I was hitting kCFI crashes when building with clang, and after
some digging finally narrowed it down to the
dsi_mgr_connector_mode_valid() function being implemented as
returning an int, instead of an enum drm_mode_status.
This patch fixes it, and appeases the opaque word of the kCFI
gods (seriously, clang inlining everything makes the kCFI
backtraces only really rough estimates of where things went
wrong).
Thanks as always to Sami for his help narrowing this down.
Cc: Rob Clark <[email protected]>
Cc: Sean Paul <[email protected]>
Cc: Sami Tolvanen <[email protected]>
Cc: Todd Kjos <[email protected]>
Cc: Alistair Delva <[email protected]>
Cc: Amit Pundir <[email protected]>
Cc: Sumit Semwal <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: John Stultz <[email protected]>
---
drivers/gpu/drm/msm/dsi/dsi_manager.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
index 271aa7bbca925..355a60b4a536f 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
@@ -336,7 +336,7 @@ static int dsi_mgr_connector_get_modes(struct drm_connector *connector)
return num;
}
-static int dsi_mgr_connector_mode_valid(struct drm_connector *connector,
+static enum drm_mode_status dsi_mgr_connector_mode_valid(struct drm_connector *connector,
struct drm_display_mode *mode)
{
int id = dsi_mgr_connector_get_id(connector);
--
2.17.1
On Wed, Jan 29, 2020 at 12:12 PM John Stultz <[email protected]> wrote:
>
> I was hitting kCFI crashes when building with clang, and after
> some digging finally narrowed it down to the
> dsi_mgr_connector_mode_valid() function being implemented as
> returning an int, instead of an enum drm_mode_status.
>
> This patch fixes it, and appeases the opaque word of the kCFI
> gods (seriously, clang inlining everything makes the kCFI
> backtraces only really rough estimates of where things went
> wrong).
>
> Thanks as always to Sami for his help narrowing this down.
>
> Cc: Rob Clark <[email protected]>
> Cc: Sean Paul <[email protected]>
> Cc: Sami Tolvanen <[email protected]>
> Cc: Todd Kjos <[email protected]>
> Cc: Alistair Delva <[email protected]>
> Cc: Amit Pundir <[email protected]>
> Cc: Sumit Semwal <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: John Stultz <[email protected]>
John, thanks for fixing this. Our inliner is a point of pride
(inlining indirect function calls; you're welcome). ;)
Indeed, the function pointer member `mode_valid` in `struct
drm_connector_helper_funcs` in
include/drm/drm_modeset_helper_vtables.h returns an `enum
drm_mode_status`.
Reviewed-by: Nick Desaulniers <[email protected]>
> ---
> drivers/gpu/drm/msm/dsi/dsi_manager.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> index 271aa7bbca925..355a60b4a536f 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> @@ -336,7 +336,7 @@ static int dsi_mgr_connector_get_modes(struct drm_connector *connector)
> return num;
> }
>
> -static int dsi_mgr_connector_mode_valid(struct drm_connector *connector,
> +static enum drm_mode_status dsi_mgr_connector_mode_valid(struct drm_connector *connector,
> struct drm_display_mode *mode)
> {
> int id = dsi_mgr_connector_get_id(connector);
> --
--
Thanks,
~Nick Desaulniers
On Thu, 30 Jan 2020 at 01:42, John Stultz <[email protected]> wrote:
>
> I was hitting kCFI crashes when building with clang, and after
> some digging finally narrowed it down to the
> dsi_mgr_connector_mode_valid() function being implemented as
> returning an int, instead of an enum drm_mode_status.
>
> This patch fixes it, and appeases the opaque word of the kCFI
> gods (seriously, clang inlining everything makes the kCFI
> backtraces only really rough estimates of where things went
> wrong).
>
> Thanks as always to Sami for his help narrowing this down.
>
> Cc: Rob Clark <[email protected]>
> Cc: Sean Paul <[email protected]>
> Cc: Sami Tolvanen <[email protected]>
> Cc: Todd Kjos <[email protected]>
> Cc: Alistair Delva <[email protected]>
> Cc: Amit Pundir <[email protected]>
> Cc: Sumit Semwal <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: John Stultz <[email protected]>
Tested-by: Amit Pundir <[email protected]>
Cc: [email protected] # v4.4+
> ---
> drivers/gpu/drm/msm/dsi/dsi_manager.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> index 271aa7bbca925..355a60b4a536f 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> @@ -336,7 +336,7 @@ static int dsi_mgr_connector_get_modes(struct drm_connector *connector)
> return num;
> }
>
> -static int dsi_mgr_connector_mode_valid(struct drm_connector *connector,
> +static enum drm_mode_status dsi_mgr_connector_mode_valid(struct drm_connector *connector,
> struct drm_display_mode *mode)
> {
> int id = dsi_mgr_connector_get_id(connector);
> --
> 2.17.1
>