From 7a074e96dee62586c935c80cecd931431bfdd0be Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 2 May 2018 19:51:00 +0200 Subject: aio: implement io_pgetevents This is the io_getevents equivalent of ppoll/pselect and allows to properly mix signals and aio completions (especially with IOCB_CMD_POLL) and atomically executes the following sequence: sigset_t origmask; pthread_sigmask(SIG_SETMASK, &sigmask, &origmask); ret = io_getevents(ctx, min_nr, nr, events, timeout); pthread_sigmask(SIG_SETMASK, &origmask, NULL); Note that unlike many other signal related calls we do not pass a sigmask size, as that would get us to 7 arguments, which aren't easily supported by the syscall infrastructure. It seems a lot less painful to just add a new syscall variant in the unlikely case we're going to increase the sigset size. Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman Reviewed-by: Darrick J. Wong --- fs/aio.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 104 insertions(+), 10 deletions(-) (limited to 'fs/aio.c') diff --git a/fs/aio.c b/fs/aio.c index 61d2e6942951..f3eae5d5771b 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1303,10 +1303,6 @@ static long read_events(struct kioctx *ctx, long min_nr, long nr, wait_event_interruptible_hrtimeout(ctx->wait, aio_read_events(ctx, min_nr, nr, event, &ret), until); - - if (!ret && signal_pending(current)) - ret = -EINTR; - return ret; } @@ -1921,13 +1917,60 @@ SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id, struct timespec __user *, timeout) { struct timespec64 ts; + int ret; + + if (timeout && unlikely(get_timespec64(&ts, timeout))) + return -EFAULT; + + ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL); + if (!ret && signal_pending(current)) + ret = -EINTR; + return ret; +} - if (timeout) { - if (unlikely(get_timespec64(&ts, timeout))) +SYSCALL_DEFINE6(io_pgetevents, + aio_context_t, ctx_id, + long, min_nr, + long, nr, + struct io_event __user *, events, + struct timespec __user *, timeout, + const struct __aio_sigset __user *, usig) +{ + struct __aio_sigset ksig = { NULL, }; + sigset_t ksigmask, sigsaved; + struct timespec64 ts; + int ret; + + if (timeout && unlikely(get_timespec64(&ts, timeout))) + return -EFAULT; + + if (usig && copy_from_user(&ksig, usig, sizeof(ksig))) + return -EFAULT; + + if (ksig.sigmask) { + if (ksig.sigsetsize != sizeof(sigset_t)) + return -EINVAL; + if (copy_from_user(&ksigmask, ksig.sigmask, sizeof(ksigmask))) return -EFAULT; + sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP)); + sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved); + } + + ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL); + if (signal_pending(current)) { + if (ksig.sigmask) { + current->saved_sigmask = sigsaved; + set_restore_sigmask(); + } + + if (!ret) + ret = -ERESTARTNOHAND; + } else { + if (ksig.sigmask) + sigprocmask(SIG_SETMASK, &sigsaved, NULL); } - return do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL); + return ret; } #ifdef CONFIG_COMPAT @@ -1938,13 +1981,64 @@ COMPAT_SYSCALL_DEFINE5(io_getevents, compat_aio_context_t, ctx_id, struct compat_timespec __user *, timeout) { struct timespec64 t; + int ret; + + if (timeout && compat_get_timespec64(&t, timeout)) + return -EFAULT; + + ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL); + if (!ret && signal_pending(current)) + ret = -EINTR; + return ret; +} + - if (timeout) { - if (compat_get_timespec64(&t, timeout)) +struct __compat_aio_sigset { + compat_sigset_t __user *sigmask; + compat_size_t sigsetsize; +}; + +COMPAT_SYSCALL_DEFINE6(io_pgetevents, + compat_aio_context_t, ctx_id, + compat_long_t, min_nr, + compat_long_t, nr, + struct io_event __user *, events, + struct compat_timespec __user *, timeout, + const struct __compat_aio_sigset __user *, usig) +{ + struct __compat_aio_sigset ksig = { NULL, }; + sigset_t ksigmask, sigsaved; + struct timespec64 t; + int ret; + + if (timeout && compat_get_timespec64(&t, timeout)) + return -EFAULT; + + if (usig && copy_from_user(&ksig, usig, sizeof(ksig))) + return -EFAULT; + + if (ksig.sigmask) { + if (ksig.sigsetsize != sizeof(compat_sigset_t)) + return -EINVAL; + if (get_compat_sigset(&ksigmask, ksig.sigmask)) return -EFAULT; + sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP)); + sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved); + } + ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL); + if (signal_pending(current)) { + if (ksig.sigmask) { + current->saved_sigmask = sigsaved; + set_restore_sigmask(); + } + if (!ret) + ret = -ERESTARTNOHAND; + } else { + if (ksig.sigmask) + sigprocmask(SIG_SETMASK, &sigsaved, NULL); } - return do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL); + return ret; } #endif -- cgit v1.2.3