Module: xenomai-3
Branch: wip/dovetail
Commit: 37f90fb2a9d1d8ad6e120e01c8972817b315baf6
URL:
http://git.xenomai.org/?p=xenomai-3.git;a=commit;h=37f90fb2a9d1d8ad6e120e01c8972817b315baf6
Author: Philippe Gerum <r...@xenomai.org>
Date: Thu Jul 7 18:35:47 2016 +0200
cobalt/rtdm: leave mode selection to I/O syscall handlers
We don't want requests bearing invalid file descriptors (RTDM-wise) to
trigger any mode switch, so that RTDM requests on regular fildes can
be rejected with little overhead.
Tell the core to hand over mode selection to RTDM I/O syscall
handlers, which now check the file descriptor prior to triggering any
mode transition.
---
kernel/cobalt/posix/io.c | 10 +--
kernel/cobalt/posix/syscall32.c | 4 +-
kernel/cobalt/rtdm/fd.c | 144 +++++++++++++++++++++++----------------
3 files changed, 92 insertions(+), 66 deletions(-)
diff --git a/kernel/cobalt/posix/io.c b/kernel/cobalt/posix/io.c
index 7110d21..42b7b00 100644
--- a/kernel/cobalt/posix/io.c
+++ b/kernel/cobalt/posix/io.c
@@ -58,25 +58,25 @@ COBALT_SYSCALL(fcntl, current, (int fd, int cmd, int arg))
return rtdm_fd_fcntl(fd, cmd, arg);
}
-COBALT_SYSCALL(ioctl, probing,
+COBALT_SYSCALL(ioctl, handover,
(int fd, unsigned int request, void __user *arg))
{
return rtdm_fd_ioctl(fd, request, arg);
}
-COBALT_SYSCALL(read, probing,
+COBALT_SYSCALL(read, handover,
(int fd, void __user *buf, size_t size))
{
return rtdm_fd_read(fd, buf, size);
}
-COBALT_SYSCALL(write, probing,
+COBALT_SYSCALL(write, handover,
(int fd, const void __user *buf, size_t size))
{
return rtdm_fd_write(fd, buf, size);
}
-COBALT_SYSCALL(recvmsg, probing,
+COBALT_SYSCALL(recvmsg, handover,
(int fd, struct user_msghdr __user *umsg, int flags))
{
struct user_msghdr m;
@@ -93,7 +93,7 @@ COBALT_SYSCALL(recvmsg, probing,
return cobalt_copy_to_user(umsg, &m, sizeof(*umsg)) ?: ret;
}
-COBALT_SYSCALL(sendmsg, probing,
+COBALT_SYSCALL(sendmsg, handover,
(int fd, struct user_msghdr __user *umsg, int flags))
{
struct user_msghdr m;
diff --git a/kernel/cobalt/posix/syscall32.c b/kernel/cobalt/posix/syscall32.c
index 0576b37..bc8b9d9 100644
--- a/kernel/cobalt/posix/syscall32.c
+++ b/kernel/cobalt/posix/syscall32.c
@@ -766,7 +766,7 @@ COBALT_SYSCALL32emu(select, nonrestartable,
return err;
}
-COBALT_SYSCALL32emu(recvmsg, probing,
+COBALT_SYSCALL32emu(recvmsg, handover,
(int fd, struct compat_msghdr __user *umsg,
int flags))
{
@@ -784,7 +784,7 @@ COBALT_SYSCALL32emu(recvmsg, probing,
return sys32_put_msghdr(umsg, &m) ?: ret;
}
-COBALT_SYSCALL32emu(sendmsg, probing,
+COBALT_SYSCALL32emu(sendmsg, handover,
(int fd, struct compat_msghdr __user *umsg, int flags))
{
struct user_msghdr m;
diff --git a/kernel/cobalt/rtdm/fd.c b/kernel/cobalt/rtdm/fd.c
index d82cfe4..3381dea 100644
--- a/kernel/cobalt/rtdm/fd.c
+++ b/kernel/cobalt/rtdm/fd.c
@@ -392,6 +392,44 @@ int rtdm_fd_fcntl(int ufd, int cmd, ...)
