Module Name: src
Committed By: yamt
Date: Tue Oct 11 23:55:30 UTC 2011
Modified Files:
src/sys/dev: rnd.c
Log Message:
- make rnd.c mpsafe
- malloc -> kmem_alloc
To generate a diff of this commit:
cvs rdiff -u -r1.81 -r1.82 src/sys/dev/rnd.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/rnd.c
diff -u src/sys/dev/rnd.c:1.81 src/sys/dev/rnd.c:1.82
--- src/sys/dev/rnd.c:1.81 Thu Jun 30 20:09:40 2011
+++ src/sys/dev/rnd.c Tue Oct 11 23:55:30 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: rnd.c,v 1.81 2011/06/30 20:09:40 wiz Exp $ */
+/* $NetBSD: rnd.c,v 1.82 2011/10/11 23:55:30 yamt Exp $ */
/*-
* Copyright (c) 1997 The NetBSD Foundation, Inc.
@@ -31,14 +31,14 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rnd.c,v 1.81 2011/06/30 20:09:40 wiz Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rnd.c,v 1.82 2011/10/11 23:55:30 yamt Exp $");
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <sys/select.h>
#include <sys/poll.h>
-#include <sys/malloc.h>
+#include <sys/kmem.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/kernel.h>
@@ -75,7 +75,7 @@ int rnd_debug = 0;
#endif
/*
- * The size of a temporary buffer, malloc()ed when needed, and used for
+ * The size of a temporary buffer, kmem_alloc()ed when needed, and used for
* reading and writing data.
*/
#define RND_TEMP_BUFFER_SIZE 128
@@ -110,12 +110,6 @@ kmutex_t rnd_mtx;
struct selinfo rnd_selq;
/*
- * Set when there are readers blocking on data from us
- */
-#define RND_READWAITING 0x00000001
-volatile u_int32_t rnd_status;
-
-/*
* Memory pool for sample buffers
*/
static struct pool rnd_mempool;
@@ -130,6 +124,7 @@ static struct pool rnd_mempool;
*/
rndpool_t rnd_pool;
kmutex_t rndpool_mtx;
+kcondvar_t rndpool_cv;
/*
* This source is used to easily "remove" queue entries when the source
@@ -156,13 +151,14 @@ dev_type_kqfilter(rndkqfilter);
const struct cdevsw rnd_cdevsw = {
rndopen, nullclose, rndread, rndwrite, rndioctl,
- nostop, notty, rndpoll, nommap, rndkqfilter, D_OTHER,
+ nostop, notty, rndpoll, nommap, rndkqfilter, D_OTHER|D_MPSAFE,
};
static inline void rnd_wakeup_readers(void);
static inline u_int32_t rnd_estimate_entropy(rndsource_t *, u_int32_t);
static inline u_int32_t rnd_counter(void);
static void rnd_timeout(void *);
+static u_int32_t rnd_extract_data_locked(void *, u_int32_t, u_int32_t);
static int rnd_ready = 0;
static int rnd_have_entropy = 0;
@@ -203,12 +199,7 @@ rnd_wakeup_readers(void)
*/
mutex_enter(&rndpool_mtx);
if (rndpool_get_entropy_count(&rnd_pool) > RND_ENTROPY_THRESHOLD * 8) {
- if (rnd_status & RND_READWAITING) {
- DPRINTF(RND_DEBUG_SNOOZE,
- ("waking up pending readers.\n"));
- rnd_status &= ~RND_READWAITING;
- wakeup(&rnd_selq);
- }
+ cv_broadcast(&rndpool_cv);
selnotify(&rnd_selq, 0, 0);
#ifdef RND_VERBOSE
@@ -328,6 +319,7 @@ rnd_init(void)
rndpool_init(&rnd_pool);
mutex_init(&rndpool_mtx, MUTEX_DEFAULT, IPL_SOFTCLOCK);
+ cv_init(&rndpool_cv, "rndread");
/* Mix *something*, *anything* into the pool to help it get started.
* However, it's not safe for rnd_counter() to call microtime() yet,
@@ -389,9 +381,7 @@ rndread(dev_t dev, struct uio *uio, int
}
ret = 0;
-
- bf = malloc(RND_TEMP_BUFFER_SIZE, M_TEMP, M_WAITOK);
-
+ bf = kmem_alloc(RND_TEMP_BUFFER_SIZE, KM_SLEEP);
while (uio->uio_resid > 0) {
n = min(RND_TEMP_BUFFER_SIZE, uio->uio_resid);
@@ -400,42 +390,37 @@ rndread(dev_t dev, struct uio *uio, int
* is, do the I/O even if it is partial. If not,
* sleep unless the user has requested non-blocking
* I/O.
+ *
+ * If not requesting strong randomness, we can always read.
*/
- for (;;) {
- /*
- * If not requesting strong randomness, we
- * can always read.
- */
- if (mode == RND_EXTRACT_ANY)
- break;
-
- /*
- * How much entropy do we have? If it is enough for
- * one hash, we can read.
