Author: mjg
Date: Sun Jul 6 22:47:18 2014
New Revision: 268335
URL: http://svnweb.freebsd.org/changeset/base/268335
Log:
MFC r265206:
Ignore the error from pipespace_new when creating a pipe.
It can fail if pipe map is exhausted (as a result of too many pipes created),
but it is not fatal and could be provoked by unprivileged users. The only
consequence is worse performance with given pipe.
Modified:
stable/10/sys/fs/fifofs/fifo_vnops.c
stable/10/sys/kern/sys_pipe.c
stable/10/sys/sys/pipe.h
Modified: stable/10/sys/fs/fifofs/fifo_vnops.c
==============================================================================
--- stable/10/sys/fs/fifofs/fifo_vnops.c Sun Jul 6 22:09:50 2014
(r268334)
+++ stable/10/sys/fs/fifofs/fifo_vnops.c Sun Jul 6 22:47:18 2014
(r268335)
@@ -146,9 +146,7 @@ fifo_open(ap)
if (fp == NULL || (ap->a_mode & FEXEC) != 0)
return (EINVAL);
if ((fip = vp->v_fifoinfo) == NULL) {
- error = pipe_named_ctor(&fpipe, td);
- if (error != 0)
- return (error);
+ pipe_named_ctor(&fpipe, td);
fip = malloc(sizeof(*fip), M_VNODE, M_WAITOK);
fip->fi_pipe = fpipe;
fpipe->pipe_wgen = fip->fi_readers = fip->fi_writers = 0;
Modified: stable/10/sys/kern/sys_pipe.c
==============================================================================
--- stable/10/sys/kern/sys_pipe.c Sun Jul 6 22:09:50 2014
(r268334)
+++ stable/10/sys/kern/sys_pipe.c Sun Jul 6 22:47:18 2014
(r268335)
@@ -221,8 +221,8 @@ SYSCTL_INT(_kern_ipc, OID_AUTO, piperesi
static void pipeinit(void *dummy __unused);
static void pipeclose(struct pipe *cpipe);
static void pipe_free_kmem(struct pipe *cpipe);
-static int pipe_create(struct pipe *pipe, int backing);
-static int pipe_paircreate(struct thread *td, struct pipepair **p_pp);
+static void pipe_create(struct pipe *pipe, int backing);
+static void pipe_paircreate(struct thread *td, struct pipepair **p_pp);
static __inline int pipelock(struct pipe *cpipe, int catch);
static __inline void pipeunlock(struct pipe *cpipe);
#ifndef PIPE_NODIRECT
@@ -331,12 +331,11 @@ pipe_zone_fini(void *mem, int size)
mtx_destroy(&pp->pp_mtx);
}
-static int
+static void
pipe_paircreate(struct thread *td, struct pipepair **p_pp)
{
struct pipepair *pp;
struct pipe *rpipe, *wpipe;
- int error;
*p_pp = pp = uma_zalloc(pipe_zone, M_WAITOK);
#ifdef MAC
@@ -355,30 +354,21 @@ pipe_paircreate(struct thread *td, struc
knlist_init_mtx(&wpipe->pipe_sel.si_note, PIPE_MTX(wpipe));
/* Only the forward direction pipe is backed by default */
- if ((error = pipe_create(rpipe, 1)) != 0 ||
- (error = pipe_create(wpipe, 0)) != 0) {
- pipeclose(rpipe);
- pipeclose(wpipe);
- return (error);
- }
+ pipe_create(rpipe, 1);
+ pipe_create(wpipe, 0);
rpipe->pipe_state |= PIPE_DIRECTOK;
wpipe->pipe_state |= PIPE_DIRECTOK;
- return (0);
}
-int
+void
pipe_named_ctor(struct pipe **ppipe, struct thread *td)
{
struct pipepair *pp;
- int error;
- error = pipe_paircreate(td, &pp);
- if (error != 0)
- return (error);
+ pipe_paircreate(td, &pp);
pp->pp_rpipe.pipe_state |= PIPE_NAMED;
*ppipe = &pp->pp_rpipe;
- return (0);
}
void
@@ -419,9 +409,7 @@ kern_pipe2(struct thread *td, int fildes
int fd, fflags, error;
fdp = td->td_proc->p_fd;
- error = pipe_paircreate(td, &pp);
- if (error != 0)
- return (error);
+ pipe_paircreate(td, &pp);
rpipe = &pp->pp_rpipe;
wpipe = &pp->pp_wpipe;
error = falloc(td, &rf, &fd, flags);
@@ -642,24 +630,27 @@ pipeselwakeup(cpipe)
* Initialize and allocate VM and memory for pipe. The structure
* will start out zero'd from the ctor, so we just manage the kmem.
*/
-static int
+static void
pipe_create(pipe, backing)
struct pipe *pipe;
int backing;
{
- int error;
if (backing) {
+ /*
+ * Note that these functions can fail if pipe map is exhausted
+ * (as a result of too many pipes created), but we ignore the
+ * error as it is not fatal and could be provoked by
+ * unprivileged users. The only consequence is worse performance
+ * with given pipe.
+ */
if (amountpipekva > maxpipekva / 2)
- error = pipespace_new(pipe, SMALL_PIPE_SIZE);
+ (void)pipespace_new(pipe, SMALL_PIPE_SIZE);
else
- error = pipespace_new(pipe, PIPE_SIZE);
- } else {
- /* If we're not backing this pipe, no need to do anything. */
- error = 0;
+ (void)pipespace_new(pipe, PIPE_SIZE);
}
+
pipe->pipe_ino = -1;
- return (error);
}
/* ARGSUSED */
Modified: stable/10/sys/sys/pipe.h
==============================================================================
--- stable/10/sys/sys/pipe.h Sun Jul 6 22:09:50 2014 (r268334)
+++ stable/10/sys/sys/pipe.h Sun Jul 6 22:47:18 2014 (r268335)
@@ -142,6 +142,6 @@ struct pipepair {
#define PIPE_LOCK_ASSERT(pipe, type) mtx_assert(PIPE_MTX(pipe), (type))
void pipe_dtor(struct pipe *dpipe);
-int pipe_named_ctor(struct pipe **ppipe, struct thread *td);
+void pipe_named_ctor(struct pipe **ppipe, struct thread *td);
void pipeselwakeup(struct pipe *cpipe);
#endif /* !_SYS_PIPE_H_ */
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