(), id);
 	if (ret < 0)
 		return NULL;
 
-- 
2.37.2