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| author | H. Peter Anvin <hpa@zytor.com> | 2009-12-08 14:01:32 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-12-11 15:27:47 -0800 |
| commit | b925585039cf39275c2e0e57512e5df27fa73aad (patch) | |
| tree | 1e264b4e3470013aabc10c27bf5054729b5b269f | |
| parent | 2eaad1fddd7450a48ad464229775f97fbfe8af36 (diff) | |
| download | linux-stable-b925585039cf39275c2e0e57512e5df27fa73aad.tar.gz linux-stable-b925585039cf39275c2e0e57512e5df27fa73aad.tar.bz2 linux-stable-b925585039cf39275c2e0e57512e5df27fa73aad.zip | |
mm: Adjust do_pages_stat() so gcc can see copy_from_user() is safe
Slightly adjust the logic for determining the size of the
copy_form_user() in do_pages_stat(); with this change, gcc can see
that the copying is safe.
Without this, we get a build error for i386 allyesconfig:
/home/hpa/kernel/linux-2.6-tip.urgent/arch/x86/include/asm/uaccess_32.h:213:
error: call to ‘copy_from_user_overflow’ declared with attribute
error: copy_from_user() buffer size is not provably correct
Unlike an earlier patch from Arjan, this doesn't introduce new
variables; merely reshuffles the compare so that gcc can see that an
overflow cannot happen.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Brice Goglin <Brice.Goglin@inria.fr>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
LKML-Reference: <20090926205406.30d55b08@infradead.org>
| -rw-r--r-- | mm/migrate.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 7dbcb22316d2..0bc640fd68fa 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1044,7 +1044,7 @@ static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages, int err; for (i = 0; i < nr_pages; i += chunk_nr) { - if (chunk_nr + i > nr_pages) + if (chunk_nr > nr_pages - i) chunk_nr = nr_pages - i; err = copy_from_user(chunk_pages, &pages[i], |