Commit 7fe924d9 authored by Sam bobroff's avatar Sam bobroff Committed by Michael Ellerman
Browse files

selftests/powerpc: Add transactional syscall test 



Check that a syscall made during an active transaction will fail with
the correct failure code and that one made during a suspended
transaction will succeed.

Signed-off-by: default avatarSam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 2b03fc1d

tools/testing/selftests/powerpc/tm/.gitignore

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tm-resched-dscr

tm-syscall

tools/testing/selftests/powerpc/tm/Makefile

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PROGS := tm-resched-dscr

PROGS := tm-resched-dscr tm-syscall



all: $(PROGS)



$(PROGS): ../harness.c



tm-syscall: tm-syscall-asm.S

tm-syscall: CFLAGS += -mhtm



run_tests: all

	@-for PROG in $(PROGS); do \

		./$$PROG; \

tools/testing/selftests/powerpc/tm/tm-syscall-asm.S

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#include <ppc-asm.h>

#include <asm/unistd.h>



	.text

FUNC_START(getppid_tm_active)

	tbegin.

	beq 1f

	li	r0, __NR_getppid

	sc

	tend.

	blr

1:

	li	r3, -1

	blr



FUNC_START(getppid_tm_suspended)

	tbegin.

	beq 1f

	li	r0, __NR_getppid

	tsuspend.

	sc

	tresume.

	tend.

	blr

1:

	li	r3, -1

	blr

tools/testing/selftests/powerpc/tm/tm-syscall.c

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/*

 * Copyright 2015, Sam Bobroff, IBM Corp.

 * Licensed under GPLv2.

 *

 * Test the kernel's system call code to ensure that a system call

 * made from within an active HTM transaction is aborted with the

 * correct failure code.

 * Conversely, ensure that a system call made from within a

 * suspended transaction can succeed.

 */



#include <stdio.h>

#include <unistd.h>

#include <sys/syscall.h>

#include <asm/tm.h>

#include <asm/cputable.h>

#include <linux/auxvec.h>

#include <sys/time.h>

#include <stdlib.h>



#include "utils.h"



extern int getppid_tm_active(void);

extern int getppid_tm_suspended(void);



unsigned retries = 0;



#define TEST_DURATION 10 /* seconds */

#define TM_RETRIES 100



long failure_code(void)

{

	return __builtin_get_texasru() >> 24;

}



bool failure_is_persistent(void)

{

	return (failure_code() & TM_CAUSE_PERSISTENT) == TM_CAUSE_PERSISTENT;

}



bool failure_is_syscall(void)

{

	return (failure_code() & TM_CAUSE_SYSCALL) == TM_CAUSE_SYSCALL;

}



pid_t getppid_tm(bool suspend)

{

	int i;

	pid_t pid;



	for (i = 0; i < TM_RETRIES; i++) {

		if (suspend)

			pid = getppid_tm_suspended();

		else

			pid = getppid_tm_active();



		if (pid >= 0)

			return pid;



		if (failure_is_persistent()) {

			if (failure_is_syscall())

				return -1;



			printf("Unexpected persistent transaction failure.\n");

			printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n",

			       __builtin_get_texasr(), __builtin_get_tfiar());

			exit(-1);

		}



		retries++;

	}



	printf("Exceeded limit of %d temporary transaction failures.\n", TM_RETRIES);

	printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n",

	       __builtin_get_texasr(), __builtin_get_tfiar());



	exit(-1);

}



int tm_syscall(void)

{

	unsigned count = 0;

	struct timeval end, now;



	SKIP_IF(!((long)get_auxv_entry(AT_HWCAP2) & PPC_FEATURE2_HTM));

	setbuf(stdout, NULL);



	printf("Testing transactional syscalls for %d seconds...\n", TEST_DURATION);



	gettimeofday(&end, NULL);

	now.tv_sec = TEST_DURATION;

	now.tv_usec = 0;

	timeradd(&end, &now, &end);



	for (count = 0; timercmp(&now, &end, <); count++) {

		/*

		 * Test a syscall within a suspended transaction and verify

		 * that it succeeds.

		 */

		FAIL_IF(getppid_tm(true) == -1); /* Should succeed. */



		/*

		 * Test a syscall within an active transaction and verify that

		 * it fails with the correct failure code.

		 */

		FAIL_IF(getppid_tm(false) != -1);  /* Should fail... */

		FAIL_IF(!failure_is_persistent()); /* ...persistently... */

		FAIL_IF(!failure_is_syscall());    /* ...with code syscall. */

		gettimeofday(&now, 0);

	}



	printf("%d active and suspended transactions behaved correctly.\n", count);

	printf("(There were %d transaction retries.)\n", retries);



	return 0;

}



int main(void)

{

	return test_harness(tm_syscall, "tm_syscall");

}