}
EXPORT_SYMBOL_GPL(rtdm_fd_fcntl);
+static struct rtdm_fd *get_fd_fixup_mode(int ufd)
+{
+ struct xnthread *thread;
+ struct rtdm_fd *fd;
+
+ fd = rtdm_fd_get(ufd, 0);
+ if (IS_ERR(fd))
+ return fd;
+
+ /*
+ * Mode is selected according to the following convention:
+ *
+ * - Cobalt threads must try running the syscall from primary
+ * mode as a first attempt, regardless of their scheduling
+ * class. The driver handler may ask for demoting the caller
+ * to secondary mode by returning -ENOSYS.
+ *
+ * - Regular threads (i.e. not bound to Cobalt) may only run
+ * the syscall from secondary mode.
+ */
+ thread = xnthread_current();
+ if (unlikely(ipipe_root_p)) {
+ if (thread == NULL ||
+ xnthread_test_localinfo(thread, XNDESCENT))
+ return fd;
+ } else if (likely(thread))
+ return fd;
+
+ /*
+ * We need to switch to the converse mode. Since all callers
+ * bear the "adaptive" tag, we just pass -ENOSYS back to the
+ * syscall dispatcher to get switched to the next mode.
+ */
+ rtdm_fd_put(fd);
+
+ return ERR_PTR(-ENOSYS);
+}
+
int rtdm_fd_ioctl(int ufd, unsigned int request, ...)
{
struct rtdm_fd *fd;
@@ -399,16 +437,14 @@ int rtdm_fd_ioctl(int ufd, unsigned int request, ...)
va_list args;
int err, ret;
+ fd = get_fd_fixup_mode(ufd);
+ if (IS_ERR(fd))
+ return PTR_ERR(fd);
+
va_start(args, request);
arg = va_arg(args, void __user *);
va_end(args);
- fd = rtdm_fd_get(ufd, 0);
- if (IS_ERR(fd)) {
- err = PTR_ERR(fd);
- goto out;
- }
-
set_compat_bit(fd);
trace_cobalt_fd_ioctl(current, fd, ufd, request);
@@ -419,7 +455,7 @@ int rtdm_fd_ioctl(int ufd, unsigned int request, ...)
err = fd->ops->ioctl_rt(fd, request, arg);
if (!XENO_ASSERT(COBALT, !spltest()))
- splnone();
+ splnone();
if (err < 0) {
ret = __rtdm_dev_ioctl_core(fd, request, arg);
@@ -428,7 +464,7 @@ int rtdm_fd_ioctl(int ufd, unsigned int request, ...)
}
rtdm_fd_put(fd);
- out:
+
if (err < 0)
trace_cobalt_fd_ioctl_status(current, fd, ufd, err);
@@ -440,130 +476,120 @@ ssize_t
rtdm_fd_read(int ufd, void __user *buf, size_t size)
{
struct rtdm_fd *fd;
- ssize_t err;
+ ssize_t ret;
- fd = rtdm_fd_get(ufd, 0);
- if (IS_ERR(fd)) {
- err = PTR_ERR(fd);
- goto out;
- }
+ fd = get_fd_fixup_mode(ufd);
+ if (IS_ERR(fd))
+ return PTR_ERR(fd);
set_compat_bit(fd);
trace_cobalt_fd_read(current, fd, ufd, size);
if (ipipe_root_p)
- err = fd->ops->read_nrt(fd, buf, size);
+ ret = fd->ops->read_nrt(fd, buf, size);
else
- err = fd->ops->read_rt(fd, buf, size);
+ ret = fd->ops->read_rt(fd, buf, size);
if (!XENO_ASSERT(COBALT, !spltest()))
- splnone();
+ splnone();
rtdm_fd_put(fd);
- out:
- if (err < 0)
- trace_cobalt_fd_read_status(current, fd, ufd, err);
+ if (ret < 0)
+ trace_cobalt_fd_read_status(current, fd, ufd, ret);
