diff options
author | Ingo Molnar <mingo@kernel.org> | 2015-06-03 18:41:06 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2015-06-04 07:37:37 +0200 |
commit | 00398a0018d1334fedabfeaabd0fa563121de612 (patch) | |
tree | 81d6a7ccfabbf9d48126c5110678ce8de9775317 /arch/x86/kernel | |
parent | 1f57d5d85ba7f1f467173ff33f51d01a91f9aaf1 (diff) |
x86/asm/entry: Move the vsyscall code to arch/x86/entry/vsyscall/
The vsyscall code is entry code too, so move it to arch/x86/entry/vsyscall/.
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r-- | arch/x86/kernel/Makefile | 3 | ||||
-rw-r--r-- | arch/x86/kernel/syscall_32.c | 33 | ||||
-rw-r--r-- | arch/x86/kernel/syscall_64.c | 32 | ||||
-rw-r--r-- | arch/x86/kernel/vsyscall_64.c | 335 | ||||
-rw-r--r-- | arch/x86/kernel/vsyscall_emu_64.S | 37 | ||||
-rw-r--r-- | arch/x86/kernel/vsyscall_gtod.c | 70 | ||||
-rw-r--r-- | arch/x86/kernel/vsyscall_trace.h | 29 |
7 files changed, 0 insertions, 539 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 9d3ee054453d..01663ee5f1b7 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -31,9 +31,6 @@ obj-y += probe_roms.o obj-$(CONFIG_X86_32) += i386_ksyms_32.o obj-$(CONFIG_X86_64) += sys_x86_64.o x8664_ksyms_64.o obj-$(CONFIG_X86_64) += mcount_64.o -obj-y += syscall_$(BITS).o vsyscall_gtod.o -obj-$(CONFIG_IA32_EMULATION) += syscall_32.o -obj-$(CONFIG_X86_VSYSCALL_EMULATION) += vsyscall_64.o vsyscall_emu_64.o obj-$(CONFIG_X86_ESPFIX64) += espfix_64.o obj-$(CONFIG_SYSFS) += ksysfs.o obj-y += bootflag.o e820.o diff --git a/arch/x86/kernel/syscall_32.c b/arch/x86/kernel/syscall_32.c deleted file mode 100644 index 3777189c4a19..000000000000 --- a/arch/x86/kernel/syscall_32.c +++ /dev/null @@ -1,33 +0,0 @@ -/* System call table for i386. */ - -#include <linux/linkage.h> -#include <linux/sys.h> -#include <linux/cache.h> -#include <asm/asm-offsets.h> - -#ifdef CONFIG_IA32_EMULATION -#define SYM(sym, compat) compat -#else -#define SYM(sym, compat) sym -#define ia32_sys_call_table sys_call_table -#define __NR_ia32_syscall_max __NR_syscall_max -#endif - -#define __SYSCALL_I386(nr, sym, compat) extern asmlinkage void SYM(sym, compat)(void) ; -#include <asm/syscalls_32.h> -#undef __SYSCALL_I386 - -#define __SYSCALL_I386(nr, sym, compat) [nr] = SYM(sym, compat), - -typedef asmlinkage void (*sys_call_ptr_t)(void); - -extern asmlinkage void sys_ni_syscall(void); - -__visible const sys_call_ptr_t ia32_sys_call_table[__NR_ia32_syscall_max+1] = { - /* - * Smells like a compiler bug -- it doesn't work - * when the & below is removed. - */ - [0 ... __NR_ia32_syscall_max] = &sys_ni_syscall, -#include <asm/syscalls_32.h> -}; diff --git a/arch/x86/kernel/syscall_64.c b/arch/x86/kernel/syscall_64.c deleted file mode 100644 index 4ac730b37f0b..000000000000 --- a/arch/x86/kernel/syscall_64.c +++ /dev/null @@ -1,32 +0,0 @@ -/* System call table for x86-64. */ - -#include <linux/linkage.h> -#include <linux/sys.h> -#include <linux/cache.h> -#include <asm/asm-offsets.h> -#include <asm/syscall.h> - -#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym, compat) - -#ifdef CONFIG_X86_X32_ABI -# define __SYSCALL_X32(nr, sym, compat) __SYSCALL_64(nr, sym, compat) -#else -# define __SYSCALL_X32(nr, sym, compat) /* nothing */ -#endif - -#define __SYSCALL_64(nr, sym, compat) extern