[PATCH 1/3] arch/tile: implement user_regset interface on tilegx

[Simon Marchi <simon.marchi@polymtl.ca>]

This is an implementation of user_regset for the tilegx architecture. It
reuses the basic blocks that were already there.

Signed-off-by: Simon Marchi <simon.marchi@polymtl.ca>
---
I only tested these patches on a 3.0 kernel, as this is what my current
setup allows me. Some testing on more recent versions would be
appreciated, although I don't think the user_regset framework changed
much since then.

Also, I put some ifdefs so that these patches only affect tilegx and not
the older tile architectures, which I don't have access to. Hopefully
someone else can finish the work for those, it's probably not much.

 arch/tile/kernel/ptrace.c |   65 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 65 insertions(+), 0 deletions(-)

diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c
index b32bc3f..0e68d06 100644
--- a/arch/tile/kernel/ptrace.c
+++ b/arch/tile/kernel/ptrace.c
@@ -19,6 +19,8 @@
 #include <linux/kprobes.h>
 #include <linux/compat.h>
 #include <linux/uaccess.h>
+#include <linux/regset.h>
+#include <linux/elf.h>
 #include <asm/traps.h>
 
 void user_enable_single_step(struct task_struct *child)
@@ -80,6 +82,69 @@ static void putregs(struct task_struct *child, struct pt_regs *uregs)
 	*regs = *uregs;
 }
 
+#ifdef __tilegx__
+
+enum tile_regset {
+	REGSET_GPR,
+};
+
+static int tile_gpr_get(struct task_struct *target,
+			  const struct user_regset *regset,
+			  unsigned int pos, unsigned int count,
+			  void *kbuf, void __user *ubuf)
+{
+	struct pt_regs regs;
+
+	getregs(target, &regs);
+
+	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs, 0,
+				   sizeof(regs));
+}
+
+static int tile_gpr_set(struct task_struct *target,
+			  const struct user_regset *regset,
+			  unsigned int pos, unsigned int count,
+			  const void *kbuf, const void __user *ubuf)
+{
+	int ret;
+	struct pt_regs regs;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0,
+				 sizeof(regs));
+	if (ret)
+		return ret;
+
+	putregs(target, &regs);
+
+	return 0;
+}
+
+static const struct user_regset tile_user_regset[] = {
+	[REGSET_GPR] = {
+		.core_note_type = NT_PRSTATUS,
+		.n = ELF_NGREG,
+		.size = sizeof(elf_greg_t),
+		.align = sizeof(elf_greg_t),
+		.get = tile_gpr_get,
+		.set = tile_gpr_set,
+	},
+};
+
+static const struct user_regset_view tile_user_regset_view = {
+	.name = "tilegx",
+	.e_machine = ELF_ARCH,
+	.ei_osabi = ELF_OSABI,
+	.regsets = tile_user_regset,
+	.n = ARRAY_SIZE(tile_user_regset),
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	return &tile_user_regset_view;
+}
+
+#endif /* __tilegx__ */
+
 long arch_ptrace(struct task_struct *child, long request,
 		 unsigned long addr, unsigned long data)
 {
-- 
1.7.1