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comparison mem.c @ 803:236a184bf6f0

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Merge
author Michael Pavone <pavone@retrodev.com>
date Sun, 26 Jul 2015 16:51:03 -0700
parents c3e3a0d734e2
children 9f149f0e98b7
comparison
equal deleted inserted replaced
802:6811f601008f 803:236a184bf6f0
6 #include <sys/mman.h> 6 #include <sys/mman.h>
7 #include <stddef.h> 7 #include <stddef.h>
8 #include <stdint.h> 8 #include <stdint.h>
9 #include <stdlib.h> 9 #include <stdlib.h>
10 #include <unistd.h> 10 #include <unistd.h>
11 #include <errno.h>
12 #include <stdio.h>
13
11 #include "mem.h" 14 #include "mem.h"
15 #ifndef MAP_ANONYMOUS
16 #define MAP_ANONYMOUS MAP_ANON
17 #endif
12 18
13 /* 19 #ifndef MAP_32BIT
14 void * alloc_code(size_t *size) 20 #define MAP_32BIT 0
15 { 21 #endif
16 *size += PAGE_SIZE - (*size & (PAGE_SIZE - 1));
17 return mmap(NULL, *size, PROT_EXEC | PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
18 }
19 */
20
21 /*
22 void * alloc_code(size_t *size)
23 {
24 char * ret = malloc(*size);
25 char * base = (char *)(((intptr_t)ret) & (~(PAGE_SIZE-1)));
26 mprotect(base, (ret + *size) - base, PROT_EXEC | PROT_READ | PROT_WRITE);
27 return ret;
28 }
29 */
30 22
31 void * alloc_code(size_t *size) 23 void * alloc_code(size_t *size)
32 { 24 {
25 //start at the 1GB mark to allow plenty of room for sbrk based malloc implementations
26 //while still keeping well within 32-bit displacement range for calling code compiled into the executable
27 static uint8_t *next = (uint8_t *)0x40000000;
33 *size += PAGE_SIZE - (*size & (PAGE_SIZE - 1)); 28 *size += PAGE_SIZE - (*size & (PAGE_SIZE - 1));
34 void * ret = sbrk(*size); 29 uint8_t *ret = mmap(NULL, *size, PROT_EXEC | PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_32BIT, -1, 0);
35 if (ret == ((void *)-1)) { 30 if (ret == MAP_FAILED) {
31 perror("alloc_code");
36 return NULL; 32 return NULL;
37 } 33 }
38 mprotect(ret, *size, PROT_EXEC | PROT_READ | PROT_WRITE); 34 next = ret + *size;
39 return ret; 35 return ret;
40 } 36 }
37