[PATCH] uml: start cross-build support : mk_user_constants

Beginning of cross-build fixes.  Instead of expecting that mk_user_constants
(compiled and executed on the build box) will see the sizeof, etc.  for target
box, we do what every architecture already does for asm-offsets.  Namely, have
user-offsets.c compiled *for* *target* into user-offsets.s and sed it into the
header with relevant constants.  We don't need to reinvent any wheels - all
tools are already there.

This patch deals with mk_user_constants.  It doesn't assume any relationship
between target and build environment anymore - we pick all defines we need
from user-offsets.h.  Later patches will deal with the rest of mk_...  helpers
in the same way.

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/arch/um/sys-x86_64/user-offsets.c b/arch/um/sys-x86_64/user-offsets.c
new file mode 100644
index 000000000000..5e14792e4838
--- /dev/null
+++ b/arch/um/sys-x86_64/user-offsets.c
@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <stddef.h>
+#include <signal.h>
+#define __FRAME_OFFSETS
+#include <asm/ptrace.h>
+#include <asm/user.h>
+
+#define DEFINE(sym, val) \
+        asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+
+#define OFFSET(sym, str, mem) \
+	DEFINE(sym, offsetof(struct str, mem));
+
+void foo(void)
+{
+	OFFSET(SC_RBX, sigcontext, rbx);
+	OFFSET(SC_RCX, sigcontext, rcx);
+	OFFSET(SC_RDX, sigcontext, rdx);
+	OFFSET(SC_RSI, sigcontext, rsi);
+	OFFSET(SC_RDI, sigcontext, rdi);
+	OFFSET(SC_RBP, sigcontext, rbp);
+	OFFSET(SC_RAX, sigcontext, rax);
+	OFFSET(SC_R8, sigcontext, r8);
+	OFFSET(SC_R9, sigcontext, r9);
+	OFFSET(SC_R10, sigcontext, r10);
+	OFFSET(SC_R11, sigcontext, r11);
+	OFFSET(SC_R12, sigcontext, r12);
+	OFFSET(SC_R13, sigcontext, r13);
+	OFFSET(SC_R14, sigcontext, r14);
+	OFFSET(SC_R15, sigcontext, r15);
+	OFFSET(SC_IP, sigcontext, rip);
+	OFFSET(SC_SP, sigcontext, rsp);
+	OFFSET(SC_CR2, sigcontext, cr2);
+	OFFSET(SC_ERR, sigcontext, err);
+	OFFSET(SC_TRAPNO, sigcontext, trapno);
+	OFFSET(SC_CS, sigcontext, cs);
+	OFFSET(SC_FS, sigcontext, fs);
+	OFFSET(SC_GS, sigcontext, gs);
+	OFFSET(SC_EFLAGS, sigcontext, eflags);
+	OFFSET(SC_SIGMASK, sigcontext, oldmask);
+#if 0
+	OFFSET(SC_ORIG_RAX, sigcontext, orig_rax);
+	OFFSET(SC_DS, sigcontext, ds);
+	OFFSET(SC_ES, sigcontext, es);
+	OFFSET(SC_SS, sigcontext, ss);
+#endif
+
+	DEFINE(HOST_FRAME_SIZE, FRAME_SIZE);
+	DEFINE(HOST_RBX, RBX);
+	DEFINE(HOST_RCX, RCX);
+	DEFINE(HOST_RDI, RDI);
+	DEFINE(HOST_RSI, RSI);
+	DEFINE(HOST_RDX, RDX);
+	DEFINE(HOST_RBP, RBP);
+	DEFINE(HOST_RAX, RAX);
+	DEFINE(HOST_R8, R8);
+	DEFINE(HOST_R9, R9);
+	DEFINE(HOST_R10, R10);
+	DEFINE(HOST_R11, R11);
+	DEFINE(HOST_R12, R12);
+	DEFINE(HOST_R13, R13);
+	DEFINE(HOST_R14, R14);
+	DEFINE(HOST_R15, R15);
+	DEFINE(HOST_ORIG_RAX, ORIG_RAX);
+	DEFINE(HOST_CS, CS);
+	DEFINE(HOST_SS, SS);
+	DEFINE(HOST_EFLAGS, EFLAGS);
+#if 0
+	DEFINE(HOST_FS, FS);
+	DEFINE(HOST_GS, GS);
+	DEFINE(HOST_DS, DS);
+	DEFINE(HOST_ES, ES);
+#endif
+
+	DEFINE(HOST_IP, RIP);
+	DEFINE(HOST_SP, RSP);
+	DEFINE(__UM_FRAME_SIZE, sizeof(struct user_regs_struct));
+}