- return err;
+ return ret;
}
EXPORT_SYMBOL_GPL(rtdm_fd_read);
ssize_t rtdm_fd_write(int ufd, const void __user *buf, size_t size)
{
struct rtdm_fd *fd;
- ssize_t err;
+ ssize_t ret;
- fd = rtdm_fd_get(ufd, 0);
- if (IS_ERR(fd)) {
- err = PTR_ERR(fd);
- goto out;
- }
+ fd = get_fd_fixup_mode(ufd);
+ if (IS_ERR(fd))
+ return PTR_ERR(fd);
set_compat_bit(fd);
trace_cobalt_fd_write(current, fd, ufd, size);
if (ipipe_root_p)
- err = fd->ops->write_nrt(fd, buf, size);
+ ret = fd->ops->write_nrt(fd, buf, size);
else
- err = fd->ops->write_rt(fd, buf, size);
+ ret = fd->ops->write_rt(fd, buf, size);
if (!XENO_ASSERT(COBALT, !spltest()))
- splnone();
+ splnone();
rtdm_fd_put(fd);
- out:
- if (err < 0)
- trace_cobalt_fd_write_status(current, fd, ufd, err);
+ if (ret < 0)
+ trace_cobalt_fd_write_status(current, fd, ufd, ret);
- return err;
+ return ret;
}
EXPORT_SYMBOL_GPL(rtdm_fd_write);
ssize_t rtdm_fd_recvmsg(int ufd, struct user_msghdr *msg, int flags)
{
struct rtdm_fd *fd;
- ssize_t err;
+ ssize_t ret;
- fd = rtdm_fd_get(ufd, 0);
- if (IS_ERR(fd)) {
- err = PTR_ERR(fd);
- goto out;
- }
+ fd = get_fd_fixup_mode(ufd);
+ if (IS_ERR(fd))
+ return PTR_ERR(fd);
set_compat_bit(fd);
trace_cobalt_fd_recvmsg(current, fd, ufd, flags);
if (ipipe_root_p)
- err = fd->ops->recvmsg_nrt(fd, msg, flags);
+ ret = fd->ops->recvmsg_nrt(fd, msg, flags);
else
- err = fd->ops->recvmsg_rt(fd, msg, flags);
+ ret = fd->ops->recvmsg_rt(fd, msg, flags);
if (!XENO_ASSERT(COBALT, !spltest()))
splnone();
rtdm_fd_put(fd);
-out:
- if (err < 0)
- trace_cobalt_fd_recvmsg_status(current, fd, ufd, err);
- return err;
+ if (ret < 0)
+ trace_cobalt_fd_recvmsg_status(current, fd, ufd, ret);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(rtdm_fd_recvmsg);
ssize_t rtdm_fd_sendmsg(int ufd, const struct user_msghdr *msg, int flags)
{
struct rtdm_fd *fd;
- ssize_t err;
+ ssize_t ret;
- fd = rtdm_fd_get(ufd, 0);
- if (IS_ERR(fd)) {
- err = PTR_ERR(fd);
- goto out;
- }
+ fd = get_fd_fixup_mode(ufd);
+ if (IS_ERR(fd))
+ return PTR_ERR(fd);
set_compat_bit(fd);
trace_cobalt_fd_sendmsg(current, fd, ufd, flags);
if (ipipe_root_p)
- err = fd->ops->sendmsg_nrt(fd, msg, flags);
+ ret = fd->ops->sendmsg_nrt(fd, msg, flags);
else
- err = fd->ops->sendmsg_rt(fd, msg, flags);
+ ret = fd->ops->sendmsg_rt(fd, msg, flags);
if (!XENO_ASSERT(COBALT, !spltest()))
- splnone();
+ splnone();
rtdm_fd_put(fd);
-out:
- if (err < 0)
- trace_cobalt_fd_sendmsg_status(current, fd, ufd, err);
- return err;
+ if (ret < 0)
+ trace_cobalt_fd_sendmsg_status(current, fd, ufd, ret);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(rtdm_fd_sendmsg);
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