721 lines
18 KiB
C
721 lines
18 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
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* Copyright (C) 2002- 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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*/
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#include <stdlib.h>
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#include <unistd.h>
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#include <sched.h>
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#include <errno.h>
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#include <string.h>
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#include <sys/mman.h>
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#include <sys/wait.h>
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#include <asm/unistd.h>
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#include <as-layout.h>
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#include <init.h>
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#include <kern_util.h>
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#include <mem.h>
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#include <os.h>
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#include <ptrace_user.h>
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#include <registers.h>
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#include <skas.h>
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#include <sysdep/stub.h>
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#include <linux/threads.h>
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int is_skas_winch(int pid, int fd, void *data)
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{
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return pid == getpgrp();
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}
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static const char *ptrace_reg_name(int idx)
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{
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#define R(n) case HOST_##n: return #n
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switch (idx) {
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#ifdef __x86_64__
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R(BX);
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R(CX);
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R(DI);
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R(SI);
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R(DX);
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R(BP);
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R(AX);
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R(R8);
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R(R9);
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R(R10);
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R(R11);
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R(R12);
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R(R13);
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R(R14);
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R(R15);
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R(ORIG_AX);
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R(CS);
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R(SS);
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R(EFLAGS);
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#elif defined(__i386__)
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R(IP);
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R(SP);
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R(EFLAGS);
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R(AX);
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R(BX);
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R(CX);
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R(DX);
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R(SI);
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R(DI);
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R(BP);
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R(CS);
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R(SS);
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R(DS);
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R(FS);
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R(ES);
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R(GS);
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R(ORIG_AX);
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#endif
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}
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return "";
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}
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static int ptrace_dump_regs(int pid)
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{
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unsigned long regs[MAX_REG_NR];
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int i;
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if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
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return -errno;
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printk(UM_KERN_ERR "Stub registers -\n");
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for (i = 0; i < ARRAY_SIZE(regs); i++) {
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const char *regname = ptrace_reg_name(i);
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printk(UM_KERN_ERR "\t%s\t(%2d): %lx\n", regname, i, regs[i]);
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}
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return 0;
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}
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/*
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* Signals that are OK to receive in the stub - we'll just continue it.
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* SIGWINCH will happen when UML is inside a detached screen.
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*/
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#define STUB_SIG_MASK ((1 << SIGALRM) | (1 << SIGWINCH))
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/* Signals that the stub will finish with - anything else is an error */
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#define STUB_DONE_MASK (1 << SIGTRAP)
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void wait_stub_done(int pid)
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{
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int n, status, err;
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while (1) {
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CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL));
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if ((n < 0) || !WIFSTOPPED(status))
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goto bad_wait;
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if (((1 << WSTOPSIG(status)) & STUB_SIG_MASK) == 0)
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break;
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err = ptrace(PTRACE_CONT, pid, 0, 0);
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if (err) {
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printk(UM_KERN_ERR "wait_stub_done : continue failed, "
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"errno = %d\n", errno);
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fatal_sigsegv();
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}
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}
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if (((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0)
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return;
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bad_wait:
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err = ptrace_dump_regs(pid);
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if (err)
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printk(UM_KERN_ERR "Failed to get registers from stub, "
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"errno = %d\n", -err);
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printk(UM_KERN_ERR "wait_stub_done : failed to wait for SIGTRAP, "
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"pid = %d, n = %d, errno = %d, status = 0x%x\n", pid, n, errno,
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status);
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fatal_sigsegv();
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}
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extern unsigned long current_stub_stack(void);
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static void get_skas_faultinfo(int pid, struct faultinfo *fi, unsigned long *aux_fp_regs)
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{
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int err;
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err = get_fp_registers(pid, aux_fp_regs);
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if (err < 0) {
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printk(UM_KERN_ERR "save_fp_registers returned %d\n",
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err);
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fatal_sigsegv();
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}
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err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV);
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if (err) {
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printk(UM_KERN_ERR "Failed to continue stub, pid = %d, "
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"errno = %d\n", pid, errno);
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fatal_sigsegv();
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}
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wait_stub_done(pid);
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/*
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* faultinfo is prepared by the stub_segv_handler at start of
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* the stub stack page. We just have to copy it.
