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| author | Arnd Bergmann <arnd@arndb.de> | 2024-02-16 23:23:34 +0300 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2024-03-27 01:21:47 +0300 |
| commit | a0bccba5f50384ee7623f80aef9abd947a327394 (patch) | |
| tree | b52a43c7f31ba05fee08b1bb0fc3781583ff3aa5 /include/linux | |
| parent | 4af837db0fd3679fabc7b7758397090b0c06dced (diff) | |
| download | linux-a0bccba5f50384ee7623f80aef9abd947a327394.tar.xz | |
fs/select: rework stack allocation hack for clang
[ Upstream commit ddb9fd7a544088ed70eccbb9f85e9cc9952131c1 ]
A while ago, we changed the way that select() and poll() preallocate
a temporary buffer just under the size of the static warning limit of
1024 bytes, as clang was frequently going slightly above that limit.
The warnings have recently returned and I took another look. As it turns
out, clang is not actually inherently worse at reserving stack space,
it just happens to inline do_select() into core_sys_select(), while gcc
never inlines it.
Annotate do_select() to never be inlined and in turn remove the special
case for the allocation size. This should give the same behavior for
both clang and gcc all the time and once more avoids those warnings.
Fixes: ad312f95d41c ("fs/select: avoid clang stack usage warning")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240216202352.2492798-1-arnd@kernel.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/poll.h | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/include/linux/poll.h b/include/linux/poll.h index 1cdc32b1f1b0..7e0fdcf905d2 100644 --- a/include/linux/poll.h +++ b/include/linux/poll.h @@ -16,11 +16,7 @@ extern struct ctl_table epoll_table[]; /* for sysctl */ /* ~832 bytes of stack space used max in sys_select/sys_poll before allocating additional memory. */ -#ifdef __clang__ -#define MAX_STACK_ALLOC 768 -#else #define MAX_STACK_ALLOC 832 -#endif #define FRONTEND_STACK_ALLOC 256 #define SELECT_STACK_ALLOC FRONTEND_STACK_ALLOC #define POLL_STACK_ALLOC FRONTEND_STACK_ALLOC |