From e82b3a63a9a91cc5c585efb3e28f32100f24e3e1 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 10 Jun 2025 11:24:04 +0200 Subject: [PATCH] bcachefs: ioctl: avoid stack overflow warning Multiple ioctl handlers individually use a lot of stack space, and clang chooses to inline them into the bch2_fs_ioctl() function, blowing through the warning limit: fs/bcachefs/chardev.c:655:6: error: stack frame size (1032) exceeds limit (1024) in 'bch2_fs_ioctl' [-Werror,-Wframe-larger-than] 655 | long bch2_fs_ioctl(struct bch_fs *c, unsigned cmd, void __user *arg) By marking the largest two of them as noinline_for_stack, no indidual code path ends up using this much, which avoids the warning and reduces the possible total stack usage in the ioctl handler. Signed-off-by: Arnd Bergmann Signed-off-by: Kent Overstreet --- fs/bcachefs/chardev.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/bcachefs/chardev.c b/fs/bcachefs/chardev.c index 2d38466eddfd..fde3c2380e28 100644 --- a/fs/bcachefs/chardev.c +++ b/fs/bcachefs/chardev.c @@ -399,7 +399,7 @@ static long bch2_ioctl_data(struct bch_fs *c, return ret; } -static long bch2_ioctl_fs_usage(struct bch_fs *c, +static noinline_for_stack long bch2_ioctl_fs_usage(struct bch_fs *c, struct bch_ioctl_fs_usage __user *user_arg) { struct bch_ioctl_fs_usage arg = {}; @@ -469,7 +469,7 @@ err: } /* obsolete, didn't allow for new data types: */ -static long bch2_ioctl_dev_usage(struct bch_fs *c, +static noinline_for_stack long bch2_ioctl_dev_usage(struct bch_fs *c, struct bch_ioctl_dev_usage __user *user_arg) { struct bch_ioctl_dev_usage arg; -- 2.25.1