ptrace: Add support for generic PTRACE_GETREGSET/PTRACE_SETREGSET

Generic support for PTRACE_GETREGSET/PTRACE_SETREGSET commands which
export the regsets supported by each architecture using the correponding
NT_* types. These NT_* types are already part of the userland ABI, used
in representing the architecture specific register sets as different NOTES
in an ELF core file.

'addr' parameter for the ptrace system call encode the REGSET type (using
the corresppnding NT_* type) and the 'data' parameter points to the
struct iovec having the user buffer and the length of that buffer.

	struct iovec iov = { buf, len};
	ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov);

On 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.

x86 extended state registers are primarily exported using this interface.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20100211195614.886724710@sbs-t61.sc.intel.com>
Acked-by: Hongjiu Lu <hjl.tools@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 56f2d63a5cbb..dbfa821d5a6e 100644
--- a/include/linux/ptrace.h
+++ b/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