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author | bz <bz@FreeBSD.org> | 2009-08-14 21:46:54 +0000 |
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committer | bz <bz@FreeBSD.org> | 2009-08-14 21:46:54 +0000 |
commit | bf6acf798532962c108b5e0944b855cf7cfb5ff8 (patch) | |
tree | ea52f93659c64af89eda73d8980d2b5ab4e028a9 /sys/kern/kern_mutex.c | |
parent | d51166f15e1c08fdaa3df0992553ad5127da220c (diff) | |
download | FreeBSD-src-bf6acf798532962c108b5e0944b855cf7cfb5ff8.zip FreeBSD-src-bf6acf798532962c108b5e0944b855cf7cfb5ff8.tar.gz |
Add a new macro to test that a variable could be loaded atomically.
Check that the given variable is at most uintptr_t in size and that
it is aligned.
Note: ASSERT_ATOMIC_LOAD() uses ALIGN() to check for adequate
alignment -- however, the function of ALIGN() is to guarantee
alignment, and therefore may lead to stronger alignment
enforcement than necessary for types that are smaller than
sizeof(uintptr_t).
Add checks to mtx, rw and sx locks init functions to detect possible
breakage. This was used during debugging of the problem fixed with
r196118 where a pointer was on an un-aligned address in the dpcpu area.
In collaboration with: rwatson
Reviewed by: rwatson
Approved by: re (kib)
Diffstat (limited to 'sys/kern/kern_mutex.c')
-rw-r--r-- | sys/kern/kern_mutex.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c index fc342c5..f625098 100644 --- a/sys/kern/kern_mutex.c +++ b/sys/kern/kern_mutex.c @@ -783,6 +783,8 @@ mtx_init(struct mtx *m, const char *name, const char *type, int opts) MPASS((opts & ~(MTX_SPIN | MTX_QUIET | MTX_RECURSE | MTX_NOWITNESS | MTX_DUPOK | MTX_NOPROFILE)) == 0); + ASSERT_ATOMIC_LOAD(m->mtx_lock, ("%s: mtx_lock not aligned for %s: %p", + __func__, name, &m->mtx_lock)); #ifdef MUTEX_DEBUG /* Diagnostic and error correction */ |