The branch stable/13 has been updated by cy: URL: https://cgit.FreeBSD.org/src/commit/?id=8711fd2103d2a580bd4671f3f1c7da0fc791e5db
commit 8711fd2103d2a580bd4671f3f1c7da0fc791e5db Author: Dmitriy Alexandrov <[email protected]> AuthorDate: 2023-06-08 09:08:46 +0000 Commit: Cy Schubert <[email protected]> CommitDate: 2023-06-23 04:34:11 +0000 kern_ntptime: Fix undefined behavior of the shift operator L_LINT macro is used with negative numbers [i.e. L_LINT(time_freq, -MAXFREQ)], it could cause undefined behavior. It should be similar to the L_RSHIFT(v, n) macro. MFC after: 2 weeks Reviewed by: cy Pull Request: https://github.com/freebsd/freebsd-src/pull/769 Signed-off-by: Dmitriy Alexandrov <[email protected]> (cherry picked from commit af9ce4e9bb7d717279e02d46455e85ef6fb828f7) --- sys/kern/kern_ntptime.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/sys/kern/kern_ntptime.c b/sys/kern/kern_ntptime.c index a8418248abd7..7e0595c4b643 100644 --- a/sys/kern/kern_ntptime.c +++ b/sys/kern/kern_ntptime.c @@ -73,7 +73,13 @@ typedef int64_t l_fp; #define L_MPY(v, a) ((v) *= (a)) #define L_CLR(v) ((v) = 0) #define L_ISNEG(v) ((v) < 0) -#define L_LINT(v, a) ((v) = (int64_t)(a) << 32) +#define L_LINT(v, a) \ + do { \ + if ((a) < 0) \ + ((v) = -((int64_t)(-(a)) << 32)); \ + else \ + ((v) = (int64_t)(a) << 32); \ + } while (0) #define L_GINT(v) ((v) < 0 ? -(-(v) >> 32) : (v) >> 32) /*
