From: Christoph Hellwig <hch@lst.de>
To: scherr@net4you.at
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] fix module reference counting in zoran driver
Date: Thu, 19 Feb 2004 16:05:10 +0100 [thread overview]
Message-ID: <20040219150510.GA29687@lst.de> (raw)
Take a reference before calling into the module and release it after
we're done. Also remove the useless (and wrong) refcounting in
videocodec - symbols from this module are used by other modules if
we call into those functions so it can't be unloaded anyway.
We really need to add a debug check to tip all those
try_module_get(THIS_MODULE) callers..
--- 1.3/drivers/media/video/videocodec.c Thu Feb 19 04:42:41 2004
+++ edited/drivers/media/video/videocodec.c Wed Feb 18 03:45:29 2004
@@ -108,13 +108,17 @@
if ((master->flags & h->codec->flags) == master->flags) {
dprintk(4, "videocodec_attach: try '%s'\n",
h->codec->name);
+
+ if (!try_module_get(h->codec->owner))
+ return NULL;
+
codec =
kmalloc(sizeof(struct videocodec), GFP_KERNEL);
if (!codec) {
dprintk(1,
KERN_ERR
"videocodec_attach: no mem\n");
- return NULL;
+ goto out_module_put;
}
memcpy(codec, h->codec, sizeof(struct videocodec));
@@ -132,26 +136,12 @@
dprintk(1,
KERN_ERR
"videocodec_attach: no memory\n");
- kfree(codec);
- return NULL;
+ goto out_kfree;
}
memset(ptr, 0,
sizeof(struct attached_list));
ptr->codec = codec;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
- MOD_INC_USE_COUNT;
-#else
- if (!try_module_get(THIS_MODULE)) {
- dprintk(1,
- KERN_ERR
- "videocodec: failed to increment usecount\n");
- kfree(codec);
- kfree(ptr);
- return NULL;
- }
-#endif
-
a = h->list;
if (!a) {
h->list = ptr;
@@ -177,6 +167,12 @@
dprintk(1, KERN_ERR "videocodec_attach: no codec found!\n");
return NULL;
+
+ out_module_put:
+ module_put(h->codec->owner);
+ out_kfree:
+ kfree(codec);
+ return NULL;
}
int
@@ -228,16 +224,10 @@
dprintk(4,
"videocodec: delete middle\n");
}
+ module_put(a->codec->owner);
kfree(a->codec);
kfree(a);
h->attached -= 1;
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
- MOD_DEC_USE_COUNT;
-#else
- module_put(THIS_MODULE);
-#endif
-
return 0;
}
prev = a;
@@ -274,18 +264,6 @@
memset(ptr, 0, sizeof(struct codec_list));
ptr->codec = codec;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
- MOD_INC_USE_COUNT;
-#else
- if (!try_module_get(THIS_MODULE)) {
- dprintk(1,
- KERN_ERR
- "videocodec: failed to increment module count\n");
- kfree(ptr);
- return -ENODEV;
- }
-#endif
-
if (!h) {
codeclist_top = ptr;
dprintk(4, "videocodec: hooked in as first element\n");
@@ -342,13 +320,6 @@
"videocodec: delete middle element\n");
}
kfree(h);
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
- MOD_DEC_USE_COUNT;
-#else
- module_put(THIS_MODULE);
-#endif
-
return 0;
}
prev = h;
===== drivers/media/video/videocodec.h 1.1 vs edited =====
--- 1.1/drivers/media/video/videocodec.h Wed Aug 20 23:29:31 2003
+++ edited/drivers/media/video/videocodec.h Wed Feb 18 03:45:29 2004
@@ -249,6 +249,7 @@
};
struct videocodec {
+ struct module *owner;
/* -- filled in by slave device during register -- */
char name[32];
unsigned long magic; /* may be used for client<->master attaching */
