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authorAl Viro <viro@ftp.linux.org.uk>2011-08-18 20:06:39 +0100
committerRichard Weinberger <richard@nod.at>2011-11-02 14:15:05 +0100
commit5c48b108ecbf6505d929e64d50dace13ac2bdf34 (patch)
tree016904f84fbe05aa301c5cdfe712d90f6bb828fe /arch/x86/um/os-Linux
parent7bbe7204e93734fe79d8aac3e08a7cb4624b5004 (diff)
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>
Diffstat (limited to 'arch/x86/um/os-Linux')
-rw-r--r--arch/x86/um/os-Linux/Makefile13
-rw-r--r--arch/x86/um/os-Linux/mcontext.c31
-rw-r--r--arch/x86/um/os-Linux/prctl.c12
-rw-r--r--arch/x86/um/os-Linux/registers.c111
-rw-r--r--arch/x86/um/os-Linux/task_size.c150
-rw-r--r--arch/x86/um/os-Linux/tls.c35
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;
+}