148 lines
3.0 KiB
C
148 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Userspace test harness for load_unaligned_zeropad. Creates two
|
|
* pages and uses mprotect to prevent access to the second page and
|
|
* a SEGV handler that walks the exception tables and runs the fixup
|
|
* routine.
|
|
*
|
|
* The results are compared against a normal load that is that is
|
|
* performed while access to the second page is enabled via mprotect.
|
|
*
|
|
* Copyright (C) 2014 Anton Blanchard <anton@au.ibm.com>, IBM
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <stdio.h>
|
|
#include <stdbool.h>
|
|
#include <signal.h>
|
|
#include <unistd.h>
|
|
#include <sys/mman.h>
|
|
|
|
#define FIXUP_SECTION ".ex_fixup"
|
|
|
|
static inline unsigned long __fls(unsigned long x);
|
|
|
|
#include "word-at-a-time.h"
|
|
|
|
#include "utils.h"
|
|
|
|
static inline unsigned long __fls(unsigned long x)
|
|
{
|
|
int lz;
|
|
|
|
asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (x));
|
|
return sizeof(unsigned long) - 1 - lz;
|
|
}
|
|
|
|
static int page_size;
|
|
static char *mem_region;
|
|
|
|
static int protect_region(void)
|
|
{
|
|
if (mprotect(mem_region + page_size, page_size, PROT_NONE)) {
|
|
perror("mprotect");
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int unprotect_region(void)
|
|
{
|
|
if (mprotect(mem_region + page_size, page_size, PROT_READ|PROT_WRITE)) {
|
|
perror("mprotect");
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
extern char __start___ex_table[];
|
|
extern char __stop___ex_table[];
|
|
|
|
struct extbl_entry {
|
|
int insn;
|
|
int fixup;
|
|
};
|
|
|
|
static void segv_handler(int signr, siginfo_t *info, void *ptr)
|
|
{
|
|
ucontext_t *uc = (ucontext_t *)ptr;
|
|
unsigned long addr = (unsigned long)info->si_addr;
|
|
unsigned long *ip = &UCONTEXT_NIA(uc);
|
|
struct extbl_entry *entry = (struct extbl_entry *)__start___ex_table;
|
|
|
|
while (entry < (struct extbl_entry *)__stop___ex_table) {
|
|
unsigned long insn, fixup;
|
|
|
|
insn = (unsigned long)&entry->insn + entry->insn;
|
|
fixup = (unsigned long)&entry->fixup + entry->fixup;
|
|
|
|
if (insn == *ip) {
|
|
*ip = fixup;
|
|
return;
|
|
}
|
|
}
|
|
|
|
printf("No exception table match for NIA %lx ADDR %lx\n", *ip, addr);
|
|
abort();
|
|
}
|
|
|
|
static void setup_segv_handler(void)
|
|
{
|
|
struct sigaction action;
|
|
|
|
memset(&action, 0, sizeof(action));
|
|
action.sa_sigaction = segv_handler;
|
|
action.sa_flags = SA_SIGINFO;
|
|
sigaction(SIGSEGV, &action, NULL);
|
|
}
|
|
|
|
static int do_one_test(char *p, int page_offset)
|
|
{
|
|
unsigned long should;
|
|
unsigned long got;
|
|
|
|
FAIL_IF(unprotect_region());
|
|
should = *(unsigned long *)p;
|
|
FAIL_IF(protect_region());
|
|
|
|
got = load_unaligned_zeropad(p);
|
|
|
|
if (should != got) {
|
|
printf("offset %u load_unaligned_zeropad returned 0x%lx, should be 0x%lx\n", page_offset, got, should);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int test_body(void)
|
|
{
|
|
unsigned long i;
|
|
|
|
page_size = getpagesize();
|
|
mem_region = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE,
|
|
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
|
|
|
|
FAIL_IF(mem_region == MAP_FAILED);
|
|
|
|
for (i = 0; i < page_size; i++)
|
|
mem_region[i] = i;
|
|
|
|
memset(mem_region+page_size, 0, page_size);
|
|
|
|
setup_segv_handler();
|
|
|
|
for (i = 0; i < page_size; i++)
|
|
FAIL_IF(do_one_test(mem_region+i, i));
|
|
|
|
return 0;
|
|
}
|
|
|
|
int main(void)
|
|
{
|
|
return test_harness(test_body, "load_unaligned_zeropad");
|
|
}
|