[Xenomai-git] Philippe Gerum : cobalt/rtdm/core: enable legacy pathnames for named devices
Module: xenomai-forge
Branch: next
Commit: 7d7a1936a2968b1f5415651725835e7790afcbbf
URL:
http://git.xenomai.org/?p=xenomai-forge.git;a=commit;h=7d7a1936a2968b1f5415651725835e7790afcbbf
Author: Philippe Gerum
Date: Sun Sep 21 10:16:43 2014 +0200
cobalt/rtdm/core: enable legacy pathnames for named devices
---
kernel/cobalt/rtdm/core.c | 48 -
kernel/drivers/Kconfig| 21
2 files changed, 68 insertions(+), 1 deletion(-)
diff --git a/kernel/cobalt/rtdm/core.c b/kernel/cobalt/rtdm/core.c
index 896f139..f5c82f7 100644
--- a/kernel/cobalt/rtdm/core.c
+++ b/kernel/cobalt/rtdm/core.c
@@ -96,6 +96,40 @@ static int create_instance(int ufd, struct rtdm_device *dev,
return rtdm_fd_enter(&context->fd, ufd, RTDM_FD_MAGIC, &dev->ops);
}
+#ifdef CONFIG_XENO_OPT_RTDM_COMPAT_DEVNODE
+
+static inline struct file *
+open_devnode(struct rtdm_device *dev, const char *path, int oflag)
+{
+ struct file *filp;
+ char *filename;
+
+#ifdef CONFIG_XENO_OPT_DEBUG_USER
+ if (strncmp(path, "/dev/rtdm/", 10))
+ printk(XENO_WARN
+ "%s[%d] opens obsolete device path: %s\n",
+ current->comm, current->pid, path);
+#endif
+ filename = kasprintf(GFP_KERNEL, "/dev/rtdm/%s", dev->name);
+ if (filename == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ filp = filp_open(filename, oflag, 0);
+ kfree(filename);
+
+ return filp;
+}
+
+#else /* !CONFIG_XENO_OPT_RTDM_COMPAT_DEVNODE */
+
+static inline struct file *
+open_devnode(struct rtdm_device *dev, const char *path, int oflag)
+{
+ return filp_open(path, oflag, 0);
+}
+
+#endif /* !CONFIG_XENO_OPT_RTDM_COMPAT_DEVNODE */
+
int __rtdm_dev_open(const char *path, int oflag)
{
struct rtdm_dev_context *context;
@@ -105,6 +139,18 @@ int __rtdm_dev_open(const char *path, int oflag)
secondary_mode_only();
+ /*
+* CAUTION: we do want a lookup into the registry to happen
+* before any attempt is made to open the devnode, so that we
+* don't inadvertently open a regular (i.e. non-RTDM) device.
+* Reason is that opening, then closing a device - because we
+* don't manage it - may incur side-effects we don't want,
+* e.g. opening then closing one end of a pipe would cause the
+* other side to read the EOF condition. This is basically
+* why we keep a RTDM registry for named devices, so that we
+* can figure out whether an open() request is going to be
+* valid, without having to open the devnode yet.
+*/
dev = __rtdm_get_namedev(path);
if (dev == NULL)
return -ENODEV;
@@ -115,7 +161,7 @@ int __rtdm_dev_open(const char *path, int oflag)
goto fail_fd;
}
- filp = filp_open(path, oflag, 0);
+ filp = open_devnode(dev, path, oflag);
if (IS_ERR(filp)) {
ret = PTR_ERR(filp);
goto fail_fopen;
diff --git a/kernel/drivers/Kconfig b/kernel/drivers/Kconfig
index 5496f30..a01eb8c 100644
--- a/kernel/drivers/Kconfig
+++ b/kernel/drivers/Kconfig
@@ -1,5 +1,26 @@
menu "Drivers"
+config XENO_OPT_RTDM_COMPAT_DEVNODE
+bool "Enable legacy pathnames for named RTDM devices"
+ default y
+ help
+
+ This compatibility option allows applications to open named
+ RTDM devices using the legacy naming scheme, i.e.
+
+ fd = open("devname", ...);
+ or
+ fd = open("/dev/devname", ...);
+
+ When such a request is received by RTDM, a warning message is
+ issued to the kernel log whenever XENO_OPT_DEBUG_USER is
+ also enabled in the kernel configuration.
+
+ Applications should open named devices via their actual device
+ nodes instead, i.e.
