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/*
* Copyright IBM Corp.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*/
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/ptrace.h>
#include <sys/syscall.h>
#include <ucontext.h>
#include <unistd.h>
#include "utils.h"
char *file_name;
int in_test;
volatile int faulted;
volatile void *dar;
int errors;
static void segv(int signum, siginfo_t *info, void *ctxt_v)
{
ucontext_t *ctxt = (ucontext_t *)ctxt_v;
struct pt_regs *regs = ctxt->uc_mcontext.regs;
if (!in_test) {
fprintf(stderr, "Segfault outside of test !\n");
exit(1);
}
faulted = 1;
dar = (void *)regs->dar;
regs->nip += 4;
}
static inline void do_read(const volatile void *addr)
{
int ret;
asm volatile("lwz %0,0(%1); twi 0,%0,0; isync;\n"
: "=r" (ret) : "r" (addr) : "memory");
}
static inline void do_write(const volatile void *addr)
{
int val = 0x1234567;
asm volatile("stw %0,0(%1); sync; \n"
: : "r" (val), "r" (addr) : "memory");
}
static inline void check_faulted(void *addr, long page, long subpage, int write)
{
int want_fault = (subpage == ((page + 3) % 16));
if (write)
want_fault |= (subpage == ((page + 1) % 16));
if (faulted != want_fault) {
printf("Failed at %p (p=%ld,sp=%ld,w=%d), want=%s, got=%s !\n",
addr, page, subpage, write,
want_fault ? "fault" : "pass",
faulted ? "fault" : "pass");
++errors;
}
if (faulted) {
if (dar != addr) {
printf("Fault expected at %p and happened at %p !\n",
addr, dar);
}
faulted = 0;
asm volatile("sync" : : : "memory");
}
}
static int run_test(void *addr, unsigned long size)
{
unsigned int *map;
long i, j, pages, err;
pages = size / 0x10000;
map = malloc(pages * 4);
assert(map);
/*
* for each page, mark subpage i % 16 read only and subpage
* (i + 3) % 16 inaccessible
*/
for (i = 0; i < pages; i++) {
map[i] = (0x40000000 >> (((i + 1) * 2) % 32)) |
(0xc0000000 >> (((i + 3) * 2) % 32));
}
err = syscall(__NR_subpage_prot, addr, size, map);
if (err) {
perror("subpage_perm");
return 1;
}
free(map);
in_test = 1;
errors = 0;
for (i = 0; i < pages; i++) {
for (j = 0; j < 16; j++, addr += 0x1000) {
do_read(addr);
check_faulted(addr, i, j, 0);
do_write(addr);
check_faulted(addr, i, j, 1);
}
}
in_test = 0;
if (errors) {
printf("%d errors detected\n", errors);
return 1;
}
return 0;
}
static int syscall_available(void)
{
int rc;
errno = 0;
rc = syscall(__NR_subpage_prot, 0, 0, 0);
return rc == 0 || (errno != ENOENT && errno != ENOSYS);
}
int test_anon(void)
{
unsigned long align;
struct sigaction act = {
.sa_sigaction = segv,
.sa_flags = SA_SIGINFO
};
void *mallocblock;
unsigned long mallocsize;
SKIP_IF(!syscall_available());
if (getpagesize() != 0x10000) {
fprintf(stderr, "Kernel page size must be 64K!\n");
return 1;
}
sigaction(SIGSEGV, &act, NULL);
mallocsize = 4 * 16 * 1024 * 1024;
FAIL_IF(posix_memalign(&mallocblock, 64 * 1024, mallocsize));
align = (unsigned long)mallocblock;
if (align & 0xffff)
align = (align | 0xffff) + 1;
mallocblock = (void *)align;
printf("allocated malloc block of 0x%lx bytes at %p\n",
mallocsize, mallocblock);
printf("testing malloc block...\n");
return run_test(mallocblock, mallocsize);
}
int test_file(void)
{
struct sigaction act = {
.sa_sigaction = segv,
.sa_flags = SA_SIGINFO
};
void *fileblock;
off_t filesize;
int fd;
SKIP_IF(!syscall_available());
fd = open(file_name, O_RDWR);
if (fd == -1) {
perror("failed to open file");
return 1;
}
sigaction(SIGSEGV, &act, NULL);
filesize = lseek(fd, 0, SEEK_END);
if (filesize & 0xffff)
filesize &= ~0xfffful;
fileblock = mmap(NULL, filesize, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, 0);
if (fileblock == MAP_FAILED) {
perror("failed to map file");
return 1;
}
printf("allocated %s for 0x%lx bytes at %p\n",
file_name, filesize, fileblock);
printf("testing file map...\n");
return run_test(fileblock, filesize);
}
int main(int argc, char *argv[])
{
int rc;
rc = test_harness(test_anon, "subpage_prot_anon");
if (rc)
return rc;
if (argc > 1)
file_name = argv[1];
else
file_name = "tempfile";
return test_harness(test_file, "subpage_prot_file");
}
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