sparc64: Fix accidental syscall restart on child return from clone/fork/vfork.
This fixes a regression added by
238468b2ac76020c192a7402c92df5097916bf4a ("[SPARC64]: Use trap type
stored in pt_regs to handle syscall restart.")
Because we now encode the "returning from syscall" status in the
pt_regs area, we have to be mindful to zap it out in the child
of a fork.
During a parallel kernel build I saw an accidental -EINTR return
from vfork() in 'make' because of this bug.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c
index 500ac6d..0560137 100644
--- a/arch/sparc64/kernel/process.c
+++ b/arch/sparc64/kernel/process.c
@@ -591,6 +591,12 @@
if (clone_flags & CLONE_SETTLS)
t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
+ /* We do not want to accidently trigger system call restart
+ * handling in the new thread. Therefore, clear out the trap
+ * type, which will make pt_regs_regs_is_syscall() return false.
+ */
+ pt_regs_clear_trap_type(t->kregs);
+
return 0;
}