From: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> commit 93cad5f789951eaa27c3392b15294b4e51253944 upstream. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> [mpe: Some minor fixes to make it build] Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20190924035254.24612-4-aneesh.kumar@xxxxxxxxxxxxx Signed-off-by: Sandipan Das <sandipan@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/powerpc/mm/Makefile | 2 tools/testing/selftests/powerpc/mm/tlbie_test.c | 734 ++++++++++++++++++++++++ 2 files changed, 736 insertions(+) --- a/tools/testing/selftests/powerpc/mm/Makefile +++ b/tools/testing/selftests/powerpc/mm/Makefile @@ -4,6 +4,7 @@ noarg: TEST_GEN_PROGS := hugetlb_vs_thp_test subpage_prot prot_sao segv_errors wild_bctr \ large_vm_fork_separation +TEST_GEN_PROGS_EXTENDED := tlbie_test TEST_GEN_FILES := tempfile top_srcdir = ../../../../.. @@ -19,3 +20,4 @@ $(OUTPUT)/large_vm_fork_separation: CFLA $(OUTPUT)/tempfile: dd if=/dev/zero of=$@ bs=64k count=1 +$(OUTPUT)/tlbie_test: LDLIBS += -lpthread --- /dev/null +++ b/tools/testing/selftests/powerpc/mm/tlbie_test.c @@ -0,0 +1,734 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright 2019, Nick Piggin, Gautham R. Shenoy, Aneesh Kumar K.V, IBM Corp. + */ + +/* + * + * Test tlbie/mtpidr race. We have 4 threads doing flush/load/compare/store + * sequence in a loop. The same threads also rung a context switch task + * that does sched_yield() in loop. + * + * The snapshot thread mark the mmap area PROT_READ in between, make a copy + * and copy it back to the original area. This helps us to detect if any + * store continued to happen after we marked the memory PROT_READ. + */ + +#define _GNU_SOURCE +#include <stdio.h> +#include <sys/mman.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <sys/ipc.h> +#include <sys/shm.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <linux/futex.h> +#include <unistd.h> +#include <asm/unistd.h> +#include <string.h> +#include <stdlib.h> +#include <fcntl.h> +#include <sched.h> +#include <time.h> +#include <stdarg.h> +#include <sched.h> +#include <pthread.h> +#include <signal.h> +#include <sys/prctl.h> + +static inline void dcbf(volatile unsigned int *addr) +{ + __asm__ __volatile__ ("dcbf %y0; sync" : : "Z"(*(unsigned char *)addr) : "memory"); +} + +static void err_msg(char *msg) +{ + + time_t now; + time(&now); + printf("=================================\n"); + printf(" Error: %s\n", msg); + printf(" %s", ctime(&now)); + printf("=================================\n"); + exit(1); +} + +static char *map1; +static char *map2; +static pid_t rim_process_pid; + +/* + * A "rim-sequence" is defined to be the sequence of the following + * operations performed on a memory word: + * 1) FLUSH the contents of that word. + * 2) LOAD the contents of that word. + * 3) COMPARE the contents of that word with the content that was + * previously stored at that word + * 4) STORE new content into that word. + * + * The threads in this test that perform the rim-sequence are termed + * as rim_threads. + */ + +/* + * A "corruption" is defined to be the failed COMPARE operation in a + * rim-sequence. + * + * A rim_thread that detects a corruption informs about it to all the + * other rim_threads, and the mem_snapshot thread. + */ +static volatile unsigned int corruption_found; + +/* + * This defines the maximum number of rim_threads in this test. + * + * The THREAD_ID_BITS denote the number of bits required + * to represent