WSL2-Linux-Kernel/arch/um/os-Linux/process.c

298 строки
6.4 KiB
C

/*
* Copyright (C) 2002 Jeff Dike (jdike@addtoit.com)
* Licensed under the GPL
*/
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <signal.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include "ptrace_user.h"
#include "os.h"
#include "user.h"
#include "process.h"
#include "irq_user.h"
#include "kern_util.h"
#include "longjmp.h"
#include "skas_ptrace.h"
#include "kern_constants.h"
#include "uml-config.h"
#include "init.h"
#define ARBITRARY_ADDR -1
#define FAILURE_PID -1
#define STAT_PATH_LEN sizeof("/proc/#######/stat\0")
#define COMM_SCANF "%*[^)])"
unsigned long os_process_pc(int pid)
{
char proc_stat[STAT_PATH_LEN], buf[256];
unsigned long pc;
int fd, err;
sprintf(proc_stat, "/proc/%d/stat", pid);
fd = os_open_file(proc_stat, of_read(OPENFLAGS()), 0);
if(fd < 0){
printk("os_process_pc - couldn't open '%s', err = %d\n",
proc_stat, -fd);
return ARBITRARY_ADDR;
}
CATCH_EINTR(err = read(fd, buf, sizeof(buf)));
if(err < 0){
printk("os_process_pc - couldn't read '%s', err = %d\n",
proc_stat, errno);
os_close_file(fd);
return ARBITRARY_ADDR;
}
os_close_file(fd);
pc = ARBITRARY_ADDR;
if(sscanf(buf, "%*d " COMM_SCANF " %*c %*d %*d %*d %*d %*d %*d %*d "
"%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d "
"%*d %*d %*d %*d %*d %lu", &pc) != 1){
printk("os_process_pc - couldn't find pc in '%s'\n", buf);
}
return pc;
}
int os_process_parent(int pid)
{
char stat[STAT_PATH_LEN];
char data[256];
int parent, n, fd;
if(pid == -1)
return -1;
snprintf(stat, sizeof(stat), "/proc/%d/stat", pid);
fd = os_open_file(stat, of_read(OPENFLAGS()), 0);
if(fd < 0){
printk("Couldn't open '%s', err = %d\n", stat, -fd);
return FAILURE_PID;
}
CATCH_EINTR(n = read(fd, data, sizeof(data)));
os_close_file(fd);
if(n < 0){
printk("Couldn't read '%s', err = %d\n", stat, errno);
return FAILURE_PID;
}
parent = FAILURE_PID;
n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent);
if(n != 1)
printk("Failed to scan '%s'\n", data);
return parent;
}
void os_stop_process(int pid)
{
kill(pid, SIGSTOP);
}
void os_kill_process(int pid, int reap_child)
{
kill(pid, SIGKILL);
if(reap_child)
CATCH_EINTR(waitpid(pid, NULL, 0));
}
/* This is here uniquely to have access to the userspace errno, i.e. the one
* used by ptrace in case of error.
*/
long os_ptrace_ldt(long pid, long addr, long data)
{
int ret;
ret = ptrace(PTRACE_LDT, pid, addr, data);
if (ret < 0)
return -errno;
return ret;
}
/* Kill off a ptraced child by all means available. kill it normally first,
* then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from
* which it can't exit directly.
*/
void os_kill_ptraced_process(int pid, int reap_child)
{
kill(pid, SIGKILL);
ptrace(PTRACE_KILL, pid);
ptrace(PTRACE_CONT, pid);
if(reap_child)
CATCH_EINTR(waitpid(pid, NULL, 0));
}
#ifdef UML_CONFIG_MODE_TT
void os_usr1_process(int pid)
{
kill(pid, SIGUSR1);
}
#endif
/* Don't use the glibc version, which caches the result in TLS. It misses some
* syscalls, and also breaks with clone(), which does not unshare the TLS.
*/
int os_getpid(void)
{
return syscall(__NR_getpid);
}
int os_getpgrp(void)
{
return getpgrp();
}
int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len,
int r, int w, int x)
{
void *loc;
int prot;
prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
(x ? PROT_EXEC : 0);
loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED,
fd, off);
if(loc == MAP_FAILED)
return -errno;
return 0;
}
int os_protect_memory(void *addr, unsigned long len, int r, int w, int x)
{
int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
(x ? PROT_EXEC : 0));
if(mprotect(addr, len, prot) < 0)
return -errno;
return 0;
}
int os_unmap_memory(void *addr, int len)
{
int err;
err = munmap(addr, len);
if(err < 0)
return -errno;
return 0;
}
#ifndef MADV_REMOVE
#define MADV_REMOVE KERNEL_MADV_REMOVE
#endif
int __init os_drop_memory(void *addr, int length)
{
int err;
err = madvise(addr, length, MADV_REMOVE);
if(err < 0)
err = -errno;
return err;
}
int __init can_drop_memory(void)
{
void *addr;
int fd, ok = 0;
printk("Checking host MADV_REMOVE support...");
fd = create_mem_file(UM_KERN_PAGE_SIZE);
if(fd < 0){
printk("Creating test memory file failed, err = %d\n", -fd);
goto out;
}
addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, 0);
if(addr == MAP_FAILED){
printk("Mapping test memory file failed, err = %d\n", -errno);
goto out_close;
}
if(madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0){
printk("MADV_REMOVE failed, err = %d\n", -errno);
goto out_unmap;
}
printk("OK\n");
ok = 1;
out_unmap:
munmap(addr, UM_KERN_PAGE_SIZE);
out_close:
close(fd);
out:
return ok;
}
#ifdef UML_CONFIG_MODE_TT
void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int))
{
int flags = 0, pages;
if(sig_stack != NULL){
pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER);
set_sigstack(sig_stack, pages * UM_KERN_PAGE_SIZE);
flags = SA_ONSTACK;
}
if(usr1_handler){
struct sigaction sa;
sa.sa_handler = usr1_handler;
sigemptyset(&sa.sa_mask);
sa.sa_flags = flags;
sa.sa_restorer = NULL;
if(sigaction(SIGUSR1, &sa, NULL) < 0)
panic("init_new_thread_stack - sigaction failed - "
"errno = %d\n", errno);
}
}
#endif
void init_new_thread_signals(void)
{
set_handler(SIGSEGV, (__sighandler_t) sig_handler, SA_ONSTACK,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
set_handler(SIGTRAP, (__sighandler_t) sig_handler, SA_ONSTACK,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
set_handler(SIGFPE, (__sighandler_t) sig_handler, SA_ONSTACK,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
set_handler(SIGILL, (__sighandler_t) sig_handler, SA_ONSTACK,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
set_handler(SIGBUS, (__sighandler_t) sig_handler, SA_ONSTACK,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
set_handler(SIGUSR2, (__sighandler_t) sig_handler,
SA_ONSTACK, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM,
-1);
signal(SIGHUP, SIG_IGN);
init_irq_signals(1);
}
int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr)
{
jmp_buf buf;
int n;
*jmp_ptr = &buf;
n = UML_SETJMP(&buf);
if(n != 0)
return n;
(*fn)(arg);
return 0;
}