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f2fs: fix overflow of size calculation

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We have potential overflow issue when calculating size of object, when
we left shift index with PAGE_CACHE_SHIFT bits, if type of index has only
32-bits space in 32-bit architecture, left shifting will incur overflow,
i.e:

pgoff_t index =  0xFFFFFFFF;
loff_t size = index << PAGE_CACHE_SHIFT;
size: 0xFFFFF000

So we should cast index with 64-bits type to avoid this issue.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Chao Yu 2015-09-11 14:43:52 +08:00 • committed by Jaegeuk Kim
parent 100136acfb
commit 9edcdabf36
5 changed files with 24 additions and 21 deletions
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12
fs/f2fs/debug.c
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@ -198,9 +198,9 @@ get_cache:
si->page_mem = 0;
npages = NODE_MAPPING(sbi)->nrpages;
si->page_mem += npages << PAGE_CACHE_SHIFT;
si->page_mem += (unsigned long long)npages << PAGE_CACHE_SHIFT;
npages = META_MAPPING(sbi)->nrpages;
si->page_mem += npages << PAGE_CACHE_SHIFT;
si->page_mem += (unsigned long long)npages << PAGE_CACHE_SHIFT;
}
static int stat_show(struct seq_file *s, void *v)
@ -333,13 +333,13 @@ static int stat_show(struct seq_file *s, void *v)
/* memory footprint */
update_mem_info(si->sbi);
seq_printf(s, "\nMemory: %u KB\n",
seq_printf(s, "\nMemory: %llu KB\n",
(si->base_mem + si->cache_mem + si->page_mem) >> 10);
seq_printf(s, " - static: %u KB\n",
seq_printf(s, " - static: %llu KB\n",
si->base_mem >> 10);
seq_printf(s, " - cached: %u KB\n",
seq_printf(s, " - cached: %llu KB\n",
si->cache_mem >> 10);
seq_printf(s, " - paged : %u KB\n",
seq_printf(s, " - paged : %llu KB\n",
si->page_mem >> 10);
}
mutex_unlock(&f2fs_stat_mutex);