[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: Stephen 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/compat.c b/fs/compat.c
index 0ec70e3..040a8be 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -48,6 +48,7 @@
#include <linux/highmem.h>
#include <linux/poll.h>
#include <linux/mm.h>
+#include <linux/eventpoll.h>
#include <net/sock.h> /* siocdevprivate_ioctl */
@@ -2235,3 +2236,102 @@
return sys_ni_syscall();
}
#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(¤t->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 */