Commit 06c2d9a0 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Thierry Reding
Browse files

firmware: tegra: Reduce stack usage 

Building the bpmp-debugfs driver for Arm results in a warning for stack usage:

drivers/firmware/tegra/bpmp-debugfs.c:321:16: error: stack frame size of 1224 bytes in function 'bpmp_debug_store' [-Werror,-Wframe-larger-than=]
static ssize_t bpmp_debug_store(struct file *file, const char __user *buf,

It should be possible to rearrange the code to not require two separate
buffers for the file name, but the easiest workaround is to use dynamic
allocation.

Fixes: 5e37b9c1 ("firmware: tegra: Add support for in-band debug")
Link: https://lore.kernel.org/all/20201204193714.3134651-1-arnd@kernel.org/


Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
[treding@nvidia.com: consistently return NULL on failure]
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent 6880fa6c

drivers/firmware/tegra/bpmp-debugfs.c

+17 −9
Original line number Diff line number Diff line
@@ -74,28 +74,36 @@ static void seqbuf_seek(struct seqbuf *seqbuf, ssize_t offset) 
static const char *get_filename(struct tegra_bpmp *bpmp,

				const struct file *file, char *buf, int size)

{

	char root_path_buf[512];

	const char *root_path;

	const char *filename;

	const char *root_path, *filename = NULL;

	char *root_path_buf;

	size_t root_len;



	root_path_buf = kzalloc(512, GFP_KERNEL);

	if (!root_path_buf)

		goto out;



	root_path = dentry_path(bpmp->debugfs_mirror, root_path_buf,

				sizeof(root_path_buf));

	if (IS_ERR(root_path))

		return NULL;

		goto out;



	root_len = strlen(root_path);



	filename = dentry_path(file->f_path.dentry, buf, size);

	if (IS_ERR(filename))

		return NULL;

	if (IS_ERR(filename)) {

		filename = NULL;

		goto out;

	}



	if (strlen(filename) < root_len ||

			strncmp(filename, root_path, root_len))

		return NULL;

	if (strlen(filename) < root_len || strncmp(filename, root_path, root_len)) {

		filename = NULL;

		goto out;

	}



	filename += root_len;



out:

	kfree(root_path_buf);

	return filename;

}