UPSTREAM: 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.
Bug: 261962742
Fixes: 5e37b9c137ee ("firmware: tegra: Add support for in-band debug")
Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Arnd Bergmann <[email protected]>
[[email protected]: consistently return NULL on failure]
Signed-off-by: Thierry Reding <[email protected]>
(cherry picked from commit 06c2d9a078abe784fd9fd0f1534e318e827712b4)
Signed-off-by: Lee Jones <[email protected]>
Change-Id: Ic147141781cc5fd4250a6d09e283c23ba45cbd9a
diff --git a/drivers/firmware/tegra/bpmp-debugfs.c b/drivers/firmware/tegra/bpmp-debugfs.c
index fad97ec..286fe12 100644
--- a/drivers/firmware/tegra/bpmp-debugfs.c
+++ b/drivers/firmware/tegra/bpmp-debugfs.c
@@ -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;
}
