これは、更新された Xcode で 11.1 を実行している M1 mini 上にあります。(すべての保留中の更新が適用されています。) SIP は無効になっていません (可能であれば、M1 上で)。
mmap()移植中のアプリケーションの障害をテストするために使用しているプログラムがあります。次のようにテスト プログラムを作成します。
cc -v -arch arm64 -m64 -Wl,-no_adhoc_codesign -o mapfail mapfail.c
次に、署名します。正しく署名されているようです:
@macarm[git:master]$ codesign -vvv mapfail
mapfail: valid on disk
mapfail: satisfies its Designated Requirement
@macarm[git:master]$
システムで開発者モードを有効にしました。また、ユーザーを_developerグループに追加しました。私のユーザーは管理者ではありませんが、管理者として試してみましたが、同じ結果になりました。
プログラムを実行すると、セグメンテーション違反 (SIGSEGV) が発生するため、 でデバッグしたいのですが、次のようになりlldbます。
@macarm[git:master]$ lldb mapfail
(lldb) target create "mapfail"
Current executable set to '/Users/layer/mapfail' (arm64).
(lldb) run
error: process exited with status -1 (attach failed ((os/kern) invalid argument))
(lldb)
これを検索しても、Apple 開発者フォーラムでさえ情報が得られませんでした。
のコードmapfail.c:
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <mach/mach.h>
#include <mach/machine/vm_param.h>
#define nat long
#define UseMAP_ANON
/* define UseDevZero */
#define FIROUNDUP(a, n) (((a) + ((n) - 1)) & ~((n) - 1))
#define FIROUNDDOWN(a, n) ((a) & ~((n) - 1))
int bucket_o_zeros = -1;
int ChunkSize;
# ifdef UseMAP_ANON
# define FIMAP_ANON MAP_ANON
# else
# define FIMAP_ANON 0
# endif
typedef struct {
char *base; /* lowest address -- 64k aligned */
char *pos; /* 1+ highest address allocated */
char *commit; /* 1+ highest address committed */
} heap_descriptor;
heap_descriptor test1, test2;
unsigned nat test1_base, test1_size;
int
ok_to_map(unsigned nat base, unsigned nat top)
{
/* check if the specified memory is free */
unsigned nat address = base;
vm_size_t size;
mach_port_t object_name;
task_t task = mach_task_self();
struct vm_region_basic_info_64 info;
mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT_64;
kern_return_t retval;
int res = 0;
retval = vm_region_64(task, &address, &size, VM_REGION_BASIC_INFO_64,
(vm_region_info_64_t)&info, &info_count, &object_name);
if (retval == KERN_NO_SPACE) {
res = 1;
} else if ((retval == KERN_SUCCESS) && (address > top)) {
res = 1;
}
if (object_name != MACH_PORT_NULL)
mach_port_deallocate(mach_task_self(), object_name);
printf("maping from 0x%lx to 0x%lx is %s\n", base, top, res ? "OK" : "BAD");
return res;
}
char *
setup_heap( heap_descriptor *hd, unsigned nat base, unsigned nat size)
{
/* allocate memory at the given address, and return the address
* which was allocated
*/
char *res = (char *)MAP_FAILED;
/* initial setup of heap when there is nothing to map in or commit */
base = FIROUNDDOWN(base, ChunkSize);
size = FIROUNDUP(size, ChunkSize);
/* we demand that OS puts memory at our base, so we can grow later */
if (base == 0 || ok_to_map(base, base+size)) {
res = (char *) mmap((void *) base, size, PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | FIMAP_ANON | (base ? MAP_FIXED : 0),
bucket_o_zeros, 0);
}
if (res != (char *) MAP_FAILED) {
/* success - check alignment */
if (base == 0) {
nat diff;
base = (unsigned nat) res;
res = (char *) FIROUNDUP((nat) res, ChunkSize);
diff = ((unsigned nat)res - base);
if (diff > 0) {
/* this had been over-requested already */
size -= ChunkSize;
/* must munmap the two ends */
munmap((caddr_t) base, diff);
munmap((caddr_t) (res + size), diff);
}
}
/* initialize the heap descriptor */
hd->pos = hd->base = res;
hd->commit = (char *) (hd->base + size);
return hd->base;
} else {
return 0; /* failure */
}
}
int
try_setup_heap(char *kind, heap_descriptor *hd, unsigned nat base, unsigned nat size)
{
/* try to allocate where first requested, and then let the system decide.
* return true or false depending on whether it worked.
*/
char *result_base;
base = FIROUNDUP(base,ChunkSize);
size = FIROUNDUP(size,ChunkSize);
/* ask for a specific area */
if (setup_heap(hd, base, size)) return 1; /* success */
/* now ask for any location */
if ((result_base = setup_heap(hd, 0, size + ChunkSize)) == 0) {
fprintf(stderr,
"Unable to reserve at %ld (0x%lx) bytes of memory for the %s heap\n",
size, size, kind);
return 0;
} else {
fprintf(stderr,
"Unable to reserve 0x%lx for the %s heap,\n using 0x%lx instead\n",
base, kind, (unsigned nat) result_base);
return 1;
}
}
int main(int argc, char **argv, char**envp)
{
ChunkSize = getpagesize();
#if defined(UseDevZero)
if(bucket_o_zeros == -1){
bucket_o_zeros = open("/dev/zero", O_RDWR);
}
#endif
if (argc > 2) {
sscanf(argv[1], "%lx", &test1_base);
sscanf(argv[2], "%lx", &test1_size);
if (try_setup_heap("test1", &test1, test1_base, test1_size)) {
printf("test1 heap mapped from 0x%lx to 0x%lx\n",
(unsigned nat) test1.base, (unsigned nat)test1.commit);
} else {
printf("test1 not mapped\n");
}
} else {
unsigned nat addr = 0x100000000;
unsigned nat size = 0x100000;
int i, n, didit=0;;
sscanf(argv[1], "%d", &n);
for (i=0; i < n; i++) {
if (try_setup_heap("test2", &test2, addr, size)) {
printf("test1 heap mapped from 0x%lx to 0x%lx\n",
(unsigned nat) test2.base, (unsigned nat)test2.commit);
didit++;
}
addr += 0x100000000;
}
printf("Total mappings: %d\n", didit);
}
}
/*
* To compile on M1 with debugging:
* cc -v -arch arm64 -m64 -Wl,-no_adhoc_codesign -o mapfail mapfail.c
*/