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linux/arch/um/os-Linux/process.c
Jeff Dike a61f334fd2 uml: convert libc layer to call read and write 
This patch converts calls in the os layer to os_{read,write}_file to calls
directly to libc read() and write() where it is clear that the I/O buffer is
in the kernel.

We can do that here instead of calling os_{read,write}_file_k since we are in
libc code and can call libc directly.

With the change in the calls, error handling needs to be changed to refer to
errno directly rather than the return value of the call.

CATCH_EINTR wrappers were also added where needed.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:13:03 -07:00

295 lines
6.3 KiB
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/*
* 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;
}
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);
}
}
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;
}
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