From ded653ccbec0335a78fa7a7aff3ec9870349fafb Mon Sep 17 00:00:00 2001 From: Deepa Dinamani Date: Wed, 19 Sep 2018 21:41:04 -0700 Subject: signal: Add set_user_sigmask() Refactor reading sigset from userspace and updating sigmask into an api. This is useful for versions of syscalls that pass in the sigmask and expect the current->sigmask to be changed during, and restored after, the execution of the syscall. With the advent of new y2038 syscalls in the subsequent patches, we add two more new versions of the syscalls (for pselect, ppoll, and io_pgetevents) in addition to the existing native and compat versions. Adding such an api reduces the logic that would need to be replicated otherwise. Note that the calls to sigprocmask() ignored the return value from the api as the function only returns an error on an invalid first argument that is hardcoded at these call sites. The updated logic uses set_current_blocked() instead. Signed-off-by: Deepa Dinamani Signed-off-by: Arnd Bergmann --- fs/aio.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) (limited to 'fs/aio.c') diff --git a/fs/aio.c b/fs/aio.c index 301e6314183b..6ddb63ee8eb6 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -2104,14 +2104,10 @@ SYSCALL_DEFINE6(io_pgetevents, 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 = set_user_sigmask(ksig.sigmask, &ksigmask, &sigsaved, ksig.sigsetsize); + if (ret) + return ret; ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL); if (signal_pending(current)) { @@ -2174,14 +2170,9 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents, 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 = set_compat_user_sigmask(ksig.sigmask, &ksigmask, &sigsaved, ksig.sigsetsize); + if (ret) + return ret; ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL); if (signal_pending(current)) { -- cgit v1.2.1 From 854a6ed56839a40f6b5d02a2962f48841482eec4 Mon Sep 17 00:00:00 2001 From: Deepa Dinamani Date: Wed, 19 Sep 2018 21:41:05 -0700 Subject: signal: Add restore_user_sigmask() Refactor the logic to restore the sigmask before the syscall returns into an api. This is useful for versions of syscalls that pass in the sigmask and expect the current->sigmask to be changed during the execution and restored after the execution of the syscall. With the advent of new y2038 syscalls in the subsequent patches, we add two more new versions of the syscalls (for pselect, ppoll and io_pgetevents) in addition to the existing native and compat versions. Adding such an api reduces the logic that would need to be replicated otherwise. Signed-off-by: Deepa Dinamani Signed-off-by: Arnd Bergmann --- fs/aio.c | 29 ++++++----------------------- 1 file changed, 6 insertions(+), 23 deletions(-) (limited to 'fs/aio.c') diff --git a/fs/aio.c b/fs/aio.c index 6ddb63ee8eb6..39a1f2df6805 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -2110,18 +2110,9 @@ SYSCALL_DEFINE6(io_pgetevents, return ret; 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); - } + restore_user_sigmask(ksig.sigmask, &sigsaved); + if (signal_pending(current) && !ret) + ret = -ERESTARTNOHAND; return ret; } @@ -2175,17 +2166,9 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents, return ret; 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); - } + restore_user_sigmask(ksig.sigmask, &sigsaved); + if (signal_pending(current) && !ret) + ret = -ERESTARTNOHAND; return ret; } -- cgit v1.2.1 From 7a35397f8c06bffd4c747537095321ff971045a5 Mon Sep 17 00:00:00 2001 From: Deepa Dinamani Date: Wed, 19 Sep 2018 21:41:08 -0700 Subject: io_pgetevents: use __kernel_timespec struct timespec is not y2038 safe. struct __kernel_timespec is the new y2038 safe structure for all syscalls that are using struct timespec. Update io_pgetevents interfaces to use struct __kernel_timespec. sigset_t also has different representations on 32 bit and 64 bit architectures. Hence, we need to support the following different syscalls: New y2038 safe syscalls: (Controlled by CONFIG_64BIT_TIME for 32 bit ABIs) Native 64 bit(unchanged) and native 32 bit : sys_io_pgetevents Compat : compat_sys_io_pgetevents_time64 Older y2038 unsafe syscalls: (Controlled by CONFIG_32BIT_COMPAT_TIME for 32 bit ABIs) Native 32 bit : sys_io_pgetevents_time32 Compat : compat_sys_io_pgetevents Note that io_getevents syscalls do not have a y2038 safe solution. Signed-off-by: Deepa Dinamani Signed-off-by: Arnd Bergmann --- fs/aio.