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[4/7] hurd: Make _exit work during early boot-up

Message ID 20230429131354.2507443-4-bugaevc@gmail.com
State Committed, archived
Headers
Series [1/7] hurd: Simplify _hurd_critical_section_lock a bit |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

Sergey Bugaev April 29, 2023, 1:13 p.m. UTC 
  If any of the early boot-up tasks calls exit () or returns from main (),
terminate it properly instead of crashing on trying to dereference
_hurd_ports and getting forcibly terminated by the kernel.

We sadly cannot make the __USEPORT macro do the check for _hurd_ports
being unset, because it evaluates to the value of the expression
provided as the second argument, and that can be of any type; so there
is no single suitable fallback value for the macro to evaluate to in
case _hurd_ports is unset. Instead, each use site that wants to care for
this case will have to do its own checking.

Checked on x86_64-gnu.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
---
 sysdeps/mach/hurd/_exit.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Samuel Thibault April 29, 2023, 2:54 p.m. UTC | #1 
Applied, thanks!

Sergey Bugaev, le sam. 29 avril 2023 16:13:51 +0300, a ecrit:
> If any of the early boot-up tasks calls exit () or returns from main (),
> terminate it properly instead of crashing on trying to dereference
> _hurd_ports and getting forcibly terminated by the kernel.
> 
> We sadly cannot make the __USEPORT macro do the check for _hurd_ports
> being unset, because it evaluates to the value of the expression
> provided as the second argument, and that can be of any type; so there
> is no single suitable fallback value for the macro to evaluate to in
> case _hurd_ports is unset. Instead, each use site that wants to care for
> this case will have to do its own checking.
> 
> Checked on x86_64-gnu.

\o/

> Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
> ---
>  sysdeps/mach/hurd/_exit.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/sysdeps/mach/hurd/_exit.c b/sysdeps/mach/hurd/_exit.c
> index 73957744..80cfe532 100644
> --- a/sysdeps/mach/hurd/_exit.c
> +++ b/sysdeps/mach/hurd/_exit.c
> @@ -24,8 +24,9 @@
>  void
>  _hurd_exit (int status)
>  {
> -  /* Give the proc server our exit status.  */
> -  __USEPORT (PROC, __proc_mark_exit (port, status, 0));
> +  if (_hurd_ports != NULL)
> +    /* Give the proc server our exit status.  */
> +    __USEPORT (PROC, __proc_mark_exit (port, status, 0));
>  
>    /* Commit suicide.  */
>    __task_terminate (__mach_task_self ());
> -- 
> 2.40.1
>
diff mbox series

Patch

diff --git a/sysdeps/mach/hurd/_exit.c b/sysdeps/mach/hurd/_exit.c
index 73957744..80cfe532 100644
--- a/sysdeps/mach/hurd/_exit.c
+++ b/sysdeps/mach/hurd/_exit.c
@@ -24,8 +24,9 @@ 
 void
 _hurd_exit (int status)
 {
-  /* Give the proc server our exit status.  */
-  __USEPORT (PROC, __proc_mark_exit (port, status, 0));
+  if (_hurd_ports != NULL)
+    /* Give the proc server our exit status.  */
+    __USEPORT (PROC, __proc_mark_exit (port, status, 0));
 
   /* Commit suicide.  */
   __task_terminate (__mach_task_self ());