x86_64: Fix compat emulation of PTRACE_GET/SET_THREAD_AREA

Since the 64bit kernel has different indexes for this TLS segments
the address needs to be adjusted in the ptrace 32bit emulation.

[ tglx: arch/x86 adaptation ]

Reported-by: Amnon Shiloh
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 8 insertions, 2 deletions

diff --git a/arch/x86/ia32/ptrace32.c b/arch/x86/ia32/ptrace32.c
index 4a233ad6269c..f52770ef0ee3 100644
--- a/arch/x86/ia32/ptrace32.c
+++ b/arch/x86/ia32/ptrace32.c
@@ -228,6 +228,8 @@ static long ptrace32_siginfo(unsigned request, u32 pid, u32 addr, u32 data)
         return ret;
 }
 
+#define COMPAT_GDT_ENTRY_TLS_MIN 6
+
 asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 {
         struct task_struct *child;
@@ -246,8 +248,6 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
         case PTRACE_SYSCALL:
         case PTRACE_OLDSETOPTIONS:
         case PTRACE_SETOPTIONS:
-        case PTRACE_SET_THREAD_AREA:
-        case PTRACE_GET_THREAD_AREA:
                 return sys_ptrace(request, pid, addr, data); 
 
         default:
@@ -271,6 +271,12 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
         case PTRACE_SETSIGINFO:
         case PTRACE_GETSIGINFO:
                 return ptrace32_siginfo(request, pid, addr, data);
+
+        case PTRACE_SET_THREAD_AREA:
+        case PTRACE_GET_THREAD_AREA:
+                return sys_ptrace(request, pid,
+                        addr + GDT_ENTRY_TLS_MIN - COMPAT_GDT_ENTRY_TLS_MIN,
+                        data);
         }
 
         child = ptrace_get_task_struct(pid);