[PATCH 2/2] drm/mgag200: Fix driver_load error handling

From: Archit Taneja
Date: Thu Sep 17 2015 - 07:01:16 EST


mgag200_driver_load's error path just calls the drm driver's
driver_unload op. It isn't safe to call this because it doesn't handle
things well if driver_load fails somewhere mid way.

Replace the call to mgag200_driver_unload with a more finegrained
error handling path.

Link: http://lkml.kernel.org/r/55F6E68D.8070800@xxxxxxxxxxxxxx
Reported-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Dave Airlie <airlied@xxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: dri-devel <dri-devel@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Archit Taneja <architt@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/mgag200/mgag200_main.c | 36 +++++++++++++++++++---------------
1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/mgag200/mgag200_main.c b/drivers/gpu/drm/mgag200/mgag200_main.c
index de06388..b1a0f56 100644
--- a/drivers/gpu/drm/mgag200/mgag200_main.c
+++ b/drivers/gpu/drm/mgag200/mgag200_main.c
@@ -220,7 +220,7 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
}
r = mgag200_mm_init(mdev);
if (r)
- goto out;
+ goto err_mm;

drm_mode_config_init(dev);
dev->mode_config.funcs = (void *)&mga_mode_funcs;
@@ -233,7 +233,7 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
r = mgag200_modeset_init(mdev);
if (r) {
dev_err(&dev->pdev->dev, "Fatal error during modeset init: %d\n", r);
- goto out;
+ goto err_modeset;
}

/* Make small buffers to store a hardware cursor (double buffered icon updates) */
@@ -241,20 +241,24 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
&mdev->cursor.pixels_1);
mgag200_bo_create(dev, roundup(48*64, PAGE_SIZE), 0, 0,
&mdev->cursor.pixels_2);
- if (!mdev->cursor.pixels_2 || !mdev->cursor.pixels_1)
- goto cursor_nospace;
- mdev->cursor.pixels_current = mdev->cursor.pixels_1;
- mdev->cursor.pixels_prev = mdev->cursor.pixels_2;
- goto cursor_done;
- cursor_nospace:
- mdev->cursor.pixels_1 = NULL;
- mdev->cursor.pixels_2 = NULL;
- dev_warn(&dev->pdev->dev, "Could not allocate space for cursors. Not doing hardware cursors.\n");
- cursor_done:
-
-out:
- if (r)
- mgag200_driver_unload(dev);
+ if (!mdev->cursor.pixels_2 || !mdev->cursor.pixels_1) {
+ mdev->cursor.pixels_1 = NULL;
+ mdev->cursor.pixels_2 = NULL;
+ dev_warn(&dev->pdev->dev,
+ "Could not allocate space for cursors. Not doing hardware cursors.\n");
+ } else {
+ mdev->cursor.pixels_current = mdev->cursor.pixels_1;
+ mdev->cursor.pixels_prev = mdev->cursor.pixels_2;
+ }
+
+ return 0;
+
+err_modeset:
+ drm_mode_config_cleanup(dev);
+ mgag200_mm_fini(mdev);
+err_mm:
+ dev->dev_private = NULL;
+
return r;
}

--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/