Archipelago » qemu

/*

 * os-posix-lib.c

 *

 * Copyright (c) 2003-2008 Fabrice Bellard

 * Copyright (c) 2010 Red Hat, Inc.

 *

 * QEMU library functions on POSIX which are shared between QEMU and

 * the QEMU tools.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

/* The following block of code temporarily renames the daemon() function so the

   compiler does not see the warning associated with it in stdlib.h on OSX */

#ifdef __APPLE__

#define daemon qemu_fake_daemon_function

#include <stdlib.h>

#undef daemon

extern int daemon(int, int);

#endif

#if defined(__linux__) && defined(__x86_64__)

   /* Use 2 MiB alignment so transparent hugepages can be used by KVM.

      Valgrind does not support alignments larger than 1 MiB,

      therefore we need special code which handles running on Valgrind. */

#  define QEMU_VMALLOC_ALIGN (512 * 4096)

#  define CONFIG_VALGRIND

#elif defined(__linux__) && defined(__s390x__)

   /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */

#  define QEMU_VMALLOC_ALIGN (256 * 4096)

#else

#  define QEMU_VMALLOC_ALIGN getpagesize()

#endif

#include "config-host.h"

#include "sysemu.h"

#include "trace.h"

#include "qemu_socket.h"

#if defined(CONFIG_VALGRIND)

static int running_on_valgrind = -1;

#else

#  define running_on_valgrind 0

#endif

#ifdef CONFIG_LINUX

#include <sys/syscall.h>

#endif

#ifdef CONFIG_EVENTFD

#include <sys/eventfd.h>

#endif

int qemu_get_thread_id(void)

{

#if defined(__linux__)

    return syscall(SYS_gettid);

#else

    return getpid();

#endif

}

int qemu_daemon(int nochdir, int noclose)

{

    return daemon(nochdir, noclose);

}

void *qemu_oom_check(void *ptr)

{

    if (ptr == NULL) {

        fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));

        abort();

    }

    return ptr;

}

void *qemu_memalign(size_t alignment, size_t size)

{

    void *ptr;

#if defined(_POSIX_C_SOURCE) && !defined(__sun__)

    int ret;

    ret = posix_memalign(&ptr, alignment, size);

    if (ret != 0) {

        fprintf(stderr, "Failed to allocate %zu B: %s\n",

                size, strerror(ret));

        abort();

    }

#elif defined(CONFIG_BSD)

    ptr = qemu_oom_check(valloc(size));

#else

    ptr = qemu_oom_check(memalign(alignment, size));

#endif

    trace_qemu_memalign(alignment, size, ptr);

    return ptr;

}

/* conflicts with qemu_vmalloc in bsd-user/mmap.c */

#if !defined(CONFIG_BSD_USER)

/* alloc shared memory pages */

void *qemu_vmalloc(size_t size)

{

    void *ptr;

    size_t align = QEMU_VMALLOC_ALIGN;

#if defined(CONFIG_VALGRIND)

    if (running_on_valgrind < 0) {

        /* First call, test whether we are running on Valgrind.

           This is a substitute for RUNNING_ON_VALGRIND from valgrind.h. */

        const char *ld = getenv("LD_PRELOAD");

        running_on_valgrind = (ld != NULL && strstr(ld, "vgpreload"));

    }

#endif

    if (size < align || running_on_valgrind) {

        align = getpagesize();

    }

    ptr = qemu_memalign(align, size);

    trace_qemu_vmalloc(size, ptr);

    return ptr;

}

#endif

void qemu_vfree(void *ptr)

{

    trace_qemu_vfree(ptr);

    free(ptr);

}

void socket_set_block(int fd)

{

    int f;

    f = fcntl(fd, F_GETFL);

    fcntl(fd, F_SETFL, f & ~O_NONBLOCK);

}

void socket_set_nonblock(int fd)

{

    int f;

    f = fcntl(fd, F_GETFL);

    fcntl(fd, F_SETFL, f | O_NONBLOCK);

}

void qemu_set_cloexec(int fd)

{

    int f;

    f = fcntl(fd, F_GETFD);

    fcntl(fd, F_SETFD, f | FD_CLOEXEC);

}

/*

 * Creates a pipe with FD_CLOEXEC set on both file descriptors

 */

int qemu_pipe(int pipefd[2])

{

    int ret;

#ifdef CONFIG_PIPE2

    ret = pipe2(pipefd, O_CLOEXEC);

    if (ret != -1 || errno != ENOSYS) {

        return ret;

    }

#endif

    ret = pipe(pipefd);

    if (ret == 0) {

        qemu_set_cloexec(pipefd[0]);

        qemu_set_cloexec(pipefd[1]);

    }

    return ret;

}

/*

 * Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set.

 */

int qemu_eventfd(int fds[2])

{

#ifdef CONFIG_EVENTFD

    int ret;

    ret = eventfd(0, 0);

    if (ret >= 0) {

        fds[0] = ret;

        fds[1] = dup(ret);

        if (fds[1] == -1) {

            close(ret);

            return -1;

        }

        qemu_set_cloexec(ret);

        qemu_set_cloexec(fds[1]);

        return 0;

    }

    if (errno != ENOSYS) {

        return -1;

    }

#endif

    return qemu_pipe(fds);

}

int qemu_utimens(const char *path, const struct timespec *times)

{

    struct timeval tv[2], tv_now;

    struct stat st;

    int i;

#ifdef CONFIG_UTIMENSAT

    int ret;

    ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);

    if (ret != -1 || errno != ENOSYS) {

        return ret;

    }

#endif

    /* Fallback: use utimes() instead of utimensat() */

    /* happy if special cases */

    if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {

        return 0;

    }

    if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {

        return utimes(path, NULL);

    }

    /* prepare for hard cases */

    if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {

        gettimeofday(&tv_now, NULL);

    }

    if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {

        stat(path, &st);

    }

    for (i = 0; i < 2; i++) {

        if (times[i].tv_nsec == UTIME_NOW) {

            tv[i].tv_sec = tv_now.tv_sec;

            tv[i].tv_usec = tv_now.tv_usec;

        } else if (times[i].tv_nsec == UTIME_OMIT) {

            tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;

            tv[i].tv_usec = 0;

        } else {

            tv[i].tv_sec = times[i].tv_sec;

            tv[i].tv_usec = times[i].tv_nsec / 1000;

        }

    }

    return utimes(path, &tv[0]);

}