gcc/libgo/runtime/mem.c

51 lines
1.1 KiB
C

#include <errno.h>
#include "runtime.h"
#include "malloc.h"
void*
runtime_SysAlloc(uintptr n)
{
void *p;
mstats.sys += n;
p = runtime_mmap(nil, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
if (p == MAP_FAILED) {
if(errno == EACCES) {
printf("mmap: access denied\n");
printf("If you're running SELinux, enable execmem for this process.\n");
} else {
printf("mmap: errno=%d\n", errno);
}
exit(2);
}
return p;
}
void
runtime_SysUnused(void *v, uintptr n)
{
USED(v);
USED(n);
// TODO(rsc): call madvise MADV_DONTNEED
}
void
runtime_SysFree(void *v, uintptr n)
{
mstats.sys -= n;
runtime_munmap(v, n);
}
void
runtime_SysMemInit(void)
{
// Code generators assume that references to addresses
// on the first page will fault. Map the page explicitly with
// no permissions, to head off possible bugs like the system
// allocating that page as the virtual address space fills.
// Ignore any error, since other systems might be smart
// enough to never allow anything there.
runtime_mmap(nil, 4096, PROT_NONE, MAP_FIXED|MAP_ANON|MAP_PRIVATE, -1, 0);
}