d634f194d4
User Mode Linux can also benefit from earlyprintk. UML's earlyprintk writes kernel messages directly to stdout. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
146 lines
3.3 KiB
C
146 lines
3.3 KiB
C
/*
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* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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* Licensed under the GPL
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*/
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#include <stdio.h>
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#include <stdlib.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 <string.h>
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#include <termios.h>
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#include <wait.h>
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#include <sys/mman.h>
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#include <sys/utsname.h>
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#include "kern_constants.h"
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#include "os.h"
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#include "user.h"
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void stack_protections(unsigned long address)
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{
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if (mprotect((void *) address, UM_THREAD_SIZE,
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PROT_READ | PROT_WRITE | PROT_EXEC) < 0)
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panic("protecting stack failed, errno = %d", errno);
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}
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int raw(int fd)
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{
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struct termios tt;
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int err;
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CATCH_EINTR(err = tcgetattr(fd, &tt));
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if (err < 0)
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return -errno;
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cfmakeraw(&tt);
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CATCH_EINTR(err = tcsetattr(fd, TCSADRAIN, &tt));
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if (err < 0)
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return -errno;
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/*
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* XXX tcsetattr could have applied only some changes
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* (and cfmakeraw() is a set of changes)
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*/
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return 0;
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}
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void setup_machinename(char *machine_out)
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{
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struct utsname host;
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uname(&host);
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#ifdef UML_CONFIG_UML_X86
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# ifndef UML_CONFIG_64BIT
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if (!strcmp(host.machine, "x86_64")) {
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strcpy(machine_out, "i686");
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return;
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}
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# else
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if (!strcmp(host.machine, "i686")) {
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strcpy(machine_out, "x86_64");
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return;
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}
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# endif
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#endif
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strcpy(machine_out, host.machine);
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}
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void setup_hostinfo(char *buf, int len)
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{
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struct utsname host;
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uname(&host);
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snprintf(buf, len, "%s %s %s %s %s", host.sysname, host.nodename,
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host.release, host.version, host.machine);
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}
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/*
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* We cannot use glibc's abort(). It makes use of tgkill() which
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* has no effect within UML's kernel threads.
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* After that glibc would execute an invalid instruction to kill
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* the calling process and UML crashes with SIGSEGV.
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*/
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static inline void __attribute__ ((noreturn)) uml_abort(void)
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{
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sigset_t sig;
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fflush(NULL);
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if (!sigemptyset(&sig) && !sigaddset(&sig, SIGABRT))
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sigprocmask(SIG_UNBLOCK, &sig, 0);
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for (;;)
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if (kill(getpid(), SIGABRT) < 0)
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exit(127);
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}
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void os_dump_core(void)
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{
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int pid;
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signal(SIGSEGV, SIG_DFL);
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/*
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* We are about to SIGTERM this entire process group to ensure that
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* nothing is around to run after the kernel exits. The
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* kernel wants to abort, not die through SIGTERM, so we
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* ignore it here.
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*/
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signal(SIGTERM, SIG_IGN);
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kill(0, SIGTERM);
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/*
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* Most of the other processes associated with this UML are
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* likely sTopped, so give them a SIGCONT so they see the
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* SIGTERM.
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*/
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kill(0, SIGCONT);
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/*
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* Now, having sent signals to everyone but us, make sure they
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* die by ptrace. Processes can survive what's been done to
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* them so far - the mechanism I understand is receiving a
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* SIGSEGV and segfaulting immediately upon return. There is
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* always a SIGSEGV pending, and (I'm guessing) signals are
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* processed in numeric order so the SIGTERM (signal 15 vs
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* SIGSEGV being signal 11) is never handled.
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*
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* Run a waitpid loop until we get some kind of error.
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* Hopefully, it's ECHILD, but there's not a lot we can do if
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* it's something else. Tell os_kill_ptraced_process not to
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* wait for the child to report its death because there's
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* nothing reasonable to do if that fails.
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*/
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while ((pid = waitpid(-1, NULL, WNOHANG | __WALL)) > 0)
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os_kill_ptraced_process(pid, 0);
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uml_abort();
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}
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void um_early_printk(const char *s, unsigned int n)
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{
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printf("%.*s", n, s);
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}
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