powerpc/ptrace: Create ptrace_get_fpr() and ptrace_put_fpr()

On the same model as ptrace_get_reg() and ptrace_put_reg(),
create ptrace_get_fpr() and ptrace_put_fpr() to get/set
the floating points registers.

We move the boundary checkings in them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/24a1baedea7f7ae7b6bf27be98bab6d01b5ca2c1.1597770847.git.christophe.leroy@csgroup.eu

1 files changed, 40 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/ptrace/ptrace-fpu.c b/arch/powerpc/kernel/ptrace/ptrace-fpu.c
new file mode 100644
index 000000000000..8301cb52dd99
--- /dev/null
+++ b/arch/powerpc/kernel/ptrace/ptrace-fpu.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/regset.h>
+
+#include <asm/switch_to.h>
+
+#include "ptrace-decl.h"
+
+int ptrace_get_fpr(struct task_struct *child, int index, unsigned long *data)
+{
+	unsigned int fpidx = index - PT_FPR0;
+
+	if (index > PT_FPSCR)
+		return -EIO;
+
+	flush_fp_to_thread(child);
+	if (fpidx < (PT_FPSCR - PT_FPR0))
+		memcpy(data, &child->thread.TS_FPR(fpidx), sizeof(long));
+	else
+		*data = child->thread.fp_state.fpscr;
+
+	return 0;
+}
+
+int ptrace_put_fpr(struct task_struct *child, int index, unsigned long data)
+{
+	unsigned int fpidx = index - PT_FPR0;
+
+	if (index > PT_FPSCR)
+		return -EIO;
+
+	flush_fp_to_thread(child);
+	if (fpidx < (PT_FPSCR - PT_FPR0))
+		memcpy(&child->thread.TS_FPR(fpidx), &data, sizeof(long));
+	else
+		child->thread.fp_state.fpscr = data;
+
+	return 0;
+}
+