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*/
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memcpy(fi, (void *)current_stub_stack(), sizeof(*fi));
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err = put_fp_registers(pid, aux_fp_regs);
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if (err < 0) {
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printk(UM_KERN_ERR "put_fp_registers returned %d\n",
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err);
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fatal_sigsegv();
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}
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}
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static void handle_segv(int pid, struct uml_pt_regs *regs, unsigned long *aux_fp_regs)
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{
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get_skas_faultinfo(pid, ®s->faultinfo, aux_fp_regs);
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segv(regs->faultinfo, 0, 1, NULL);
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}
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/*
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* To use the same value of using_sysemu as the caller, ask it that value
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* (in local_using_sysemu
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*/
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static void handle_trap(int pid, struct uml_pt_regs *regs,
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int local_using_sysemu)
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{
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int err, status;
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if ((UPT_IP(regs) >= STUB_START) && (UPT_IP(regs) < STUB_END))
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fatal_sigsegv();
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if (!local_using_sysemu)
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{
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err = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET,
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__NR_getpid);
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if (err < 0) {
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printk(UM_KERN_ERR "handle_trap - nullifying syscall "
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"failed, errno = %d\n", errno);
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fatal_sigsegv();
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}
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err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
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if (err < 0) {
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printk(UM_KERN_ERR "handle_trap - continuing to end of "
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"syscall failed, errno = %d\n", errno);
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fatal_sigsegv();
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}
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CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL));
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if ((err < 0) || !WIFSTOPPED(status) ||
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(WSTOPSIG(status) != SIGTRAP + 0x80)) {
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err = ptrace_dump_regs(pid);
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if (err)
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printk(UM_KERN_ERR "Failed to get registers "
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"from process, errno = %d\n", -err);
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printk(UM_KERN_ERR "handle_trap - failed to wait at "
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"end of syscall, errno = %d, status = %d\n",
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errno, status);
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fatal_sigsegv();
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}
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}
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handle_syscall(regs);
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}
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extern char __syscall_stub_start[];
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/**
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* userspace_tramp() - userspace trampoline
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* @stack: pointer to the new userspace stack page, can be NULL, if? FIXME:
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*
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* The userspace trampoline is used to setup a new userspace process in start_userspace() after it was clone()'ed.
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* This function will run on a temporary stack page.
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* It ptrace()'es itself, then
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* Two pages are mapped into the userspace address space:
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* - STUB_CODE (with EXEC), which contains the skas stub code
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* - STUB_DATA (with R/W), which contains a data page that is used to transfer certain data between the UML userspace process and the UML kernel.
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* Also for the userspace process a SIGSEGV handler is installed to catch pagefaults in the userspace process.
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* And last the process stops itself to give control to the UML kernel for this userspace process.
