584 lines
15 KiB
C
584 lines
15 KiB
C
/*
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* Copyright (C) 2002- 2004 Jeff Dike (jdike@addtoit.com)
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* Licensed under the GPL
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*/
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <errno.h>
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#include <signal.h>
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#include <sched.h>
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#include "ptrace_user.h"
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#include <sys/wait.h>
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#include <sys/mman.h>
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#include <sys/user.h>
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#include <sys/time.h>
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#include <asm/unistd.h>
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#include <asm/types.h>
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#include "user.h"
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#include "sysdep/ptrace.h"
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#include "user_util.h"
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#include "kern_util.h"
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#include "skas.h"
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#include "stub-data.h"
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#include "mm_id.h"
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#include "sysdep/sigcontext.h"
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#include "sysdep/stub.h"
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#include "os.h"
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#include "proc_mm.h"
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#include "skas_ptrace.h"
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#include "chan_user.h"
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#include "registers.h"
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#include "mem.h"
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#include "uml-config.h"
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#include "process.h"
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#include "longjmp.h"
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int is_skas_winch(int pid, int fd, void *data)
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{
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if(pid != os_getpgrp())
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return(0);
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register_winch_irq(-1, fd, -1, data);
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return(1);
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}
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void wait_stub_done(int pid, int sig, char * fname)
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{
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int n, status, err;
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do {
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if ( sig != -1 ) {
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err = ptrace(PTRACE_CONT, pid, 0, sig);
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if(err)
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panic("%s : continue failed, errno = %d\n",
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fname, errno);
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}
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sig = 0;
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CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
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} while((n >= 0) && WIFSTOPPED(status) &&
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((WSTOPSIG(status) == SIGVTALRM) ||
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/* running UML inside a detached screen can cause
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* SIGWINCHes
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*/
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(WSTOPSIG(status) == SIGWINCH)));
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if((n < 0) || !WIFSTOPPED(status) ||
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(WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){
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unsigned long regs[HOST_FRAME_SIZE];
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if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
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printk("Failed to get registers from stub, "
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"errno = %d\n", errno);
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else {
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int i;
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printk("Stub registers -\n");
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for(i = 0; i < HOST_FRAME_SIZE; i++)
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printk("\t%d - %lx\n", i, regs[i]);
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}
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panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
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"pid = %d, n = %d, errno = %d, status = 0x%x\n",
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fname, pid, n, errno, status);
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}
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}
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extern unsigned long current_stub_stack(void);
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void get_skas_faultinfo(int pid, struct faultinfo * fi)
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{
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int err;
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if(ptrace_faultinfo){
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err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
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if(err)
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panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
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"errno = %d\n", errno);
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/* Special handling for i386, which has different structs */
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if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
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memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
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sizeof(struct faultinfo) -
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sizeof(struct ptrace_faultinfo));
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}
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else {
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wait_stub_done(pid, SIGSEGV, "get_skas_faultinfo");
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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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}
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}
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static void handle_segv(int pid, union uml_pt_regs * regs)
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{
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get_skas_faultinfo(pid, ®s->skas.faultinfo);
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segv(regs->skas.faultinfo, 0, 1, NULL);
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}
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/*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/
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static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu)
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{
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int err, status;
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/* Mark this as a syscall */
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UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->skas.regs);
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if (!local_using_sysemu)
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{
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err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
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__NR_getpid);
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if(err < 0)
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panic("handle_trap - nullifying syscall failed errno = %d\n",
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errno);
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err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
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if(err < 0)
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panic("handle_trap - continuing to end of syscall failed, "
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"errno = %d\n", errno);
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CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
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if((err < 0) || !WIFSTOPPED(status) ||
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(WSTOPSIG(status) != SIGTRAP + 0x80))
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panic("handle_trap - failed to wait at end of syscall, "
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"errno = %d, status = %d\n", errno, status);
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}
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handle_syscall(regs);
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}
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extern int __syscall_stub_start;
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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 err;
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ptrace(PTRACE_TRACEME, 0, 0, 0);