asmlinkage void sym(void) ; -#include <asm/syscalls_64.h> -#undef __SYSCALL_64 - -#define __SYSCALL_64(nr, sym, compat) [nr] = sym, - -extern void sys_ni_syscall(void); - -asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = { - /* - * Smells like a compiler bug -- it doesn't work - * when the & below is removed. - */ - [0 ... __NR_syscall_max] = &sys_ni_syscall, -#include <asm/syscalls_64.h> -}; diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c deleted file mode 100644 index 2dcc6ff6fdcc..000000000000 --- a/arch/x86/kernel/vsyscall_64.c +++ /dev/null @@ -1,335 +0,0 @@ -/* - * Copyright (c) 2012-2014 Andy Lutomirski <luto@amacapital.net> - * - * Based on the original implementation which is: - * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE - * Copyright 2003 Andi Kleen, SuSE Labs. - * - * Parts of the original code have been moved to arch/x86/vdso/vma.c - * - * This file implements vsyscall emulation. vsyscalls are a legacy ABI: - * Userspace can request certain kernel services by calling fixed - * addresses. This concept is problematic: - * - * - It interferes with ASLR. - * - It's awkward to write code that lives in kernel addresses but is - * callable by userspace at fixed addresses. - * - The whole concept is impossible for 32-bit compat userspace. - * - UML cannot easily virtualize a vsyscall. - * - * As of mid-2014, I believe that there is no new userspace code that - * will use a vsyscall if the vDSO is present. I hope that there will - * soon be no new userspace code that will ever use a vsyscall. - * - * The code in this file emulates vsyscalls when notified of a page - * fault to a vsyscall address. - */ - -#include <linux/kernel.h> -#include <linux/timer.h> -#include <linux/syscalls.h> -#include <linux/ratelimit.h> - -#include <asm/vsyscall.h> -#include <asm/unistd.h> -#include <asm/fixmap.h> -#include <asm/traps.h> - -#define CREATE_TRACE_POINTS -#include "vsyscall_trace.h" - -static enum { EMULATE, NATIVE, NONE } vsyscall_mode = EMULATE; - -static int __init vsyscall_setup(char *str) -{ - if (str) { - if (!strcmp("emulate", str)) - vsyscall_mode = EMULATE; - else if (!strcmp("native", str)) - vsyscall_mode = NATIVE; - else if (!strcmp("none", str)) - vsyscall_mode = NONE; - else - return -EINVAL; - - return 0; - } - - return -EINVAL; -} -early_param("vsyscall", vsyscall_setup); - -static void warn_bad_vsyscall(const char *level, struct pt_regs *regs, - const char *message) -{ - if (!show_unhandled_signals) - return; - - printk_ratelimited("%s%s[%d] %s ip:%lx cs:%lx sp:%lx ax:%lx si:%lx di:%lx\n", - level, current->comm, task_pid_nr(current), - message, regs->ip, regs->cs, - regs->sp, regs->ax, regs->si, regs->di); -} - -static int addr_to_vsyscall_nr(unsigned long addr) -{ - int nr; - - if ((addr & ~0xC00UL) != VSYSCALL_ADDR) - return -EINVAL; - - nr = (addr & 0xC00UL) >> 10; - if (nr >= 3) - return -EINVAL; - - return nr; -} - -static bool write_ok_or_segv(unsigned long ptr, size_t size) -{ - /* - * XXX: if access_ok, get_user, and put_user handled - * sig_on_uaccess_error, this could go away. - */ - - if (!access_ok(VERIFY_WRITE, (void __user *)ptr, size)) { - siginfo_t info; - struct thread_struct *thread = ¤t->thread; - - thread->error_code = 6; /* user fault, no page, write */ - thread->cr2 = ptr; - thread->trap_nr = X86_TRAP_PF; - - memset(&info, 0, sizeof(info)); - info.si_signo = SIGSEGV; - info.si_errno = 0; - info.si_code = SEGV_MAPERR; - info.si_addr = (void __user *)ptr; - - force_sig_info(SIGSEGV, &info, current); - return false; - } else { - return true; - } -} - -bool emulate_vsyscall(struct pt_regs *regs, unsigned long address) -{ - struct task_struct *tsk; - unsigned long caller; - int vsyscall_nr, syscall_nr, tmp; - int prev_sig_on_uaccess_error; - long ret; - - /* - * No point in checking CS -- the only way to get here is a user mode - * trap to a high address, which means that we're in 64-bit user code. - */ - - WARN_ON_ONCE(address != regs->ip); - - if (vsyscall_mode == NONE) { - warn_bad_vsyscall(KERN_INFO, regs, - "vsyscall attempted with vsyscall=none"); - return false; - } - - vsyscall_nr = addr_to_vsyscall_nr(address); - - trace_emulate_vsyscall(vsyscall_nr); - - if (vsyscall_nr < 0) { - warn_bad_vsyscall(KERN_WARNING, regs, - "misaligned vsyscall (exploit attempt or buggy program) -- look up the vsyscall kernel parameter if you need a workaround"); - goto sigsegv; - } - - if (get_user(caller, (unsigned long __user *)regs->sp) != 0) { - warn_bad_vsyscall(KERN_WARNING, regs, - "vsyscall with bad stack (exploit attempt?)"); - goto sigsegv; - } - - tsk = current; - - /* - * Check for access_ok violations and find the syscall nr. - * - * NULL is a valid user pointer (in the access_ok sense) on 32-bit and - * 64-bit, so we don't need to special-case it here. For all the - * vsyscalls, NULL means "don't write anything" not "write it at - * address 0". - */ - switch (vsyscall_nr) { - case 0: - if (!write_ok_or_segv(regs->di, sizeof(struct timeval)) || - !write_ok_or_segv(regs->si, sizeof(struct timezone))) { - ret = -EFAULT; - goto check_fault; - } - - syscall_nr = __NR_gettimeofday; - break; - - case 1: - if (!write_ok_or_segv(regs->di, sizeof(time_t))) { - ret = -EFAULT; - goto check_fault; - } - - syscall_nr = __NR_time; - break; - - case 2: - if (!write_ok_or_segv(regs->di, sizeof(unsigned)) || - !write_ok_or_segv(regs->si, sizeof(unsigned))) { - ret = -EFAULT; - goto check_fault; - } - - syscall_nr = __NR_getcpu; - break; - } - - /* - * Handle seccomp. regs->ip must be the original value. - * See seccomp_send_sigsys and Documentation/prctl/seccomp_filter.txt. - * - * We could optimize the seccomp disabled case, but performance - * here doesn't matter. - */ - regs->orig_ax = syscall_nr; - regs->ax = -ENOSYS; - tmp = secure_computing(); - if ((!tmp && regs->orig_ax != syscall_nr) || regs->ip != address) { - warn_bad_vsyscall(KERN_DEBUG, regs, - "seccomp tried to change syscall nr or ip"); - do_exit(SIGSYS); - } - regs->orig_ax = -1; - if (tmp) - goto do_ret; /* skip requested */ - - /* - * With a real vsyscall, page faults cause SIGSEGV. We want to - * preserve that behavior to make writing exploits harder. - */ - prev_sig_on_uaccess_error = current_thread_info()->sig_on_uaccess_error; - current_thread_info()->sig_on_uaccess_error = 1; - - ret = -EFAULT; - switch (vsyscall_nr) { - case 0: - ret = sys_gettimeofday( - (struct timeval __user *)regs->di, - (struct timezone __user *)regs->si); - break; - - case 1: - ret = sys_time((time_t __user *)regs->di); - break; - - case 