1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
diff --git a/bsd-user/elfload.c b/bsd-user/elfload.c
index 7cccf3eb..195875af 100644
--- a/bsd-user/elfload.c
+++ b/bsd-user/elfload.c
@@ -15,6 +15,8 @@
#undef ELF_ARCH
#endif
+extern abi_ulong afl_entry_point, afl_start_code, afl_end_code;
+
/* from personality.h */
/*
@@ -737,9 +739,13 @@ static void padzero(abi_ulong elf_bss, abi_ulong last_bss)
end_addr1 = REAL_HOST_PAGE_ALIGN(elf_bss);
end_addr = HOST_PAGE_ALIGN(elf_bss);
if (end_addr1 < end_addr) {
- mmap((void *)g2h(end_addr1), end_addr - end_addr1,
+ void *p = mmap((void *)g2h(end_addr1), end_addr - end_addr1,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_FIXED|MAP_PRIVATE|MAP_ANON, -1, 0);
+ if (p == MAP_FAILED) {
+ perror("padzero: cannot mmap");
+ exit(-1);
+ }
}
}
@@ -979,9 +985,13 @@ static abi_ulong load_elf_interp(struct elfhdr * interp_elf_ex,
/* Map the last of the bss segment */
if (last_bss > elf_bss) {
- target_mmap(elf_bss, last_bss-elf_bss,
+ void *p = target_mmap(elf_bss, last_bss-elf_bss,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_FIXED|MAP_PRIVATE|MAP_ANON, -1, 0);
+ if (p == MAP_FAILED) {
+ perror("load_elf_interp: cannot mmap");
+ exit(-1);
+ }
}
free(elf_phdata);
@@ -1522,6 +1532,8 @@ int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
info->start_data = start_data;
info->end_data = end_data;
info->start_stack = bprm->p;
+ if (!afl_start_code) afl_start_code = vaddr;
+ if (!afl_end_code) afl_end_code = vaddr_ef;
/* Calling set_brk effectively mmaps the pages that we need for the bss and break
sections */
@@ -1544,11 +1556,29 @@ int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
and some applications "depend" upon this behavior.
Since we do not have the power to recompile these, we
emulate the SVr4 behavior. Sigh. */
- target_mmap(0, qemu_host_page_size, PROT_READ | PROT_EXEC,
+ void *p = target_mmap(0, qemu_host_page_size, PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE, -1, 0);
+ if (p == MAP_FAILED) {
+ perror("load_elf_binary: cannot mmap");
+ exit(-1);
+ }
}
info->entry = elf_entry;
+ if (!afl_entry_point) {
+ char *ptr;
+ if ((ptr = getenv("AFL_ENTRYPOINT")) != NULL) {
+ afl_entry_point = strtoul(ptr, NULL, 16);
+ } else {
+ afl_entry_point = info->entry;
+ }
+#ifdef TARGET_ARM
+ /* The least significant bit indicates Thumb mode. */
+ afl_entry_point = afl_entry_point & ~(target_ulong)1;
+#endif
+ }
+ if (getenv("AFL_DEBUG") != NULL)
+ fprintf(stderr, "AFL forkserver entrypoint: %p\n", (void*)afl_entry_point);
return 0;
}
|
