On Mon, Mar 20, 2017 at 10:40:27AM +0100, Arnd Bergmann wrote:
A struct file is a bit too large to put on the kernel stack in general and triggers a warning for low settings of CONFIG_FRAME_WARN:
drivers/gpu/drm/i915/selftests/mock_drm.c: In function 'mock_file': drivers/gpu/drm/i915/selftests/mock_drm.c:46:1: error: the frame size of 1328 bytes is larger than 1280 bytes [-Werror=frame-larger-than=] drivers/gpu/drm/i915/selftests/mock_drm.c: In function 'mock_file_free': drivers/gpu/drm/i915/selftests/mock_drm.c:54:1: error: the frame size of 1312 bytes is larger than 1280 bytes [-Werror=frame-larger-than=]
It's also slightly dangerous to leave a reference to a stack object in the drm_file structure after leaving the stack frame. This changes the code to just allocate the object dynamically and release it when we are done with it.
Fixes: 66d9cb5d805a ("drm/i915: Mock the GEM device for self-testing") Signed-off-by: Arnd Bergmann arnd@arndb.de
drivers/gpu/drm/i915/selftests/mock_drm.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/selftests/mock_drm.c b/drivers/gpu/drm/i915/selftests/mock_drm.c index 113dec05c7dc..18514065c93d 100644 --- a/drivers/gpu/drm/i915/selftests/mock_drm.c +++ b/drivers/gpu/drm/i915/selftests/mock_drm.c @@ -32,15 +32,15 @@ static inline struct inode fake_inode(struct drm_i915_private *i915) struct drm_file *mock_file(struct drm_i915_private *i915) { struct inode inode = fake_inode(i915);
- struct file filp = {};
- struct file *filp = kzalloc(sizeof(struct file), GFP_KERNEL); struct drm_file *file; int err;
- err = drm_open(&inode, &filp);
- err = drm_open(&inode, filp);
Aside: We should have a FIXME and/or merge David Herrmanns code to allow a drm_file without a real struct file for kernel-internal use ... -Daniel
if (unlikely(err)) return ERR_PTR(err);
- file = filp.private_data;
- file = filp->private_data; file->authenticated = true; return file;
} @@ -48,7 +48,9 @@ struct drm_file *mock_file(struct drm_i915_private *i915) void mock_file_free(struct drm_i915_private *i915, struct drm_file *file) { struct inode inode = fake_inode(i915);
- struct file filp = { .private_data = file };
- struct file *filp = file->filp;
- drm_release(&inode, &filp);
- drm_release(&inode, filp);
- kfree(filp);
}
2.9.0
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