elfcore.h

能把所有线程的数据和环境记录到文件,方便调试.

#elif defined(__x86_64__) && defined(__GNUC__)
  /* The FRAME and SET_FRAME macros for x86_64.  */
  typedef struct Frame {
    struct i386_regs uregs;
    int              errno_;
    pid_t            tid;
  } Frame;
  #define FRAME(f) Frame f;                                           \
                   do {                                               \
                     f.errno_ = errno;                                \
                     f.tid    = sys_gettid();                         \
                     __asm__ volatile (                               \
                       "push %%rbp\n"                                 \
                       "push %%rbx\n"                                 \
                       "mov  %%r15,0(%%rax)\n"                        \
                       "mov  %%r14,8(%%rax)\n"                        \
                       "mov  %%r13,16(%%rax)\n"                       \
                       "mov  %%r12,24(%%rax)\n"                       \
                       "mov  %%rbp,32(%%rax)\n"                       \
                       "mov  %%rbx,40(%%rax)\n"                       \
                       "mov  %%r11,48(%%rax)\n"                       \
                       "mov  %%r10,56(%%rax)\n"                       \
                       "mov  %%r9,64(%%rax)\n"                        \
                       "mov  %%r8,72(%%rax)\n"                        \
                       "mov  %%rax,80(%%rax)\n"                       \
                       "mov  %%rcx,88(%%rax)\n"                       \
                       "mov  %%rdx,96(%%rax)\n"                       \
                       "mov  %%rsi,104(%%rax)\n"                      \
                       "mov  %%rdi,112(%%rax)\n"                      \
                       "mov  %%ds,%%rbx\n"                            \
                       "mov  %%rbx,184(%%rax)\n"                      \
                       "mov  %%es,%%rbx\n"                            \
                       "mov  %%rbx,192(%%rax)\n"                      \
                       "mov  %%fs,%%rbx\n"                            \
                       "mov  %%rbx,200(%%rax)\n"                      \
                       "mov  %%gs,%%rbx\n"                            \
                       "mov  %%rbx,208(%%rax)\n"                      \
                       "call 0f\n"                                    \
                     "0:pop %%rbx\n"                                  \
                       "add  $1f-0b,%%rbx\n"                          \
                       "mov  %%rbx,128(%%rax)\n"                      \
                       "mov  %%cs,%%rbx\n"                            \
                       "mov  %%rbx,136(%%rax)\n"                      \
                       "pushf\n"                                      \
                       "pop  %%rbx\n"                                 \
                       "mov  %%rbx,144(%%rax)\n"                      \
                       "mov  %%rsp,%%rbx\n"                           \
                       "add  $16,%%ebx\n"                             \
                       "mov  %%rbx,152(%%rax)\n"                      \
                       "mov  %%ss,%%rbx\n"                            \
                       "mov  %%rbx,160(%%rax)\n"                      \
                       "pop  %%rbx\n"                                 \
                       "pop  %%rbp\n"                                 \
                     "1:"                                             \
                       : : "a" (&f) : "memory");                      \
                     } while (0)
  #define SET_FRAME(f,r)                                              \
                     do {                                             \
                       errno = (f).errno_;                            \
                       (f).uregs.fs_base = (r).fs_base;               \
                       (f).uregs.gs_base = (r).gs_base;               \
                       (r)   = (f).uregs;                             \
                     } while (0)
#elif defined(__ARM_ARCH_3__) && defined(__GNUC__)
  /* ARM calling conventions are a little more tricky. A little assembly
   * helps in obtaining an accurate snapshot of all registers.
   */
  typedef struct Frame {
    struct arm_regs arm;
    int             errno_;
    pid_t           tid;
  } Frame;
  #define FRAME(f) Frame f;                                           \
                   do {                                               \
                     long cpsr;                                       \
                     f.errno_ = errno;                                \
                     f.tid    = sys_gettid();                         \
                     __asm__ volatile(                                \
                       "stmia %0, {r0-r15}\n" /* All integer regs   */\
                       : : "r"(&f.arm) : "memory");                   \
                     f.arm.uregs[16] = 0;                             \
                     __asm__ volatile(                                \
                       "mrs %0, cpsr\n"       /* Condition code reg */\
                       : "=r"(cpsr));                                 \
                     f.arm.uregs[17] = cpsr;                          \
                   } while (0)
  #define SET_FRAME(f,r)                                              \
                     do {                                             \
                       /* Don't override the FPU status register.   */\
                       /* Use the value obtained from ptrace(). This*/\
                       /* works, because our code does not perform  */\
                       /* any FPU operations, itself.               */\
                       long fps      = (f).arm.uregs[16];             \
                       errno         = (f).errno_;                    \
                       (r)           = (f).arm;                       \
                       (r).uregs[16] = fps;                           \
                     } while (0)
#else
  /* If we do not have a hand-optimized assembly version of the FRAME()
   * macro, we cannot reliably unroll the stack. So, we show a few additional
   * stack frames for the coredumper.
   */
  typedef struct Frame {
    pid_t tid;
  } Frame;
  #define FRAME(f) Frame f; do { f.tid = sys_gettid(); } while (0)
  #define SET_FRAME(f,r) do { } while (0)
#endif


/* Internal function for generating a core file. This API can change without
 * notice and is only supposed to be used internally by the core dumper.
 *
 * This function works for both single- and multi-threaded core
 * dumps. If called as
 *
 *   FRAME(frame);
 *   InternalGetCoreDump(&frame, 0, NULL, ap);
 *
 * it creates a core file that only contains information about the
 * calling thread.
 *
 * Optionally, the caller can provide information about other threads
 * by passing their process ids in "thread_pids". The process id of
 * the caller should not be included in this array. All of the threads
 * must have been attached to with ptrace(), prior to calling this
 * function. They will be detached when "InternalGetCoreDump()" returns.
 *
 * This function either returns a file handle that can be read for obtaining
 * a core dump, or "-1" in case of an error. In the latter case, "errno"
 * will be set appropriately.
 *
 * While "InternalGetCoreDump()" is not technically async signal safe, you
 * might be tempted to invoke it from a signal handler. The code goes to
 * great lengths to make a best effort that this will actually work. But in
 * any case, you must make sure that you preserve the value of "errno"
 * yourself. It is guaranteed to be clobbered otherwise.
 *
 * Also, "InternalGetCoreDump" is not strictly speaking re-entrant. Again,
 * it makes a best effort to behave reasonably when called in a multi-
 * threaded environment, but it is ultimately the caller's responsibility
 * to provide locking.
 */
int InternalGetCoreDump(void *frame, int num_threads, pid_t *thread_pids,
                        va_list ap
                     /* const char *PATH,
                        const struct CoredumperCompressor *compressors,
                        const struct CoredumperCompressor **selected_comp */);

#endif

#endif /* _ELFCORE_H */