the thread_ids [0..MAX_THREADS - 1]. + * We are being a bit paranoid here and set it to 8 bits, + * though 6 bits suffice. + * + */ +#define MAX_THREADS 64 +#define THREAD_ID_BITS 8 +#define THREAD_ID_MASK ((1 << THREAD_ID_BITS) - 1) +static unsigned int rim_thread_ids[MAX_THREADS]; +static pthread_t rim_threads[MAX_THREADS]; + + +/* + * Each rim_thread works on an exclusive "chunk" of size + * RIM_CHUNK_SIZE. + * + * The ith rim_thread works on the ith chunk. + * + * The ith chunk begins at + * map1 + (i * RIM_CHUNK_SIZE) + */ +#define RIM_CHUNK_SIZE 1024 +#define BITS_PER_BYTE 8 +#define WORD_SIZE (sizeof(unsigned int)) +#define WORD_BITS (WORD_SIZE * BITS_PER_BYTE) +#define WORDS_PER_CHUNK (RIM_CHUNK_SIZE/WORD_SIZE) + +static inline char *compute_chunk_start_addr(unsigned int thread_id) +{ + char *chunk_start; + + chunk_start = (char *)((unsigned long)map1 + + (thread_id * RIM_CHUNK_SIZE)); + + return chunk_start; +} + +/* + * The "word-offset" of a word-aligned address inside a chunk, is + * defined to be the number of words that precede the address in that + * chunk. + * + * WORD_OFFSET_BITS denote the number of bits required to represent + * the word-offsets of all the word-aligned addresses of a chunk. + */ +#define WORD_OFFSET_BITS (__builtin_ctz(WORDS_PER_CHUNK)) +#define WORD_OFFSET_MASK ((1 << WORD_OFFSET_BITS) - 1) + +static inline unsigned int compute_word_offset(char *start, unsigned int *addr) +{ + unsigned int delta_bytes, ret; + delta_bytes = (unsigned long)addr - (unsigned long)start; + + ret = delta_bytes/WORD_SIZE; + + return ret; +} + +/* + * A "sweep" is defined to be the sequential execution of the + * rim-sequence by a rim_thread on its chunk one word at a time, + * starting from the first word of its chunk and ending with the last + * word of its chunk. + * + * Each sweep of a rim_thread is uniquely identified by a sweep_id. + * SWEEP_ID_BITS denote the number of bits required to represent + * the sweep_ids of rim_threads. + * + * As to why SWEEP_ID_BITS are computed as a function of THREAD_ID_BITS, + * WORD_OFFSET_BITS, and WORD_BITS, see the "store-pattern" below. + */ +#define SWEEP_ID_BITS (WORD_BITS - (THREAD_ID_BITS + WORD_OFFSET_BITS)) +#define SWEEP_ID_MASK ((1 << SWEEP_ID_BITS) - 1) + +/* + * A "store-pattern" is the word-pattern that is stored into a word + * location in the 4)STORE step of the rim-sequence. + * + * In the store-pattern, we shall encode: + * + * - The thread-id of the rim_thread performing the store + * (The most significant THREAD_ID_BITS) + * + * - The word-offset of the address into which the store is being + * performed (The next WORD_OFFSET_BITS) + * + * - The sweep_id of the current sweep in which the store is + * being performed. (The lower SWEEP_ID_BITS) + * + * Store Pattern: 32 bits + * |------------------|--------------------|---------------------------------| + * | Thread id | Word offset | sweep_id | + * |------------------|--------------------|---------------------------------| + * THREAD_ID_BITS WORD_OFFSET_BITS SWEEP_ID_BITS + * + * In the store pattern, the (Thread-id + Word-offset) uniquely identify the + * address to which the store is being performed i.e, + * address == map1 + + * (Thread-id * RIM_CHUNK_SIZE) + (Word-offset * WORD_SIZE) + * + * And the sweep_id in the store pattern identifies the time when the + * store was performed by the rim_thread. + * + * We shall use this property in the 3)COMPARE step of the + * rim-sequence. + */ +#define SWEEP_ID_SHIFT 0 +#define WORD_OFFSET_SHIFT (SWEEP_ID_BITS) +#define THREAD_ID_SHIFT (WORD_OFFSET_BITS + SWEEP_ID_BITS) + +/* + * Compute the store pattern for a given thread with id @tid, at + * location @addr in the sweep identified by @sweep_id + */ +static inline unsigned int compute_store_pattern(unsigned int tid, + unsigned int *addr, + unsigned int sweep_id) +{ + unsigned int ret = 0; + char *start = compute_chunk_start_addr(tid); + unsigned int word_offset = compute_word_offset(start, addr); + + ret += (tid & THREAD_ID_MASK) << THREAD_ID_SHIFT; + ret += (word_offset & WORD_OFFSET_MASK) << WORD_OFFSET_SHIFT; + ret += (sweep_id & SWEEP_ID_MASK) << SWEEP_ID_SHIFT; + return ret; +} + +/* Extract the thread-id from the given store-pattern */ +static inline unsigned int extract_tid(unsigned int pattern) +{ + unsigned int ret; + + ret = (pattern >> THREAD_ID_SHIFT) & THREAD_ID_MASK; + return ret; +} + +/* Extract the word-offset from the given store-pattern */ +static inline unsigned int extract_word_offset(unsigned int pattern) +{ + unsigned int ret; + + ret = (pattern >> WORD_OFFSET_SHIFT) & WORD_OFFSET_MASK; + + return ret; +} + +/* Extract the sweep-id from the given store-pattern */ +static inline unsigned int extract_sweep_id(unsigned int pattern) + +{ + unsigned int ret; + + ret = (pattern >> SWEEP_ID_SHIFT) & SWEEP_ID_MASK; + + return ret; +} + +/************************************************************ + * * + * Logging the output of the verification * + * * + ************************************************************/ +#define LOGDIR_NAME_SIZE 100 +static char logdir[LOGDIR_NAME_SIZE]; + +static FILE *fp[MAX_THREADS]; +static const char logfilename[] ="Thread-%02d-Chunk"; + +static inline void start_verification_log(unsigned int tid, + unsigned int *addr, + unsigned int cur_sweep_id, + unsigned int prev_sweep_id) +{ + FILE *f; + char logfile[30]; + char path[LOGDIR_NAME_SIZE + 30]; + char separator[2] = "/"; + char *chunk_start = compute_chunk_start_addr(tid); + unsigned int size = RIM_CHUNK_SIZE; + + sprintf(logfile, logfilename, tid); + strcpy(path, logdir); + strcat(path, separator); + strcat(path, logfile); + f = fopen(path, "w"); + + if (!f) { + err_msg("Unable to create logfile\n"); + } + + fp[tid] = f; + + fprintf(f, "----------------------------------------------------------\n"); + fprintf(f, "PID = %d\n", rim_process_pid); + fprintf(f, "Thread id = %02d\n", tid); + fprintf(f, "Chunk Start Addr = 0x%016lx\n", (unsigned long)chunk_start); + fprintf(f, "Chunk Size = %d\n", size); + fprintf(f, "Next Store Addr = 0x%016lx\n", (unsigned long)addr); + fprintf(f, "Current sweep-id = 0x%08x\n", cur_sweep_id); + fprintf(f, "Previous sweep-id = 0x%08x\n", prev_sweep_id); + fprintf(f, "----------------------------------------------------------\n"); +} + +static inline void log_anamoly(unsigned int tid, unsigned int *addr, + unsigned int expected, unsigned int observed) +{ + FILE *f = fp[tid]; + + fprintf(f, "Thread %02d: Addr 0x%lx: Expected 0x%x, Observed 0x%x\n", + tid, (unsigned long)addr, expected, observed); + fprintf(f, "Thread %02d: Expected Thread id = %02d\n", tid, extract_tid(expected)); + fprintf(f, "Thread %02d: Observed Thread id = %02d\n", tid, extract_tid(observed)); + fprintf(f, "Thread %02d: Expected Word offset = %03d\n", tid, extract_word_offset(expected)); + fprintf(f, "Thread %02d: Observed Word offset = %03d\n", tid, extract_word_offset(observed)); + fprintf(f, "Thread %02d: Expected sweep-id = 0x%x\n", tid, extract_sweep_id(expected)); + fprintf(f, "Thread %02d: Observed sweep-id = 0x%x\n", tid, extract_sweep_id(observed)); + fprintf(f, "----------------------------------------------------------\n"); +} + +static inline void end_verification_log(unsigned int tid, unsigned nr_anamolies) +{ + FILE *f = fp[tid]; + char logfile[30]; + char path[LOGDIR_NAME_SIZE + 30]; + char separator[] = "/"; + + fclose(f); + + if (nr_anamolies == 0) { + remove(path); + return; + } + + sprintf(logfile, logfilename, tid); + strcpy(path, logdir); + strcat(path, separator); + strcat(path, logfile); + + printf("Thread %02d chunk has %d corrupted words. For details check %s\n", + tid, nr_anamolies, path); +} + +/* + * When a COMPARE step of a rim-sequence fails, the rim_thread informs + * everyone else via the shared_memory pointed to by + * corruption_found variable. On seeing this, every thread verifies the + * content of its chunk as follows. + * + * Suppose a thread identified with @tid was about to store (but not + * yet stored) to @next_store_addr in its current sweep identified + * @cur_sweep_id. Let @prev_sweep_id indicate the previous sweep_id. + * + * This implies that for all the addresses @addr < @next_store_addr, + * Thread @tid has already performed a store as part of its current + * sweep. Hence we expect the content of such @addr to be: + * |-------------------------------------------------| + * | tid | word_offset(addr) | cur_sweep_id | + * |-------------------------------------------------| + * + * Since Thread @tid is yet to perform stores on address + * @next_store_addr and above, we expect the content of such an + * address @addr to be: + * |-------------------------------------------------| + * | tid | word_offset(addr) | prev_sweep_id | + * |-------------------------------------------------| + * + * The verifier function @verify_chunk does this verification and logs + * any anamolies that it finds. + */ +static void verify_chunk(unsigned int tid, unsigned int *next_store_addr, + unsigned int cur_sweep_id, + unsigned int prev_sweep_id) +{ + unsigned int *iter_ptr; + unsigned int size = RIM_CHUNK_SIZE; + unsigned int expected; + unsigned int observed; + char *chunk_start = compute_chunk_start_addr(tid); + + int nr_anamolies = 0; + + start_verification_log(tid, next_store_addr, + cur_sweep_id, prev_sweep_id); + + for (iter_ptr = (unsigned int *)chunk_start; + (unsigned long)iter_ptr < (unsigned long)chunk_start + size; + iter_ptr++) { + unsigned int expected_sweep_id; + + if (iter_ptr < next_store_addr) { + expected_sweep_id = cur_sweep_id; + } else { + expected_sweep_id = prev_sweep_id; + } + + expected = compute_store_pattern(tid, iter_ptr, expected_sweep_id); + + dcbf((volatile unsigned int*)iter_ptr); //Flush before reading + observed = *iter_ptr; + + if (observed != expected) { + nr_anamolies++; + log_anamoly(tid, iter_ptr, expected, observed); + } + } + + end_verification_log(tid, nr_anamolies); +} + +static void set_pthread_cpu(pthread_t th, int cpu) +{ + cpu_set_t run_cpu_mask; + struct sched_param param; + + CPU_ZERO(&run_cpu_mask); + CPU_SET(cpu, &run_cpu_mask); + pthread_setaffinity_np(th, sizeof(cpu_set_t), &run_cpu_mask); + + param.sched_priority = 1; + if (0 && sched_setscheduler(0, SCHED_FIFO, ¶m) == -1) { + /* haven't reproduced with this setting, it kills random preemption which may be a factor */ + fprintf(stderr, "could not set SCHED_FIFO, run as root?