---

yaml
---
r: 182595
b: refs/heads/master
c: 2225a12
h: refs/heads/master
i:
  182593: 5500e82
  182591: 6169847
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5b3efd500854d45d305b53c54c97db5970959980
+refs/heads/master: 2225a122ae26d542bdce523d9d87a4a7ba10e07b

trunk/include/linux/elf.h

@@ -349,7 +349,11 @@ typedef struct elf64_shdr {
 #define ELF_OSABI ELFOSABI_NONE
 #endif
 
-/* Notes used in ET_CORE */
+/*
+ * Notes used in ET_CORE. Architectures export some of the arch register sets
+ * using the corresponding note types via the PTRACE_GETREGSET and
+ * PTRACE_SETREGSET requests.
+ */
 #define NT_PRSTATUS	1
 #define NT_PRFPREG	2
 #define NT_PRPSINFO	3

trunk/include/linux/ptrace.h

@@ -27,6 +27,21 @@
 #define PTRACE_GETSIGINFO	0x4202
 #define PTRACE_SETSIGINFO	0x4203
 
+/*
+ * Generic ptrace interface that exports the architecture specific regsets
+ * using the corresponding NT_* types (which are also used in the core dump).
+ *
+ * This interface usage is as follows:
+ *	struct iovec iov = { buf, len};
+ *
+ *	ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov);
+ *
+ * On the successful completion, iov.len will be updated by the kernel,
+ * specifying how much the kernel has written/read to/from the user's iov.buf.
+ */
+#define PTRACE_GETREGSET	0x4204
+#define PTRACE_SETREGSET	0x4205
+
 /* options set using PTRACE_SETOPTIONS */
 #define PTRACE_O_TRACESYSGOOD	0x00000001
 #define PTRACE_O_TRACEFORK	0x00000002

trunk/kernel/ptrace.c

@@ -22,6 +22,7 @@
 #include <linux/pid_namespace.h>
 #include <linux/syscalls.h>
 #include <linux/uaccess.h>
+#include <linux/regset.h>
 
 
 /*
@@ -511,6 +512,47 @@ static int ptrace_resume(struct task_struct *child, long request, long data)
 	return 0;
 }
 
+#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
+
+static const struct user_regset *
+find_regset(const struct user_regset_view *view, unsigned int type)
+{
+	const struct user_regset *regset;
+	int n;
+
+	for (n = 0; n < view->n; ++n) {
+		regset = view->regsets + n;
+		if (regset->core_note_type == type)
+			return regset;
+	}
+
+	return NULL;
+}
+
+static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
+			 struct iovec *kiov)
+{
+	const struct user_regset_view *view = task_user_regset_view(task);
+	const struct user_regset *regset = find_regset(view, type);
+	int regset_no;
+
+	if (!regset || (kiov->iov_len % regset->size) != 0)
+		return -EIO;
+
+	regset_no = regset - view->regsets;
+	kiov->iov_len = min(kiov->iov_len,
+			    (__kernel_size_t) (regset->n * regset->size));
+
+	if (req == PTRACE_GETREGSET)
+		return copy_regset_to_user(task, view, regset_no, 0,
+					   kiov->iov_len, kiov->iov_base);
+	else
+		return copy_regset_from_user(task, view, regset_no, 0,
+					     kiov->iov_len, kiov->iov_base);
+}
+
+#endif
+
 int ptrace_request(struct task_struct *child, long request,
 		   long addr, long data)
 {
@@ -573,6 +615,26 @@ int ptrace_request(struct task_struct *child, long request,
 			return 0;
 		return ptrace_resume(child, request, SIGKILL);
 
+#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
+	case PTRACE_GETREGSET:
+	case PTRACE_SETREGSET:
+	{
+		struct iovec kiov;
+		struct iovec __user *uiov = (struct iovec __user *) data;
+
+		if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
+			return -EFAULT;
+
+		if (__get_user(kiov.iov_base, &uiov->iov_base) ||
+		    __get_user(kiov.iov_len, &uiov->iov_len))
+			return -EFAULT;
+
+		ret = ptrace_regset(child, request, addr, &kiov);
+		if (!ret)
+			ret = __put_user(kiov.iov_len, &uiov->iov_len);
+		break;
+	}
+#endif
 	default:
 		break;
 	}
@@ -711,6 +773,32 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request,
 		else
 			ret = ptrace_setsiginfo(child, &siginfo);
 		break;
+#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
+	case PTRACE_GETREGSET:
+	case PTRACE_SETREGSET:
+	{
+		struct iovec kiov;
+		struct compat_iovec __user *uiov =
+			(struct compat_iovec __user *) datap;
+		compat_uptr_t ptr;
+		compat_size_t len;
+
+		if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
+			return -EFAULT;
+
+		if (__get_user(ptr, &uiov->iov_base) ||
+		    __get_user(len, &uiov->iov_len))
+			return -EFAULT;
+
+		kiov.iov_base = compat_ptr(ptr);
+		kiov.iov_len = len;
+
+		ret = ptrace_regset(child, request, addr, &kiov);
+		if (!ret)
+			ret = __put_user(kiov.iov_len, &uiov->iov_len);
+		break;
+	}
+#endif
 
 	default:
 		ret = ptrace_request(child, request, addr, data);