pidfd: fix selftest compilation by removing linux/wait.h

Commit Message

Christian Kellner Oct. 11, 2019, 4:38 p.m. UTC

From: Christian Kellner <[e-mail]>

The pidfd_{open,poll}_test.c files both include `linux/wait.h` and
later `sys/wait.h`. The former has `#define P_ALL 0`, but in the
latter P_ALL is part of idtype_t enum, where it gets substituted
due to the aforementioned define to be `0`, which then results in
`typedef enum {0, ...`, which then results into a compiler error:
"error: expected identifier before numeric constant".
Since we need `sys/wait.h` for waitpid, drop `linux/wait.h`.

Signed-off-by: Christian Kellner <[e-mail]>
---
 tools/testing/selftests/pidfd/pidfd_open_test.c | 1 -
 tools/testing/selftests/pidfd/pidfd_poll_test.c | 1 -
 2 files changed, 2 deletions(-)

Comments

Christian Brauner Oct. 15, 2019, 2:28 p.m. UTC | #1

On Fri, Oct 11, 2019 at 06:38:11PM +0200, Christian Kellner wrote:
> From: Christian Kellner <[e-mail]>
> 
> The pidfd_{open,poll}_test.c files both include `linux/wait.h` and
> later `sys/wait.h`. The former has `#define P_ALL 0`, but in the
> latter P_ALL is part of idtype_t enum, where it gets substituted
> due to the aforementioned define to be `0`, which then results in
> `typedef enum {0, ...`, which then results into a compiler error:
> "error: expected identifier before numeric constant".
> Since we need `sys/wait.h` for waitpid, drop `linux/wait.h`.
> 
> Signed-off-by: Christian Kellner <[e-mail]>

Sorry, I missed this patch.
This is problematic and your patch would only temporarily fix it.
If glibc adds a P_PIDFD to the enum we'll run into the same issue.
So please:
- remove the linux/wait.h header (as you've already done here)
- add a custom define for P_PIDFD under a different name, e.g.:
  #ifndef __P_PIDFD
  #define __P_PIDFD 3
  #endif
  and add a comment above it explaining the reason for this mess.


Thanks and (_ugh_)
Christian

Patch

diff --git a/tools/testing/selftests/pidfd/pidfd_open_test.c b/tools/testing/selftests/pidfd/pidfd_open_test.c
index b9fe75fc3e51..8a59438ccc78 100644
--- a/tools/testing/selftests/pidfd/pidfd_open_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_open_test.c
@@ -6,7 +6,6 @@ 
 #include <inttypes.h>
 #include <limits.h>
 #include <linux/types.h>
-#include <linux/wait.h>
 #include <sched.h>
 #include <signal.h>
 #include <stdbool.h>
diff --git a/tools/testing/selftests/pidfd/pidfd_poll_test.c b/tools/testing/selftests/pidfd/pidfd_poll_test.c
index 4b115444dfe9..610811275357 100644
--- a/tools/testing/selftests/pidfd/pidfd_poll_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_poll_test.c
@@ -3,7 +3,6 @@ 
 #define _GNU_SOURCE
 #include <errno.h>
 #include <linux/types.h>
-#include <linux/wait.h>
 #include <poll.h>
 #include <signal.h>
 #include <stdbool.h>