Re: [PATCH] coredump: reduce stack usage in vfs_coredump()

From: Christian Brauner
Date: Mon Jun 23 2025 - 06:42:40 EST


On Fri, 20 Jun 2025 13:21:01 +0200, Arnd Bergmann wrote:
> The newly added socket coredump code runs into some corner cases
> with KASAN that end up needing a lot of stack space:
>
> fs/coredump.c:1206:1: error: the frame size of 1680 bytes is larger than 1280 bytes [-Werror=frame-larger-than=]
>
> Mark the socket helper function as noinline_for_stack so its stack
> usage does not leak out to the other code paths. This also seems to
> help with register pressure, and the resulting combined stack usage of
> vfs_coredump() and coredump_socket() is actually lower than the inlined
> version.
>
> [...]

Applied to the vfs-6.17.coredump branch of the vfs/vfs.git tree.
Patches in the vfs-6.17.coredump branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-6.17.coredump

[1/1] coredump: reduce stack usage in vfs_coredump()
https://git.kernel.org/vfs/vfs/c/fb82645d3f72