From 4ff17cf0aa8854941dc0538c74d4f1677a570575 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 14 Jan 2022 15:50:32 +0000 Subject: linux-user: Remove stale "not threadsafe" comments MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In linux-user/signal.c we have two FIXME comments claiming that parts of the signal-handling code are not threadsafe. These are very old, as they were first introduced in commit 624f7979058 in 2008. Since then we've radically overhauled the signal-handling logic, while carefully preserving these FIXME comments. It's unclear exactly what thread-safety issue the original author was trying to point out -- the relevant data structures are in the TaskStruct, which makes them per-thread and only operated on by that thread. The old code at the time of that commit did have various races involving signal handlers being invoked at awkward times; possibly this was what was meant. Delete these FIXME comments: * they were written at a time when the way we handled signals was completely different * the code today appears to us to not have thread-safety issues * nobody knows what the problem the comments were trying to point out was so they are serving no useful purpose for us today. Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée Reviewed-by: Warner Losh Message-Id: <20220114155032.3767771-1-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/signal.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'linux-user') diff --git a/linux-user/signal.c b/linux-user/signal.c index 27a0ff3..2a3f3cc 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -999,7 +999,6 @@ int do_sigaction(int sig, const struct target_sigaction *act, oact->sa_mask = k->sa_mask; } if (act) { - /* FIXME: This is not threadsafe. */ __get_user(k->_sa_handler, &act->_sa_handler); __get_user(k->sa_flags, &act->sa_flags); #ifdef TARGET_ARCH_HAS_SA_RESTORER @@ -1149,7 +1148,6 @@ void process_pending_signals(CPUArchState *cpu_env) sigset_t *blocked_set; while (qatomic_read(&ts->signal_pending)) { - /* FIXME: This is not threadsafe. */ sigfillset(&set); sigprocmask(SIG_SETMASK, &set, 0); -- cgit v1.1