Commit 9bdfa4d2 authored by Shu-Chun Weng's avatar Shu-Chun Weng Committed by Laurent Vivier
Browse files

linux-user: add memfd_create 

Add support for the memfd_create syscall. If the host does not have the
libc wrapper, translate to a direct syscall with NC-macro.

Buglink: https://bugs.launchpad.net/qemu/+bug/1734792


Signed-off-by: default avatarShu-Chun Weng <scw@google.com>
Reviewed-by: default avatarLaurent Vivier <laurent@vivier.eu>
Message-Id: <20190819180947.180725-1-scw@google.com>
Signed-off-by: default avatarLaurent Vivier <laurent@vivier.eu>
parent 7f4341e8

include/qemu/memfd.h

+4 −0
Original line number Diff line number Diff line
@@ -32,6 +32,10 @@ 
#define MFD_HUGE_SHIFT 26

#endif



#if defined CONFIG_LINUX && !defined CONFIG_MEMFD

int memfd_create(const char *name, unsigned int flags);

#endif



int qemu_memfd_create(const char *name, size_t size, bool hugetlb,

                      uint64_t hugetlbsize, unsigned int seals, Error **errp);

bool qemu_memfd_alloc_check(void);

linux-user/syscall.c

+12 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include "qemu/osdep.h"

#include "qemu/cutils.h"

#include "qemu/path.h"

#include "qemu/memfd.h"

#include "qemu/queue.h"

#include <elf.h>

#include <endian.h>
@@ -11938,6 +11939,17 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1, 
        /* PowerPC specific.  */

        return do_swapcontext(cpu_env, arg1, arg2, arg3);

#endif

#ifdef TARGET_NR_memfd_create

    case TARGET_NR_memfd_create:

        p = lock_user_string(arg1);

        if (!p) {

            return -TARGET_EFAULT;

        }

        ret = get_errno(memfd_create(p, arg2));

        fd_trans_unregister(ret);

        unlock_user(p, arg1, 0);

        return ret;

#endif



    default:

        qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);

util/memfd.c

+1 −1
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ 
#include <sys/syscall.h>

#include <asm/unistd.h>



static int memfd_create(const char *name, unsigned int flags)

int memfd_create(const char *name, unsigned int flags)

{

#ifdef __NR_memfd_create

    return syscall(__NR_memfd_create, name, flags);