xref: /linux/tools/testing/selftests/powerpc/security/flush_utils.c (revision 7ae9fb1b7ecbb5d85d07857943f677fd1a559b18)
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 "reg.h"
18 #include "utils.h"
19 #include "flush_utils.h"
20 
load(void * addr)21 static inline __u64 load(void *addr)
22 {
23 	__u64 tmp;
24 
25 	asm volatile("ld %0,0(%1)" : "=r"(tmp) : "b"(addr));
26 
27 	return tmp;
28 }
29 
syscall_loop(char * p,unsigned long iterations,unsigned long zero_size)30 void syscall_loop(char *p, unsigned long iterations,
31 		  unsigned long zero_size)
32 {
33 	for (unsigned long i = 0; i < iterations; i++) {
34 		for (unsigned long j = 0; j < zero_size; j += CACHELINE_SIZE)
35 			load(p + j);
36 		getppid();
37 	}
38 }
39 
syscall_loop_uaccess(char * p,unsigned long iterations,unsigned long zero_size)40 void syscall_loop_uaccess(char *p, unsigned long iterations,
41 			  unsigned long zero_size)
42 {
43 	struct utsname utsname;
44 
45 	for (unsigned long i = 0; i < iterations; i++) {
46 		for (unsigned long j = 0; j < zero_size; j += CACHELINE_SIZE)
47 			load(p + j);
48 		uname(&utsname);
49 	}
50 }
51 
sigill_handler(int signr,siginfo_t * info,void * unused)52 static void sigill_handler(int signr, siginfo_t *info, void *unused)
53 {
54 	static int warned;
55 	ucontext_t *ctx = (ucontext_t *)unused;
56 	unsigned long *pc = &UCONTEXT_NIA(ctx);
57 
58 	/* mtspr 3,RS to check for move to DSCR below */
59 	if ((*((unsigned int *)*pc) & 0xfc1fffff) == 0x7c0303a6) {
60 		if (!warned++)
61 			printf("WARNING: Skipping over dscr setup. Consider running 'ppc64_cpu --dscr=1' manually.\n");
62 		*pc += 4;
63 	} else {
64 		printf("SIGILL at %p\n", pc);
65 		abort();
66 	}
67 }
68 
set_dscr(unsigned long val)69 void set_dscr(unsigned long val)
70 {
71 	static int init;
72 	struct sigaction sa;
73 
74 	if (!init) {
75 		memset(&sa, 0, sizeof(sa));
76 		sa.sa_sigaction = sigill_handler;
77 		sa.sa_flags = SA_SIGINFO;
78 		if (sigaction(SIGILL, &sa, NULL))
79 			perror("sigill_handler");
80 		init = 1;
81 	}
82 
83 	mtspr(SPRN_DSCR, val);
84 }
85