From: Davide Libenzi Date: Thu, 8 Mar 2007 04:41:21 +0000 (-0800) Subject: [PATCH] Add epoll compat_ code to fs/compat.c X-Git-Tag: v2.6.21-rc4~87 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f6dfb4fd7dd94429ef1d5233688aaed2a63f856b;p=linux-2.6 [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 Cc: David Woodhouse Cc: Russell King Cc: "Luck, Tony" Cc: "David S. Miller" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c index 30d433f14f..1df544c1f9 100644 --- a/arch/mips/kernel/linux32.c +++ b/arch/mips/kernel/linux32.c @@ -564,49 +564,3 @@ _sys32_clone(nabi_no_regargs struct pt_regs regs) return do_fork(clone_flags, newsp, ®s, 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(¤t->saved_sigmask, &sigsaved, - sizeof(sigsaved)); - set_thread_flag(TIF_RESTORE_SIGMASK); - } else - sigprocmask(SIG_SETMASK, &sigsaved, NULL); - } - - return error; -} diff --git a/fs/compat.c b/fs/compat.c index 0ec70e3cee..040a8be38a 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -48,6 +48,7 @@ #include #include #include +#include #include /* siocdevprivate_ioctl */ @@ -2235,3 +2236,102 @@ long asmlinkage compat_sys_nfsservctl(int cmd, void *notused, void *notused2) 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 */ diff --git a/include/linux/compat.h b/include/linux/compat.h index 80b17f440e..ccd863dd77 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -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, 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 /* _LINUX_COMPAT_H */