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| author | Sasha Levin <levinsasha928@gmail.com> | 2012-05-10 13:01:44 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-10 15:06:44 -0700 |
| commit | 93278814d3590eba0ee360b8d69a35c7f2203ea8 (patch) | |
| tree | 17784192015e71464f1064af2b071c8cd7fe7f13 /mm/page_alloc.c | |
| parent | 16fbdce62d9c89b794e303f4a232e4749b77e9ac (diff) | |
| download | lwn-93278814d3590eba0ee360b8d69a35c7f2203ea8.tar.gz lwn-93278814d3590eba0ee360b8d69a35c7f2203ea8.zip | |
mm: fix division by 0 in percpu_pagelist_fraction()
percpu_pagelist_fraction_sysctl_handler() has only considered -EINVAL as
a possible error from proc_dointvec_minmax().
If any other error is returned, it would proceed to divide by zero since
percpu_pagelist_fraction wasn't getting initialized at any point. For
example, writing 0 bytes into the proc file would trigger the issue.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a712fb9e04ce..b21b3db15a7f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -105,7 +105,7 @@ unsigned long totalreserve_pages __read_mostly; */ unsigned long dirty_balance_reserve __read_mostly; -int percpu_pagelist_fraction; +int percpu_pagelist_fraction = 8; gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; #ifdef CONFIG_PM_SLEEP @@ -5203,7 +5203,7 @@ int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, int ret; ret = proc_dointvec_minmax(table, write, buffer, length, ppos); - if (!write || (ret == -EINVAL)) + if (!write || (ret < 0)) return ret; for_each_populated_zone(zone) { for_each_possible_cpu(cpu) { |