[PATCH 1/2] lib/cobalt: start helper thread with signals blocked

[PATCH 1/2] lib/cobalt: start helper thread with signals blocked

[Norbert Lange]

Delivery mechanisms like sigwait and signalfd require *all* threads
to block the relevant signals.
The cobalt init should not spawn a thread affecting the
signal-handling.

Signed-off-by: Norbert Lange <norbert.lange@andritz.com>
---
 lib/cobalt/printf.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/cobalt/printf.c b/lib/cobalt/printf.c
index e109deaec..33ff7f9ac 100644
--- a/lib/cobalt/printf.c
+++ b/lib/cobalt/printf.c
@@ -20,6 +20,7 @@
 #include <inttypes.h>
 #include <limits.h>
 #include <pthread.h>
+#include <signal.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -640,9 +641,13 @@ static void *printer_loop(void *arg)
 static void spawn_printer_thread(void)
 {
 	pthread_attr_t thattr;
+	sigset_t sset, oset;
 
 	pthread_attr_init(&thattr);
+	sigfillset(&sset);
+	pthread_sigmask(SIG_BLOCK, &sset, &oset);
 	pthread_create(&printer_thread, &thattr, printer_loop, NULL);
+	sigprocmask(SIG_SETMASK, &oset, NULL);
 }
 
 void cobalt_print_init_atfork(void)
-- 
2.20.1

[PATCH 2/2] lib/cobalt: set name for printf thread to help debugging

[Norbert Lange]

Signed-off-by: Norbert Lange <norbert.lange@andritz.com>
---
 lib/cobalt/printf.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/cobalt/printf.c b/lib/cobalt/printf.c
index 33ff7f9ac..7426f2bda 100644
--- a/lib/cobalt/printf.c
+++ b/lib/cobalt/printf.c
@@ -648,6 +648,7 @@ static void spawn_printer_thread(void)
 	pthread_sigmask(SIG_BLOCK, &sset, &oset);
 	pthread_create(&printer_thread, &thattr, printer_loop, NULL);
 	sigprocmask(SIG_SETMASK, &oset, NULL);
+	pthread_setname_np(printer_thread, "cobalt_printf");
 }
 
 void cobalt_print_init_atfork(void)
-- 
2.20.1

Re: [PATCH 2/2] lib/cobalt: set name for printf thread to help debugging

[Jan Kiszka]

On 14.06.19 12:23, Norbert Lange via Xenomai wrote:
> Signed-off-by: Norbert Lange <norbert.lange@andritz.com>
> ---
>   lib/cobalt/printf.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/lib/cobalt/printf.c b/lib/cobalt/printf.c
> index 33ff7f9ac..7426f2bda 100644
> --- a/lib/cobalt/printf.c
> +++ b/lib/cobalt/printf.c
> @@ -648,6 +648,7 @@ static void spawn_printer_thread(void)
>   	pthread_sigmask(SIG_BLOCK, &sset, &oset);
>   	pthread_create(&printer_thread, &thattr, printer_loop, NULL);
>   	sigprocmask(SIG_SETMASK, &oset, NULL);
> +	pthread_setname_np(printer_thread, "cobalt_printf");
>   }
>   
>   void cobalt_print_init_atfork(void)
> 

Thanks, both applied.

Jan

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