- */
- mutex_enter(&rndpool_mtx);
- entcnt = rndpool_get_entropy_count(&rnd_pool);
- mutex_exit(&rndpool_mtx);
- if (entcnt >= RND_ENTROPY_THRESHOLD * 8)
- break;
-
- /*
- * Data is not available.
- */
- if (ioflag & IO_NDELAY) {
- ret = EWOULDBLOCK;
- goto out;
+ mutex_enter(&rndpool_mtx);
+ if (mode != RND_EXTRACT_ANY) {
+ for (;;) {
+ /*
+ * How much entropy do we have?
+ * If it is enough for one hash, we can read.
+ */
+ entcnt = rndpool_get_entropy_count(&rnd_pool);
+ if (entcnt >= RND_ENTROPY_THRESHOLD * 8)
+ break;
+
+ /*
+ * Data is not available.
+ */
+ if (ioflag & IO_NDELAY) {
+ mutex_exit(&rndpool_mtx);
+ ret = EWOULDBLOCK;
+ goto out;
+ }
+ ret = cv_wait_sig(&rndpool_cv, &rndpool_mtx);
+ if (ret) {
+ mutex_exit(&rndpool_mtx);
+ goto out;
+ }
}
-
- rnd_status |= RND_READWAITING;
- ret = tsleep(&rnd_selq, PRIBIO|PCATCH,
- "rndread", 0);
-
- if (ret)
- goto out;
}
-
- nread = rnd_extract_data(bf, n, mode);
+ nread = rnd_extract_data_locked(bf, n, mode);
+ mutex_exit(&rndpool_mtx);
/*
* Copy (possibly partial) data to the user.
@@ -448,7 +433,7 @@ rndread(dev_t dev, struct uio *uio, int
}
out:
- free(bf, M_TEMP);
+ kmem_free(bf, RND_TEMP_BUFFER_SIZE);
return (ret);
}
@@ -463,11 +448,8 @@ rndwrite(dev_t dev, struct uio *uio, int
if (uio->uio_resid == 0)
return (0);
-
ret = 0;
-
- bf = malloc(RND_TEMP_BUFFER_SIZE, M_TEMP, M_WAITOK);
-
+ bf = kmem_alloc(RND_TEMP_BUFFER_SIZE, KM_SLEEP);
while (uio->uio_resid > 0) {
n = min(RND_TEMP_BUFFER_SIZE, uio->uio_resid);
@@ -484,8 +466,7 @@ rndwrite(dev_t dev, struct uio *uio, int
DPRINTF(RND_DEBUG_WRITE, ("Random: Copied in %d bytes\n", n));
}
-
- free(bf, M_TEMP);
+ kmem_free(bf, RND_TEMP_BUFFER_SIZE);
return (ret);
}
@@ -711,12 +692,11 @@ rndpoll(dev_t dev, int events, struct lw
*/
mutex_enter(&rndpool_mtx);
entcnt = rndpool_get_entropy_count(&rnd_pool);
- mutex_exit(&rndpool_mtx);
-
if (entcnt >= RND_ENTROPY_THRESHOLD * 8)
revents |= events & (POLLIN | POLLRDNORM);
else
selrecord(l, &rnd_selq);
+ mutex_exit(&rndpool_mtx);
return (revents);
}
@@ -734,7 +714,9 @@ filt_rndread(struct knote *kn, long hint
{
uint32_t entcnt;
+ mutex_enter(&rndpool_mtx);
entcnt = rndpool_get_entropy_count(&rnd_pool);
+ mutex_exit(&rndpool_mtx);
if (entcnt >= RND_ENTROPY_THRESHOLD * 8) {
kn->kn_data = RND_TEMP_BUFFER_SIZE;
return (1);
@@ -1071,14 +1053,14 @@ rnd_timeout(void *arg)
rnd_wakeup_readers();
}
-u_int32_t
-rnd_extract_data(void *p, u_int32_t len, u_int32_t flags)
+static u_int32_t
+rnd_extract_data_locked(void *p, u_int32_t len, u_int32_t flags)
{
- int retval;
- u_int32_t c;
- mutex_enter(&rndpool_mtx);
+ KASSERT(mutex_owned(&rndpool_mtx));
if (!rnd_have_entropy) {
+ u_int32_t c;
+
#ifdef RND_VERBOSE
printf("rnd: WARNING! initial entropy low (%u).\n",
rndpool_get_entropy_count(&rnd_pool));
@@ -1087,8 +1069,16 @@ rnd_extract_data(void *p, u_int32_t len,
c = rnd_counter();
rndpool_add_data(&rnd_pool, &c, sizeof(u_int32_t), 1);
}
- retval = rndpool_extract_data(&rnd_pool, p, len, flags);
- mutex_exit(&rndpool_mtx);
+ return rndpool_extract_data(&rnd_pool, p, len, flags);
+}
- return (retval);
+u_int32_t
+rnd_extract_data(void *p, u_int32_t len, u_int32_t flags)
+{
+ uint32_t retval;
+
+ mutex_enter(&rndpool_mtx);
+ retval = rnd_extract_data_locked(p, len, flags);
+ mutex_exit(&rndpool_mtx);
+ return retval;
}
