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Message-Id: <20180415150108.1341-8-hch@lst.de> Date: Sun, 15 Apr 2018 17:01:08 +0200 From: Christoph Hellwig <hch@....de> To: viro@...iv.linux.org.uk Cc: Avi Kivity <avi@...lladb.com>, linux-aio@...ck.org, linux-fsdevel@...r.kernel.org, linux-api@...r.kernel.org, linux-kernel@...r.kernel.org Subject: [PATCH 7/7] 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 <hch@....de> Reviewed-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org> Reviewed-by: Darrick J. Wong <darrick.wong@...cle.com> --- arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/entry/syscalls/syscall_64.tbl | 1 + fs/aio.c | 114 ++++++++++++++++++++++--- include/linux/compat.h | 7 ++ include/linux/syscalls.h | 6 ++ include/uapi/asm-generic/unistd.h | 4 +- include/uapi/linux/aio_abi.h | 6 ++ kernel/sys_ni.c | 2 + 8 files changed, 130 insertions(+), 11 deletions(-) diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index c58f75b088c5..99b6f7a36178 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -391,3 +391,4 @@ 382 i386 pkey_free sys_pkey_free 383 i386 statx sys_statx 384 i386 arch_prctl sys_arch_prctl compat_sys_arch_prctl +385 i386 io_pgetevents sys_io_pgetevents compat_sys_io_pgetevents diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 5aef183e2f85..e995cd2b4e65 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -339,6 +339,7 @@ 330 common pkey_alloc sys_pkey_alloc 331 common pkey_free sys_pkey_free 332 common statx sys_statx +333 common io_pgetevents sys_io_pgetevents # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/fs/aio.c b/fs/aio.c index de56496ba86c..5cfeb5bc3a7d 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; } @@ -1913,13 +1909,60 @@ 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 @@ -1930,13 +1973,64 @@ 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 diff --git a/include/linux/compat.h b/include/linux/compat.h index f188eab10570..fdd068f192c1 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -310,6 +310,7 @@ extern int put_compat_rusage(const struct rusage *, struct compat_rusage __user *); struct compat_siginfo; +struct __compat_aio_sigset; struct compat_dirent { u32 d_ino; @@ -528,6 +529,12 @@ asmlinkage long compat_sys_io_getevents(compat_aio_context_t ctx_id, compat_long_t nr, struct io_event __user *events, struct compat_timespec __user *timeout); +asmlinkage long compat_sys_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); /* fs/cookies.c */ asmlinkage long compat_sys_lookup_dcookie(u32, u32, char __user *, compat_size_t); diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index b961184f597a..c40cf5ec24c9 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -264,6 +264,12 @@ asmlinkage long sys_io_getevents(aio_context_t ctx_id, long nr, struct io_event __user *events, struct timespec __user *timeout); +asmlinkage long sys_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 *sig); /* fs/xattr.c */ asmlinkage long sys_setxattr(const char __user *path, const char __user *name, diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 8bcb186c6f67..42990676a55e 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -732,9 +732,11 @@ __SYSCALL(__NR_pkey_alloc, sys_pkey_alloc) __SYSCALL(__NR_pkey_free, sys_pkey_free) #define __NR_statx 291 __SYSCALL(__NR_statx, sys_statx) +#define __NR_io_pgetevents 292 +__SC_COMP(__NR_io_pgetevents, sys_io_pgetevents, compat_sys_io_pgetevents) #undef __NR_syscalls -#define __NR_syscalls 292 +#define __NR_syscalls 293 /* * 32 bit systems traditionally used different diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h index a04adbc70ddf..2c0a3415beee 100644 --- a/include/uapi/linux/aio_abi.h +++ b/include/uapi/linux/aio_abi.h @@ -29,6 +29,7 @@ #include <linux/types.h> #include <linux/fs.h> +#include <linux/signal.h> #include <asm/byteorder.h> typedef __kernel_ulong_t aio_context_t; @@ -108,5 +109,10 @@ struct iocb { #undef IFBIG #undef IFLITTLE +struct __aio_sigset { + sigset_t __user *sigmask; + size_t sigsetsize; +}; + #endif /* __LINUX__AIO_ABI_H */ diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 6cafc008f6db..7571cf9d7424 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -33,7 +33,9 @@ COND_SYSCALL(io_submit); COND_SYSCALL_COMPAT(io_submit); COND_SYSCALL(io_cancel); COND_SYSCALL(io_getevents); +COND_SYSCALL(io_pgetevents); COND_SYSCALL_COMPAT(io_getevents); +COND_SYSCALL_COMPAT(io_pgetevents); /* fs/xattr.c */ -- 2.17.0
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