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;