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linuxkpi: Fix atomic_long_sub() overflow

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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
This commit is contained in:
Jean-Sébastien Pédron 2023-01-15 15:56:48 +01:00
parent b99bc86232
commit 9491ea7c68
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GPG Key ID: 39E99761A5FD94CC
1 changed files with 7 additions and 1 deletions
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8
sys/compat/linuxkpi/common/include/asm/atomic-long.h
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@ -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)
{