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*
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* Return: Always zero, otherwise the current userspace process is ended with non null exit() call
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*/
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static int userspace_tramp(void *stack)
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{
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void *addr;
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int fd;
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unsigned long long offset;
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ptrace(PTRACE_TRACEME, 0, 0, 0);
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signal(SIGTERM, SIG_DFL);
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signal(SIGWINCH, SIG_IGN);
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fd = phys_mapping(to_phys(__syscall_stub_start), &offset);
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addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE,
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PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
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if (addr == MAP_FAILED) {
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printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, "
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"errno = %d\n", STUB_CODE, errno);
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exit(1);
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}
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if (stack != NULL) {
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fd = phys_mapping(to_phys(stack), &offset);
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addr = mmap((void *) STUB_DATA,
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UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
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MAP_FIXED | MAP_SHARED, fd, offset);
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if (addr == MAP_FAILED) {
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printk(UM_KERN_ERR "mapping segfault stack "
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"at 0x%lx failed, errno = %d\n",
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STUB_DATA, errno);
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exit(1);
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}
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}
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if (stack != NULL) {
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struct sigaction sa;
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unsigned long v = STUB_CODE +
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(unsigned long) stub_segv_handler -
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(unsigned long) __syscall_stub_start;
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set_sigstack((void *) STUB_DATA, UM_KERN_PAGE_SIZE);
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sigemptyset(&sa.sa_mask);
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sa.sa_flags = SA_ONSTACK | SA_NODEFER | SA_SIGINFO;
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sa.sa_sigaction = (void *) v;
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sa.sa_restorer = NULL;
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if (sigaction(SIGSEGV, &sa, NULL) < 0) {
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printk(UM_KERN_ERR "userspace_tramp - setting SIGSEGV "
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"handler failed - errno = %d\n", errno);
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exit(1);
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}
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}
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|
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kill(os_getpid(), SIGSTOP);
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return 0;
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|
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}
|
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|
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int userspace_pid[NR_CPUS];
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int kill_userspace_mm[NR_CPUS];
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|
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/**
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* start_userspace() - prepare a new userspace process
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* @stub_stack: pointer to the stub stack. Can be NULL, if? FIXME:
|
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|
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*
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* Setups a new temporary stack page that is used while userspace_tramp() runs
|
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* Clones the kernel process into a new userspace process, with FDs only.
|
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|
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*
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* Return: When positive: the process id of the new userspace process,
|
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|
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* when negative: an error number.
|
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|
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* FIXME: can PIDs become negative?!
|
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|
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*/
|
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|
