From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.osdl.org ([65.172.181.24]:51622 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030476AbXBTV7l (ORCPT ); Tue, 20 Feb 2007 16:59:41 -0500 Message-Id: <200702202159.l1KLxMcC021074@shell0.pdx.osdl.net> Subject: [patch 18/50] add epoll compat code to kernel/compat.c From: akpm@linux-foundation.org Date: Tue, 20 Feb 2007 13:57:58 -0800 Sender: linux-arch-owner@vger.kernel.org To: torvalds@linux-foundation.org Cc: akpm@linux-foundation.org, davidel@xmailserver.org, dwmw2@infradead.org, linux-arch@vger.kernel.org, rmk@arm.linux.org.uk, tony.luck@intel.com List-ID: From: Davide Libenzi Add epoll compat_ code to kernel/compat.c. IA64 and ARM-OABI are currently using their own version of epoll compat_ code and they could probably wire to the new common code. Unfortunately, sys_epoll_pwait needs two compat versions, one for sigset_t only, and one for sigset_t+epoll_event. Architectures that do not require epoll_event translation [1] whould wire compat_sys_epoll_pwait, while the ones that do require it, should wire compat_sys_epoll_pwait2. Architectures that do not require epoll_event translation, should *not* wire neither compat_sys_epoll_ctl nor compat_sys_epoll_wait. Patch over 2.6.20. [1] An architecture needs epoll_event translation is alignof(u64) in 32 bits mode is 4, *and* alignof(u64) in 64 bits mode is 8. [akpm@linux-foundation.org: cleanups] Signed-off-by: Davide Libenzi Cc: David Woodhouse Cc: Russell King Cc: "Luck, Tony" Cc: Signed-off-by: Andrew Morton --- fs/eventpoll.c | 9 +- include/linux/compat.h | 34 +++++++++ kernel/compat.c | 145 ++++++++++++++++++++++++++++++++++++++- 3 files changed, 183 insertions(+), 5 deletions(-) diff -puN fs/eventpoll.c~add-epoll-compat-code-to-kernel-compatc fs/eventpoll.c --- a/fs/eventpoll.c~add-epoll-compat-code-to-kernel-compatc +++ a/fs/eventpoll.c @@ -544,8 +544,8 @@ eexit_1: * file descriptors inside the interest set. It represents * the kernel part of the user space epoll_ctl(2). */ -asmlinkage long -sys_epoll_ctl(int epfd, int op, int fd, struct epoll_event __user *event) +asmlinkage long sys_epoll_ctl(int epfd, int op, int fd, + struct epoll_event __user *event) { int error; struct file *file, *tfile; @@ -707,8 +707,9 @@ eexit_1: * part of the user space epoll_pwait(2). */ asmlinkage long sys_epoll_pwait(int epfd, struct epoll_event __user *events, - int maxevents, int timeout, const sigset_t __user *sigmask, - size_t sigsetsize) + int maxevents, int timeout, + const sigset_t __user *sigmask, + size_t sigsetsize) { int error; sigset_t ksigmask, sigsaved; diff -puN include/linux/compat.h~add-epoll-compat-code-to-kernel-compatc include/linux/compat.h --- a/include/linux/compat.h~add-epoll-compat-code-to-kernel-compatc +++ a/include/linux/compat.h @@ -234,5 +234,39 @@ asmlinkage long compat_sys_migrate_pages 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 ... + */ +struct epoll_event; + +struct compat_epoll_event { + u32 events; + u32 data[2]; +}; + +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); + +/* + * Architectures that does not need "struct epoll_event" translation + * should wire compat_sys_epoll_pwait. The ones that needs "struct epoll_event" + * translation, should wire compat_sys_epoll_pwait2. An architecture needs + * "struct epoll_event" translation is alignof(u64) in 32 bits mode is 4, and + * alignof(u64) in 64 bits mode is 8. + */ +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); +asmlinkage long compat_sys_epoll_pwait2(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 */ diff -puN kernel/compat.c~add-epoll-compat-code-to-kernel-compatc kernel/compat.c --- a/kernel/compat.c~add-epoll-compat-code-to-kernel-compatc +++ a/kernel/compat.c @@ -23,6 +23,7 @@ #include #include #include +#include #include @@ -1017,6 +1018,149 @@ asmlinkage long compat_sys_migrate_pages } #endif +#ifdef CONFIG_EPOLL + +/* + * epoll (fs/eventpoll.c) compat functions follow ... + */ + +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; + union { + u64 q; + u32 d[2]; + } mux; + + 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); + mux.d[0] = user.data[0]; + mux.d[1] = user.data[1]; + err |= __put_user(mux.q, &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; + union { + u64 q; + u32 d[2]; + } mux; + + 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); + mux.q = ev.data; + err |= put_user(mux.d[0], &events->data[0]); + err |= put_user(mux.d[1], &events->data[1]); + events++; + } + + return err ? -EFAULT: ret; +} + + +#ifdef TIF_RESTORE_SIGMASK + +static long __sys_epoll_pwait(int epfd, void __user *events, int maxevents, + int timeout, const compat_sigset_t __user *sigmask, + compat_size_t sigsetsize, + long (asmlinkage *proc)(int, void __user *, int, int)) +{ + long err; + 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); + } + + err = (*proc)(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 (err == -EINTR) { + memcpy(¤t->saved_sigmask, &sigsaved, + sizeof(sigsaved)); + set_thread_flag(TIF_RESTORE_SIGMASK); + } else + sigprocmask(SIG_SETMASK, &sigsaved, NULL); + } + + return err; +} + +/* + * Architectures that does not need "struct epoll_event" translation + * should wire compat_sys_epoll_pwait. The ones that needs "struct epoll_event" + * translation, should wire compat_sys_epoll_pwait2. An architecture needs + * "struct epoll_event" translation is alignof(u64) in 32 bits mode is 4, and + * alignof(u64) in 64 bits mode is 8. + */ +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) +{ + return __sys_epoll_pwait(epfd, events, maxevents, timeout, sigmask, + sigsetsize, + (long (asmlinkage *)(int, void __user *, int, int)) + sys_epoll_wait); +} + + +asmlinkage long compat_sys_epoll_pwait2(int epfd, + struct compat_epoll_event __user *events, + int maxevents, int timeout, + const compat_sigset_t __user *sigmask, + compat_size_t sigsetsize) +{ + return __sys_epoll_pwait(epfd, events, maxevents, timeout, sigmask, + sigsetsize, + (long (asmlinkage *)(int, void __user *, int, int)) + compat_sys_epoll_wait); +} + +#endif /* TIF_RESTORE_SIGMASK */ +#endif /* CONFIG_EPOLL */ + struct compat_sysinfo { s32 uptime; u32 loads[3]; @@ -1081,4 +1225,3 @@ compat_sys_sysinfo(struct compat_sysinfo return 0; } - _