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 81 insertions(+), 3 deletions(-) (limited to 'fs/aio.c') diff --git a/fs/aio.c b/fs/aio.c index 39a1f2df6805..62a0c560cd3d 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -2062,11 +2062,13 @@ static long do_io_getevents(aio_context_t ctx_id, * specifies an infinite timeout. Note that the timeout pointed to by * timeout is relative. Will fail with -ENOSYS if not implemented. */ +#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT) + SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id, long, min_nr, long, nr, struct io_event __user *, events, - struct timespec __user *, timeout) + struct __kernel_timespec __user *, timeout) { struct timespec64 ts; int ret; @@ -2080,6 +2082,8 @@ SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id, return ret; } +#endif + struct __aio_sigset { const sigset_t __user *sigmask; size_t sigsetsize; @@ -2090,7 +2094,7 @@ SYSCALL_DEFINE6(io_pgetevents, long, min_nr, long, nr, struct io_event __user *, events, - struct timespec __user *, timeout, + struct __kernel_timespec __user *, timeout, const struct __aio_sigset __user *, usig) { struct __aio_sigset ksig = { NULL, }; @@ -2104,6 +2108,39 @@ SYSCALL_DEFINE6(io_pgetevents, if (usig && copy_from_user(&ksig, usig, sizeof(ksig))) return -EFAULT; + ret = set_user_sigmask(ksig.sigmask, &ksigmask, &sigsaved, ksig.sigsetsize); + if (ret) + return ret; + + ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL); + restore_user_sigmask(ksig.sigmask, &sigsaved); + if (signal_pending(current) && !ret) + ret = -ERESTARTNOHAND; + + return ret; +} + +#if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) + +SYSCALL_DEFINE6(io_pgetevents_time32, + aio_context_t, ctx_id, + long, min_nr, + long, nr, + struct io_event __user *, events, + struct old_timespec32 __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_old_timespec32(&ts, timeout))) + return -EFAULT; + + if (usig && copy_from_user(&ksig, usig, sizeof(ksig))) + return -EFAULT; + ret = set_user_sigmask(ksig.sigmask, &ksigmask, &sigsaved, ksig.sigsetsize); if (ret) @@ -2117,7 +2154,10 @@ SYSCALL_DEFINE6(io_pgetevents, return ret; } -#ifdef CONFIG_COMPAT +#endif + +#if defined(CONFIG_COMPAT_32BIT_TIME) + COMPAT_SYSCALL_DEFINE5(io_getevents, compat_aio_context_t, ctx_id, compat_long_t, min_nr, compat_long_t, nr, @@ -2136,12 +2176,17 @@ COMPAT_SYSCALL_DEFINE5(io_getevents, compat_aio_context_t, ctx_id, return ret; } +#endif + +#ifdef CONFIG_COMPAT struct __compat_aio_sigset { compat_sigset_t __user *sigmask; compat_size_t sigsetsize; }; +#if defined(CONFIG_COMPAT_32BIT_TIME) + COMPAT_SYSCALL_DEFINE6(io_pgetevents, compat_aio_context_t, ctx_id, compat_long_t, min_nr, @@ -2172,4 +2217,37 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents, return ret; } + +#endif + +COMPAT_SYSCALL_DEFINE6(io_pgetevents_time64, + compat_aio_context_t, ctx_id, + compat_long_t, min_nr, + compat_long_t, nr, + struct io_event __user *, events, + struct __kernel_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 && get_timespec64(&t, timeout)) + return -EFAULT; + + if (usig && copy_from_user(&ksig, usig, sizeof(ksig))) + return -EFAULT; + + ret = set_compat_user_sigmask(ksig.sigmask, &ksigmask, &sigsaved, ksig.sigsetsize); + if (ret) + return ret; + + ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL); + restore_user_sigmask(ksig.sigmask, &sigsaved); + if (signal_pending(current) && !ret) + ret = -ERESTARTNOHAND; + + return ret; +} #endif -- cgit v1.2.1