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 <sys/utsname.h>
  17#include "utils.h"
  18#include "flush_utils.h"
  19
  20static inline __u64 load(void *addr)
  21{
  22        __u64 tmp;
  23
  24        asm volatile("ld %0,0(%1)" : "=r"(tmp) : "b"(addr));
  25
  26        return tmp;
  27}
  28
  29void syscall_loop(char *p, unsigned long iterations,
  30                  unsigned long zero_size)
  31{
  32        for (unsigned long i = 0; i < iterations; i++) {
  33                for (unsigned long j = 0; j < zero_size; j += CACHELINE_SIZE)
  34                        load(p + j);
  35                getppid();
  36        }
  37}
  38
  39void syscall_loop_uaccess(char *p, unsigned long iterations,
  40                          unsigned long zero_size)
  41{
  42        struct utsname utsname;
  43
  44        for (unsigned long i = 0; i < iterations; i++) {
  45                for (unsigned long j = 0; j < zero_size; j += CACHELINE_SIZE)
  46                        load(p + j);
  47                uname(&utsname);
  48        }
  49}
  50
  51static void sigill_handler(int signr, siginfo_t *info, void *unused)
  52{
  53        static int warned;
  54        ucontext_t *ctx = (ucontext_t *)unused;
  55        unsigned long *pc = &UCONTEXT_NIA(ctx);
  56
  57        /* mtspr 3,RS to check for move to DSCR below */
  58        if ((*((unsigned int *)*pc) & 0xfc1fffff) == 0x7c0303a6) {
  59                if (!warned++)
  60                        printf("WARNING: Skipping over dscr setup. Consider running 'ppc64_cpu --dscr=1' manually.\n");
  61                *pc += 4;
  62        } else {
  63                printf("SIGILL at %p\n", pc);
  64                abort();
  65        }
  66}
  67
  68void set_dscr(unsigned long val)
  69{
  70        static int init;
  71        struct sigaction sa;
  72
  73        if (!init) {
  74                memset(&sa, 0, sizeof(sa));
  75                sa.sa_sigaction = sigill_handler;
  76                sa.sa_flags = SA_SIGINFO;
  77                if (sigaction(SIGILL, &sa, NULL))
  78                        perror("sigill_handler");
  79                init = 1;
  80        }
  81
  82        asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
  83}
  84