| // Copyright 2016 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef SRC_LIB_DEBUG_BACKTRACE_REQUEST_H_ |
| #define SRC_LIB_DEBUG_BACKTRACE_REQUEST_H_ |
| |
| #include <stdint.h> |
| #include <zircon/compiler.h> |
| |
| // Special values we put in the first register to let the exception handler know |
| // that we are just requesting a backtrace and we should resume the thread. |
| #define BACKTRACE_REQUEST_MAGIC_ALL_THREADS ((uint64_t)0xee726573756d65ee) |
| #define BACKTRACE_REQUEST_MAGIC_CURRENT_THREAD ((uint64_t)0xee726573756d65ef) |
| |
| __ALWAYS_INLINE static inline void software_break(uint64_t magic) { |
| // We set a software breakpoint to trigger the exception handling in |
| // crashsvc, which will print the debug info, including the backtrace. |
| // |
| // We write the "magic" value in the first register (rax on x64, x0 on arm64) so that the |
| // exception handler can check for it and resume the thread rather than kill the process. |
| #ifdef __x86_64__ |
| __asm__ volatile("int3" : : "a"(magic)); |
| #endif |
| #ifdef __aarch64__ |
| // This is what gdb uses. |
| __asm__ volatile( |
| "mov x0, %0\n\t" |
| "brk 0" |
| : |
| : "r"(magic) |
| : "x0"); |
| #endif |
| #ifdef __riscv |
| __asm__ volatile( |
| ".option push\n" |
| ".option arch, +c\n" |
| "mv a0, %0\n" |
| "c.ebreak\n" |
| ".option pop" |
| : |
| : "r"(magic) |
| : "a0"); |
| #endif |
| } |
| |
| // Prints backtrace for all threads and resumes without killing the process. |
| __ALWAYS_INLINE static inline void backtrace_request_all_threads(void) { |
| software_break(BACKTRACE_REQUEST_MAGIC_ALL_THREADS); |
| } |
| |
| // Requests a backtrace only for the current thread. |
| __ALWAYS_INLINE static inline void backtrace_request_current_thread(void) { |
| software_break(BACKTRACE_REQUEST_MAGIC_CURRENT_THREAD); |
| } |
| |
| #endif // SRC_LIB_DEBUG_BACKTRACE_REQUEST_H_ |