The patch titled
Subject: ocfs2: reduce ioctl stack usage
has been added to the -mm mm-nonmm-unstable branch. Its filename is
ocfs2-reduce-ioctl-stack-usage.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ocfs2-reduce-ioctl-stack-usage.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Arnd Bergmann <arnd@xxxxxxxx>
Subject: ocfs2: reduce ioctl stack usage
Date: Mon, 17 Apr 2023 22:56:24 +0200
On 32-bit architectures with KASAN_STACK enabled, the total stack usage of
the ocfs2_ioctl function grows beyond the warning limit:
fs/ocfs2/ioctl.c: In function 'ocfs2_ioctl':
fs/ocfs2/ioctl.c:934:1: error: the frame size of 1448 bytes is larger than 1400 bytes [-Werror=frame-larger-than=]
Move each of the variables into a basic block, and mark
ocfs2_info_handle() as noinline_for_stack, in order to have the variable
share stack slots.
Link: https://lkml.kernel.org/r/20230417205631.1956027-1-arnd@xxxxxxxxxx
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Cc: Changwei Ge <gechangwei@xxxxxxx>
Cc: Gang He <ghe@xxxxxxxx>
Cc: Jun Piao <piaojun@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/ioctl.c | 37 ++++++++++++++++++++++++++-----------
1 file changed, 26 insertions(+), 11 deletions(-)
--- a/fs/ocfs2/ioctl.c~ocfs2-reduce-ioctl-stack-usage
+++ a/fs/ocfs2/ioctl.c
@@ -803,8 +803,8 @@ bail:
* a better backward&forward compatibility, since a small piece of
* request will be less likely to be broken if disk layout get changed.
*/
-static int ocfs2_info_handle(struct inode *inode, struct ocfs2_info *info,
- int compat_flag)
+static noinline_for_stack int
+ocfs2_info_handle(struct inode *inode, struct ocfs2_info *info, int compat_flag)
{
int i, status = 0;
u64 req_addr;
@@ -840,27 +840,26 @@ bail:
long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
- int new_clusters;
- int status;
- struct ocfs2_space_resv sr;
- struct ocfs2_new_group_input input;
- struct reflink_arguments args;
- const char __user *old_path;
- const char __user *new_path;
- bool preserve;
- struct ocfs2_info info;
void __user *argp = (void __user *)arg;
+ int status;
switch (cmd) {
case OCFS2_IOC_RESVSP:
case OCFS2_IOC_RESVSP64:
case OCFS2_IOC_UNRESVSP:
case OCFS2_IOC_UNRESVSP64:
+ {
+ struct ocfs2_space_resv sr;
+
if (copy_from_user(&sr, (int __user *) arg, sizeof(sr)))
return -EFAULT;
return ocfs2_change_file_space(filp, cmd, &sr);
+ }
case OCFS2_IOC_GROUP_EXTEND:
+ {
+ int new_clusters;
+
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
@@ -873,8 +872,12 @@ long ocfs2_ioctl(struct file *filp, unsi
status = ocfs2_group_extend(inode, new_clusters);
mnt_drop_write_file(filp);
return status;
+ }
case OCFS2_IOC_GROUP_ADD:
case OCFS2_IOC_GROUP_ADD64:
+ {
+ struct ocfs2_new_group_input input;
+
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
@@ -887,7 +890,14 @@ long ocfs2_ioctl(struct file *filp, unsi
status = ocfs2_group_add(inode, &input);
mnt_drop_write_file(filp);
return status;
+ }
case OCFS2_IOC_REFLINK:
+ {
+ struct reflink_arguments args;
+ const char __user *old_path;
+ const char __user *new_path;
+ bool preserve;
+
if (copy_from_user(&args, argp, sizeof(args)))
return -EFAULT;
old_path = (const char __user *)(unsigned long)args.old_path;
@@ -895,11 +905,16 @@ long ocfs2_ioctl(struct file *filp, unsi
preserve = (args.preserve != 0);
return ocfs2_reflink_ioctl(inode, old_path, new_path, preserve);
+ }
case OCFS2_IOC_INFO:
+ {
+ struct ocfs2_info info;
+
if (copy_from_user(&info, argp, sizeof(struct ocfs2_info)))
return -EFAULT;
return ocfs2_info_handle(inode, &info, 0);
+ }
case FITRIM:
{
struct super_block *sb = inode->i_sb;
_
Patches currently in -mm which might be from arnd@xxxxxxxx are
mm-make-arch_has_descending_max_zone_pfns-static.patch
mm-make-arch_has_descending_max_zone_pfns-static-v2.patch
kasan-remove-hwasan-kernel-mem-intrinsic-prefix=1-for-clang-14.patch
ocfs2-reduce-ioctl-stack-usage.patch
