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| author | Vinod Koul | 2019-06-28 21:07:21 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2019-07-21 09:03:11 +0200 |
| commit | 2656ee5a5ad59300bbe183d0833867a582910dcc (patch) | |
| tree | c49b4837b593a50cc449142b8a29d4f4b6180303 | |
| parent | pinctrl: mediatek: Update cur_mask in mask/mask ops (diff) | |
| download | kernel-qcow2-linux-2656ee5a5ad59300bbe183d0833867a582910dcc.tar.gz kernel-qcow2-linux-2656ee5a5ad59300bbe183d0833867a582910dcc.tar.xz kernel-qcow2-linux-2656ee5a5ad59300bbe183d0833867a582910dcc.zip | |
linux/kernel.h: fix overflow for DIV_ROUND_UP_ULL
[ Upstream commit 8f9fab480c7a87b10bb5440b5555f370272a5d59 ]
DIV_ROUND_UP_ULL adds the two arguments and then invokes
DIV_ROUND_DOWN_ULL. But on a 32bit system the addition of two 32 bit
values can overflow. DIV_ROUND_DOWN_ULL does it correctly and stashes
the addition into a unsigned long long so cast the result to unsigned
long long here to avoid the overflow condition.
[akpm@linux-foundation.org: DIV_ROUND_UP_ULL must be an rval]
Link: http://lkml.kernel.org/r/20190625100518.30753-1-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | include/linux/kernel.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 3d83ebb302cf..f6f94e54ab96 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -118,7 +118,8 @@ #define DIV_ROUND_DOWN_ULL(ll, d) \ ({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; }) -#define DIV_ROUND_UP_ULL(ll, d) DIV_ROUND_DOWN_ULL((ll) + (d) - 1, (d)) +#define DIV_ROUND_UP_ULL(ll, d) \ + DIV_ROUND_DOWN_ULL((unsigned long long)(ll) + (d) - 1, (d)) #if BITS_PER_LONG == 32 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d) |