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int start_userspace(unsigned long stub_stack)
|
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{
|
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void *stack;
|
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|
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unsigned long sp;
|
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|
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int pid, status, n, flags, err;
|
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|
|
|
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|
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/* setup a temporary stack page */
|
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|
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stack = mmap(NULL, UM_KERN_PAGE_SIZE,
|
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|
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PROT_READ | PROT_WRITE | PROT_EXEC,
|
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|
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
||
|
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if (stack == MAP_FAILED) {
|
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|
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err = -errno;
|
||
|
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printk(UM_KERN_ERR "start_userspace : mmap failed, "
|
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|
|
"errno = %d\n", errno);
|
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|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* set stack pointer to the end of the stack page, so it can grow downwards */
|
||
|
|
sp = (unsigned long)stack + UM_KERN_PAGE_SIZE;
|
||
|
|
|
||
|
|
flags = CLONE_FILES | SIGCHLD;
|
||
|
|
|
||
|
|
/* clone into new userspace process */
|
||
|
|
pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
|
||
|
|
if (pid < 0) {
|
||
|
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err = -errno;
|
||
|
|
printk(UM_KERN_ERR "start_userspace : clone failed, "
|
||
|
|
"errno = %d\n", errno);
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
do {
|
||
|
|
CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL));
|
||
|
|
if (n < 0) {
|
||
|
|
err = -errno;
|
||
|
|
printk(UM_KERN_ERR "start_userspace : wait failed, "
|
||
|
|
"errno = %d\n", errno);
|
||
|
|
goto out_kill;
|
||
|
|
}
|
||
|
|
} while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGALRM));
|
||
|
|
|
||
|
|
if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) {
|
||
|
|
err = -EINVAL;
|
||
|
|
printk(UM_KERN_ERR "start_userspace : expected SIGSTOP, got "
|
||
|
|
"status = %d\n", status);
|
||
|
|
goto out_kill;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
|
||
|
|
(void *) PTRACE_O_TRACESYSGOOD) < 0) {
|
||
|
|
err = -errno;
|
||
|
|
printk(UM_KERN_ERR "start_userspace : PTRACE_OLDSETOPTIONS "
|
||
|
|
"failed, errno = %d\n", errno);
|
||
|
|
goto out_kill;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (munmap(stack, UM_KERN_PAGE_SIZE) < 0) {
|
||
|
|
err = -errno;
|
||
|
|
printk(UM_KERN_ERR "start_userspace : munmap failed, "
|
||
|
|
"errno = %d\n", errno);
|
||
|
|
goto out_kill;
|
||
|
|
}
|
||
|
|
|
||
|
|
return pid;
|
||
|
|
|
||
|
|
out_kill:
|
||
|
|
os_kill_ptraced_process(pid, 1);
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs)
|
||
|
|
{
|
||
|
|
int err, status, op, pid = userspace_pid[0];
|
||
|
|
/* To prevent races if using_sysemu changes under us.*/
|
||
|
|
int local_using_sysemu;
|
||
|
|
siginfo_t si;
|
||
|
|
|
||
|
|
/* Handle any immediate reschedules or signals */
|
||
|
|
interrupt_end();
|
||
|
|
|
||
|
|
while (1) {
|
||
|
|
if (kill_userspace_mm[0])
|
||
|
|
fatal_sigsegv();
|
||
|
|
|
||
|
|
/*
|
||
|
|
* This can legitimately fail if the process loads a
|
||
|
|
* bogus value into a segment register. It will
|
||
|
|
* segfault and PTRACE_GETREGS will read that value
|
||
|
|
* out of the process. However, PTRACE_SETREGS will
|
||
|
|
* fail. In this case, there is nothing to do but
|
||
|
|
* just kill the process.
|
||
|
|
*/
|
||
|
|
if (ptrace(PTRACE_SETREGS, pid, 0, regs->gp)) {
|
||
|
|
printk(UM_KERN_ERR "userspace - ptrace set regs "
|
||
|
|
"failed, errno = %d\n", errno);
|
||
|
|
fatal_sigsegv();
|
||
|
|
}
|
||
|
|
|
||
|
|
if (put_fp_registers(pid, regs->fp)) {
|
||
|
|
printk(UM_KERN_ERR "userspace - ptrace set fp regs "
|
||
|
|
"failed, errno = %d\n", errno);
|
||
|
|
fatal_sigsegv();
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Now we set local_using_sysemu to be used for one loop */
|
||
|
|
local_using_sysemu = get_using_sysemu();
|
||
|
|
|
||
|
|
op = SELECT_PTRACE_OPERATION(local_using_sysemu,
|
||
|
|
singlestepping(NULL));
|
||
|
|
|
||
|
|
if (ptrace(op, pid, 0, 0)) {
|
||
|
|
printk(UM_KERN_ERR "userspace - ptrace continue "
|
||
|
|
"failed, op = %d, errno = %d\n", op, errno);
|
||
|
|
fatal_sigsegv();
|
||
|
|
}
|
||
|
|
|
||
|
|
CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL));
|
||
|
|
if (err < 0) {
|
||
|
|
printk(UM_KERN_ERR "userspace - wait failed, "
|
||
|
|
"errno = %d\n", errno);
|
||
|
|
fatal_sigsegv();
|
||
|
|
}
|
||
|
|
|
||
|
|
regs->is_user = 1;
|
||
|
|
if (ptrace(PTRACE_GETREGS, pid, 0, regs->gp)) {
|
||
|
|
printk(UM_KERN_ERR "userspace - PTRACE_GETREGS failed, "
|
||
|
|
"errno = %d\n", errno);
|
||
|
|
fatal_sigsegv();
|
||
|
|
}
|
||
|
|
|
||
|
|
if (get_fp_registers(pid, regs->fp)) {
|
||
|
|
printk(UM_KERN_ERR "userspace - get_fp_registers failed, "
|
||
|
|
"errno = %d\n", errno);
|
||
|
|
fatal_sigsegv();
|
||
|
|
}
|
||
|
|
|
||
|
|
UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
|
||
|
|
|
||
|
|
if (WIFSTOPPED(status)) {
|
||
|
|
int sig = WSTOPSIG(status);
|
||
|
|
|
||
|
|
/* These signal handlers need the si argument.