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init_new_thread_signals();
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err = set_interval(1);
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if(err)
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panic("userspace_tramp - setting timer failed, errno = %d\n",
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err);
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if(!proc_mm){
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/* This has a pte, but it can't be mapped in with the usual
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* tlb_flush mechanism because this is part of that mechanism
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*/
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int fd;
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__u64 offset;
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fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
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addr = mmap64((void *) UML_CONFIG_STUB_CODE, 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("mapping mmap stub failed, errno = %d\n",
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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 *) UML_CONFIG_STUB_DATA, page_size(),
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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("mapping segfault stack failed, "
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"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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if(!ptrace_faultinfo && (stack != NULL)){
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struct sigaction sa;
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unsigned long v = UML_CONFIG_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 *) UML_CONFIG_STUB_DATA, page_size());
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sigemptyset(&sa.sa_mask);
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sigaddset(&sa.sa_mask, SIGIO);
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sigaddset(&sa.sa_mask, SIGWINCH);
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sigaddset(&sa.sa_mask, SIGALRM);
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sigaddset(&sa.sa_mask, SIGVTALRM);
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sigaddset(&sa.sa_mask, SIGUSR1);
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sa.sa_flags = SA_ONSTACK;
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sa.sa_handler = (void *) v;
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sa.sa_restorer = NULL;
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if(sigaction(SIGSEGV, &sa, NULL) < 0)
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panic("userspace_tramp - setting SIGSEGV handler "
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"failed - errno = %d\n", errno);
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}
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os_stop_process(os_getpid());
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return(0);
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}
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/* Each element set once, and only accessed by a single processor anyway */
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#undef NR_CPUS
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#define NR_CPUS 1
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int userspace_pid[NR_CPUS];
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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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unsigned long sp;
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int pid, status, n, flags;
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stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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if(stack == MAP_FAILED)
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panic("start_userspace : mmap failed, errno = %d", errno);
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sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
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flags = CLONE_FILES | SIGCHLD;
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if(proc_mm) flags |= CLONE_VM;
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pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
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if(pid < 0)
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panic("start_userspace : clone failed, errno = %d", errno);
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do {
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CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
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if(n < 0)
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panic("start_userspace : wait failed, errno = %d",
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errno);
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} while(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
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if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
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panic("start_userspace : expected SIGSTOP, got status = %d",
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status);
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if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0)
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panic("start_userspace : PTRACE_OLDSETOPTIONS failed, errno=%d\n",
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errno);
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if(munmap(stack, PAGE_SIZE) < 0)
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panic("start_userspace : munmap failed, errno = %d\n", errno);
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return(pid);
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}
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void userspace(union uml_pt_regs *regs)
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{
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int err, status, op, pid = userspace_pid[0];
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int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/
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while(1){
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restore_registers(pid, regs);
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/* Now we set local_using_sysemu to be used for one loop */
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local_using_sysemu = get_using_sysemu();
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op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
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err = ptrace(op, pid, 0, 0);
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if(err)
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panic("userspace - could not resume userspace process, "
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"pid=%d, ptrace operation = %d, errno = %d\n",
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pid, op, errno);
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CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
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if(err < 0)
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panic("userspace - waitpid failed, errno = %d\n",
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errno);
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regs->skas.is_user = 1;
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save_registers(pid, regs);
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UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
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if(WIFSTOPPED(status)){
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switch(WSTOPSIG(status)){
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case SIGSEGV:
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if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo)
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user_signal(SIGSEGV, regs, pid);
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else handle_segv(pid, regs);
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break;
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case SIGTRAP + 0x80:
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handle_trap(pid, regs, local_using_sysemu);
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break;
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case SIGTRAP:
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relay_signal(SIGTRAP, regs);
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break;
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case SIGIO:
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case SIGVTALRM:
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case SIGILL:
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case SIGBUS:
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case SIGFPE:
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case SIGWINCH:
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user_signal(WSTOPSIG(status), regs, pid);
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break;
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default:
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printk("userspace - child stopped with signal "
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"%d\n", WSTOPSIG(status));
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}
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pid = userspace_pid[0];
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interrupt_end();
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/* Avoid -ERESTARTSYS handling in host */
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if(PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET)
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PT_SYSCALL_NR(regs->skas.regs) = -1;
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}
