Recently two patches [1] [2] have hit a case of mistakenly picking
an IOCTL number which was already in-use. This is hard to debug
because the last definition wins and there is no indication that
there is a conflict.
Fix this by enabling -Werror=override-init for the IOCTL table.
When there is a duplicate entry, the compiler now errors out:
CC [M] drivers/gpu/drm/drm_ioctl.o
drivers/gpu/drm/drm_ioctl.c:555:33: error: initialized field overwritten
[-Werror=override-init]
555 | [DRM_IOCTL_NR(ioctl)] = { \
| ^
drivers/gpu/drm/drm_ioctl.c:708:9: note: in expansion of macro
‘DRM_IOCTL_DEF’
708 | DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_EVENTFD,
drm_syncobj_reset_ioctl,
| ^~~~~~~~~~~~~
drivers/gpu/drm/drm_ioctl.c:555:33: note: (near initialization for
‘drm_ioctls[207]’)
555 | [DRM_IOCTL_NR(ioctl)] = { \
| ^
drivers/gpu/drm/drm_ioctl.c:708:9: note: in expansion of macro
‘DRM_IOCTL_DEF’
708 | DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_EVENTFD,
drm_syncobj_reset_ioctl,
| ^~~~~~~~~~~~~
cc1: some warnings being treated as errors
[1]:
https://lore.kernel.org/dri-devel/[email protected]/
[2]:
https://lore.kernel.org/dri-devel/vVFDBgHpdcB0vOwnl02QPOFmAZPEbIV56E_wQ8B012K2GZ-fAGyG0JMbSrMu3-IcKYVf0JpJyrf71e6KFHfeMoSPJlYRACxlxy91eW9c6Fc=@emersion.fr/
Signed-off-by: Simon Ser <[email protected]>
Cc: Erik Kurzinger <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Cc: Christian König <[email protected]>
---
drivers/gpu/drm/drm_ioctl.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index f03ffbacfe9b..cd485eb54d2a 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -566,6 +566,8 @@ static int drm_ioctl_permit(u32 flags, struct drm_file
*file_priv)
#endif
/* Ioctl table */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic error "-Woverride-init"
static const struct drm_ioctl_desc drm_ioctls[] = {
DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
@@ -718,6 +720,7 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl,
DRM_MASTER),
DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl,
DRM_MASTER),
};
+#pragma GCC diagnostic pop
#define DRM_CORE_IOCTL_COUNT ARRAY_SIZE(drm_ioctls)
--
2.41.0