|
||
|
|
* The SIGIO and SIGALARM handlers which constitute the
|
||
|
|
* majority of invocations, do not use it.
|
||
|
|
*/
|
||
|
|
switch (sig) {
|
||
|
|
case SIGSEGV:
|
||
|
|
case SIGTRAP:
|
||
|
|
case SIGILL:
|
||
|
|
case SIGBUS:
|
||
|
|
case SIGFPE:
|
||
|
|
case SIGWINCH:
|
||
|
|
ptrace(PTRACE_GETSIGINFO, pid, 0, (struct siginfo *)&si);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
switch (sig) {
|
||
|
|
case SIGSEGV:
|
||
|
|
if (PTRACE_FULL_FAULTINFO) {
|
||
|
|
get_skas_faultinfo(pid,
|
||
|
|
®s->faultinfo, aux_fp_regs);
|
||
|
|
(*sig_info[SIGSEGV])(SIGSEGV, (struct siginfo *)&si,
|
||
|
|
regs);
|
||
|
|
}
|
||
|
|
else handle_segv(pid, regs, aux_fp_regs);
|
||
|
|
break;
|
||
|
|
case SIGTRAP + 0x80:
|
||
|
|
handle_trap(pid, regs, local_using_sysemu);
|
||
|
|
break;
|
||
|
|
case SIGTRAP:
|
||
|
|
relay_signal(SIGTRAP, (struct siginfo *)&si, regs);
|
||
|
|
break;
|
||
|
|
case SIGALRM:
|
||
|
|
break;
|
||
|
|
case SIGIO:
|
||
|
|
case SIGILL:
|
||
|
|
case SIGBUS:
|
||
|
|
case SIGFPE:
|
||
|
|
case SIGWINCH:
|
||
|
|
block_signals_trace();
|
||
|
|
(*sig_info[sig])(sig, (struct siginfo *)&si, regs);
|
||
|
|
unblock_signals_trace();
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
printk(UM_KERN_ERR "userspace - child stopped "
|
||
|
|
"with signal %d\n", sig);
|
||
|
|
fatal_sigsegv();
|
||
|
|
}
|
||
|
|
pid = userspace_pid[0];
|
||
|
|
interrupt_end();
|
||
|
|
|
||
|
|
/* Avoid -ERESTARTSYS handling in host */
|
||
|
|
if (PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET)
|
||
|
|
PT_SYSCALL_NR(regs->gp) = -1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static unsigned long thread_regs[MAX_REG_NR];
|
||
|
|
static unsigned long thread_fp_regs[FP_SIZE];
|
||
|
|
|
||
|
|
static int __init init_thread_regs(void)
|
||
|
|
{
|
||
|
|
get_safe_registers(thread_regs, thread_fp_regs);
|
||
|
|
/* Set parent's instruction pointer to start of clone-stub */
|
||
|
|
thread_regs[REGS_IP_INDEX] = STUB_CODE +
|
||
|
|
(unsigned long) stub_clone_handler -
|
||
|
|
(unsigned long) __syscall_stub_start;
|
||
|
|
thread_regs[REGS_SP_INDEX] = STUB_DATA + UM_KERN_PAGE_SIZE -
|
||
|
|
sizeof(void *);
|
||
|
|
#ifdef __SIGNAL_FRAMESIZE
|
||
|
|
thread_regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
|
||
|
|
#endif
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
__initcall(init_thread_regs);
|
||
|
|
|
||
|
|
int copy_context_skas0(unsigned long new_stack, int pid)
|
||
|
|
{
|
||
|
|
int err;
|
||
|
|
unsigned long current_stack = current_stub_stack();
|
||
|
|
struct stub_data *data = (struct stub_data *) current_stack;
|
||
|
|
struct stub_data *child_data = (struct stub_data *) new_stack;
|
||
|
|
unsigned long long new_offset;
|
||
|
|
int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* prepare offset and fd of child's stack as argument for parent's
|
||
|
|
* and child's mmap2 calls
|
||
|
|
*/
|
||
|
|
*data = ((struct stub_data) {
|
||
|
|
.offset = MMAP_OFFSET(new_offset),
|
||
|
|
.fd = new_fd,
|
||
|
|
.parent_err = -ESRCH,
|
||
|
|
.child_err = 0,
|
||
|
|
});
|
||
|
|
|
||
|
|
*child_data = ((struct stub_data) {
|
||
|
|
.child_err = -ESRCH,
|
||
