From: Oleg Nesterov <oleg@redhat.com> mainline inclusion from mainline-5.3-rc1 commit 8cf8b5539a414da3257db6d121bcee2d883135cb category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA --------------------------- do_poll() returns -EINTR if interrupted and after that all its callers have to translate it into -ERESTARTNOHAND. Change do_poll() to return -ERESTARTNOHAND and update (simplify) the callers. Note that this also unifies all users of restore_saved_sigmask_unless(), see the next patch. Linus: : The *right* return value will actually be then chosen by : poll_select_copy_remaining(), which will turn ERESTARTNOHAND to EINTR : when it can't update the timeout. : : Except for the cases that use restart_block and do that instead and : don't have the whole timeout restart issue as a result. Link: http://lkml.kernel.org/r/20190606140852.GB13440@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Laight <David.Laight@aculab.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Deepa Dinamani <deepa.kernel@gmail.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Eric Wong <e@80x24.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Conflicts: fs/select.c Signed-off-by: yangerkun <yangerkun@huawei.com> Reviewed-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Cheng Jian <cj.chengjian@huawei.com> --- fs/select.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) diff --git a/fs/select.c b/fs/select.c index baed50c60083..bf2395de6437 100644 --- a/fs/select.c +++ b/fs/select.c @@ -925,7 +925,7 @@ static int do_poll(struct poll_list *list, struct poll_wqueues *wait, if (!count) { count = wait->error; if (signal_pending(current)) - count = -EINTR; + count = -ERESTARTNOHAND; } if (count || timed_out) break; @@ -1040,7 +1040,7 @@ static long do_restart_poll(struct restart_block *restart_block) ret = do_sys_poll(ufds, nfds, to); - if (ret == -EINTR) + if (ret == -ERESTARTNOHAND) ret = set_restart_fn(restart_block, do_restart_poll); return ret; @@ -1060,7 +1060,7 @@ SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds, ret = do_sys_poll(ufds, nfds, to); - if (ret == -EINTR) { + if (ret == -ERESTARTNOHAND) { struct restart_block *restart_block; restart_block = ¤t->restart_block; @@ -1100,11 +1100,7 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds, return ret; ret = do_sys_poll(ufds, nfds, to); - - restore_saved_sigmask_unless(ret == -EINTR); - /* We can restart this syscall, usually */ - if (ret == -EINTR) - ret = -ERESTARTNOHAND; + restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret); return ret; @@ -1133,11 +1129,7 @@ SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds, return ret; ret = do_sys_poll(ufds, nfds, to); - - restore_saved_sigmask_unless(ret == -EINTR); - /* We can restart this syscall, usually */ - if (ret == -EINTR) - ret = -ERESTARTNOHAND; + restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret); return ret; @@ -1411,11 +1403,7 @@ COMPAT_SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, return ret; ret = do_sys_poll(ufds, nfds, to); - - restore_saved_sigmask_unless(ret == -EINTR); - /* We can restart this syscall, usually */ - if (ret == -EINTR) - ret = -ERESTARTNOHAND; + restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret); return ret; @@ -1444,11 +1432,7 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds, return ret; ret = do_sys_poll(ufds, nfds, to); - - restore_saved_sigmask_unless(ret == -EINTR); - /* We can restart this syscall, usually */ - if (ret == -EINTR) - ret = -ERESTARTNOHAND; + restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret); return ret; -- 2.25.1