\n"); + } +} + +static void set_mycpu(int cpu) +{ + cpu_set_t run_cpu_mask; + struct sched_param param; + + CPU_ZERO(&run_cpu_mask); + CPU_SET(cpu, &run_cpu_mask); + sched_setaffinity(0, sizeof(cpu_set_t), &run_cpu_mask); + + param.sched_priority = 1; + if (0 && sched_setscheduler(0, SCHED_FIFO, ¶m) == -1) { + fprintf(stderr, "could not set SCHED_FIFO, run as root?\n"); + } +} + +static volatile int segv_wait; + +static void segv_handler(int signo, siginfo_t *info, void *extra) +{ + while (segv_wait) { + sched_yield(); + } + +} + +static void set_segv_handler(void) +{ + struct sigaction sa; + + sa.sa_flags = SA_SIGINFO; + sa.sa_sigaction = segv_handler; + + if (sigaction(SIGSEGV, &sa, NULL) == -1) { + perror("sigaction"); + exit(EXIT_FAILURE); + } +} + +int timeout = 0; +/* + * This function is executed by every rim_thread. + * + * This function performs sweeps over the exclusive chunks of the + * rim_threads executing the rim-sequence one word at a time. + */ +static void *rim_fn(void *arg) +{ + unsigned int tid = *((unsigned int *)arg); + + int size = RIM_CHUNK_SIZE; + char *chunk_start = compute_chunk_start_addr(tid); + + unsigned int prev_sweep_id; + unsigned int cur_sweep_id = 0; + + /* word access */ + unsigned int pattern = cur_sweep_id; + unsigned int *pattern_ptr = &pattern; + unsigned int *w_ptr, read_data; + + set_segv_handler(); + + /* + * Let us initialize the chunk: + * + * Each word-aligned address addr in the chunk, + * is initialized to : + * |-------------------------------------------------| + * | tid | word_offset(addr) | 0 | + * |-------------------------------------------------| + */ + for (w_ptr = (unsigned int *)chunk_start; + (unsigned long)w_ptr < (unsigned long)(chunk_start) + size; + w_ptr++) { + + *pattern_ptr = compute_store_pattern(tid, w_ptr, cur_sweep_id); + *w_ptr = *pattern_ptr; + } + + while (!corruption_found && !timeout) { + prev_sweep_id = cur_sweep_id; + cur_sweep_id = cur_sweep_id + 1; + + for (w_ptr = (unsigned int *)chunk_start; + (unsigned long)w_ptr < (unsigned long)(chunk_start) + size; + w_ptr++) { + unsigned int old_pattern; + + /* + * Compute the pattern that we would have + * stored at this location in the previous + * sweep. + */ + old_pattern = compute_store_pattern(tid, w_ptr, prev_sweep_id); + + /* + * FLUSH:Ensure that we flush the contents of + * the cache before loading + */ + dcbf((volatile unsigned int*)w_ptr); //Flush + + /* LOAD: Read the value */ + read_data = *w_ptr; //Load + + /* + * COMPARE: Is it the same as what we had stored + * in the previous sweep ? It better be! + */ + if (read_data != old_pattern) { + /* No it isn't! Tell everyone */ + corruption_found = 1; + } + + /* + * Before performing a store, let us check if + * any rim_thread has found a corruption. + */ + if (corruption_found || timeout) { + /* + * Yes. Someone (including us!) has found + * a corruption :( + * + * Let us verify that our chunk is + * correct. + */ + /* But first, let us allow the dust to settle down! */ + verify_chunk(tid, w_ptr, cur_sweep_id, prev_sweep_id); + + return 0; + } + + /* + * Compute the new pattern that we are going + * to write to this location + */ + *pattern_ptr = compute_store_pattern(tid, w_ptr, cur_sweep_id); + + /* + * STORE: Now let us write this pattern into + * the location + */ + *w_ptr = *pattern_ptr; + } + } + + return NULL; +} + + +static unsigned long start_cpu = 0; +static unsigned long nrthreads = 