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| author | Eduard Zingerman <eddyz87@gmail.com> | 2026-09-04 17:05:56 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-04 18:17:30 -0700 |
| commit | 506ada89629ec7059b96ecfb0dc7d33ece0103ca (patch) | |
| tree | 0b07297409b68d2333fb4f0eae7f3b072eb68d4c /lib/math/lcm.c | |
| download | linux-stable-506ada89629ec7059b96ecfb0dc7d33ece0103ca.tar.gz linux-stable-506ada89629ec7059b96ecfb0dc7d33ece0103ca.zip | |
bpf: mark a NULL kfunc argument precisegrafted
check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.
Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'lib/math/lcm.c')
| -rw-r--r-- | lib/math/lcm.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/lib/math/lcm.c b/lib/math/lcm.c new file mode 100644 index 000000000..6e0b2e736 --- /dev/null +++ b/lib/math/lcm.c @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/compiler.h> +#include <linux/gcd.h> +#include <linux/export.h> +#include <linux/lcm.h> + +/* Lowest common multiple */ +unsigned long lcm(unsigned long a, unsigned long b) +{ + if (a && b) + return (a / gcd(a, b)) * b; + else + return 0; +} +EXPORT_SYMBOL_GPL(lcm); + +unsigned long lcm_not_zero(unsigned long a, unsigned long b) +{ + unsigned long l = lcm(a, b); + + if (l) + return l; + + return (b ? : a); +} +EXPORT_SYMBOL_GPL(lcm_not_zero); |