On Sun, Jun 19, 2016 at 02:31:29PM +0200, Mathias Krause wrote:
The callback function dma_buf_describe() returns an int not void so the function pointer cast in dma_buf_show() is wrong. dma_buf_describe() can also fail when acquiring the mutex gets interrupted so always returning 0 in dma_buf_show() is wrong, too.
Fix both issues by avoiding the indirection via dma_buf_show() and call dma_buf_describe() directly. Rename it to dma_buf_debug_show() to get it in line with the other functions.
This type mismatch was caught by the PaX RAP plugin.
Signed-off-by: Mathias Krause minipli@googlemail.com Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Brad Spengler spender@grsecurity.net Cc: PaX Team pageexec@freemail.hu
drivers/dma-buf/dma-buf.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 6355ab38d630..7094b19bb495 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -824,7 +824,7 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) EXPORT_SYMBOL_GPL(dma_buf_vunmap);
#ifdef CONFIG_DEBUG_FS -static int dma_buf_describe(struct seq_file *s) +static int dma_buf_debug_show(struct seq_file *s, void *unused) { int ret; struct dma_buf *buf_obj; @@ -879,17 +879,9 @@ static int dma_buf_describe(struct seq_file *s) return 0; }
-static int dma_buf_show(struct seq_file *s, void *unused) -{
- void (*func)(struct seq_file *) = s->private;
- func(s);
- return 0;
-}
static int dma_buf_debug_open(struct inode *inode, struct file *file) {
- return single_open(file, dma_buf_show, inode->i_private);
- return single_open(file, dma_buf_debug_show, NULL);
}
static const struct file_operations dma_buf_debug_fops = { @@ -913,7 +905,7 @@ static int dma_buf_init_debugfs(void) return err; }
- err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe);
- err = dma_buf_debugfs_create_file("bufinfo", NULL);
This indirection now doesn't make much sense I think. I think more sensible to instead pass drm_buf_debug_show, since that's the parametrization that matters. Or just inline that one too. -Daniel
if (err) pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); -- 1.7.10.4