===== drivers/media/video/zr36016.c 1.1 vs edited =====
--- 1.1/drivers/media/video/zr36016.c Wed Aug 20 23:29:31 2003
+++ edited/drivers/media/video/zr36016.c Wed Feb 18 03:45:29 2004
@@ -422,12 +422,6 @@
codec->data = NULL;
zr36016_codecs--;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
- MOD_DEC_USE_COUNT;
-#else
- module_put(THIS_MODULE);
-#endif
-
return 0;
}
@@ -470,19 +464,6 @@
ptr->num = zr36016_codecs++;
ptr->codec = codec;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
- MOD_INC_USE_COUNT;
-#else
- if (!try_module_get(THIS_MODULE)) {
- dprintk(1,
- KERN_ERR
- "zr36016: failed to increase module use count\n");
- kfree(ptr);
- zr36016_codecs--;
- return -ENODEV;
- }
-#endif
-
//testing
res = zr36016_basic_test(ptr);
if (res < 0) {
@@ -504,6 +485,7 @@
}
static const struct videocodec zr36016_codec = {
+ .owner = THIS_MODULE,
.name = "zr36016",
.magic = 0L, // magic not used
.flags =
===== drivers/media/video/zr36050.c 1.1 vs edited =====
--- 1.1/drivers/media/video/zr36050.c Wed Aug 20 23:29:31 2003
+++ edited/drivers/media/video/zr36050.c Wed Feb 18 03:45:29 2004
@@ -737,12 +737,6 @@
codec->data = NULL;
zr36050_codecs--;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
- MOD_DEC_USE_COUNT;
-#else
- module_put(THIS_MODULE);
-#endif
-
return 0;
}
@@ -785,19 +779,6 @@
ptr->num = zr36050_codecs++;
ptr->codec = codec;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
- MOD_INC_USE_COUNT;
-#else
- if (!try_module_get(THIS_MODULE)) {
- dprintk(1,
- KERN_ERR
- "zr36050: failed to increase module use count\n");
- kfree(ptr);
- zr36050_codecs--;
- return -ENODEV;
- }
-#endif
-
//testing
res = zr36050_basic_test(ptr);
if (res < 0) {
@@ -826,6 +807,7 @@
}
static const struct videocodec zr36050_codec = {
+ .owner = THIS_MODULE,
.name = "zr36050",
.magic = 0L, // magic not used
.flags =
===== drivers/media/video/zr36060.c 1.1 vs edited =====
--- 1.1/drivers/media/video/zr36060.c Wed Aug 20 23:29:31 2003
+++ edited/drivers/media/video/zr36060.c Wed Feb 18 03:45:29 2004
@@ -868,12 +868,6 @@
codec->data = NULL;
zr36060_codecs--;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
- MOD_DEC_USE_COUNT;
-#else
- module_put(THIS_MODULE);
-#endif
-
return 0;
}
@@ -916,19 +910,6 @@
ptr->num = zr36060_codecs++;
ptr->codec = codec;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
- MOD_INC_USE_COUNT;
-#else
- if (!try_module_get(THIS_MODULE)) {
- dprintk(1,
- KERN_ERR
- "zr36060: failed to increase module use count\n");
- kfree(ptr);
- zr36060_codecs--;
- return -ENODEV;
- }
-#endif
-
//testing
res = zr36060_basic_test(ptr);
if (res < 0) {
@@ -958,6 +939,7 @@
}
static const struct videocodec zr36060_codec = {
+ .owner = THIS_MODULE,
.name = "zr36060",
.magic = 0L, // magic not used
.flags =
===== drivers/scsi/megaraid.c 1.59 vs edited =====
--- 1.59/drivers/scsi/megaraid.c Fri Jan 23 06:37:03 2004
+++ edited/drivers/scsi/megaraid.c Wed Feb 18 03:45:29 2004
@@ -4614,6 +4614,7 @@
}
static struct scsi_host_template megaraid_template = {
+ .module = THIS_MODULE,
.name = "MegaRAID",
.proc_name = "megaraid",
.info = megaraid_info,
reply other threads:[~2004-02-19 15:12 UTC|newest]
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