um: take arch/um/sys-x86 to arch/x86/um

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

6 files changed, 352 insertions, 0 deletions

diff --git a/arch/x86/um/os-Linux/Makefile b/arch/x86/um/os-Linux/Makefile
new file mode 100644
index 000000000000..253bfb8cb702
--- /dev/null
+++ b/arch/x86/um/os-Linux/Makefile
@@ -0,0 +1,13 @@
+#
+# Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+# Licensed under the GPL
+#
+
+obj-y = registers.o task_size.o mcontext.o
+
+obj-$(CONFIG_X86_32) += tls.o
+obj-$(CONFIG_64BIT) += prctl.o
+
+USER_OBJS := $(obj-y)
+
+include arch/um/scripts/Makefile.rules
diff --git a/arch/x86/um/os-Linux/mcontext.c b/arch/x86/um/os-Linux/mcontext.c
new file mode 100644
index 000000000000..1d33d72c6284
--- /dev/null
+++ b/arch/x86/um/os-Linux/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
+}
diff --git a/arch/x86/um/os-Linux/prctl.c b/arch/x86/um/os-Linux/prctl.c
new file mode 100644
index 000000000000..9d34eddb517f
--- /dev/null
+++ b/arch/x86/um/os-Linux/prctl.c
@@ -0,0 +1,12 @@
+/*
+ * Copyright (C) 2007 Jeff Dike (jdike@{addtoit.com,linux.intel.com})
+ * Licensed under the GPL
+ */
+
+#include <sys/ptrace.h>
+#include <linux/ptrace.h>
+
+int os_arch_prctl(int pid, int code, unsigned long *addr)
+{
+        return ptrace(PTRACE_ARCH_PRCTL, pid, (unsigned long) addr, code);
+}
diff --git a/arch/x86/um/os-Linux/registers.c b/arch/x86/um/os-Linux/registers.c
new file mode 100644
index 000000000000..3a9b6247bbbc
--- /dev/null
+++ b/arch/x86/um/os-Linux/registers.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2004 PathScale, Inc
+ * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <errno.h>
+#include <sys/ptrace.h>
+#include <sys/user.h>
+#include "longjmp.h"
+#include "sysdep/ptrace_user.h"
+
+int save_fp_registers(int pid, unsigned long *fp_regs)
+{
+	if (ptrace(PTRACE_GETFPREGS, pid, 0, fp_regs) < 0)
+		return -errno;
+	return 0;
+}
+
+int restore_fp_registers(int pid, unsigned long *fp_regs)
+{
+	if (ptrace(PTRACE_SETFPREGS, pid, 0, fp_regs) < 0)
+		return -errno;
+	return 0;
+}
+
+#ifdef __i386__
+int have_fpx_regs = 1;
+int save_fpx_registers(int pid, unsigned long *fp_regs)
+{
+	if (ptrace(PTRACE_GETFPXREGS, pid, 0, fp_regs) < 0)
+		return -errno;
+	return 0;
+}
+
+int restore_fpx_registers(int pid, unsigned long *fp_regs)
+{
+	if (ptrace(PTRACE_SETFPXREGS, pid, 0, fp_regs) < 0)
+		return -errno;
+	return 0;
+}
+
+int get_fp_registers(int pid, unsigned long *regs)
+{
+	if (have_fpx_regs)
+		return save_fpx_registers(pid, regs);
+	else
+		return save_fp_registers(pid, regs);
+}
+
+int put_fp_registers(int pid, unsigned long *regs)
+{
+	if (have_fpx_regs)
+		return restore_fpx_registers(pid, regs);
+	else
+		return restore_fp_registers(pid, regs);
+}
+
+void arch_init_registers(int pid)
+{
+	struct user_fpxregs_struct fpx_regs;
+	int err;
+
+	err = ptrace(PTRACE_GETFPXREGS, pid, 0, &fpx_regs);
+	if (!err)
+		return;
+
+	if (errno != EIO)
+		panic("check_ptrace : PTRACE_GETFPXREGS failed, errno = %d",
+		      errno);
+
+	have_fpx_regs = 0;
+}
+#else
+
+int get_fp_registers(int pid, unsigned long *regs)
+{
+	return save_fp_registers(pid, regs);
+}
+
+int put_fp_registers(int pid, unsigned long *regs)
+{
+	return restore_fp_registers(pid, regs);
+}
+
+#endif
+
+unsigned long get_thread_reg(int reg, jmp_buf *buf)
+{
+	switch (reg) {
+#ifdef __i386__
+	case EIP:
+		return buf[0]->__eip;
+	case UESP:
+		return buf[0]->__esp;
+	case EBP:
+		return buf[0]->__ebp;
+#else
+	case RIP:
+		return buf[0]->__rip;
+	case RSP:
+		return buf[0]->__rsp;
+	case RBP:
+		return buf[0]->__rbp;
+#endif
+	default:
+		printk(UM_KERN_ERR "get_thread_regs - unknown register %d\n",
+		       reg);
+		return 0;
+	}
+}
diff --git a/arch/x86/um/os-Linux/task_size.c b/arch/x86/um/os-Linux/task_size.c
new file mode 100644
index 000000000000..efb16c5c9bcf
--- /dev/null
+++ b/arch/x86/um/os-Linux/task_size.c
@@ -0,0 +1,150 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/mman.h>
+#include "longjmp.h"
+
+#ifdef __i386__
+
+static jmp_buf buf;
+
+static void segfault(int sig)
+{
+	longjmp(buf, 1);
+}
+
+static int page_ok(unsigned long page)
+{
+	unsigned long *address = (unsigned long *) (page << UM_KERN_PAGE_SHIFT);
+	unsigned long n = ~0UL;
