blob: 8d5e044b8a4a3d054462fd2e49abf14757c3e1fa [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Instruction Execution Prevention (IEP) DAT test.
*
* Copyright (c) 2018 IBM Corp
*
* Authors:
* Janosch Frank <frankja@linux.ibm.com>
*/
#include <libcflat.h>
#include <vmalloc.h>
#include <asm/facility.h>
#include <asm/interrupt.h>
#include <mmu.h>
#include <asm/pgtable.h>
#include <asm-generic/barrier.h>
static void test_iep(void)
{
uint16_t *code;
uint8_t *iepbuf = NULL;
void (*fn)(void);
/* Enable IEP */
ctl_set_bit(0, CTL0_IEP);
/* Get and protect a page with the IEP bit */
iepbuf = alloc_page();
protect_page(iepbuf, PAGE_ENTRY_IEP);
/* Code branches into r14 which contains the return address. */
code = (uint16_t *)iepbuf;
*code = 0x07fe;
fn = (void *)code;
report_prefix_push("iep protection");
expect_pgm_int();
/* Jump into protected page */
fn();
check_pgm_int_code(PGM_INT_CODE_PROTECTION);
report_prefix_pop();
unprotect_page(iepbuf, PAGE_ENTRY_IEP);
ctl_clear_bit(0, CTL0_IEP);
free_page(iepbuf);
}
int main(void)
{
bool has_iep = test_facility(130);
report_prefix_push("iep");
if (!has_iep) {
report_skip("DAT IEP is not available");
goto done;
}
/* Setup DAT 1:1 mapping and memory management */
setup_vm();
test_iep();
done:
report_prefix_pop();
return report_summary();
}