2: - ret = sys_getcpu((unsigned __user *)regs->di, - (unsigned __user *)regs->si, - NULL); - break; - } - - current_thread_info()->sig_on_uaccess_error = prev_sig_on_uaccess_error; - -check_fault: - if (ret == -EFAULT) { - /* Bad news -- userspace fed a bad pointer to a vsyscall. */ - warn_bad_vsyscall(KERN_INFO, regs, - "vsyscall fault (exploit attempt?)"); - - /* - * If we failed to generate a signal for any reason, - * generate one here. (This should be impossible.) - */ - if (WARN_ON_ONCE(!sigismember(&tsk->pending.signal, SIGBUS) && - !sigismember(&tsk->pending.signal, SIGSEGV))) - goto sigsegv; - - return true; /* Don't emulate the ret. */ - } - - regs->ax = ret; - -do_ret: - /* Emulate a ret instruction. */ - regs->ip = caller; - regs->sp += 8; - return true; - -sigsegv: - force_sig(SIGSEGV, current); - return true; -} - -/* - * A pseudo VMA to allow ptrace access for the vsyscall page. This only - * covers the 64bit vsyscall page now. 32bit has a real VMA now and does - * not need special handling anymore: - */ -static const char *gate_vma_name(struct vm_area_struct *vma) -{ - return "[vsyscall]"; -} -static struct vm_operations_struct gate_vma_ops = { - .name = gate_vma_name, -}; -static struct vm_area_struct gate_vma = { - .vm_start = VSYSCALL_ADDR, - .vm_end = VSYSCALL_ADDR + PAGE_SIZE, - .vm_page_prot = PAGE_READONLY_EXEC, - .vm_flags = VM_READ | VM_EXEC, - .vm_ops = &gate_vma_ops, -}; - -struct vm_area_struct *get_gate_vma(struct mm_struct *mm) -{ -#ifdef CONFIG_IA32_EMULATION - if (!mm || mm->context.ia32_compat) - return NULL; -#endif - if (vsyscall_mode == NONE) - return NULL; - return &gate_vma; -} - -int in_gate_area(struct mm_struct *mm, unsigned long addr) -{ - struct vm_area_struct *vma = get_gate_vma(mm); - - if (!vma) - return 0; - - return (addr >= vma->vm_start) && (addr < vma->vm_end); -} - -/* - * Use this when you have no reliable mm, typically from interrupt - * context. It is less reliable than using a task's mm and may give - * false positives. - */ -int in_gate_area_no_mm(unsigned long addr) -{ - return vsyscall_mode != NONE && (addr & PAGE_MASK) == VSYSCALL_ADDR; -} - -void __init map_vsyscall(void) -{ - extern char __vsyscall_page; - unsigned long physaddr_vsyscall = __pa_symbol(&__vsyscall_page); - - if (vsyscall_mode != NONE) - __set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall, - vsyscall_mode == NATIVE - ? PAGE_KERNEL_VSYSCALL - : PAGE_KERNEL_VVAR); - - BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) != - (unsigned long)VSYSCALL_ADDR); -} diff --git a/arch/x86/kernel/vsyscall_emu_64.S b/arch/x86/kernel/vsyscall_emu_64.S deleted file mode 100644 index c9596a9af159..000000000000 --- a/arch/x86/kernel/vsyscall_emu_64.S +++ /dev/null @@ -1,37 +0,0 @@ -/* - * vsyscall_emu_64.S: Vsyscall emulation page - * - * Copyright (c) 2011 Andy Lutomirski - * - * Subject to the GNU General Public License, version 2 - */ - -#include <linux/linkage.h> - -#include <asm/irq_vectors.h> -#include <asm/page_types.h> -#include <asm/unistd_64.h> - -__PAGE_ALIGNED_DATA - .globl __vsyscall_page - .balign PAGE_SIZE, 0xcc - .type __vsyscall_page, @object -__vsyscall_page: - - mov $__NR_gettimeofday, %rax - syscall - ret - - .balign 1024, 0xcc - mov $__NR_time, %rax - syscall - ret - - .balign 