Hi Javier,
On Tue, May 03, 2022 at 06:46:16PM +0200, Javier Martinez Canillas wrote:
A reference to the framebuffer device struct fb_info is stored in the file private data, but this reference could no longer be valid and must not be accessed directly. Instead, the file_fb_info() accessor function must be used since it does sanity checking to make sure that the fb_info is valid.
This can happen for example if the registered framebuffer device is for a driver that just uses a framebuffer provided by the system firmware. In that case, the fbdev core would unregister the framebuffer device when a real video driver is probed and ask to remove conflicting framebuffers.
Most fbdev file operations already use the helper to get the fb_info but get_fb_unmapped_area() and fb_deferred_io_fsync() don't. Fix those two.
Since fb_deferred_io_fsync() is not in fbmem.o, the helper has to be exported. Rename it and add a fb_ prefix to denote that is public now.
Reported-by: Junxiao Chang junxiao.chang@intel.com Signed-off-by: Javier Martinez Canillas javierm@redhat.com
drivers/video/fbdev/core/fb_defio.c | 5 ++++- drivers/video/fbdev/core/fbmem.c | 24 +++++++++++++++--------- include/linux/fb.h | 1 + 3 files changed, 20 insertions(+), 10 deletions(-)
diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c index 842c66b3e33d..ac1c88b3fbb5 100644 --- a/drivers/video/fbdev/core/fb_defio.c +++ b/drivers/video/fbdev/core/fb_defio.c @@ -68,12 +68,15 @@ static vm_fault_t fb_deferred_io_fault(struct vm_fault *vmf)
int fb_deferred_io_fsync(struct file *file, loff_t start, loff_t end, int datasync) {
- struct fb_info *info = file->private_data;
- struct fb_info *info = fb_file_fb_info(file->private_data);
This looks wrong. I assume you wanted to write:
- struct fb_info *info = fb_file_fb_info(file);
Sam