[MIPS] Fix sigset_t endianess swapping issues in 32-bit compat code.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index ca7ad78f4def..fc4dd6c9dd80 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -39,6 +39,7 @@
 #include <net/sock.h>
 #include <net/scm.h>
 
+#include <asm/compat-signal.h>
 #include <asm/ipc.h>
 #include <asm/sim.h>
 #include <asm/uaccess.h>
@@ -736,3 +737,49 @@ _sys32_clone(nabi_no_regargs struct pt_regs regs)
         return do_fork(clone_flags, newsp, &regs, 0,
                        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;
+}