diff options
Diffstat (limited to 'arch/x86/um/os-Linux')
| -rw-r--r-- | arch/x86/um/os-Linux/Makefile | 13 | ||||
| -rw-r--r-- | arch/x86/um/os-Linux/mcontext.c | 31 | ||||
| -rw-r--r-- | arch/x86/um/os-Linux/prctl.c | 12 | ||||
| -rw-r--r-- | arch/x86/um/os-Linux/registers.c | 111 | ||||
| -rw-r--r-- | arch/x86/um/os-Linux/task_size.c | 150 | ||||
| -rw-r--r-- | arch/x86/um/os-Linux/tls.c | 35 |
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 00000000000..253bfb8cb70 --- /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 00000000000..1d33d72c628 --- /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 00000000000..9d34eddb517 --- /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 00000000000..3a9b6247bbb --- /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 00000000000..efb16c5c9bc --- /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 00000000000..281e83ecce3 --- /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; +} |