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Subject[PATCH] 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>
---
arch/tile/kernel/intvec_64.S | 21 ++++++++++++++++++---
1 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S
index 6a1ea82..cbf7334 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>
@@ -1047,11 +1048,25 @@ 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:
/*
--
1.6.5.2


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