diff options
| author | Claudio Jeker <claudio@cvs.openbsd.org> | 2019-05-22 18:45:08 +0000 |
|---|---|---|
| committer | Claudio Jeker <claudio@cvs.openbsd.org> | 2019-05-22 18:45:08 +0000 |
| commit | 0218d2364b8dbd7d1fac92150c117dd08e20c7b6 (patch) | |
| tree | a78715aadc208c881372580e4f5e4d7a93d28efa | |
| parent | 2e0cdd7e7341d4f12421c98ffb59a5d02d4dd48d (diff) | |
Read and assign the integer value only once. With this sysctl_int() will
do word loads and stores and so partial updates should no longer be observed.
With this accessing global variables set by sysctl_int() should be mostly MP
save.
OK dlg@ mpi@
| -rw-r--r-- | sys/kern/kern_sysctl.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c index 465bb6038ef..82f26655caf 100644 --- a/sys/kern/kern_sysctl.c +++ b/sys/kern/kern_sysctl.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_sysctl.c,v 1.355 2019/05/09 14:59:30 claudio Exp $ */ +/* $OpenBSD: kern_sysctl.c,v 1.356 2019/05/22 18:45:07 claudio Exp $ */ /* $NetBSD: kern_sysctl.c,v 1.17 1996/05/20 17:49:05 mrg Exp $ */ /*- @@ -868,16 +868,20 @@ int sysctl_int(void *oldp, size_t *oldlenp, void *newp, size_t newlen, int *valp) { int error = 0; + int val; if (oldp && *oldlenp < sizeof(int)) return (ENOMEM); if (newp && newlen != sizeof(int)) return (EINVAL); *oldlenp = sizeof(int); + val = *valp; if (oldp) - error = copyout(valp, oldp, sizeof(int)); + error = copyout(&val, oldp, sizeof(int)); if (error == 0 && newp) - error = copyin(newp, valp, sizeof(int)); + error = copyin(newp, &val, sizeof(int)); + if (error == 0) + *valp = val; return (error); } |