1 #include <stdlib.h>
2 #include <signal.h>
3 #include "syscall.h"
4 #include "pthread_impl.h"
5 #include "atomic.h"
6 #include "lock.h"
7 #include "ksigaction.h"
8 #if defined(MUSL_AARCH64_ARCH)
9 #include <stdint.h>
10 #include <stdio.h>
11 #include <inttypes.h>
12 #include <info/fatal_message.h>
13
14 #define MESSAGE_BUFFER_SIZE 512
15
16 /**
17 * @brief Retrieves the current value of the x1 register on AArch64.
18 *
19 * This function is used in CFI checks to obtain the function address
20 * stored in the x1 register during calls involving function pointers,
21 * virtual calls (vcall), and non-virtual calls (nvcall) using vtable addresses.
22 *
23 * @return Value of the x1 register.
24 */
fetch_function_addressnull25 uint64_t fetch_function_address()
26 {
27 uint64_t val;
28 __asm__ __volatile__(
29 "mov %0, x1"
30 : "=r" (val)
31 :
32 : "memory"
33 );
34 return val;
35 }
36 #endif
37
__cfi_fail_report(void)38 _Noreturn void __cfi_fail_report(void)
39 {
40 #if defined(MUSL_AARCH64_ARCH)
41 uint64_t function_address = fetch_function_address();
42 char message[MESSAGE_BUFFER_SIZE];
43 snprintf(message, sizeof(message),
44 " CFI check failed. Function Address: 0x%" PRIx64, function_address);
45 set_fatal_message(message);
46 #endif
47 abort();
48 }
49
abort(void)50 _Noreturn void abort(void)
51 {
52 #ifdef __LITEOS_A__
53 sigset_t set, pending;
54 sigemptyset(&set);
55 sigaddset(&set, SIGABRT);
56
57 sigpending(&pending);
58 __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK, &set, 0, _NSIG / 8);
59 if (!sigismember(&pending, SIGABRT)) {
60 raise(SIGABRT);
61 }
62 #else
63 raise(SIGABRT);
64 #endif
65
66 /* If there was a SIGABRT handler installed and it returned, or if
67 * SIGABRT was blocked or ignored, take an AS-safe lock to prevent
68 * sigaction from installing a new SIGABRT handler, uninstall any
69 * handler that may be present, and re-raise the signal to generate
70 * the default action of abnormal termination. */
71 __block_all_sigs(0);
72 LOCK(__abort_lock);
73 #ifdef __LITEOS_A__
74 signal(SIGABRT, SIG_DFL);
75 #else
76 __syscall(SYS_rt_sigaction, SIGABRT,
77 &(struct k_sigaction){.handler = SIG_DFL}, 0, _NSIG/8);
78 #endif
79 __syscall(SYS_tkill, __pthread_self()->tid, SIGABRT);
80 __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK,
81 &(long[_NSIG/(8*sizeof(long))]){1UL<<(SIGABRT-1)}, 0, _NSIG/8);
82
83 /* Beyond this point should be unreachable. */
84 a_crash();
85 raise(SIGKILL);
86 _Exit(127);
87 }
88