selftests/powerpc: Add TM signal return test

tm-resched-dscr

tm-syscall

tm-signal-msr-resv

TEST_PROGS := tm-resched-dscr tm-syscall

TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv

all: $(TEST_PROGS)

/*

 * Copyright 2015, Michael Neuling, IBM Corp.

 * Licensed under GPLv2.

 *

 * Test the kernel's signal return code to ensure that it doesn't

 * crash when both the transactional and suspend MSR bits are set in

 * the signal context.

 *

 * For this test, we send ourselves a SIGUSR1.  In the SIGUSR1 handler

 * we modify the signal context to set both MSR TM S and T bits (which

 * is "reserved" by the PowerISA). When we return from the signal

 * handler (implicit sigreturn), the kernel should detect reserved MSR

 * value and send us with a SIGSEGV.

 */

#include <stdlib.h>

#include <stdio.h>

#include <signal.h>

#include <unistd.h>

#include "utils.h"

#include "tm.h"

int segv_expected = 0;

void signal_segv(int signum)

{

	if (segv_expected && (signum == SIGSEGV))

		_exit(0);

	_exit(1);

}

void signal_usr1(int signum, siginfo_t *info, void *uc)

{

	ucontext_t *ucp = uc;

	/* Link tm checkpointed context to normal context */

	ucp->uc_link = ucp;

	/* Set all TM bits so that the context is now invalid */

#ifdef __powerpc64__

	ucp->uc_mcontext.gp_regs[PT_MSR] |= (7ULL << 32);

#else

	ucp->uc_mcontext.regs->gpr[PT_MSR] |= (7ULL);

#endif

	/* Should segv on return becuase of invalid context */

	segv_expected = 1;

}

int tm_signal_msr_resv()

{

	struct sigaction act;

	SKIP_IF(!have_htm());

	act.sa_sigaction = signal_usr1;

	sigemptyset(&act.sa_mask);

	act.sa_flags = SA_SIGINFO;

	if (sigaction(SIGUSR1, &act, NULL) < 0) {

		perror("sigaction sigusr1");

		exit(1);

	}

	if (signal(SIGSEGV, signal_segv) == SIG_ERR)

		exit(1);

	raise(SIGUSR1);

	/* We shouldn't get here as we exit in the segv handler */

	return 1;

}

int main(void)

{

	return test_harness(tm_signal_msr_resv, "tm_signal_msr_resv");

}