1024, 0xcc - mov $__NR_getcpu, %rax - syscall - ret - - .balign 4096, 0xcc - - .size __vsyscall_page, 4096 diff --git a/arch/x86/kernel/vsyscall_gtod.c b/arch/x86/kernel/vsyscall_gtod.c deleted file mode 100644 index 51e330416995..000000000000 --- a/arch/x86/kernel/vsyscall_gtod.c +++ /dev/null @@ -1,70 +0,0 @@ -/* - * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE - * Copyright 2003 Andi Kleen, SuSE Labs. - * - * Modified for x86 32 bit architecture by - * Stefani Seibold <stefani@seibold.net> - * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany - * - * Thanks to hpa@transmeta.com for some useful hint. - * Special thanks to Ingo Molnar for his early experience with - * a different vsyscall implementation for Linux/IA32 and for the name. - * - */ - -#include <linux/timekeeper_internal.h> -#include <asm/vgtod.h> -#include <asm/vvar.h> - -DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data); - -void update_vsyscall_tz(void) -{ - vsyscall_gtod_data.tz_minuteswest = sys_tz.tz_minuteswest; - vsyscall_gtod_data.tz_dsttime = sys_tz.tz_dsttime; -} - -void update_vsyscall(struct timekeeper *tk) -{ - struct vsyscall_gtod_data *vdata = &vsyscall_gtod_data; - - gtod_write_begin(vdata); - - /* copy vsyscall data */ - vdata->vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode; - vdata->cycle_last = tk->tkr_mono.cycle_last; - vdata->mask = tk->tkr_mono.mask; - vdata->mult = tk->tkr_mono.mult; - vdata->shift = tk->tkr_mono.shift; - - vdata->wall_time_sec = tk->xtime_sec; - vdata->wall_time_snsec = tk->tkr_mono.xtime_nsec; - - vdata->monotonic_time_sec = tk->xtime_sec - + tk->wall_to_monotonic.tv_sec; - vdata->monotonic_time_snsec = tk->tkr_mono.xtime_nsec - + ((u64)tk->wall_to_monotonic.tv_nsec - << tk->tkr_mono.shift); - while (vdata->monotonic_time_snsec >= - (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) { - vdata->monotonic_time_snsec -= - ((u64)NSEC_PER_SEC) << tk->tkr_mono.shift; - vdata->monotonic_time_sec++; - } - - vdata->wall_time_coarse_sec = tk->xtime_sec; - vdata->wall_time_coarse_nsec = (long)(tk->tkr_mono.xtime_nsec >> - tk->tkr_mono.shift); - - vdata->monotonic_time_coarse_sec = - vdata->wall_time_coarse_sec + tk->wall_to_monotonic.tv_sec; - vdata->monotonic_time_coarse_nsec = - vdata->wall_time_coarse_nsec + tk->wall_to_monotonic.tv_nsec; - - while (vdata->monotonic_time_coarse_nsec >= NSEC_PER_SEC) { - vdata->monotonic_time_coarse_nsec -= NSEC_PER_SEC; - vdata->monotonic_time_coarse_sec++; - } - - gtod_write_end(vdata); -} diff --git a/arch/x86/kernel/vsyscall_trace.h b/arch/x86/kernel/vsyscall_trace.h deleted file mode 100644 index a8b2edec54fe..000000000000 --- a/arch/x86/kernel/vsyscall_trace.h +++ /dev/null @@ -1,29 +0,0 @@ -#undef TRACE_SYSTEM -#define TRACE_SYSTEM vsyscall - -#if !defined(__VSYSCALL_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) -#define __VSYSCALL_TRACE_H - -#include <linux/tracepoint.h> - -TRACE_EVENT(emulate_vsyscall, - - TP_PROTO(int nr), - - TP_ARGS(nr), - - TP_STRUCT__entry(__field(int, nr)), - - TP_fast_assign( - __entry->nr = nr; - ), - - TP_printk("nr = %d", __entry->nr) -); - -#endif - -#undef TRACE_INCLUDE_PATH -#define TRACE_INCLUDE_PATH ../../arch/x86/kernel -#define TRACE_INCLUDE_FILE vsyscall_trace -#include <trace/define_trace.h> |