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authorRoland McGrath <roland@redhat.com>2007-12-20 03:57:51 -0800
committerPaul Mackerras <paulus@samba.org>2008-02-07 20:38:56 +1100
commit26f7713020129e556e494fd36b2db1e651e33ba3 (patch)
tree3c066f2eeb71a2742c9e3b99666a2603d935bdd0 /arch/powerpc
parenta4e4b175b6028ebfb2217e0ca1fa0487dc73ccc4 (diff)
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[POWERPC] ptrace accessors for special regs MSR and TRAP
This isolates the ptrace code for the special-case registers msr and trap from the ptrace-layout dispatch code. This should inline away completely. It cleanly separates the low-level machine magic that has to be done for deep reasons, from the superficial details of the ptrace interface. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/ptrace.c45
1 files changed, 30 insertions, 15 deletions
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 8c25b003365..4edc1186f6a 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -60,20 +60,38 @@
#define PT_MAX_PUT_REG PT_CCR
#endif
+static unsigned long get_user_msr(struct task_struct *task)
+{
+ return task->thread.regs->msr | task->thread.fpexc_mode;
+}
+
+static int set_user_msr(struct task_struct *task, unsigned long msr)
+{
+ task->thread.regs->msr &= ~MSR_DEBUGCHANGE;
+ task->thread.regs->msr |= msr & MSR_DEBUGCHANGE;
+ return 0;
+}
+
+/*
+ * We prevent mucking around with the reserved area of trap
+ * which are used internally by the kernel.
+ */
+static int set_user_trap(struct task_struct *task, unsigned long trap)
+{
+ task->thread.regs->trap = trap & 0xfff0;
+ return 0;
+}
+
/*
* Get contents of register REGNO in task TASK.
*/
unsigned long ptrace_get_reg(struct task_struct *task, int regno)
{
- unsigned long tmp = 0;
-
if (task->thread.regs == NULL)
return -EIO;
- if (regno == PT_MSR) {
- tmp = ((unsigned long *)task->thread.regs)[PT_MSR];
- return tmp | task->thread.fpexc_mode;
- }
+ if (regno == PT_MSR)
+ return get_user_msr(task);
if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
return ((unsigned long *)task->thread.regs)[regno];
@@ -89,15 +107,12 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
if (task->thread.regs == NULL)
return -EIO;
- if (regno <= PT_MAX_PUT_REG || regno == PT_TRAP) {
- if (regno == PT_MSR)
- data = (data & MSR_DEBUGCHANGE)
- | (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
- /* We prevent mucking around with the reserved area of trap
- * which are used internally by the kernel
- */
- if (regno == PT_TRAP)
- data &= 0xfff0;
+ if (regno == PT_MSR)
+ return set_user_msr(task, data);
+ if (regno == PT_TRAP)
+ return set_user_trap(task, data);
+
+ if (regno <= PT_MAX_PUT_REG) {
((unsigned long *)task->thread.regs)[regno] = data;
return 0;
}