+
+ fd = open("/dev/rtdm/devname", ...);
+
source "drivers/xenomai/autotune/Kconfig"
source "drivers/xenomai/serial/Kconfig"
source "drivers/xenomai/testing/Kconfig"
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[Xenomai-git] Philippe Gerum : cobalt/rtdm/core: enable legacy pathnames for named devices
Module: xenomai-forge
Branch: next
Commit: c04e569927f783e946ed66c9569e9df0441c00b1
URL:
http://git.xenomai.org/?p=xenomai-forge.git;a=commit;h=c04e569927f783e946ed66c9569e9df0441c00b1
Author: Philippe Gerum
Date: Sun Sep 21 10:16:43 2014 +0200
cobalt/rtdm/core: enable legacy pathnames for named devices
---
kernel/cobalt/rtdm/core.c | 48 -
kernel/drivers/Kconfig| 21
2 files changed, 68 insertions(+), 1 deletion(-)
diff --git a/kernel/cobalt/rtdm/core.c b/kernel/cobalt/rtdm/core.c
index 896f139..076af73 100644
--- a/kernel/cobalt/rtdm/core.c
+++ b/kernel/cobalt/rtdm/core.c
@@ -96,6 +96,40 @@ static int create_instance(int ufd, struct rtdm_device *dev,
return rtdm_fd_enter(&context->fd, ufd, RTDM_FD_MAGIC, &dev->ops);
}
+#ifdef CONFIG_XENO_OPT_RTDM_COMPAT_DEVNODE
+
+static inline struct file *
+open_devnode(struct rtdm_device *dev, const char *path, int oflag)
+{
+ struct file *filp;
+ char *filename;
+
+#ifdef CONFIG_XENO_OPT_DEBUG_USER
+ if (strncmp(path, "/dev/rtdm/", 10))
+ printk(XENO_WARN
+ "%s[%d] opens obsolete device path: %s",
+ current->comm, current->pid, path);
+#endif
+ filename = kasprintf(GFP_KERNEL, "/dev/rtdm/%s", dev->name);
+ if (filename == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ filp = filp_open(filename, oflag, 0);
+ kfree(filename);
+
+ return filp;
+}
+
+#else /* !CONFIG_XENO_OPT_RTDM_COMPAT_DEVNODE */
+
+static inline struct file *
+open_devnode(struct rtdm_device *dev, const char *path, int oflag)
+{
+ return filp_open(path, oflag, 0);
+}
+
+#endif /* !CONFIG_XENO_OPT_RTDM_COMPAT_DEVNODE */
+
int __rtdm_dev_open(const char *path, int oflag)
{
struct rtdm_dev_context *context;
@@ -105,6 +139,18 @@ int __rtdm_dev_open(const char *path, int oflag)
secondary_mode_only();
+ /*
+* CAUTION: we do want a lookup into the registry to happen
+* before any attempt is made to open the devnode, so that we
+* don't inadvertently open a regular (i.e. non-RTDM) device.
+* Reason is that opening, then closing a device - because we
+* don't manage it - may incur side-effects we don't want,
+* e.g. opening then closing one end of a pipe would cause the
+* other side to read the EOF condition. This is basically
+* why we keep a RTDM registry for named devices, so that we
+* can figure out whether an open() request is going to be
+* valid, without having to open the devnode yet.
+*/
dev = __rtdm_get_namedev(path);
if (dev == NULL)
return -ENODEV;
@@ -115,7 +161,7 @@ int __rtdm_dev_open(const char *path, int oflag)
goto fail_fd;
}
- filp = filp_open(path, oflag, 0);
+ filp = open_devnode(dev, path, oflag);
if (IS_ERR(filp)) {
ret = PTR_ERR(filp);
goto fail_fopen;
diff --git a/kernel/drivers/Kconfig b/kernel/drivers/Kconfig
index 5496f30..a01eb8c 100644
--- a/kernel/drivers/Kconfig
+++ b/kernel/drivers/Kconfig
@@ -1,5 +1,26 @@
menu "Drivers"
+config XENO_OPT_RTDM_COMPAT_DEVNODE
+bool "Enable legacy pathnames for named RTDM devices"
+ default y
+ help
+
+ This compatibility option allows applications to open named
+ RTDM devices using the legacy naming scheme, i.e.
+
+ fd = open("devname", ...);
+ or
+ fd = open("/dev/devname", ...);
+
+ When such a request is received by RTDM, a warning message is
+ issued to the kernel log whenever XENO_OPT_DEBUG_USER is
+ also enabled in the kernel configuration.
+
+ Applications should open named devices via their actual device
+ nodes instead, i.e.
+
+ fd = open("/dev/rtdm/devname", ...);
+
source "drivers/xenomai/autotune/Kconfig"
source "drivers/xenomai/serial/Kconfig"
source "drivers/xenomai/testing/Kconfig"
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