On Tue, 2006-10-03 at 08:57 +0100, David Woodhouse wrote:
> On Tue, 2006-10-03 at 00:27 -0700, Andrew Morton wrote:
> >
> > I'm about to send this Linuswards. Architectures which implement
> > TIF_RESTORE_SIGMASK can wire it up.
>
> It needs compat_sys_epoll_wait() for the signal stuff though.
Something like the patch below ought to suffice, although it's not
tested further than just building it.
----
[PATCH] Provide compat_sys_epoll_pwait(), wire up on PowerPC.
Also add a comment trying to make sense of the definition of
struct epoll_event.
Signed-off-by: David Woodhouse <[EMAIL PROTECTED]>
diff -u a/fs/eventpoll.c b/fs/eventpoll.c
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -35,6 +35,7 @@
#include <linux/mount.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
+#include <linux/compat.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
@@ -745,6 +746,53 @@
return error;
}
+#ifdef CONFIG_COMPAT
+extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
+
+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)
+{
+ 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);
+ }
+
+ 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(¤t->saved_sigmask, &sigsaved,
sizeof(sigsaved));
+ set_thread_flag(TIF_RESTORE_SIGMASK);
+ } else
+ sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+ }
+
+ return error;
+}
+#endif /* CONFIG_COMPAT */
+
#endif /* #ifdef TIF_RESTORE_SIGMASK */
only in patch2:
unchanged:
--- a/include/asm-powerpc/systbl.h
+++ b/include/asm-powerpc/systbl.h
@@ -304,3 +304,4 @@ SYSCALL_SPU(fchmodat)
SYSCALL_SPU(faccessat)
COMPAT_SYS_SPU(get_robust_list)
COMPAT_SYS_SPU(set_robust_list)
+COMPAT_SYS(epoll_pwait)
only in patch2:
unchanged:
--- a/include/asm-powerpc/unistd.h
+++ b/include/asm-powerpc/unistd.h
@@ -323,10 +323,11 @@ #define __NR_fchmodat 297
#define __NR_faccessat 298
#define __NR_get_robust_list 299
#define __NR_set_robust_list 300
+#define __NR_epoll_pwait 301
#ifdef __KERNEL__
-#define __NR_syscalls 301
+#define __NR_syscalls 302
#define __NR__exit __NR_exit
#define NR_syscalls __NR_syscalls
only in patch2:
unchanged:
--- a/include/linux/eventpoll.h
+++ b/include/linux/eventpoll.h
@@ -29,8 +29,11 @@ #define EPOLLONESHOT (1 << 30)
#define EPOLLET (1 << 31)
/*
- * On x86-64 make the 64bit structure have the same alignment as the
- * 32bit structure. This makes 32bit emulation easier.
+ * On i386, the u64 won't be aligned to 64-bits. So on x86_64 we pack
+ * the structure to be compatible. It seems that other 32-bit architectures
+ * will align the u64 naturally anyway, so we don't have to worry there.
+ * For example, both ppc and ppc64 put an extra 32 bits of padding in
+ * between the fields.
*/
#ifdef __x86_64__
#define EPOLL_PACKED __attribute__((packed))
--
dwmw2
-
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