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authorRoland McGrath <roland@redhat.com>2007-11-06 15:30:38 -0800
committerThomas Gleixner <tglx@apollo.(none)>2007-11-10 04:30:36 +0100
commitfd181c72a3c202a3986bcee7551c0838265aec2a (patch)
treeb07b0a662baaace2c5addfca77b537e1267e8d12 /arch
parent1a0c3ea65ca4838a803a14f0ff2bfc78aa69c9a0 (diff)
downloadlinux-fd181c72a3c202a3986bcee7551c0838265aec2a.tar.gz
x86_64: ia32 ptrace THREAD_AREA fix
The addr argument to PTRACE_GET_THREAD_AREA and PTRACE_SET_THREAD_AREA is
not a magic constant.  It's derived from the segment register values being
used, which are computed originally from the index used with set_thread_area.
The value does not need to match what a native i386 kernel would accept.
It needs to match the segment selectors that can actually be in use in this
32-bit process.  The 64-bit ptrace support for PTRACE_GET_THREAD_AREA
(normally used only on 32-bit processes) is correct, but the 32-bit emulation
of ptrace is broken.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/ia32/ptrace32.c10
1 files changed, 2 insertions, 8 deletions
diff --git a/arch/x86/ia32/ptrace32.c b/arch/x86/ia32/ptrace32.c
index f52770ef0ee3..4a233ad6269c 100644
--- a/arch/x86/ia32/ptrace32.c
+++ b/arch/x86/ia32/ptrace32.c
@@ -228,8 +228,6 @@ 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;
@@ -248,6 +246,8 @@ 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:
@@ -271,12 +271,6 @@ 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);