The branch main has been updated by dumbbell (ports committer):
URL:
https://cgit.FreeBSD.org/src/commit/?id=9491ea7c68221ca7bc5e369ebb57660886ef1b13
commit 9491ea7c68221ca7bc5e369ebb57660886ef1b13
Author: Jean-Sébastien Pédron <dumbb...@freebsd.org>
AuthorDate: 2023-01-15 14:56:48 +0000
Commit: Jean-Sébastien Pédron <dumbb...@freebsd.org>
CommitDate: 2023-01-25 21:26:54 +0000
linuxkpi: Fix `atomic_long_sub()` overflow
By (ab)using `atomic_long_add_return()`, `atomic_long_sub()` was making
the atomic long overflow. Indeed the underlying FreeBSD atomic is based
on an unsigned long.
Reviewed by: manu
Approved by: manu
Differential Revision: https://reviews.freebsd.org/D38090
---
sys/compat/linuxkpi/common/include/asm/atomic-long.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/sys/compat/linuxkpi/common/include/asm/atomic-long.h
b/sys/compat/linuxkpi/common/include/asm/atomic-long.h
index f8bd9edfccf9..aeec6edd707d 100644
--- a/sys/compat/linuxkpi/common/include/asm/atomic-long.h
+++ b/sys/compat/linuxkpi/common/include/asm/atomic-long.h
@@ -41,7 +41,7 @@ typedef struct {
} atomic_long_t;
#define atomic_long_add(i, v) atomic_long_add_return((i), (v))
-#define atomic_long_sub(i, v) atomic_long_add_return(-(i),
(v))
+#define atomic_long_sub(i, v) atomic_long_sub_return((i), (v))
#define atomic_long_inc_return(v) atomic_long_add_return(1, (v))
#define atomic_long_inc_not_zero(v) atomic_long_add_unless((v), 1,
0)
@@ -51,6 +51,12 @@ atomic_long_add_return(long i, atomic_long_t *v)
return i + atomic_fetchadd_long(&v->counter, i);
}
+static inline long
+atomic_long_sub_return(long i, atomic_long_t *v)
+{
+ return atomic_fetchadd_long(&v->counter, -i) - i;
+}
+
static inline void
atomic_long_set(atomic_long_t *v, long i)
{