|
|
});
|
||
|
|
|
||
|
|
err = ptrace_setregs(pid, thread_regs);
|
||
|
|
if (err < 0) {
|
||
|
|
err = -errno;
|
||
|
|
printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_SETREGS "
|
||
|
|
"failed, pid = %d, errno = %d\n", pid, -err);
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
err = put_fp_registers(pid, thread_fp_regs);
|
||
|
|
if (err < 0) {
|
||
|
|
printk(UM_KERN_ERR "copy_context_skas0 : put_fp_registers "
|
||
|
|
"failed, pid = %d, err = %d\n", pid, err);
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Wait, until parent has finished its work: read child's pid from
|
||
|
|
* parent's stack, and check, if bad result.
|
||
|
|
*/
|
||
|
|
err = ptrace(PTRACE_CONT, pid, 0, 0);
|
||
|
|
if (err) {
|
||
|
|
err = -errno;
|
||
|
|
printk(UM_KERN_ERR "Failed to continue new process, pid = %d, "
|
||
|
|
"errno = %d\n", pid, errno);
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
wait_stub_done(pid);
|
||
|
|
|
||
|
|
pid = data->parent_err;
|
||
|
|
if (pid < 0) {
|
||
|
|
printk(UM_KERN_ERR "copy_context_skas0 - stub-parent reports "
|
||
|
|
"error %d\n", -pid);
|
||
|
|
return pid;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Wait, until child has finished too: read child's result from
|
||
|
|
* child's stack and check it.
|
||
|
|
*/
|
||
|
|
wait_stub_done(pid);
|
||
|
|
if (child_data->child_err != STUB_DATA) {
|
||
|
|
printk(UM_KERN_ERR "copy_context_skas0 - stub-child %d reports "
|
||
|
|
"error %ld\n", pid, data->child_err);
|
||
|
|
err = data->child_err;
|
||
|
|
goto out_kill;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
|
||
|
|
(void *)PTRACE_O_TRACESYSGOOD) < 0) {
|
||
|
|
err = -errno;
|
||
|
|
printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_OLDSETOPTIONS "
|
||
|
|
"failed, errno = %d\n", errno);
|
||
|
|
goto out_kill;
|
||
|
|
}
|
||
|
|
|
||
|
|
return pid;
|
||
|
|
|
||
|
|
out_kill:
|
||
|
|
os_kill_ptraced_process(pid, 1);
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
void new_thread(void *stack, jmp_buf *buf, void (*handler)(void))
|
||
|
|
{
|
||
|
|
(*buf)[0].JB_IP = (unsigned long) handler;
|
||
|
|
(*buf)[0].JB_SP = (unsigned long) stack + UM_THREAD_SIZE -
|
||
|
|
sizeof(void *);
|
||
|
|
}
|
||
|
|
|
||
|
|
#define INIT_JMP_NEW_THREAD 0
|
||
|
|
#define INIT_JMP_CALLBACK 1
|
||
|
|
#define INIT_JMP_HALT 2
|
||
|
|
#define INIT_JMP_REBOOT 3
|
||
|
|
|
||
|
|
void switch_threads(jmp_buf *me, jmp_buf *you)
|
||
|
|
{
|
||
|
|
if (UML_SETJMP(me) == 0)
|
||
|
|
UML_LONGJMP(you, 1);
|
||
|
|
}
|
||
|
|
|
||
|
|
static jmp_buf initial_jmpbuf;
|
||
|
|
|
||
|
|
/* XXX Make these percpu */
|
||
|
|
static void (*cb_proc)(void *arg);
|
||
|
|
static void *cb_arg;
|
||
|
|
static jmp_buf *cb_back;
|
||
|
|
|
||
|
|
int start_idle_thread(void *stack, jmp_buf *switch_buf)
|
||
|
|
{
|
||
|
|
int n;
|
||
|
|
|
||
|
|
set_handler(SIGWINCH);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Can't use UML_SETJMP or UML_LONGJMP here because they save
|
||
|
|
* and restore signals, with the possible side-effect of
|
||
|
|
* trying to handle any signals which came when they were
|
||
|
|
* blocked, which can't be done on this stack.
