LXR qemu/tests/tcg/aarch64/bti-crt.inc.c

   1/*
   2 * Minimal user-environment for testing BTI.
   3 *
   4 * Normal libc is not (yet) built with BTI support enabled,
   5 * and so could generate a BTI TRAP before ever reaching main.
   6 */
   7
   8#include <stdlib.h>
   9#include <signal.h>
  10#include <ucontext.h>
  11#include <asm/unistd.h>
  12
  13int main(void);
  14
  15void _start(void)
  16{
  17    exit(main());
  18}
  19
  20void exit(int ret)
  21{
  22    register int x0 __asm__("x0") = ret;
  23    register int x8 __asm__("x8") = __NR_exit;
  24
  25    asm volatile("svc #0" : : "r"(x0), "r"(x8));
  26    __builtin_unreachable();
  27}
  28
  29/*
  30 * Irritatingly, the user API struct sigaction does not match the
  31 * kernel API struct sigaction.  So for simplicity, isolate the
  32 * kernel ABI here, and make this act like signal.
  33 */
  34void signal_info(int sig, void (*fn)(int, siginfo_t *, ucontext_t *))
  35{
  36    struct kernel_sigaction {
  37        void (*handler)(int, siginfo_t *, ucontext_t *);
  38        unsigned long flags;
  39        unsigned long restorer;
  40        unsigned long mask;
  41    } sa = { fn, SA_SIGINFO, 0, 0 };
  42
  43    register int x0 __asm__("x0") = sig;
  44    register void *x1 __asm__("x1") = &sa;
  45    register void *x2 __asm__("x2") = 0;
  46    register int x3 __asm__("x3") = sizeof(unsigned long);
  47    register int x8 __asm__("x8") = __NR_rt_sigaction;
  48
  49    asm volatile("svc #0"
  50                 : : "r"(x0), "r"(x1), "r"(x2), "r"(x3), "r"(x8) : "memory");
  51}
  52