powerpc: Add PTRACE_SINGLEBLOCK support

Reworked by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This adds block-step support on powerpc, including a PTRACE_SINGLEBLOCK
request for ptrace.

The BookE implementation is tweaked to fire a single step after a
block step in order to mimmic the server behaviour.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index c9c678fb253..8c341490cfc 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -135,7 +135,9 @@ do {									      \
  * These are defined as per linux/ptrace.h, which see.
  */
 #define arch_has_single_step()  (1)
+#define arch_has_block_step()   (!cpu_has_feature(CPU_FTR_601))
 extern void user_enable_single_step(struct task_struct *);
+extern void user_enable_block_step(struct task_struct *);
 extern void user_disable_single_step(struct task_struct *);
 
 #endif /* __ASSEMBLY__ */
@@ -288,4 +290,6 @@ extern void user_disable_single_step(struct task_struct *);
 #define PPC_PTRACE_PEEKUSR_3264  0x91
 #define PPC_PTRACE_POKEUSR_3264  0x90
 
+#define PTRACE_SINGLEBLOCK      0x100   /* resume execution until next branch */
+
 #endif /* _ASM_POWERPC_PTRACE_H */