[PATCH] sigalstack.2: Mention the need for separate signal stacks for threads

[PATCH] sigalstack.2: Mention the need for separate signal stacks for threads

[Florian Weimer]

Signed-off-by: Florian Weimer <fweimer@redhat.com>

---
 man2/sigaltstack.2 | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/man2/sigaltstack.2 b/man2/sigaltstack.2
index 53268ccbe..1510a98ab 100644
--- a/man2/sigaltstack.2
+++ b/man2/sigaltstack.2
@@ -54,7 +54,10 @@ alternate signal stack.
 An alternate signal stack is used during the
 execution of a signal handler if the establishment of that handler (see
 .BR sigaction (2))
-requested it.
+requested it using the
+.B SA_ONSTACK
+flag.  Each thread that can execute such signal handlers needs its own
+separate alternate signal stack.
 .PP
 The normal sequence of events for using an alternate signal stack
 is the following:
@@ -67,7 +70,7 @@ signal stack.
 Use
 .BR sigaltstack ()
 to inform the system of the existence and
-location of the alternate signal stack.
+location of the alternate signal stack for the current thread.
 .TP
 3.
 When establishing a signal handler using

Re: [PATCH] sigalstack.2: Mention the need for separate signal stacks for threads

[Alejandro Colomar (man-pages)]

[CC += mtk]

Hi Florian,

On 5/18/21 10:40 PM, Florian Weimer wrote:
> Signed-off-by: Florian Weimer <fweimer@redhat.com>
> 

I don't understand how this works, so I'll CC Michael so that he merges it.

Thanks,

Alex

> ---
>   man2/sigaltstack.2 | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/man2/sigaltstack.2 b/man2/sigaltstack.2
> index 53268ccbe..1510a98ab 100644
> --- a/man2/sigaltstack.2
> +++ b/man2/sigaltstack.2
> @@ -54,7 +54,10 @@ alternate signal stack.
>   An alternate signal stack is used during the
>   execution of a signal handler if the establishment of that handler (see
>   .BR sigaction (2))
> -requested it.
> +requested it using the
> +.B SA_ONSTACK
> +flag.  Each thread that can execute such signal handlers needs its own
> +separate alternate signal stack.
>   .PP
>   The normal sequence of events for using an alternate signal stack
>   is the following:
> @@ -67,7 +70,7 @@ signal stack.
>   Use
>   .BR sigaltstack ()
>   to inform the system of the existence and
> -location of the alternate signal stack.
> +location of the alternate signal stack for the current thread.
>   .TP
>   3.
>   When establishing a signal handler using
> 


-- 
Alejandro Colomar
Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/
Senior SW Engineer; http://www.alejandro-colomar.es/