+	void *mapped = NULL;
+	int ok = 0;
+
+	/*
+	 * First see if the page is readable.  If it is, it may still
+	 * be a VDSO, so we go on to see if it's writable.  If not
+	 * then try mapping memory there.  If that fails, then we're
+	 * still in the kernel area.  As a sanity check, we'll fail if
+	 * the mmap succeeds, but gives us an address different from
+	 * what we wanted.
+	 */
+	if (setjmp(buf) == 0)
+		n = *address;
+	else {
+		mapped = mmap(address, UM_KERN_PAGE_SIZE,
+			      PROT_READ | PROT_WRITE,
+			      MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+		if (mapped == MAP_FAILED)
+			return 0;
+		if (mapped != address)
+			goto out;
+	}
+
+	/*
+	 * Now, is it writeable?  If so, then we're in user address
+	 * space.  If not, then try mprotecting it and try the write
+	 * again.
+	 */
+	if (setjmp(buf) == 0) {
+		*address = n;
+		ok = 1;
+		goto out;
+	} else if (mprotect(address, UM_KERN_PAGE_SIZE,
+			    PROT_READ | PROT_WRITE) != 0)
+		goto out;
+
+	if (setjmp(buf) == 0) {
+		*address = n;
+		ok = 1;
+	}
+
+ out:
+	if (mapped != NULL)
+		munmap(mapped, UM_KERN_PAGE_SIZE);
+	return ok;
+}
+
+unsigned long os_get_top_address(void)
+{
+	struct sigaction sa, old;
+	unsigned long bottom = 0;
+	/*
+	 * A 32-bit UML on a 64-bit host gets confused about the VDSO at
+	 * 0xffffe000.  It is mapped, is readable, can be reprotected writeable
+	 * and written.  However, exec discovers later that it can't be
+	 * unmapped.  So, just set the highest address to be checked to just
+	 * below it.  This might waste some address space on 4G/4G 32-bit
+	 * hosts, but shouldn't hurt otherwise.
+	 */
+	unsigned long top = 0xffffd000 >> UM_KERN_PAGE_SHIFT;
+	unsigned long test, original;
+
+	printf("Locating the bottom of the address space ... ");
+	fflush(stdout);
+
+	/*
+	 * We're going to be longjmping out of the signal handler, so
+	 * SA_DEFER needs to be set.
+	 */
+	sa.sa_handler = segfault;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_NODEFER;
+	if (sigaction(SIGSEGV, &sa, &old)) {
+		perror("os_get_top_address");
+		exit(1);
+	}
+
+	/* Manually scan the address space, bottom-up, until we find
+	 * the first valid page (or run out of them).
+	 */
+	for (bottom = 0; bottom < top; bottom++) {
+		if (page_ok(bottom))
+			break;
+	}
+
+	/* If we've got this far, we ran out of pages. */
+	if (bottom == top) {
+		fprintf(stderr, "Unable to determine bottom of address "
+			"space.\n");
+		exit(1);
+	}
+
+	printf("0x%x\n", bottom << UM_KERN_PAGE_SHIFT);
+	printf("Locating the top of the address space ... ");
+	fflush(stdout);
+
+	original = bottom;
+
+	/* This could happen with a 4G/4G split */
+	if (page_ok(top))
+		goto out;
+
+	do {
+		test = bottom + (top - bottom) / 2;
+		if (page_ok(test))
+			bottom = test;
+		else
+			top = test;
+	} while (top - bottom > 1);
+
+out:
+	/* Restore the old SIGSEGV handling */
+	if (sigaction(SIGSEGV, &old, NULL)) {
+		perror("os_get_top_address");
+		exit(1);
+	}
+	top <<= UM_KERN_PAGE_SHIFT;
+	printf("0x%x\n", top);
+
+	return top;
+}
+
+#else
+
+unsigned long os_get_top_address(void)
+{
+	/* The old value of CONFIG_TOP_ADDR */
+	return 0x7fc0000000;
+}
+
+#endif
diff --git a/arch/x86/um/os-Linux/tls.c b/arch/x86/um/os-Linux/tls.c
new file mode 100644
index 000000000000..281e83ecce3d
--- /dev/null
+++ b/arch/x86/um/os-Linux/tls.c
@@ -0,0 +1,35 @@
+#include <errno.h>
+#include <linux/unistd.h>
+
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#include "sysdep/tls.h"
+
+/* Checks whether host supports TLS, and sets *tls_min according to the value
+ * valid on the host.
+ * i386 host have it == 6; x86_64 host have it == 12, for i386 emulation. */
+void check_host_supports_tls(int *supports_tls, int *tls_min) {
+	/* Values for x86 and x86_64.*/
+	int val[] = {GDT_ENTRY_TLS_MIN_I386, GDT_ENTRY_TLS_MIN_X86_64};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(val); i++) {
+		user_desc_t info;
+		info.entry_number = val[i];
+
+		if (syscall(__NR_get_thread_area, &info) == 0) {
+			*tls_min = val[i];
+			*supports_tls = 1;
+			return;
+		} else {
+			if (errno == EINVAL)
+				continue;
+			else if (errno == ENOSYS)
+				*supports_tls = 0;
+				return;
+		}
+	}
+
+	*supports_tls = 0;
+}