ndk/sources/android/libportable/arch-mips/mmap.c

/*
 * Copyright 2012, The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <unistd.h>
#include <errno.h>
#include <sys/mman.h>
#include <mman_portable.h>

#if MAP_ANONYMOUS_PORTABLE==MAP_ANONYMOUS
#error Bad build environment
#endif

static inline int mips_change_prot(int prot)
{
    /* Only PROT_SEM is different */
    if (prot & PROT_SEM_PORTABLE) {
        prot &= ~PROT_SEM_PORTABLE;
        prot |= PROT_SEM;
    }

    return prot;
}

static inline int mips_change_flags(int flags)
{
    int mipsflags = 0;
    if (flags & MAP_SHARED_PORTABLE)
       mipsflags |= MAP_SHARED;
    if (flags & MAP_PRIVATE_PORTABLE)
       mipsflags |= MAP_PRIVATE;
    if (flags & MAP_FIXED_PORTABLE)
       mipsflags |= MAP_FIXED;
    if (flags & MAP_ANONYMOUS_PORTABLE)
       mipsflags |= MAP_ANONYMOUS;
    if (flags & MAP_GROWSDOWN_PORTABLE)
       mipsflags |= MAP_GROWSDOWN;
    if (flags & MAP_DENYWRITE_PORTABLE)
       mipsflags |= MAP_DENYWRITE;
    if (flags & MAP_EXECUTABLE_PORTABLE)
       mipsflags |= MAP_EXECUTABLE;
    if (flags & MAP_LOCKED_PORTABLE)
       mipsflags |= MAP_LOCKED;
    if (flags & MAP_NORESERVE_PORTABLE)
       mipsflags |= MAP_NORESERVE;
    if (flags & MAP_POPULATE_PORTABLE)
       mipsflags |= MAP_POPULATE;
    if (flags & MAP_NONBLOCK_PORTABLE)
       mipsflags |= MAP_NONBLOCK;

    return mipsflags;
}

#define  MMAP2_SHIFT  12
extern void *__mmap2(void *, size_t, int, int, int, size_t);
void *mmap_portable(void *addr, size_t size, int prot, int flags, int fd, long offset)
{
    void *ret;
    int mips_prot, mips_flags;

    if (offset & ((1UL << MMAP2_SHIFT)-1)) {
        errno = EINVAL;
        return MAP_FAILED;
    }

    mips_prot = mips_change_prot(prot);
    mips_flags = mips_change_flags(flags);
    ret = __mmap2(addr, size, mips_prot, mips_flags, fd,
                  (size_t)offset >> MMAP2_SHIFT);

    if (ret && (mips_flags & (MAP_PRIVATE | MAP_ANONYMOUS)))
            madvise(ret, size, MADV_MERGEABLE);

    return ret;
}

extern int    mprotect(const void *, size_t, int);
int mprotect_portable(const void *addr, size_t size, int prot)
{
    return mprotect(addr, size, mips_change_prot(prot));
}