sparc64: Fix syscall restart, for real...

The change I put into copy_thread() just papered over the real
problem.

When we are looking to see if we should do a syscall restart, when
deliverying a signal, we should only interpret the syscall return
value as an error if the carry condition code(s) are set.

Otherwise it's a success return.

Also, sigreturn paths should do a pt_regs_clear_trap_type().

It turns out that doing a syscall restart when returning from a fork()
does and should happen, from time to time.  Even if copy_thread()
returns success, copy_process() can still unwind and signal
-ERESTARTNOINTR in the parent.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 6 deletions

diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c
index 05601374915..500ac6d483a 100644
--- a/arch/sparc64/kernel/process.c
+++ b/arch/sparc64/kernel/process.c
@@ -591,12 +591,6 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 	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;
 }