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}
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}
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int copy_context_skas0(unsigned long new_stack, int pid)
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{
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int err;
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unsigned long regs[HOST_FRAME_SIZE];
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unsigned long fp_regs[HOST_FP_SIZE];
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unsigned long current_stack = current_stub_stack();
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struct stub_data *data = (struct stub_data *) current_stack;
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struct stub_data *child_data = (struct stub_data *) new_stack;
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__u64 new_offset;
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int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset);
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/* prepare offset and fd of child's stack as argument for parent's
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* and child's mmap2 calls
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*/
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*data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset),
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.fd = new_fd,
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.timer = ((struct itimerval)
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{ { 0, 1000000 / hz() },
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{ 0, 1000000 / hz() }})});
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get_safe_registers(regs, fp_regs);
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/* Set parent's instruction pointer to start of clone-stub */
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regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
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(unsigned long) stub_clone_handler -
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(unsigned long) &__syscall_stub_start;
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regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
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sizeof(void *);
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#ifdef __SIGNAL_FRAMESIZE
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regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
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#endif
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err = ptrace_setregs(pid, regs);
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if(err < 0)
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panic("copy_context_skas0 : PTRACE_SETREGS failed, "
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"pid = %d, errno = %d\n", pid, -err);
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err = ptrace_setfpregs(pid, fp_regs);
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if(err < 0)
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panic("copy_context_skas0 : PTRACE_SETFPREGS failed, "
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"pid = %d, errno = %d\n", pid, -err);
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/* set a well known return code for detection of child write failure */
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child_data->err = 12345678;
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/* Wait, until parent has finished its work: read child's pid from
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* parent's stack, and check, if bad result.
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*/
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wait_stub_done(pid, 0, "copy_context_skas0");
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pid = data->err;
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if(pid < 0)
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panic("copy_context_skas0 - stub-parent reports error %d\n",
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-pid);
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/* Wait, until child has finished too: read child's result from
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* child's stack and check it.
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*/
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wait_stub_done(pid, -1, "copy_context_skas0");
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if (child_data->err != UML_CONFIG_STUB_DATA)
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panic("copy_context_skas0 - stub-child reports error %ld\n",
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child_data->err);
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if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
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(void *)PTRACE_O_TRACESYSGOOD) < 0)
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panic("copy_context_skas0 : PTRACE_OLDSETOPTIONS failed, "
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"errno = %d\n", errno);
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return pid;
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}
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/*
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* This is used only, if stub pages are needed, while proc_mm is
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* availabl. Opening /proc/mm creates a new mm_context, which lacks
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* the stub-pages. Thus, we map them using /proc/mm-fd
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*/
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void map_stub_pages(int fd, unsigned long code,
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unsigned long data, unsigned long stack)
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{
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struct proc_mm_op mmop;
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int n;
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__u64 code_offset;
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int code_fd = phys_mapping(to_phys((void *) &__syscall_stub_start),
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&code_offset);
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mmop = ((struct proc_mm_op) { .op = MM_MMAP,
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.u =
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{ .mmap =
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{ .addr = code,
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.len = PAGE_SIZE,
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.prot = PROT_EXEC,
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.flags = MAP_FIXED | MAP_PRIVATE,
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.fd = code_fd,
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.offset = code_offset
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} } });
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n = os_write_file(fd, &mmop, sizeof(mmop));
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if(n != sizeof(mmop))
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panic("map_stub_pages : /proc/mm map for code failed, "
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"err = %d\n", -n);
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if ( stack ) {
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__u64 map_offset;
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int map_fd = phys_mapping(to_phys((void *)stack), &map_offset);
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mmop = ((struct proc_mm_op)
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{ .op = MM_MMAP,
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.u =
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{ .mmap =
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{ .addr = data,
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.len = PAGE_SIZE,
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.prot = PROT_READ | PROT_WRITE,
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.flags = MAP_FIXED | MAP_SHARED,
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.fd = map_fd,
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.offset = map_offset
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} } });
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n = os_write_file(fd, &mmop, sizeof(mmop));
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if(n != sizeof(mmop))
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panic("map_stub_pages : /proc/mm map for data failed, "
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"err = %d\n", -n);
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}
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}
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void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
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void (*handler)(int))
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{
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unsigned long flags;
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jmp_buf switch_buf, fork_buf;
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*switch_buf_ptr = &switch_buf;
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*fork_buf_ptr = &fork_buf;
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/* Somewhat subtle - siglongjmp restores the signal mask before doing
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* the longjmp. This means that when jumping from one stack to another
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* when the target stack has interrupts enabled, an interrupt may occur
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* on the source stack. This is bad when starting up a process because
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* it's not supposed to get timer ticks until it has been scheduled.
