git: e3799530b3ba - main - sys/time: Add saturating sbt conversions

The branch main has been updated by jfree:

URL: https://cgit.FreeBSD.org/src/commit/?id=e3799530b3ba38567f8052b9e107884609fc71ea

commit e3799530b3ba38567f8052b9e107884609fc71ea
Author:     Jake Freeland <jfree@FreeBSD.org>
AuthorDate: 2026-03-20 06:33:20 +0000
Commit:     Jake Freeland <jfree@FreeBSD.org>
CommitDate: 2026-03-20 07:15:08 +0000

    sys/time: Add saturating sbt conversions
    
    When converting from timespec to sbintime, the timespec's 64-bit tv_sec
    component is shifted to the left 32 bits, causing any information in the
    upper 32 bits to be lost.
    
    This data loss during conversion can turn timespecs with very large
    tv_sec counters into sbintimes that represent much smaller time
    durations.
    
    Add tstosbt_sat() and tvtosbt_sat(), which are saturating versions of
    tstosbt and tvtosbt. With these routines, any overflow resulting from
    the conversion is clamped to [-SBT_MAX - 1, SBT_MAX].
    
    Reviewed by:            imp, markj
    Differential Revision:  https://reviews.freebsd.org/D55791
    MFC after:              2 weeks
---
 sys/sys/time.h | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/sys/sys/time.h b/sys/sys/time.h
index d3a19ebfc811..707565b6a6f1 100644
--- a/sys/sys/time.h
+++ b/sys/sys/time.h
@@ -352,6 +352,16 @@ tstosbt(struct timespec _ts)
 	return (((sbintime_t)_ts.tv_sec << 32) + nstosbt(_ts.tv_nsec));
 }
 
+static __inline sbintime_t
+tstosbt_sat(struct timespec _ts)
+{
+	if (_ts.tv_sec > SBT_MAX >> 32)
+		return (SBT_MAX);
+	if (_ts.tv_sec < -(SBT_MAX >> 32) - 1)
+		return (-SBT_MAX - 1);
+	return (tstosbt(_ts));
+}
+
 static __inline struct timeval
 sbttotv(sbintime_t _sbt)
 {
@@ -368,6 +378,17 @@ tvtosbt(struct timeval _tv)
 
 	return (((sbintime_t)_tv.tv_sec << 32) + ustosbt(_tv.tv_usec));
 }
+
+static __inline sbintime_t
+tvtosbt_sat(struct timeval _tv)
+{
+	if (_tv.tv_sec > SBT_MAX >> 32)
+		return (SBT_MAX);
+	if (_tv.tv_sec < -(SBT_MAX >> 32) - 1)
+		return (-SBT_MAX - 1);
+	return (tvtosbt(_tv));
+}
+
 #endif /* __BSD_VISIBLE */
 
 #ifdef _KERNEL