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* + add-epoll-compat-code-to-kernel-compatc.patch added to -mm tree
@ 2007-02-13  6:17 akpm
  0 siblings, 0 replies; 3+ messages in thread
From: akpm @ 2007-02-13  6:17 UTC (permalink / raw)
  To: mm-commits; +Cc: davidel, dwmw2, linux-arch, rmk, tony.luck


The patch titled
     add epoll compat code to kernel/compat.c
has been added to the -mm tree.  Its filename is
     add-epoll-compat-code-to-kernel-compatc.patch

*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

------------------------------------------------------
Subject: add epoll compat code to kernel/compat.c
From: Davide Libenzi <davidel@xmailserver.org>

Add epoll compat_ code to kernel/compat.c.  IA64 and ARM-OABI are currently
using their own version of epoll compat_ code and they could probably wire to
the new common code.

Unfortunately, sys_epoll_pwait needs two compat versions, one for sigset_t
only, and one for sigset_t+epoll_event.

Architectures that do not require epoll_event translation [1] whould wire
compat_sys_epoll_pwait, while the ones that do require it, should wire
compat_sys_epoll_pwait2.

Architectures that do not require epoll_event translation, should *not* wire
neither compat_sys_epoll_ctl nor compat_sys_epoll_wait.  Patch over 2.6.20.


[1] An architecture needs epoll_event translation is alignof(u64) in 32 
    bits mode is 4, *and* alignof(u64) in 64 bits mode is 8.


Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/eventpoll.c         |    7 -
 include/linux/compat.h |   30 ++++++++
 kernel/compat.c        |  138 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 171 insertions(+), 4 deletions(-)

diff -puN fs/eventpoll.c~add-epoll-compat-code-to-kernel-compatc fs/eventpoll.c
--- a/fs/eventpoll.c~add-epoll-compat-code-to-kernel-compatc
+++ a/fs/eventpoll.c
@@ -544,8 +544,7 @@ eexit_1:
  * file descriptors inside the interest set.  It represents
  * the kernel part of the user space epoll_ctl(2).
  */
-asmlinkage long
-sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event)
+asmlinkage long sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event)
 {
 	int error;
 	struct file *file, *tfile;
@@ -707,8 +706,8 @@ eexit_1:
  * part of the user space epoll_pwait(2).
  */
 asmlinkage long sys_epoll_pwait(int epfd, struct epoll_event __user *events,
-		int maxevents, int timeout, const sigset_t __user *sigmask,
-		size_t sigsetsize)
+				int maxevents, int timeout, const sigset_t __user *sigmask,
+				size_t sigsetsize)
 {
 	int error;
 	sigset_t ksigmask, sigsaved;
diff -puN include/linux/compat.h~add-epoll-compat-code-to-kernel-compatc include/linux/compat.h
--- a/include/linux/compat.h~add-epoll-compat-code-to-kernel-compatc
+++ a/include/linux/compat.h
@@ -234,5 +234,35 @@ asmlinkage long compat_sys_migrate_pages
 		compat_ulong_t maxnode, const compat_ulong_t __user *old_nodes,
 		const compat_ulong_t __user *new_nodes);
 
+/*
+ * epoll (fs/eventpoll.c) compat bits follow ...
+ */
+struct epoll_event;
+
+struct compat_epoll_event {
+	u32 events;
+	u32 data[2];
+};
+
+asmlinkage long compat_sys_epoll_ctl(int epfd, int op, int fd,
+				     struct compat_epoll_event __user *event);
+asmlinkage long compat_sys_epoll_wait(int epfd, struct compat_epoll_event __user *events,
+				      int maxevents, int timeout);
+/*
+ * Architectures that does not need "struct epoll_event" translation
+ * should wire compat_sys_epoll_pwait. The ones that needs "struct epoll_event"
+ * translation, should wire compat_sys_epoll_pwait2. An architecture needs
+ * "struct epoll_event" translation is alignof(u64) in 32 bits mode is 4, and
+ * alignof(u64) in 64 bits mode is 8.
+ */
+asmlinkage long compat_sys_epoll_pwait(int epfd, struct epoll_event __user *events,
+				       int maxevents, int timeout,
+				       const compat_sigset_t __user *sigmask,
+				       compat_size_t sigsetsize);
+asmlinkage long compat_sys_epoll_pwait2(int epfd, struct compat_epoll_event __user *events,
+					int maxevents, int timeout,
+					const compat_sigset_t __user *sigmask,
+					compat_size_t sigsetsize);
+
 #endif /* CONFIG_COMPAT */
 #endif /* _LINUX_COMPAT_H */
diff -puN kernel/compat.c~add-epoll-compat-code-to-kernel-compatc kernel/compat.c
--- a/kernel/compat.c~add-epoll-compat-code-to-kernel-compatc
+++ a/kernel/compat.c
@@ -23,6 +23,7 @@
 #include <linux/timex.h>
 #include <linux/migrate.h>
 #include <linux/posix-timers.h>
+#include <linux/eventpoll.h>
 
