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| author | bz <bz@FreeBSD.org> | 2009-08-14 21:46:54 +0000 |
|---|---|---|
| committer | bz <bz@FreeBSD.org> | 2009-08-14 21:46:54 +0000 |
| commit | bf6acf798532962c108b5e0944b855cf7cfb5ff8 (patch) | |
| tree | ea52f93659c64af89eda73d8980d2b5ab4e028a9 /sys/kern/kern_sx.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_sx.c')
| -rw-r--r-- | sys/kern/kern_sx.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sys/kern/kern_sx.c b/sys/kern/kern_sx.c index 04c2c98..15c1c9b 100644 --- a/sys/kern/kern_sx.c +++ b/sys/kern/kern_sx.c @@ -205,6 +205,8 @@ sx_init_flags(struct sx *sx, const char *description, int opts) MPASS((opts & ~(SX_QUIET | SX_RECURSE | SX_NOWITNESS | SX_DUPOK | SX_NOPROFILE | SX_NOADAPTIVE)) == 0); + ASSERT_ATOMIC_LOAD(sx->sx_lock, ("%s: sx_lock not aligned for %s: %p", + __func__, description, &sx->sx_lock)); flags = LO_SLEEPABLE | LO_UPGRADABLE; if (opts & SX_DUPOK) |
