From: Oleg Nesterov <oleg@xxxxxxxxxx> Subject: select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR 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@xxxxxxxxxx Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Acked-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: David Laight <David.Laight@xxxxxxxxxx> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx> Cc: Deepa Dinamani <deepa.kernel@xxxxxxxxx> Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> Cc: Eric Wong <e@xxxxxxxxx> Cc: Jason Baron <jbaron@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/select.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) --- a/fs/select.c~select-change-do_poll-to-return-erestartnohand-rather-than-eintr +++ a/fs/select.c @@ -925,7 +925,7 @@ static int do_poll(struct poll_list *lis 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 resta ret = do_sys_poll(ufds, nfds, to); - if (ret == -EINTR) { + if (ret == -ERESTARTNOHAND) { restart_block->fn = do_restart_poll; ret = -ERESTART_RESTARTBLOCK; } @@ -1061,7 +1061,7 @@ SYSCALL_DEFINE3(poll, struct pollfd __us ret = do_sys_poll(ufds, nfds, to); - if (ret == -EINTR) { + if (ret == -ERESTARTNOHAND) { struct restart_block *restart_block; restart_block = ¤t->restart_block; @@ -1102,11 +1102,7 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __u 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; @@ -1135,11 +1131,7 @@ SYSCALL_DEFINE5(ppoll_time32, struct pol 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; @@ -1413,11 +1405,7 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time32, str 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; @@ -1446,11 +1434,7 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time64, str 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; _
