ARC: Implement ptrace(PTRACE_GET_THREAD_AREA)

This patch adds implementation of GET_THREAD_AREA ptrace request type. This
is required by GDB to debug NPTL applications.

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

2 files changed, 5 insertions, 0 deletions

diff --git a/arch/arc/include/uapi/asm/ptrace.h b/arch/arc/include/uapi/asm/ptrace.h
index 2618cc13ba75..76a7739aab1c 100644
--- a/arch/arc/include/uapi/asm/ptrace.h
+++ b/arch/arc/include/uapi/asm/ptrace.h
@@ -11,6 +11,7 @@
 #ifndef _UAPI__ASM_ARC_PTRACE_H
 #define _UAPI__ASM_ARC_PTRACE_H
 
+#define PTRACE_GET_THREAD_AREA  25
 
 #ifndef __ASSEMBLY__
 /*
diff --git a/arch/arc/kernel/ptrace.c b/arch/arc/kernel/ptrace.c
index 5d76706139dd..13b3ffb27a38 100644
--- a/arch/arc/kernel/ptrace.c
+++ b/arch/arc/kernel/ptrace.c
@@ -146,6 +146,10 @@ long arch_ptrace(struct task_struct *child, long request,
         pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
 
         switch (request) {
+        case PTRACE_GET_THREAD_AREA:
+                ret = put_user(task_thread_info(child)->thr_ptr,
+                               (unsigned long __user *)data);
+                break;
         default:
                 ret = ptrace_request(child, request, addr, data);
                 break;