|
||
|
|
* Signals must be blocked when jumping back here and restored
|
||
|
|
* after returning to the jumper.
|
||
|
|
*/
|
||
|
|
n = setjmp(initial_jmpbuf);
|
||
|
|
switch (n) {
|
||
|
|
case INIT_JMP_NEW_THREAD:
|
||
|
|
(*switch_buf)[0].JB_IP = (unsigned long) uml_finishsetup;
|
||
|
|
(*switch_buf)[0].JB_SP = (unsigned long) stack +
|
||
|
|
UM_THREAD_SIZE - sizeof(void *);
|
||
|
|
break;
|
||
|
|
case INIT_JMP_CALLBACK:
|
||
|
|
(*cb_proc)(cb_arg);
|
||
|
|
longjmp(*cb_back, 1);
|
||
|
|
break;
|
||
|
|
case INIT_JMP_HALT:
|
||
|
|
kmalloc_ok = 0;
|
||
|
|
return 0;
|
||
|
|
case INIT_JMP_REBOOT:
|
||
|
|
kmalloc_ok = 0;
|
||
|
|
return 1;
|
||
|
|
default:
|
||
|
|
printk(UM_KERN_ERR "Bad sigsetjmp return in "
|
||
|
|
"start_idle_thread - %d\n", n);
|
||
|
|
fatal_sigsegv();
|
||
|
|
}
|
||
|
|
longjmp(*switch_buf, 1);
|
||
|
|
|
||
|
|
/* unreachable */
|
||
|
|
printk(UM_KERN_ERR "impossible long jump!");
|
||
|
|
fatal_sigsegv();
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
void initial_thread_cb_skas(void (*proc)(void *), void *arg)
|
||
|
|
{
|
||
|
|
jmp_buf here;
|
||
|
|
|
||
|
|
cb_proc = proc;
|
||
|
|
cb_arg = arg;
|
||
|
|
cb_back = &here;
|
||
|
|
|
||
|
|
block_signals_trace();
|
||
|
|
if (UML_SETJMP(&here) == 0)
|
||
|
|
UML_LONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
|
||
|
|
unblock_signals_trace();
|
||
|
|
|
||
|
|
cb_proc = NULL;
|
||
|
|
cb_arg = NULL;
|
||
|
|
cb_back = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
void halt_skas(void)
|
||
|
|
{
|
||
|
|
block_signals_trace();
|
||
|
|
UML_LONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
|
||
|
|
}
|
||
|
|
|
||
|
|
void reboot_skas(void)
|
||
|
|
{
|
||
|
|
block_signals_trace();
|
||
|
|
UML_LONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
|
||
|
|
}
|
||
|
|
|
||
|
|
void __switch_mm(struct mm_id *mm_idp)
|
||
|
|
{
|
||
|
|
userspace_pid[0] = mm_idp->u.pid;
|
||
|
|
kill_userspace_mm[0] = mm_idp->kill;
|
||
|
|
}
|