 #include <asm/uaccess.h>
 
@@ -1017,6 +1018,143 @@ asmlinkage long compat_sys_migrate_pages
 }
 #endif
 
+#ifdef CONFIG_EPOLL
+
+/*
+
+ epoll (fs/eventpoll.c) compat functions follow ...
+ */
+
+asmlinkage long compat_sys_epoll_ctl(int epfd, int op, int fd,
+				     struct compat_epoll_event __user *event)
+{
+	long err = 0;
+	struct compat_epoll_event user;
+	struct epoll_event __user *kernel = NULL;
+	union {
+		u64 q;
+		u32 d[2];
+	} mux;
+
+	if (event) {
+		if (copy_from_user(&user, event, sizeof(user)))
+			return -EFAULT;
+		kernel = compat_alloc_user_space(sizeof(struct epoll_event));
+		err |= __put_user(user.events, &kernel->events);
+		mux.d[0] = user.data[0];
+		mux.d[1] = user.data[1];
+		err |= __put_user(mux.q, &kernel->data);
+	}
+
+	return err ? err: sys_epoll_ctl(epfd, op, fd, kernel);
+}
+
+
+asmlinkage long compat_sys_epoll_wait(int epfd, struct compat_epoll_event __user *events,
+				      int maxevents, int timeout)
+{
+	long i, ret, err = 0;
+	struct epoll_event __user *kbuf;
+	struct epoll_event ev;
+	union {
+		u64 q;
+		u32 d[2];
+	} mux;
+
+	if (maxevents <= 0 || maxevents > (INT_MAX / sizeof(struct epoll_event)))
+		return -EINVAL;
+	kbuf = compat_alloc_user_space(sizeof(struct epoll_event) * maxevents);
+	ret = sys_epoll_wait(epfd, kbuf, maxevents, timeout);
+	for (i = 0; i < ret; i++) {
+		err |= __get_user(ev.events, &kbuf[i].events);
+		err |= __get_user(ev.data, &kbuf[i].data);
+		err |= put_user(ev.events, &events->events);
+		mux.q = ev.data;
+		err |= put_user(mux.d[0], &events->data[0]);
+		err |= put_user(mux.d[1], &events->data[1]);
+		events++;
+	}
+
+	return err ? -EFAULT: ret;
+}
+
+
+#ifdef TIF_RESTORE_SIGMASK
+
+static long __sys_epoll_pwait(int epfd, void __user *events, int maxevents,
+			      int timeout, const compat_sigset_t __user *sigmask,
+			      compat_size_t sigsetsize,
+			      long (asmlinkage *proc)(int, void __user *, int, int))
+{
+	long err;
+	compat_sigset_t ss32;
+	sigset_t ksigmask, sigsaved;
+
+	/*
+	 * If the caller wants a certain signal mask to be set during the wait,
+	 * we apply it here.
+	 */
+	if (sigmask) {
+		if (sigsetsize != sizeof(compat_sigset_t))
+			return -EINVAL;
+		if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
+			return -EFAULT;
+		sigset_from_compat(&ksigmask, &ss32);
+		sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));
+		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
+	}
+
+	err = (*proc)(epfd, events, maxevents, timeout);
+
+	/*
+	 * If we changed the signal mask, we need to restore the original one.
+	 * In case we've got a signal while waiting, we do not restore the
+	 * signal mask yet, and we allow do_signal() to deliver the signal on the way
+	 * back to userspace, before the signal mask is restored.
+	 */
+	if (sigmask) {
+		if (err == -EINTR) {
+			memcpy(&current->saved_sigmask, &sigsaved,
+			       sizeof(sigsaved));
+			set_thread_flag(TIF_RESTORE_SIGMASK);
+		} else
+			sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+	}
+
+	return err;
+}
+
+
+/*
+ * Architectures that does not need "struct epoll_event" translation
+ * should wire compat_sys_epoll_pwait. The ones that needs "struct epoll_event"
+ * translation, should wire compat_sys_epoll_pwait2. An architecture needs
+ * "struct epoll_event" translation is alignof(u64) in 32 bits mode is 4, and
+ * alignof(u64) in 64 bits mode is 8.
+ */
+asmlinkage long compat_sys_epoll_pwait(int epfd, struct epoll_event __user *events,
+				       int maxevents, int timeout,
+				       const compat_sigset_t __user *sigmask,
+				       compat_size_t sigsetsize)
+{
+	return __sys_epoll_pwait(epfd, events, maxevents, timeout, sigmask, sigsetsize,
+				 (long (asmlinkage *)(int, void __user *, int, int)) sys_epoll_wait);
+}
+
+
+asmlinkage long compat_sys_epoll_pwait2(int epfd, struct compat_epoll_event __user *events,
+				       int maxevents, int timeout,
+				       const compat_sigset_t __user *sigmask,
+				       compat_size_t sigsetsize)
+{
+	return __sys_epoll_pwait(epfd, events, maxevents, timeout, sigmask, sigsetsize,
+				 (long (asmlinkage *)(int, void __user *, int, int)) compat_sys_epoll_wait);
+}
+
+#endif /* #ifdef TIF_RESTORE_SIGMASK */
+
+#endif /* #ifdef CONFIG_EPOLL */
+
 struct compat_sysinfo {
 	s32 uptime;
 	u32 loads[3];
_

