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| author | Stanislaw Gruszka <sgruszka@redhat.com> | 2019-03-07 16:28:18 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-07 18:32:00 -0800 |
| commit | cdc94a37493135e355dfc0b0e086d84e3eadb50d (patch) | |
| tree | 6ef3fffed75206a1b44d0038d55d0bad914fe497 /lib/test_ubsan.c | |
| parent | 1db604f676b2edb7b18de7881f4d5988e97be616 (diff) | |
| download | linux-riscv-cdc94a37493135e355dfc0b0e086d84e3eadb50d.tar.gz linux-riscv-cdc94a37493135e355dfc0b0e086d84e3eadb50d.tar.bz2 linux-riscv-cdc94a37493135e355dfc0b0e086d84e3eadb50d.zip | |
lib/div64.c: off by one in shift
fls counts bits starting from 1 to 32 (returns 0 for zero argument). If
we add 1 we shift right one bit more and loose precision from divisor,
what cause function incorect results with some numbers.
Corrected code was tested in user-space, see bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=202391
Link: http://lkml.kernel.org/r/1548686944-11891-1-git-send-email-sgruszka@redhat.com
Fixes: 658716d19f8f ("div64_u64(): improve precision on 32bit platforms")
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Reported-by: Siarhei Volkau <lis8215@gmail.com>
Tested-by: Siarhei Volkau <lis8215@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/test_ubsan.c')
0 files changed, 0 insertions, 0 deletions