[POWERPC] ptrace shouldn't touch FP exec mode

One of the gratuitous difference between 32 and 64-bit ptrace is
whether you can whack the MSR:FE0 and FE1 bits from ptrace.  This
patch forbids it unconditionally.  In addition, the 64-bit kernels
used to return the exception mode in the MSR on reads, but 32-bit
kernels didn't.  This patch makes it return those bits on both.

Finally, since ptrace-ppc32.h and ptrace-ppc64.h are mostly empty now, and
since the previous patch made ptrace32.c no longer need the MSR_DEBUGCHANGE
definition, we just remove those 2 files and move back the remaining bits
to ptrace.c (they were short lived heh ?).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

4 files changed, 39 insertions, 94 deletions

diff --git a/arch/powerpc/kernel/ptrace-ppc32.h b/arch/powerpc/kernel/ptrace-ppc32.h
deleted file mode 100644
index f1fd5b8a868d..000000000000
--- a/arch/powerpc/kernel/ptrace-ppc32.h
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- *    Copyright (c) 2007 Benjamin Herrenschmidt, IBM Coproration
- *    Extracted from ptrace.c and ptrace32.c
- *
- * This file is subject to the terms and conditions of the GNU General
- * Public License.  See the file README.legal in the main directory of
- * this archive for more details.
- */
-
-#ifndef _POWERPC_PTRACE_PPC32_H
-#define _POWERPC_PTRACE_PPC32_H
-
-/*
- * Set of msr bits that gdb can change on behalf of a process.
- */
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
-#define MSR_DEBUGCHANGE 0
-#else
-#define MSR_DEBUGCHANGE (MSR_SE | MSR_BE)
-#endif
-
-/*
- * Max register writeable via put_reg
- */
-#define PT_MAX_PUT_REG  PT_MQ
-
-/*
- * Munging of MSR on return from get_regs
- *
- * Nothing to do on ppc32
- */
-#define PT_MUNGE_MSR(msr, task) (msr)
-
-
-#endif /* _POWERPC_PTRACE_PPC32_H */
diff --git a/arch/powerpc/kernel/ptrace-ppc64.h b/arch/powerpc/kernel/ptrace-ppc64.h
deleted file mode 100644
index e450ce01392b..000000000000
--- a/arch/powerpc/kernel/ptrace-ppc64.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- *    Copyright (c) 2002 Stephen Rothwell, IBM Coproration
- *    Extracted from ptrace.c and ptrace32.c
- *
- * This file is subject to the terms and conditions of the GNU General
- * Public License.  See the file README.legal in the main directory of
- * this archive for more details.
- */
-
-#ifndef _POWERPC_PTRACE_PPC64_H
-#define _POWERPC_PTRACE_PPC64_H
-
-/*
- * Set of msr bits that gdb can change on behalf of a process.
- */
-#define MSR_DEBUGCHANGE (MSR_FE0 | MSR_SE | MSR_BE | MSR_FE1)
-
-/*
- * Max register writeable via put_reg
- */
-#define PT_MAX_PUT_REG  PT_CCR
-
-/*
- * Munging of MSR on return from get_regs
- *
- * Put the correct FP bits in, they might be wrong as a result
- * of our lazy FP restore.
- */
-
-#define PT_MUNGE_MSR(msr, task) ({ (msr) | (task)->thread.fpexc_mode; })
-
-static inline int ptrace_set_debugreg(struct task_struct *task,
-                                      unsigned long addr, unsigned long data)
-{
-        /* We only support one DABR and no IABRS at the moment */
-        if (addr > 0)
-                return -EINVAL;
-
-        /* The bottom 3 bits are flags */
-        if ((data & ~0x7UL) >= TASK_SIZE)
-                return -EIO;
-
-        /* Ensure translation is on */
-        if (data && !(data & DABR_TRANSLATION))
-                return -EIO;
-
-        task->thread.dabr = data;
-        return 0;
-}
-
-#endif /* _POWERPC_PTRACE_PPC64_H */
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index dd4837c4a68a..75bc744a6217 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -35,16 +35,28 @@
 #include <asm/pgtable.h>
 #include <asm/system.h>
 
-#ifdef CONFIG_PPC64
-#include "ptrace-ppc64.h"
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+/*
+ * Set of msr bits that gdb can change on behalf of a process.
+ */
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+#define MSR_DEBUGCHANGE 0
 #else
-#include "ptrace-ppc32.h"
+#define MSR_DEBUGCHANGE (MSR_SE | MSR_BE)
 #endif
 
 /*
- * does not yet catch signals sent when the child dies.
- * in exit.c or in signal.c.
+ * Max register writeable via put_reg
  */
+#ifdef CONFIG_PPC32
+#define PT_MAX_PUT_REG  PT_MQ
+#else
+#define PT_MAX_PUT_REG  PT_CCR
+#endif
 
 /*
  * Get contents of register REGNO in task TASK.
@@ -58,7 +70,7 @@ unsigned long ptrace_get_reg(struct task_struct *task, int regno)
 
         if (regno == PT_MSR) {
                 tmp = ((unsigned long *)task->thread.regs)[PT_MSR];
-                return PT_MUNGE_MSR(tmp, task);
+                return tmp | task->thread.fpexc_mode;
         }
 
         if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
@@ -274,6 +286,27 @@ static void clear_single_step(struct task_struct *task)
         clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 }
 
+#ifdef CONFIG_PPC64
+static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
+                               unsigned long data)
+{
+        /* We only support one DABR and no IABRS at the moment */
+        if (addr > 0)
+                return -EINVAL;
+
+        /* The bottom 3 bits are flags */
+        if ((data & ~0x7UL) >= TASK_SIZE)
+                return -EIO;
+
+        /* Ensure translation is on */
+        if (data && !(data & DABR_TRANSLATION))
+                return -EIO;
+
+        task->thread.dabr = data;
+        return 0;
+}
+#endif
+
 /*
  * Called by kernel/ptrace.c when detaching..
  *
diff --git a/arch/powerpc/kernel/ptrace32.c b/arch/powerpc/kernel/ptrace32.c
index aae6a988e183..9e6baeac0fb1 100644
--- a/arch/powerpc/kernel/ptrace32.c
+++ b/arch/powerpc/kernel/ptrace32.c
@@ -33,8 +33,6 @@
 #include <asm/pgtable.h>
 #include <asm/system.h>
 
-#include "ptrace-ppc64.h"
-
 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.