LXR linux/tools/testing/selftests/powerpc/security/flush

   1// SPDX-License-Identifier: GPL-2.0+
   2
   3/*
   4 * Copyright 2018 IBM Corporation.
   5 */
   6
   7#define __SANE_USERSPACE_TYPES__
   8
   9#include <sys/types.h>
  10#include <stdint.h>
  11#include <unistd.h>
  12#include <signal.h>
  13#include <stdlib.h>
  14#include <string.h>
  15#include <stdio.h>
  16#include "utils.h"
  17#include "flush_utils.h"
  18
  19static inline __u64 load(void *addr)
  20{
  21        __u64 tmp;
  22
  23        asm volatile("ld %0,0(%1)" : "=r"(tmp) : "b"(addr));
  24
  25        return tmp;
  26}
  27
  28void syscall_loop(char *p, unsigned long iterations,
  29                  unsigned long zero_size)
  30{
  31        for (unsigned long i = 0; i < iterations; i++) {
  32                for (unsigned long j = 0; j < zero_size; j += CACHELINE_SIZE)
  33                        load(p + j);
  34                getppid();
  35        }
  36}
  37
  38static void sigill_handler(int signr, siginfo_t *info, void *unused)
  39{
  40        static int warned;
  41        ucontext_t *ctx = (ucontext_t *)unused;
  42        unsigned long *pc = &UCONTEXT_NIA(ctx);
  43
  44        /* mtspr 3,RS to check for move to DSCR below */
  45        if ((*((unsigned int *)*pc) & 0xfc1fffff) == 0x7c0303a6) {
  46                if (!warned++)
  47                        printf("WARNING: Skipping over dscr setup. Consider running 'ppc64_cpu --dscr=1' manually.\n");
  48                *pc += 4;
  49        } else {
  50                printf("SIGILL at %p\n", pc);
  51                abort();
  52        }
  53}
  54
  55void set_dscr(unsigned long val)
  56{
  57        static int init;
  58        struct sigaction sa;
  59
  60        if (!init) {
  61                memset(&sa, 0, sizeof(sa));
  62                sa.sa_sigaction = sigill_handler;
  63                sa.sa_flags = SA_SIGINFO;
  64                if (sigaction(SIGILL, &sa, NULL))
  65                        perror("sigill_handler");
  66                init = 1;
  67        }
  68
  69        asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
  70}
  71