[PATCH -mm 10/43] powerpc user_regset fpregs

From: Roland McGrath
Date: Thu Dec 20 2007 - 07:05:00 EST


This implements user_regset-style accessors for the powerpc FPU data,
and rewrites the existing ptrace code in terms of those calls.

Signed-off-by: Roland McGrath <roland@xxxxxxxxxx>
---
arch/powerpc/kernel/ptrace.c | 37 +++++++++++++++++++++++++++++++------
1 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 8b056d2..f1ce646 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -21,6 +21,7 @@
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
+#include <linux/regset.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/signal.h>
@@ -103,24 +104,48 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
}


+static int fpr_get(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ flush_fp_to_thread(target);
+
+ BUILD_BUG_ON(offsetof(struct thread_struct, fpscr) !=
+ offsetof(struct thread_struct, fpr[32]));
+
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &target->thread.fpr, 0, -1);
+}
+
+static int fpr_set(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ flush_fp_to_thread(target);
+
+ BUILD_BUG_ON(offsetof(struct thread_struct, fpscr) !=
+ offsetof(struct thread_struct, fpr[32]));
+
+ return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &target->thread.fpr, 0, -1);
+}
+
static int get_fpregs(void __user *data, struct task_struct *task,
int has_fpscr)
{
unsigned int count = has_fpscr ? 33 : 32;
-
- if (copy_to_user(data, task->thread.fpr, count * sizeof(double)))
+ if (!access_ok(VERIFY_WRITE, data, count * sizeof(double)))
return -EFAULT;
- return 0;
+ return fpr_get(task, NULL, 0, count * sizeof(double), NULL, data);
}

static int set_fpregs(void __user *data, struct task_struct *task,
int has_fpscr)
{
unsigned int count = has_fpscr ? 33 : 32;
-
- if (copy_from_user(task->thread.fpr, data, count * sizeof(double)))
+ if (!access_ok(VERIFY_READ, data, count * sizeof(double)))
return -EFAULT;
- return 0;
+ return fpr_set(task, NULL, 0, count * sizeof(double), NULL, data);
}


--
1.5.3.6

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