[SPARC64]: Move syscall success and newchild state out of thread flags.
These two bits were accesses non-atomically from assembler
code. So, in order to eliminate any potential races resulting
from that, move these pieces of state into two bytes elsewhere
in struct thread_info.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/entry.S b/arch/sparc64/kernel/entry.S
index d781f10..88332f0 100644
--- a/arch/sparc64/kernel/entry.S
+++ b/arch/sparc64/kernel/entry.S
@@ -1600,11 +1600,11 @@
ba,pt %xcc, sparc_do_fork
add %sp, PTREGS_OFF, %o2
ret_from_syscall:
- /* Clear SPARC_FLAG_NEWCHILD, switch_to leaves thread.flags in
- * %o7 for us. Check performance counter stuff too.
+ /* Clear current_thread_info()->new_child, and
+ * check performance counter stuff too.
*/
- andn %o7, _TIF_NEWCHILD, %l0
- stx %l0, [%g6 + TI_FLAGS]
+ stb %g0, [%g6 + TI_NEW_CHILD]
+ ldx [%g6 + TI_FLAGS], %l0
call schedule_tail
mov %g7, %o0
andcc %l0, _TIF_PERFCTR, %g0
@@ -1720,12 +1720,11 @@
/* Check if force_successful_syscall_return()
* was invoked.
*/
- ldx [%curptr + TI_FLAGS], %l0
- andcc %l0, _TIF_SYSCALL_SUCCESS, %g0
- be,pt %icc, 1f
- andn %l0, _TIF_SYSCALL_SUCCESS, %l0
+ ldub [%curptr + TI_SYS_NOERROR], %l0
+ brz,pt %l0, 1f
+ nop
ba,pt %xcc, 80f
- stx %l0, [%curptr + TI_FLAGS]
+ stb %g0, [%curptr + TI_SYS_NOERROR]
1:
cmp %o0, -ERESTART_RESTARTBLOCK