kselftest: arm64: mangle_pstate_invalid_daif_bits

// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright (C) 2019 ARM Limited

 *

 * Try to mangle the ucontext from inside a signal handler, mangling the

 * DAIF bits in an illegal manner: this attempt must be spotted by Kernel

 * and the test case is expected to be terminated via SEGV.

 *

 */

#include "test_signals_utils.h"

#include "testcases.h"

static int mangle_invalid_pstate_run(struct tdescr *td, siginfo_t *si,

				     ucontext_t *uc)

{

	ASSERT_GOOD_CONTEXT(uc);

	/*

	 * This config should trigger a SIGSEGV by Kernel when it checks

	 * the sigframe consistency in valid_user_regs() routine.

	 */

	uc->uc_mcontext.pstate |= PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT;

	return 1;

}

struct tdescr tde = {

		.sanity_disabled = true,

		.name = "MANGLE_PSTATE_INVALID_DAIF_BITS",

		.descr = "Mangling uc_mcontext with INVALID DAIF_BITS",

		.sig_trig = SIGUSR1,

		.sig_ok = SIGSEGV,

		.run = mangle_invalid_pstate_run,

};