lkml.org 
[lkml]   [2020]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH v3] exfat: Avoid allocating upcase table using kcalloc()
Date
> The table for Unicode upcase conversion requires an order-5 allocation,
> which may fail on a highly-fragmented system:
>
> pool-udisksd: page allocation failure: order:5,
> mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO),
> nodemask=(null),cpuset=/,mems_allowed=0
> CPU: 4 PID: 3756880 Comm: pool-udisksd Tainted: G U
5.8.10-
> 200.fc32.x86_64 #1
> Hardware name: Dell Inc. XPS 13 9360/0PVG6D, BIOS 2.13.0 11/14/2019 Call
> Trace:
> dump_stack+0x6b/0x88
> warn_alloc.cold+0x75/0xd9
> ? _cond_resched+0x16/0x40
> ? __alloc_pages_direct_compact+0x144/0x150
> __alloc_pages_slowpath.constprop.0+0xcfa/0xd30
> ? __schedule+0x28a/0x840
> ? __wait_on_bit_lock+0x92/0xa0
> __alloc_pages_nodemask+0x2df/0x320
> kmalloc_order+0x1b/0x80
> kmalloc_order_trace+0x1d/0xa0
> exfat_create_upcase_table+0x115/0x390 [exfat]
> exfat_fill_super+0x3ef/0x7f0 [exfat]
> ? sget_fc+0x1d0/0x240
> ? exfat_init_fs_context+0x120/0x120 [exfat]
> get_tree_bdev+0x15c/0x250
> vfs_get_tree+0x25/0xb0
> do_mount+0x7c3/0xaf0
> ? copy_mount_options+0xab/0x180
> __x64_sys_mount+0x8e/0xd0
> do_syscall_64+0x4d/0x90
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> Convert kcalloc/kfree to their kv* variants to eliminate the issue.
>
> Cc: stable@vger.kernel.org # v5.7+
> Signed-off-by: Artem Labazov <123321artyom@gmail.com>

Looks good.
Thanks for your contribution.

Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>

> ---
> v2: replace vmalloc with vzalloc to avoid uninitialized memory access
> v3: use kv* functions to attempt kmalloc first
>
> fs/exfat/nls.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/fs/exfat/nls.c b/fs/exfat/nls.c index
> 675d0e7058c5..314d5407a1be 100644
> --- a/fs/exfat/nls.c
> +++ b/fs/exfat/nls.c
> @@ -659,7 +659,7 @@ static int exfat_load_upcase_table(struct super_block
> *sb,
> unsigned char skip = false;
> unsigned short *upcase_table;
>
> - upcase_table = kcalloc(UTBL_COUNT, sizeof(unsigned short),
> GFP_KERNEL);
> + upcase_table = kvcalloc(UTBL_COUNT, sizeof(unsigned short),
> +GFP_KERNEL);
> if (!upcase_table)
> return -ENOMEM;
>
> @@ -715,7 +715,7 @@ static int exfat_load_default_upcase_table(struct
> super_block *sb)
> unsigned short uni = 0, *upcase_table;
> unsigned int index = 0;
>
> - upcase_table = kcalloc(UTBL_COUNT, sizeof(unsigned short),
> GFP_KERNEL);
> + upcase_table = kvcalloc(UTBL_COUNT, sizeof(unsigned short),
> +GFP_KERNEL);
> if (!upcase_table)
> return -ENOMEM;
>
> @@ -803,5 +803,5 @@ int exfat_create_upcase_table(struct super_block *sb)
>
> void exfat_free_upcase_table(struct exfat_sb_info *sbi) {
> - kfree(sbi->vol_utbl);
> + kvfree(sbi->vol_utbl);
> }
> --
> 2.26.2


\
 
 \ /
  Last update: 2020-12-08 03:25    [W:0.042 / U:0.668 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site