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author | Richard Fitzgerald <rf@opensource.cirrus.com> | 2021-05-25 13:20:12 +0100 |
---|---|---|
committer | Petr Mladek <pmladek@suse.com> | 2021-05-27 15:38:17 +0200 |
commit | d327ea15a305024ef0085252fa3657bbb1ce25f5 (patch) | |
tree | f801624d48b5121671faa5850da28b92591c4f8c /include/linux | |
parent | 1b932689c77766b68e2ead51ca0fb84ec5bb8965 (diff) | |
download | linux-stable-d327ea15a305024ef0085252fa3657bbb1ce25f5.tar.gz linux-stable-d327ea15a305024ef0085252fa3657bbb1ce25f5.tar.bz2 linux-stable-d327ea15a305024ef0085252fa3657bbb1ce25f5.zip |
random32: Fix implicit truncation warning in prandom_seed_state()
sparse generates the following warning:
include/linux/prandom.h:114:45: sparse: sparse: cast truncates bits from
constant value
This is because the 64-bit seed value is manipulated and then placed in a
u32, causing an implicit cast and truncation. A forced cast to u32 doesn't
prevent this warning, which is reasonable because a typecast doesn't prove
that truncation was expected.
Logical-AND the value with 0xffffffff to make explicit that truncation to
32-bit is intended.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210525122012.6336-3-rf@opensource.cirrus.com
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/prandom.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/prandom.h b/include/linux/prandom.h index bbf4b4ad61df..056d31317e49 100644 --- a/include/linux/prandom.h +++ b/include/linux/prandom.h @@ -111,7 +111,7 @@ static inline u32 __seed(u32 x, u32 m) */ static inline void prandom_seed_state(struct rnd_state *state, u64 seed) { - u32 i = (seed >> 32) ^ (seed << 10) ^ seed; + u32 i = ((seed >> 32) ^ (seed << 10) ^ seed) & 0xffffffffUL; state->s1 = __seed(i, 2U); state->s2 = __seed(i, 8U); |