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Commit f6dfb4fd authored by Davide Libenzi's avatar Davide Libenzi Committed by Linus Torvalds
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[PATCH] Add epoll compat_ code to fs/compat.c 



IA64 and ARM-OABI are currently using their own version of epoll compat_
code.

An architecture needs epoll_event translation if alignof(u64) in 32 bit
mode is different from alignof(u64) in 64 bit mode.  If an architecture
needs epoll_event translation, it must define struct compat_epoll_event in
asm/compat.h and set CONFIG_HAVE_COMPAT_EPOLL_EVENT and use
compat_sys_epoll_ctl and compat_sys_epoll_wait.

All 64 bit architecture should use compat_sys_epoll_pwait.

[sfr: restructure and move to fs/compat.c, remove MIPS version
of compat_sys_epoll_pwait, use __put_user_unaligned]

Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b40df574

arch/mips/kernel/linux32.c

+0 −46
Original line number Original line Diff line number Diff line
@@ -564,49 +564,3 @@ _sys32_clone(nabi_no_regargs struct pt_regs regs) 
	return do_fork(clone_flags, newsp, &regs, 0,

	return do_fork(clone_flags, newsp, &regs, 0,

	               parent_tidptr, child_tidptr);

	               parent_tidptr, child_tidptr);

}
 
}
 


/*

 * Implement the event wait interface for the eventpoll file. It is the kernel

 * part of the user space epoll_pwait(2).

 */

asmlinkage long compat_sys_epoll_pwait(int epfd,

	struct epoll_event __user *events, int maxevents, int timeout,

	const compat_sigset_t __user *sigmask, size_t sigsetsize)

{

	int error;

	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(sigset_t))

			return -EINVAL;

		if (!access_ok(VERIFY_READ, sigmask, sizeof(ksigmask)))

			return -EFAULT;

		if (__copy_conv_sigset_from_user(&ksigmask, sigmask))

			return -EFAULT;

		sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));

		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);

	}



	error = sys_epoll_wait(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 (error == -EINTR) {

			memcpy(&current->saved_sigmask, &sigsaved,

				sizeof(sigsaved));

			set_thread_flag(TIF_RESTORE_SIGMASK);

		} else

			sigprocmask(SIG_SETMASK, &sigsaved, NULL);

	}



	return error;

}

fs/compat.c

+100 −0
Original line number Original line Diff line number Diff line
@@ -48,6 +48,7 @@ 
#include <linux/highmem.h>

#include <linux/highmem.h>

#include <linux/poll.h>

#include <linux/poll.h>

#include <linux/mm.h>

#include <linux/mm.h>

#include <linux/eventpoll.h>





#include <net/sock.h>		/* siocdevprivate_ioctl */

#include <net/sock.h>		/* siocdevprivate_ioctl */
@@ -2235,3 +2236,102 @@ long asmlinkage compat_sys_nfsservctl(int cmd, void *notused, void *notused2) 
	return sys_ni_syscall();

	return sys_ni_syscall();

}

}

#endif

#endif



#ifdef CONFIG_EPOLL



#ifdef CONFIG_HAS_COMPAT_EPOLL_EVENT

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;



	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);

		err |= __put_user(user.data, &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;



	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);

		err |= __put_user_unaligned(ev.data, &events->data);

		events++;

	}



	return err ? -EFAULT: ret;

}

#endif	/* CONFIG_HAS_COMPAT_EPOLL_EVENT */



#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)

{

	long err;

	compat_sigset_t csigmask;

	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(&csigmask, sigmask, sizeof(csigmask)))

			return -EFAULT;

		sigset_from_compat(&ksigmask, &csigmask);

		sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));

		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);

	}



#ifdef CONFIG_HAS_COMPAT_EPOLL_EVENT

	err = compat_sys_epoll_wait(epfd, events, maxevents, timeout);

#else

	err = sys_epoll_wait(epfd, events, maxevents, timeout);

#endif



	/*

	 * 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;

}

#endif /* TIF_RESTORE_SIGMASK */



#endif /* CONFIG_EPOLL */

include/linux/compat.h

+19 −0
Original line number Original line Diff line number Diff line
@@ -234,5 +234,24 @@ asmlinkage long compat_sys_migrate_pages(compat_pid_t pid, 
		compat_ulong_t maxnode, const compat_ulong_t __user *old_nodes,

		compat_ulong_t maxnode, const compat_ulong_t __user *old_nodes,

		const compat_ulong_t __user *new_nodes);

		const compat_ulong_t __user *new_nodes);





/*

 * epoll (fs/eventpoll.c) compat bits follow ...

 */

#ifndef CONFIG_HAS_COMPAT_EPOLL_EVENT

struct epoll_event;

#define compat_epoll_event	epoll_event

#else

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);

#endif

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 /* CONFIG_COMPAT */

#endif /* _LINUX_COMPAT_H */
 
#endif /* _LINUX_COMPAT_H */