Commit 0f2956f9 authored by Marc-André Lureau's avatar Marc-André Lureau Committed by Paolo Bonzini
Browse files

memfd: add error argument, instead of perror() 



This will allow callers to silence error report when the call is
allowed to failed.

Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180201132757.23063-2-marcandre.lureau@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent dbadee4f

hw/virtio/vhost.c

+7 −1
Original line number Diff line number Diff line
@@ -330,6 +330,7 @@ static uint64_t vhost_get_log_size(struct vhost_dev *dev) 


static struct vhost_log *vhost_log_alloc(uint64_t size, bool share)

{

    Error *err = NULL;

    struct vhost_log *log;

    uint64_t logsize = size * sizeof(*(log->log));

    int fd = -1;
@@ -338,7 +339,12 @@ static struct vhost_log *vhost_log_alloc(uint64_t size, bool share) 
    if (share) {

        log->log = qemu_memfd_alloc("vhost-log", logsize,

                                    F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL,

                                    &fd);

                                    &fd, &err);

        if (err) {

            error_report_err(err);

            g_free(log);

            return NULL;

        }

        memset(log->log, 0, logsize);

    } else {

        log->log = g_malloc0(logsize);

include/qemu/memfd.h

+3 −2
Original line number Diff line number Diff line
@@ -16,9 +16,10 @@ 
#define F_SEAL_WRITE    0x0008  /* prevent writes */

#endif



int qemu_memfd_create(const char *name, size_t size, unsigned int seals);

int qemu_memfd_create(const char *name, size_t size, unsigned int seals,

                      Error **errp);

void *qemu_memfd_alloc(const char *name, size_t size, unsigned int seals,

                       int *fd);

                       int *fd, Error **errp);

void qemu_memfd_free(void *ptr, size_t size, int fd);

bool qemu_memfd_check(void);

util/memfd.c

+30 −27
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 


#include "qemu/osdep.h"



#include "qapi/error.h"

#include "qemu/memfd.h"



#if defined CONFIG_LINUX && !defined CONFIG_MEMFD
@@ -51,11 +52,11 @@ static int memfd_create(const char *name, unsigned int flags) 
#define MFD_ALLOW_SEALING 0x0002U

#endif



int qemu_memfd_create(const char *name, size_t size, unsigned int seals)

int qemu_memfd_create(const char *name, size_t size,

                      unsigned int seals, Error **errp)

{

    int mfd = -1;



#ifdef CONFIG_LINUX

    int mfd = -1;

    unsigned int flags = MFD_CLOEXEC;



    if (seals) {
@@ -64,23 +65,26 @@ int qemu_memfd_create(const char *name, size_t size, unsigned int seals) 


    mfd = memfd_create(name, flags);

    if (mfd < 0) {

        return -1;

        goto err;

    }



    if (ftruncate(mfd, size) == -1) {

        perror("ftruncate");

        close(mfd);

        return -1;

        goto err;

    }



    if (seals && fcntl(mfd, F_ADD_SEALS, seals) == -1) {

        perror("fcntl");

        close(mfd);

        return -1;

        goto err;

    }

#endif



    return mfd;



err:

    if (mfd >= 0) {

        close(mfd);

    }

#endif

    error_setg_errno(errp, errno, "failed to create memfd");

    return -1;

}



/*
@@ -90,14 +94,14 @@ int qemu_memfd_create(const char *name, size_t size, unsigned int seals) 
 * sealing.

 */

void *qemu_memfd_alloc(const char *name, size_t size, unsigned int seals,

                       int *fd)

                       int *fd, Error **errp)

{

    void *ptr;

    int mfd = qemu_memfd_create(name, size, seals);

    int mfd = qemu_memfd_create(name, size, seals, NULL);



    /* some systems have memfd without sealing */

    if (mfd == -1) {

        mfd = qemu_memfd_create(name, size, 0);

        mfd = qemu_memfd_create(name, size, 0, NULL);

    }



    if (mfd == -1) {
@@ -109,27 +113,26 @@ void *qemu_memfd_alloc(const char *name, size_t size, unsigned int seals, 
        unlink(fname);

        g_free(fname);



        if (mfd == -1) {

            perror("mkstemp");

            return NULL;

        }



        if (ftruncate(mfd, size) == -1) {

            perror("ftruncate");

            close(mfd);

            return NULL;

        if (mfd == -1 ||

            ftruncate(mfd, size) == -1) {

            goto err;

        }

    }



    ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, mfd, 0);

    if (ptr == MAP_FAILED) {

        perror("mmap");

        close(mfd);

        return NULL;

        goto err;

    }



    *fd = mfd;

    return ptr;



err:

    error_setg_errno(errp, errno, "failed to allocate shared memory");

    if (mfd >= 0) {

        close(mfd);

    }

    return NULL;

}



void qemu_memfd_free(void *ptr, size_t size, int fd)
@@ -157,7 +160,7 @@ bool qemu_memfd_check(void) 
        int fd;

        void *ptr;



        ptr = qemu_memfd_alloc("test", 4096, 0, &fd);

        ptr = qemu_memfd_alloc("test", 4096, 0, &fd, NULL);

        memfd_check = ptr ? MEMFD_OK : MEMFD_KO;

        qemu_memfd_free(ptr, 4096, fd);

    }