Patches currently in -mm which might be from davidel@xmailserver.org are

add-epoll-compat-code-to-kernel-compatc.patch
add-epoll-compat-code-to-kernel-compatc-tidy.patch

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: + add-epoll-compat-code-to-kernel-compatc.patch added to -mm tree
  2007-02-13  6:09 akpm
@ 2007-02-13  6:17 ` Andrew Morton
  0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2007-02-13  6:17 UTC (permalink / raw)
  To: davidel, dwmw2, linux-arch, rmk, tony.luck

On Mon, 12 Feb 2007 22:09:12 -0800 akpm@linux-foundation.org wrote:

> The patch titled
>      add epoll compat code to kernel/compat.c
> has been added to the -mm tree.  Its filename is
>      add-epoll-compat-code-to-kernel-compatc.patch

argh, sorry, that was version 47.  I was supposed to merge version 56.  Let
me try again..

^ permalink raw reply	[flat|nested] 3+ messages in thread

* + add-epoll-compat-code-to-kernel-compatc.patch added to -mm tree
@ 2007-02-13  6:09 akpm
  2007-02-13  6:17 ` Andrew Morton
  0 siblings, 1 reply; 3+ messages in thread
From: akpm @ 2007-02-13  6:09 UTC (permalink / raw)
  To: mm-commits; +Cc: davidel, dwmw2, linux-arch, rmk, tony.luck


The patch titled
     add epoll compat code to kernel/compat.c
has been added to the -mm tree.  Its filename is
     add-epoll-compat-code-to-kernel-compatc.patch

*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

------------------------------------------------------
Subject: add epoll compat code to kernel/compat.c
From: Davide Libenzi <davidel@xmailserver.org>

Add epoll compat_ code to kernel/compat.c.  IA64 and ARM-OABI are currently
using their own version of epoll compat_ code and they could probably wire
to the new common code.

Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/eventpoll.c         |    7 -
 include/linux/compat.h |   17 ++++
 kernel/compat.c        |  153 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 173 insertions(+), 4 deletions(-)

diff -puN fs/eventpoll.c~add-epoll-compat-code-to-kernel-compatc fs/eventpoll.c
--- a/fs/eventpoll.c~add-epoll-compat-code-to-kernel-compatc
+++ a/fs/eventpoll.c
@@ -544,8 +544,7 @@ eexit_1:
  * file descriptors inside the interest set.  It represents
  * the kernel part of the user space epoll_ctl(2).
  */
-asmlinkage long
-sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event)
+asmlinkage long sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event)
 {
 	int error;
 	struct file *file, *tfile;
@@ -707,8 +706,8 @@ eexit_1:
  * part of the user space epoll_pwait(2).
  */
 asmlinkage long sys_epoll_pwait(int epfd, struct epoll_event __user *events,
-		int maxevents, int timeout, const sigset_t __user *sigmask,
-		size_t sigsetsize)
+				int maxevents, int timeout, const sigset_t __user *sigmask,
+				size_t sigsetsize)
 {
 	int error;
 	sigset_t ksigmask, sigsaved;
diff -puN include/linux/compat.h~add-epoll-compat-code-to-kernel-compatc include/linux/compat.h
--- a/include/linux/compat.h~add-epoll-compat-code-to-kernel-compatc
+++ a/include/linux/compat.h
@@ -234,5 +234,22 @@ asmlinkage long compat_sys_migrate_pages
 		compat_ulong_t maxnode, const compat_ulong_t __user *old_nodes,
 		const compat_ulong_t __user *new_nodes);
 
+/*
+ * epoll (fs/eventpoll.c) compat bits follow ...
+ */
+struct compat_epoll_event {
+	u32 events;
+	u32 data[2];
+};
+
+asmlinkage long compat_sys_epoll_ctl(int epfd, int op, int fd,
+				     struct compat_epoll_event __user *event);
+asmlinkage long compat_sys_epoll_wait(int epfd, struct compat_epoll_event __user *events,
+				      int maxevents, int timeout);
+asmlinkage long compat_sys_epoll_pwait(int epfd, struct compat_epoll_event __user *events,
+				       int maxevents, int timeout,
+				       const compat_sigset_t __user *sigmask,
+				       compat_size_t sigsetsize);
+
 #endif /* CONFIG_COMPAT */
 #endif /* _LINUX_COMPAT_H */
diff -puN kernel/compat.c~add-epoll-compat-code-to-kernel-compatc kernel/compat.c
--- a/kernel/compat.c~add-epoll-compat-code-to-kernel-compatc
+++ a/kernel/compat.c
@@ -23,6 +23,7 @@
 #include <linux/timex.h>
 #include <linux/migrate.h>
 #include <linux/posix-timers.h>
+#include <linux/eventpoll.h>
 
