diff mbox series

alpha: Fix generic brk system call emulation in __brk_call (bug 29490)

Message ID 87lern5qle.fsf@oldenburg.str.redhat.com
State New
Headers show
Series alpha: Fix generic brk system call emulation in __brk_call (bug 29490) | expand

Commit Message

Florian Weimer Aug. 17, 2022, 6:30 a.m. UTC 
The kernel special-cases the zero argument for alpha brk, and we can
use that to restore the generic Linux error handling behavior.

This change fixes an ldconfig crash under qemu-user for me.

---
 sysdeps/unix/sysv/linux/alpha/brk_call.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

Comments

Florian Weimer Aug. 22, 2022, 9:07 a.m. UTC | #1 
* Florian Weimer via Libc-alpha:

> The kernel special-cases the zero argument for alpha brk, and we can
> use that to restore the generic Linux error handling behavior.
>
> This change fixes an ldconfig crash under qemu-user for me.
>
> ---
>  sysdeps/unix/sysv/linux/alpha/brk_call.h | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/sysdeps/unix/sysv/linux/alpha/brk_call.h b/sysdeps/unix/sysv/linux/alpha/brk_call.h
> index b8088cf13f..0b851b6c86 100644
> --- a/sysdeps/unix/sysv/linux/alpha/brk_call.h
> +++ b/sysdeps/unix/sysv/linux/alpha/brk_call.h
> @@ -21,8 +21,7 @@ __brk_call (void *addr)
>  {
>    unsigned long int result = INTERNAL_SYSCALL_CALL (brk, addr);
>    if (result == -ENOMEM)
> -    /* Mimic the default error reporting behavior.  */
> -    return addr;
> -  else
> -    return (void *) result;
> +    /* Mimic the generic error reporting behavior.  */
> +    result = INTERNAL_SYSCALL_CALL (brk, 0);
> +  return (void *) result;
>  }

I've pushed this because I received confirmation on the bug that this
fixes things.

Thanks,
Florian
diff mbox series

Patch

diff --git a/sysdeps/unix/sysv/linux/alpha/brk_call.h b/sysdeps/unix/sysv/linux/alpha/brk_call.h
index b8088cf13f..0b851b6c86 100644
--- a/sysdeps/unix/sysv/linux/alpha/brk_call.h
+++ b/sysdeps/unix/sysv/linux/alpha/brk_call.h
@@ -21,8 +21,7 @@  __brk_call (void *addr)
 {
   unsigned long int result = INTERNAL_SYSCALL_CALL (brk, addr);
   if (result == -ENOMEM)
-    /* Mimic the default error reporting behavior.  */
-    return addr;
-  else
-    return (void *) result;
+    /* Mimic the generic error reporting behavior.  */
+    result = INTERNAL_SYSCALL_CALL (brk, 0);
+  return (void *) result;
 }