From: Chris Metcalf <cmetcalf@tilera.com>
Date: Thu, 29 Mar 2012 20:11:09 +0000 (-0400)
Subject: arch/tile: fix single-stepping over swint1 instructions on tilegx
X-Git-Tag: v3.4-rc2~7^2~13
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2858f856021340f3730fa8639dd520a2e4331f7f;p=profile%2Fivi%2Fkernel-adaptation-intel-automotive.git

arch/tile: fix single-stepping over swint1 instructions on tilegx

If we are single-stepping and make a syscall, we call ptrace_notify()
explicitly on the return path back to user space, since we are returning
to a pc value set artificially to the next instruction, and otherwise
we won't register that we stepped over the syscall instruction (swint1).

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
---

diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S
index 005535d..fdff17c 100644
--- a/arch/tile/kernel/intvec_64.S
+++ b/arch/tile/kernel/intvec_64.S
@@ -22,6 +22,7 @@
 #include <asm/irqflags.h>
 #include <asm/asm-offsets.h>
 #include <asm/types.h>
+#include <asm/signal.h>
 #include <hv/hypervisor.h>
 #include <arch/abi.h>
 #include <arch/interrupts.h>
@@ -1039,11 +1040,25 @@ handle_syscall:
 
 	/* Do syscall trace again, if requested. */
 	ld	r30, r31
-	andi    r30, r30, _TIF_SYSCALL_TRACE
-	beqzt	r30, 1f
+	andi    r0, r30, _TIF_SYSCALL_TRACE
+	{
+	 andi    r0, r30, _TIF_SINGLESTEP
+	 beqzt   r0, 1f
+	}
 	jal	do_syscall_trace
 	FEEDBACK_REENTER(handle_syscall)
-1:	j       .Lresume_userspace   /* jump into middle of interrupt_return */
+	andi    r0, r30, _TIF_SINGLESTEP
+
+1:	beqzt	r0, 2f
+
+	/* Single stepping -- notify ptrace. */
+	{
+	 movei   r0, SIGTRAP
+	 jal     ptrace_notify
+	}
+	FEEDBACK_REENTER(handle_syscall)
+
+2:	j       .Lresume_userspace   /* jump into middle of interrupt_return */
 
 .Lcompat_syscall:
 	/*