um: finish conversion to mcontext_t

now we don't mix host and guest signal frame layouts anymore; moreover,
we don't need host's struct sigcontext at all.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/os-Linux/signal.c

@@ -14,7 +14,7 @@
 #include "os.h"
 #include "process.h"
 #include "sysdep/barrier.h"
-#include "sysdep/sigcontext.h"
+#include "sysdep/mcontext.h"
 
 void (*sig_info[NSIG])(int, struct uml_pt_regs *) = {
 	[SIGTRAP]	= relay_signal,
@@ -34,7 +34,7 @@ static void sig_handler_common(int sig, mcontext_t *mc)
 	r.is_user = 0;
 	if (sig == SIGSEGV) {
 		/* For segfaults, we want the data from the sigcontext. */
-		copy_sc(&r, (struct sigcontext *)mc);
+		get_regs_from_mc(&r, mc);
 		GET_FAULTINFO_FROM_MC(r.faultinfo, mc);
 	}
 
@@ -84,7 +84,7 @@ static void real_alarm_handler(mcontext_t *mc)
 	struct uml_pt_regs regs;
 
 	if (mc != NULL)
-		copy_sc(&regs, (struct sigcontext *)mc);
+		get_regs_from_mc(&regs, mc);
 	regs.is_user = 0;
 	unblock_signals();
 	timer_handler(SIGVTALRM, &regs);

arch/um/os-Linux/sys-x86/Makefile

@@ -3,7 +3,7 @@
 # Licensed under the GPL
 #
 
-obj-y = registers.o task_size.o
+obj-y = registers.o task_size.o mcontext.o
 
 obj-$(CONFIG_X86_32) += tls.o
 obj-$(CONFIG_64BIT) += prctl.o

arch/um/os-Linux/sys-x86/mcontext.c

@@ -0,0 +1,31 @@
+#include <sys/ucontext.h>
+#define __FRAME_OFFSETS
+#include <asm/ptrace.h>
+#include <sysdep/ptrace.h>
+
+void get_regs_from_mc(struct uml_pt_regs *regs, mcontext_t *mc)
+{
+#ifdef __i386__
+#define COPY2(X,Y) regs->gp[X] = mc->gregs[REG_##Y]
+#define COPY(X) regs->gp[X] = mc->gregs[REG_##X]
+#define COPY_SEG(X) regs->gp[X] = mc->gregs[REG_##X] & 0xffff;
+#define COPY_SEG_CPL3(X) regs->gp[X] = (mc->gregs[REG_##X] & 0xffff) | 3;
+	COPY_SEG(GS); COPY_SEG(FS); COPY_SEG(ES); COPY_SEG(DS);
+	COPY(EDI); COPY(ESI); COPY(EBP);
+	COPY2(UESP, ESP); /* sic */
+	COPY(EBX); COPY(EDX); COPY(ECX); COPY(EAX);
+	COPY(EIP); COPY_SEG_CPL3(CS); COPY(EFL); COPY_SEG_CPL3(SS);
+#else
+#define COPY2(X,Y) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##Y]
+#define COPY(X) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##X]
+	COPY(R8); COPY(R9); COPY(R10); COPY(R11);
+	COPY(R12); COPY(R13); COPY(R14); COPY(R15);
+	COPY(RDI); COPY(RSI); COPY(RBP); COPY(RBX);
+	COPY(RDX); COPY(RAX); COPY(RCX); COPY(RSP);
+	COPY(RIP);
+	COPY2(EFLAGS, EFL);
+	COPY2(CS, CSGSFS);
+	regs->gp[CS / sizeof(unsigned long)] &= 0xffff;
+	regs->gp[CS / sizeof(unsigned long)] |= 3;
+#endif
+}

arch/um/sys-x86/shared/sysdep/mcontext.h

@@ -0,0 +1,31 @@
+/* 
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYS_SIGCONTEXT_X86_H
+#define __SYS_SIGCONTEXT_X86_H
+
+extern void get_regs_from_mc(struct uml_pt_regs *, mcontext_t *);
+
+#ifdef __i386__
+
+#define GET_FAULTINFO_FROM_MC(fi, mc) \
+	{ \
+		(fi).cr2 = (mc)->cr2; \
+		(fi).error_code = (mc)->gregs[REG_ERR]; \
+		(fi).trap_no = (mc)->gregs[REG_TRAPNO]; \
+	}
+
+#else
+
+#define GET_FAULTINFO_FROM_MC(fi, mc) \
+	{ \
+		(fi).cr2 = (mc)->gregs[REG_CR2]; \
+		(fi).error_code = (mc)->gregs[REG_ERR]; \
+		(fi).trap_no = (mc)->gregs[REG_TRAPNO]; \
+	}
+
+#endif
+
+#endif

arch/um/sys-x86/stub_segv.c

@@ -5,7 +5,7 @@
 
 #include "sysdep/stub.h"
 #include "sysdep/faultinfo.h"
-#include "sysdep/sigcontext.h"
+#include "sysdep/mcontext.h"
 
 void __attribute__ ((__section__ (".__syscall_stub")))
 stub_segv_handler(int sig, siginfo_t *info, void *p)

arch/um/sys-x86/user-offsets.c

@@ -14,15 +14,8 @@
 #define DEFINE_LONGS(sym, val) \
 	asm volatile("\n->" #sym " %0 " #val : : "i" (val/sizeof(unsigned long)))
 
-#define OFFSET(sym, str, mem) \
-	DEFINE(sym, offsetof(struct str, mem));
-
 void foo(void)
 {
-	OFFSET(HOST_SC_TRAPNO, sigcontext, trapno);
-	OFFSET(HOST_SC_ERR, sigcontext, err);
-	OFFSET(HOST_SC_CR2, sigcontext, cr2);
-
 #ifdef __i386__
 	DEFINE_LONGS(HOST_FP_SIZE, sizeof(struct user_fpregs_struct));
 	DEFINE_LONGS(HOST_FPX_SIZE, sizeof(struct user_fpxregs_struct));