From 5c39c0ab5e862cf71cda1fc39a5cedd4e2f18c6e Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Mon, 11 Feb 2013 20:01:24 +0530 Subject: ARC: [Review] Preparing to fix incorrect syscall restarts due to signals To avoid multiple syscall restarts (multiple signals) or no restart at all (sigreturn), we need just an extra bit of state "literally 1 bit" in struct pt_regs. orig_r8 is the best place to do this, however given the way it is encoded currently, we can't add anything simplistically. Current orig_r8: * syscalls -> 1 to NR_SYSCALLS * Exceptions -> NR_SYSCALLS + 1 * Break-point-> NR_SYSCALLS + 2 In new scheme it is a bit-field * lower short word contains the exact event type (and a new bit to represent restart semantics : if syscall was already / can't be restarted) * upper short word optionally containing the syscall num - needed by likes of tracehooks etc This patch only changes how orig_r8 is organised and nothing should change behaviourily. Signed-off-by: Vineet Gupta Cc: Al Viro --- arch/arc/kernel/entry.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arc/kernel/entry.S') diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index d625b77c14bd..ce8670da8306 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -350,8 +350,8 @@ ARC_EXIT EV_Extension trap_with_param: - ;make sure orig_r8 is a positive value - st NR_syscalls + 2, [sp, PT_orig_r8] + ; stop_pc info by gdb needs this info + st orig_r8_IS_BRKPT, [sp, PT_orig_r8] mov r0, r12 lr r1, [efa] -- cgit v1.2.2