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* So, we disable interrupts around the sigsetjmp to ensure that
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* they can't happen until we get back here where they are safe.
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*/
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flags = get_signals();
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block_signals();
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if(UML_SETJMP(&fork_buf) == 0)
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new_thread_proc(stack, handler);
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remove_sigstack();
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set_signals(flags);
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}
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#define INIT_JMP_NEW_THREAD 0
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#define INIT_JMP_REMOVE_SIGSTACK 1
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#define INIT_JMP_CALLBACK 2
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#define INIT_JMP_HALT 3
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#define INIT_JMP_REBOOT 4
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void thread_wait(void *sw, void *fb)
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{
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jmp_buf buf, **switch_buf = sw, *fork_buf;
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*switch_buf = &buf;
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fork_buf = fb;
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if(UML_SETJMP(&buf) == 0)
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UML_LONGJMP(fork_buf, INIT_JMP_REMOVE_SIGSTACK);
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}
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void switch_threads(void *me, void *next)
|
|
{
|
|
jmp_buf my_buf, **me_ptr = me, *next_buf = next;
|
|
|
|
*me_ptr = &my_buf;
|
|
if(UML_SETJMP(&my_buf) == 0)
|
|
UML_LONGJMP(next_buf, 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, void *switch_buf_ptr, void **fork_buf_ptr)
|
|
{
|
|
jmp_buf **switch_buf = switch_buf_ptr;
|
|
int n;
|
|
|
|
set_handler(SIGWINCH, (__sighandler_t) sig_handler,
|
|
SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
|
|
SIGVTALRM, -1);
|
|
|
|
*fork_buf_ptr = &initial_jmpbuf;
|
|
n = UML_SETJMP(&initial_jmpbuf);
|
|
switch(n){
|
|
case INIT_JMP_NEW_THREAD:
|
|
new_thread_proc((void *) stack, new_thread_handler);
|
|
break;
|
|
case INIT_JMP_REMOVE_SIGSTACK:
|
|
remove_sigstack();
|
|
break;
|
|
case INIT_JMP_CALLBACK:
|
|
(*cb_proc)(cb_arg);
|
|
UML_LONGJMP(cb_back, 1);
|
|
break;
|
|
case INIT_JMP_HALT:
|
|
kmalloc_ok = 0;
|
|
return(0);
|
|
case INIT_JMP_REBOOT:
|
|
kmalloc_ok = 0;
|
|
return(1);
|
|
default:
|
|
panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
|
|
}
|
|
UML_LONGJMP(*switch_buf, 1);
|
|
}
|
|
|
|
void initial_thread_cb_skas(void (*proc)(void *), void *arg)
|
|
{
|
|
jmp_buf here;
|
|
|
|
cb_proc = proc;
|
|
cb_arg = arg;
|
|
cb_back = &here;
|
|
|
|
block_signals();
|
|
if(UML_SETJMP(&here) == 0)
|
|
UML_LONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
|
|
unblock_signals();
|
|
|
|
cb_proc = NULL;
|
|
cb_arg = NULL;
|
|
cb_back = NULL;
|
|
}
|
|
|
|
void halt_skas(void)
|
|
{
|
|
block_signals();
|
|
UML_LONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
|
|
}
|
|
|
|
void reboot_skas(void)
|
|
{
|
|
block_signals();
|
|
UML_LONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
|
|
}
|
|
|
|
void switch_mm_skas(struct mm_id *mm_idp)
|
|
{
|
|
int err;
|
|
|
|
#warning need cpu pid in switch_mm_skas
|
|
if(proc_mm){
|
|
err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
|
|
mm_idp->u.mm_fd);
|
|
if(err)
|
|
panic("switch_mm_skas - PTRACE_SWITCH_MM failed, "
|
|
"errno = %d\n", errno);
|
|
}
|
|
else userspace_pid[0] = mm_idp->u.pid;
|
|
}
|