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Bring back sysctl_wire_old_buffer(). Fix a bug in sysctl_handle_opaque()

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whereby the pointers would not get reset on a retried SYSCTL_OUT() call.

Noticed by:	bde
This commit is contained in:
bms 2003-10-05 13:31:33 +00:00
parent 4357db17b4
commit 3960d861d4
1 changed files with 13 additions and 13 deletions
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26
sys/kern/kern_sysctl.c
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@ -883,6 +883,7 @@ sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
{
int error, tries;
u_int generation;
struct sysctl_req req2;
/*
* Attempt to get a coherent snapshot, by using the thread
@ -892,13 +893,17 @@ sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
* If we encounter an error, stop immediately.
*/
tries = 0;
do {
generation = curthread->td_generation;
error = SYSCTL_OUT(req, arg1, arg2);
if (error)
return (error);
tries++;
} while (generation != curthread->td_generation && tries < 3);
req2 = *req;
retry:
generation = curthread->td_generation;
error = SYSCTL_OUT(req, arg1, arg2);
if (error)
return (error);
tries++;
if (generation != curthread->td_generation && tries < 3) {
*req = req2;
goto retry;
}
error = SYSCTL_IN(req, arg1, arg2);
@ -973,10 +978,9 @@ kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
SYSCTL_LOCK();
error = sysctl_root(0, name, namelen, &req);
#if 0
if (req.lock == REQ_WIRED)
vsunlock(req.oldptr, req.oldlen);
#endif
SYSCTL_UNLOCK();
@ -1070,13 +1074,11 @@ sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
void
sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
{
#if 0
if (req->lock == REQ_LOCKED && req->oldptr &&
req->oldfunc == sysctl_old_user) {
vslock(req->oldptr, req->oldlen);
req->lock = REQ_WIRED;
}
#endif
}
int
@ -1285,10 +1287,8 @@ userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
} while (error == EAGAIN);
req = req2;
#if 0
if (req.lock == REQ_WIRED)
vsunlock(req.oldptr, req.oldlen);
#endif
SYSCTL_UNLOCK();