Commit 2d084b2d authored by Vincenzo Frascino's avatar Vincenzo Frascino Committed by Stephen Rothwell
Browse files

kselftest/arm64: check GCR_EL1 after context switch

This test is specific to MTE and verifies that the GCR_EL1 register is
context switched correctly.

It spawns 1024 processes and each process spawns 5 threads.  Each thread
writes a random setting of GCR_EL1 through the prctl() system call and
reads it back verifying that it is the same.  If the values are not the
same it reports a failure.

Note: The test has been extended to verify that even SYNC and ASYNC mode
setting is preserved correctly over context switching.

Link: https://lkml.kernel.org/r/b51a165426e906e7ec8a68d806ef3f8cd92581a6.1606161801.git.andreyknvl@google.com

Signed-off-by: Vincenzo Frascino's avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Acked-by: Catalin Marinas's avatarCatalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino's avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
parent 10688afd
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2020 ARM Limited
CFLAGS += -std=gnu99 -I.
CFLAGS += -std=gnu99 -I. -lpthread
SRCS := $(filter-out mte_common_util.c,$(wildcard *.c))
PROGS := $(patsubst %.c,%,$(SRCS))
......
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2020 ARM Limited
#define _GNU_SOURCE
#include <errno.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <sys/auxv.h>
#include <sys/mman.h>
#include <sys/prctl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include "kselftest.h"
#include "mte_common_util.h"
#define PR_SET_TAGGED_ADDR_CTRL 55
#define PR_GET_TAGGED_ADDR_CTRL 56
# define PR_TAGGED_ADDR_ENABLE (1UL << 0)
# define PR_MTE_TCF_SHIFT 1
# define PR_MTE_TCF_NONE (0UL << PR_MTE_TCF_SHIFT)
# define PR_MTE_TCF_SYNC (1UL << PR_MTE_TCF_SHIFT)
# define PR_MTE_TCF_ASYNC (2UL << PR_MTE_TCF_SHIFT)
# define PR_MTE_TCF_MASK (3UL << PR_MTE_TCF_SHIFT)
# define PR_MTE_TAG_SHIFT 3
# define PR_MTE_TAG_MASK (0xffffUL << PR_MTE_TAG_SHIFT)
#include "mte_def.h"
#define NUM_ITERATIONS 1024
#define MAX_THREADS 5
#define THREAD_ITERATIONS 1000
void *execute_thread(void *x)
{
pid_t pid = *((pid_t *)x);
pid_t tid = gettid();
uint64_t prctl_tag_mask;
uint64_t prctl_set;
uint64_t prctl_get;
uint64_t prctl_tcf;
srand(time(NULL) ^ (pid << 16) ^ (tid << 16));
prctl_tag_mask = rand() & 0xffff;
if (prctl_tag_mask % 2)
prctl_tcf = PR_MTE_TCF_SYNC;
else
prctl_tcf = PR_MTE_TCF_ASYNC;
prctl_set = PR_TAGGED_ADDR_ENABLE | prctl_tcf | (prctl_tag_mask << PR_MTE_TAG_SHIFT);
for (int j = 0; j < THREAD_ITERATIONS; j++) {
if (prctl(PR_SET_TAGGED_ADDR_CTRL, prctl_set, 0, 0, 0)) {
perror("prctl() failed");
goto fail;
}
prctl_get = prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0);
if (prctl_set != prctl_get) {
ksft_print_msg("Error: prctl_set: 0x%lx != prctl_get: 0x%lx\n",
prctl_set, prctl_get);
goto fail;
}
}
return (void *)KSFT_PASS;
fail:
return (void *)KSFT_FAIL;
}
int execute_test(pid_t pid)
{
pthread_t thread_id[MAX_THREADS];
int thread_data[MAX_THREADS];
for (int i = 0; i < MAX_THREADS; i++)
pthread_create(&thread_id[i], NULL,
execute_thread, (void *)&pid);
for (int i = 0; i < MAX_THREADS; i++)
pthread_join(thread_id[i], (void *)&thread_data[i]);
for (int i = 0; i < MAX_THREADS; i++)
if (thread_data[i] == KSFT_FAIL)
return KSFT_FAIL;
return KSFT_PASS;
}
int mte_gcr_fork_test(void)
{
pid_t pid;
int results[NUM_ITERATIONS];
pid_t cpid;
int res;
for (int i = 0; i < NUM_ITERATIONS; i++) {
pid = fork();
if (pid < 0)
return KSFT_FAIL;
if (pid == 0) {
cpid = getpid();
res = execute_test(cpid);
exit(res);
}
}
for (int i = 0; i < NUM_ITERATIONS; i++) {
wait(&res);
if (WIFEXITED(res))
results[i] = WEXITSTATUS(res);
else
--i;
}
for (int i = 0; i < NUM_ITERATIONS; i++)
if (results[i] == KSFT_FAIL)
return KSFT_FAIL;
return KSFT_PASS;
}
int main(int argc, char *argv[])
{
int err;
err = mte_default_setup();
if (err)
return err;
ksft_set_plan(1);
evaluate_test(mte_gcr_fork_test(),
"Verify that GCR_EL1 is set correctly on context switch\n");
mte_restore_setup();
ksft_print_cnts();
return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
}
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