 #include <asm/uaccess.h>
 
@@ -1017,6 +1018,158 @@ asmlinkage long compat_sys_migrate_pages
 }
 #endif
 
+#ifdef CONFIG_EPOLL
+
+/*
+ * epoll (fs/eventpoll.c) compat functions follow ...
+ *
+ *
+ * We need the compat layer over the epoll_event structure, only if the offset
+ * of the __u64 data member is not 4 (size of the events member that precedes the
+ * data one).
+ */
+#define EPOLL_NEED_EVENT_COMPAT() (offsetof(struct epoll_event, data) != 4)
+
+
+asmlinkage long compat_sys_epoll_ctl(int epfd, int op, int fd,
+				     struct compat_epoll_event __user *event)
+{
+	long ret;
+
+	/*
+	 * If compat is not needed, this simply map to a jump to sys_epoll_ctl(),
+	 * with the "else" code being dropped by GCC.
+	 */
+	if (!EPOLL_NEED_EVENT_COMPAT() || op == EPOLL_CTL_DEL)
+		ret = sys_epoll_ctl(epfd, op, fd, (struct epoll_event __user *) event);
+	else {
+		struct compat_epoll_event user;
+		struct epoll_event __user *kernel;
+		union {
+			u64 q;
+			u32 d[2];
+		} mux;
+
+		/*
+		 * The "event" pointer may be NULL in the EPOLL_CTL_DEL case,
+		 * but we handle such case above, so here we know "event" should
+		 * not be NULL.
+		 */
+		if (copy_from_user(&user, event, sizeof(user)))
+			return -EFAULT;
+		kernel = compat_alloc_user_space(sizeof(struct epoll_event));
+		ret = __put_user(user.events, &kernel->events);
+		mux.d[0] = user.data[0];
+		mux.d[1] = user.data[1];
+		if ((ret |= __put_user(mux.q, &kernel->data)) == 0)
+			ret = sys_epoll_ctl(epfd, op, fd, kernel);
+	}
+
+	return ret;
+}
+
+
+asmlinkage long compat_sys_epoll_wait(int epfd, struct compat_epoll_event __user *events,
+				      int maxevents, int timeout)
+{
+	long ret;
+
+	/*
+	 * The compat_sys_epoll_pwait() function is calling this one. We do need a
+	 * compat function for sys_epoll_pwait() due to the sigset_t size, but not
+	 * every architecture might need a compat layer over sys_epoll_wait().
+	 * With the compile-time test below, a call to compat_sys_epoll_wait() that does
+	 * not need a translation, will map directly to sys_epoll_wait() avoiding the
+	 * double buffer copy for events (that might indeed blow cache and kill
+	 * performance). GCC takes care of removing the unused code (being the condition
+	 * known at compile-time), and issues a simple jump to sys_epoll_wait().
+	 */
+	if (EPOLL_NEED_EVENT_COMPAT()) {
+		struct epoll_event __user *kbuf;
+		struct epoll_event ev;
+		long err, i;
+		union {
+			u64 q;
+			u32 d[2];
+		} mux;
+
+		if (maxevents <= 0 || maxevents > (INT_MAX / sizeof(struct epoll_event)))
+			return -EINVAL;
+		kbuf = compat_alloc_user_space(sizeof(struct epoll_event) * maxevents);
+		ret = sys_epoll_wait(epfd, kbuf, maxevents, timeout);
+		err = 0;
+		for (i = 0; i < ret; i++) {
+			err |= __get_user(ev.events, &kbuf[i].events);
+			err |= __get_user(ev.data, &kbuf[i].data);
+			err |= put_user(ev.events, &events->events);
+			mux.q = ev.data;
+			err |= put_user(mux.d[0], &events->data[0]);
+			err |= put_user(mux.d[1], &events->data[1]);
+			events++;
+		}
+		ret = err ? -EFAULT: ret;
+	} else
+		ret = sys_epoll_wait(epfd, (struct epoll_event __user *) events,
+				     maxevents, timeout);
+
+	return ret;
+}
+
+
+#ifdef TIF_RESTORE_SIGMASK
+
+asmlinkage long compat_sys_epoll_pwait(int epfd, struct compat_epoll_event __user *events,
+				       int maxevents, int timeout,
+				       const compat_sigset_t __user *sigmask,
+				       compat_size_t sigsetsize)
+{
+	int error;
+	compat_sigset_t ss32;
+	sigset_t ksigmask, sigsaved;
+
+	/*
+	 * If the caller wants a certain signal mask to be set during the wait,
+	 * we apply it here.
+	 */
+	if (sigmask) {
+		if (sigsetsize != sizeof(compat_sigset_t))
+			return -EINVAL;
+		if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
+			return -EFAULT;
+		sigset_from_compat(&ksigmask, &ss32);
+		sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));
+		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
+	}
+
+	/* Compile-time switch ... */
+	if (EPOLL_NEED_EVENT_COMPAT())
+		error = compat_sys_epoll_wait(epfd, events, maxevents, timeout);
+	else
+		error = sys_epoll_wait(epfd, (struct epoll_event __user *) events,
+				       maxevents, timeout);
+
+	/*
+	 * If we changed the signal mask, we need to restore the original one.
+	 * In case we've got a signal while waiting, we do not restore the
+	 * signal mask yet, and we allow do_signal() to deliver the signal on the way
+	 * back to userspace, before the signal mask is restored.
+	 */
+	if (sigmask) {
+		if (error == -EINTR) {
+			memcpy(&current->saved_sigmask, &sigsaved,
+			       sizeof(sigsaved));
+			set_thread_flag(TIF_RESTORE_SIGMASK);
+		} else
+			sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+	}
+
+	return error;
+}
+
+#endif /* #ifdef TIF_RESTORE_SIGMASK */
+
+#endif /* #ifdef CONFIG_EPOLL */
+
 struct compat_sysinfo {
 	s32 uptime;
 	u32 loads[3];
_

Patches currently in -mm which might be from davidel@xmailserver.org are

add-epoll-compat-code-to-kernel-compatc.patch

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2007-02-13  6:18 UTC | newest]

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2007-02-13  6:17 ` Andrew Morton

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