...like it's already done when exiting a trap. This is required, since
handing a syscall can result in an AST; in particular this happens when
the current thread is being terminated, which sets AST_TERMINATE and
expects the thread to never return to userspace.
Fixes a kernel crash upon calling exit () or pthread_exit () in glibc.
---
x86_64/locore.S | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/x86_64/locore.S b/x86_64/locore.S
index 366ef292..577a9096 100644
--- a/x86_64/locore.S
+++ b/x86_64/locore.S
@@ -1428,10 +1428,17 @@ _syscall64_args_stack:
_syscall64_call:
call *EXT(mach_trap_table)+8(%rax) /* call procedure */
- // XXX: check ast on exit?
- /* Restore thread state and return to user using sysret. */
+_syscall64_check_for_ast:
+ /* Check for ast. */
CPU_NUMBER(%r11)
+ cmpl $0,CX(EXT(need_ast),%r11)
+ jz _syscall64_restore_state
+ call EXT(i386_astintr)
+ jmp _syscall64_check_for_ast /* check again */
+
+_syscall64_restore_state:
+ /* Restore thread state and return to user using sysret. */
movq CX(EXT(active_threads),%r11),%r11 /* point to current thread */
movq TH_PCB(%r11),%r11 /* point to pcb */
addq $ PCB_ISS,%r11 /* point to saved state */
--
2.40.1
