Subversion Repositories openrisc

/* Defining _XOPEN_SOURCE hides the declaration of madvise() on Solaris <

   11 and the MADV_DONTNEED definition on IRIX 6.5.  */

#undef _XOPEN_SOURCE

#include <errno.h>

#include <unistd.h>

#include "runtime.h"

#include "arch.h"

#include "malloc.h"

#ifndef MAP_ANON

#ifdef MAP_ANONYMOUS

#define MAP_ANON MAP_ANONYMOUS

#else

#define USE_DEV_ZERO

#define MAP_ANON 0

#endif

#endif

#ifdef USE_DEV_ZERO

static int dev_zero = -1;

#endif

static _Bool

addrspace_free(void *v __attribute__ ((unused)), uintptr n __attribute__ ((unused)))

{

#ifdef HAVE_MINCORE

        size_t page_size = getpagesize();

        size_t off;

        char one_byte;

        errno = 0;

        for(off = 0; off < n; off += page_size)

                if(mincore((char *)v + off, page_size, (void *)&one_byte) != -1

                   || errno != ENOMEM)

                        return 0;

#endif

        return 1;

}

void*

runtime_SysAlloc(uintptr n)

{

        void *p;

        int fd = -1;

        mstats.sys += n;

#ifdef USE_DEV_ZERO

        if (dev_zero == -1) {

                dev_zero = open("/dev/zero", O_RDONLY);

                if (dev_zero < 0) {

                        runtime_printf("open /dev/zero: errno=%d\n", errno);

                        exit(2);

                }

        }

        fd = dev_zero;

#endif

        p = runtime_mmap(nil, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, fd, 0);

        if (p == MAP_FAILED) {

                if(errno == EACCES) {

                        runtime_printf("runtime: mmap: access denied\n");

                        runtime_printf("if you're running SELinux, enable execmem for this process.\n");

                        exit(2);

                }

                return nil;

        }

        return p;

}

void

runtime_SysUnused(void *v __attribute__ ((unused)), uintptr n __attribute__ ((unused)))

{

#ifdef MADV_DONTNEED

        runtime_madvise(v, n, MADV_DONTNEED);

#endif

}

void

runtime_SysFree(void *v, uintptr n)

{

        mstats.sys -= n;

        runtime_munmap(v, n);

}

void*

runtime_SysReserve(void *v, uintptr n)

{

        int fd = -1;

        void *p;

        // On 64-bit, people with ulimit -v set complain if we reserve too

        // much address space.  Instead, assume that the reservation is okay

        // and check the assumption in SysMap.

        if(sizeof(void*) == 8)

                return v;

#ifdef USE_DEV_ZERO

        if (dev_zero == -1) {

                dev_zero = open("/dev/zero", O_RDONLY);

                if (dev_zero < 0) {

                        runtime_printf("open /dev/zero: errno=%d\n", errno);

                        exit(2);

                }

        }

        fd = dev_zero;

#endif

        p = runtime_mmap(v, n, PROT_NONE, MAP_ANON|MAP_PRIVATE, fd, 0);

        if((uintptr)p < 4096 || -(uintptr)p < 4096) {

                return nil;

        }

        return p;

}

void

runtime_SysMap(void *v, uintptr n)

{

        void *p;

        int fd = -1;

        mstats.sys += n;

#ifdef USE_DEV_ZERO

        if (dev_zero == -1) {

                dev_zero = open("/dev/zero", O_RDONLY);

                if (dev_zero < 0) {

                        runtime_printf("open /dev/zero: errno=%d\n", errno);

                        exit(2);

                }

        }

        fd = dev_zero;

#endif

        // On 64-bit, we don't actually have v reserved, so tread carefully.

        if(sizeof(void*) == 8) {

                p = runtime_mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, fd, 0);

                if(p != v && addrspace_free(v, n)) {

                        // On some systems, mmap ignores v without

                        // MAP_FIXED, so retry if the address space is free.

                        p = runtime_mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_FIXED|MAP_PRIVATE, fd, 0);

                }

                if(p != v) {

                        runtime_printf("runtime: address space conflict: map(%p) = %p\n", v, p);

                        runtime_throw("runtime: address space conflict");

                }

                return;

        }

        p = runtime_mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_FIXED|MAP_PRIVATE, fd, 0);

        if(p != v)

                runtime_throw("runtime: cannot map pages in arena address space");

}