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- Change ktrace genio events to only copy up to ktr_geniosize bytes of a

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transfer to a malloc'd buffer and use that bufer for the ktrace event.
  This means that genio ktrace events no longer need to be synchronous.
- Now that ktr_buffer isn't overloaded to sometimes point to a cached uio
  pointer for genio requests and always points to a malloc'd buffer if not
  NULL, free the buffer in ktr_freerequest() instead of in
  ktr_writerequest().  This closes a memory leak for ktrace events that
  used a malloc'd buffer that had their vnode ripped out from under them
  while they were on the todo list.

Suggested by:	bde (1, in principle)
This commit is contained in:
John Baldwin 2002-09-11 20:56:05 +00:00
parent 12301fc3c7
commit b92584a689
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=103235
1 changed files with 19 additions and 19 deletions
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38
sys/kern/kern_ktrace.c
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@ -283,6 +283,8 @@ ktr_freerequest(struct ktr_request *req)
vrele(req->ktr_vp);
mtx_unlock(&Giant);
}
if (req->ktr_header.ktr_buffer != NULL)
free(req->ktr_header.ktr_buffer, M_KTRACE);
mtx_lock(&ktrace_mtx);
STAILQ_INSERT_HEAD(&ktr_free, req, ktr_list);
mtx_unlock(&ktrace_mtx);
@ -419,19 +421,29 @@ ktrgenio(fd, rw, uio, error)
{
struct ktr_request *req;
struct ktr_genio *ktg;
int datalen;
char *buf;
if (error)
return;
req = ktr_getrequest(KTR_GENIO);
if (req == NULL)
uio->uio_offset = 0;
uio->uio_rw = UIO_WRITE;
datalen = imin(uio->uio_resid, ktr_geniosize);
buf = malloc(datalen, M_KTRACE, M_WAITOK);
if (uiomove(buf, datalen, uio)) {
free(buf, M_KTRACE);
return;
}
req = ktr_getrequest(KTR_GENIO);
if (req == NULL) {
free(buf, M_KTRACE);
return;
}
ktg = &req->ktr_data.ktr_genio;
ktg->ktr_fd = fd;
ktg->ktr_rw = rw;
req->ktr_header.ktr_buffer = uio;
uio->uio_offset = 0;
uio->uio_rw = UIO_WRITE;
req->ktr_synchronous = 1;
req->ktr_header.ktr_len = datalen;
req->ktr_header.ktr_buffer = buf;
ktr_submitrequest(req);
}
@ -730,7 +742,6 @@ ktr_writerequest(struct ktr_request *req)
{
struct ktr_header *kth;
struct vnode *vp;
struct uio *uio = NULL;
struct proc *p;
struct thread *td;
struct ucred *cred;
@ -774,12 +785,7 @@ ktr_writerequest(struct ktr_request *req)
aiov[auio.uio_iovcnt].iov_len = buflen;
auio.uio_resid += buflen;
auio.uio_iovcnt++;
} else
uio = kth->ktr_buffer;
KASSERT((uio == NULL) ^ (kth->ktr_type == KTR_GENIO),
("ktrace: uio and genio mismatch"));
if (uio != NULL)
kth->ktr_len += uio->uio_resid;
}
mtx_lock(&Giant);
vn_start_write(vp, &mp, V_WAIT);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
@ -789,15 +795,9 @@ ktr_writerequest(struct ktr_request *req)
if (error == 0)
#endif
error = VOP_WRITE(vp, &auio, IO_UNIT | IO_APPEND, cred);
if (error == 0 && uio != NULL) {
(void)VOP_LEASE(vp, td, cred, LEASE_WRITE);
error = VOP_WRITE(vp, uio, IO_UNIT | IO_APPEND, cred);
}
VOP_UNLOCK(vp, 0, td);
vn_finished_write(mp);
mtx_unlock(&Giant);
if (buflen != 0)
free(kth->ktr_buffer, M_KTRACE);
if (!error)
return;
/*