4; + +static pthread_t mem_snapshot_thread; + +static void *mem_snapshot_fn(void *arg) +{ + int page_size = getpagesize(); + size_t size = page_size; + void *tmp = malloc(size); + + while (!corruption_found && !timeout) { + /* Stop memory migration once corruption is found */ + segv_wait = 1; + + mprotect(map1, size, PROT_READ); + + /* + * Load from the working alias (map1). Loading from map2 + * also fails. + */ + memcpy(tmp, map1, size); + + /* + * Stores must go via map2 which has write permissions, but + * the corrupted data tends to be seen in the snapshot buffer, + * so corruption does not appear to be introduced at the + * copy-back via map2 alias here. + */ + memcpy(map2, tmp, size); + /* + * Before releasing other threads, must ensure the copy + * back to + */ + asm volatile("sync" ::: "memory"); + mprotect(map1, size, PROT_READ|PROT_WRITE); + asm volatile("sync" ::: "memory"); + segv_wait = 0; + + usleep(1); /* This value makes a big difference */ + } + + return 0; +} + +void alrm_sighandler(int sig) +{ + timeout = 1; +} + +int main(int argc, char *argv[]) +{ + int c; + int page_size = getpagesize(); + time_t now; + int i, dir_error; + pthread_attr_t attr; + key_t shm_key = (key_t) getpid(); + int shmid, run_time = 20 * 60; + struct sigaction sa_alrm; + + snprintf(logdir, LOGDIR_NAME_SIZE, + "/tmp/logdir-%u", (unsigned int)getpid()); + while ((c = getopt(argc, argv, "r:hn:l:t:")) != -1) { + switch(c) { + case 'r': + start_cpu = strtoul(optarg, NULL, 10); + break; + case 'h': + printf("%s [-r <start_cpu>] [-n <nrthreads>] [-l <logdir>] [-t <timeout>]\n", argv[0]); + exit(0); + break; + case 'n': + nrthreads = strtoul(optarg, NULL, 10); + break; + case 'l': + strncpy(logdir, optarg, LOGDIR_NAME_SIZE); + break; + case 't': + run_time = strtoul(optarg, NULL, 10); + break; + default: + printf("invalid option\n"); + exit(0); + break; + } + } + + if (nrthreads > MAX_THREADS) + nrthreads = MAX_THREADS; + + shmid = shmget(shm_key, page_size, IPC_CREAT|0666); + if (shmid < 0) { + err_msg("Failed shmget\n"); + } + + map1 = shmat(shmid, NULL, 0); + if (map1 == (void *) -1) { + err_msg("Failed shmat"); + } + + map2 = shmat(shmid, NULL, 0); + if (map2 == (void *) -1) { + err_msg("Failed shmat"); + } + + dir_error = mkdir(logdir, 0755); + + if (dir_error) { + err_msg("Failed mkdir"); + } + + printf("start_cpu list:%lu\n", start_cpu); + printf("number of worker threads:%lu + 1 snapshot thread\n", nrthreads); + printf("Allocated address:0x%016lx + secondary map:0x%016lx\n", (unsigned long)map1, (unsigned long)map2); + printf("logdir at : %s\n", logdir); + printf("Timeout: %d seconds\n", run_time); + + time(&now); + printf("=================================\n"); + printf(" Starting Test\n"); + printf(" %s", ctime(&now)); + printf("=================================\n"); + + for (i = 0; i < nrthreads; i++) { + if (1 && !fork()) { + prctl(PR_SET_PDEATHSIG, SIGKILL); + set_mycpu(start_cpu + i); + for (;;) + sched_yield(); + exit(0); + } + } + + + sa_alrm.sa_handler = &alrm_sighandler; + sigemptyset(&sa_alrm.sa_mask); + sa_alrm.sa_flags = 0; + + if (sigaction(SIGALRM, &sa_alrm, 0) == -1) { + err_msg("Failed signal handler registration\n"); + } + + alarm(run_time); + + pthread_attr_init(&attr); + for (i = 0; i < nrthreads; i++) { + rim_thread_ids[i] = i; + pthread_create(&rim_threads[i], &attr, rim_fn, &rim_thread_ids[i]); + set_pthread_cpu(rim_threads[i], start_cpu + i); + } + + pthread_create(&mem_snapshot_thread, &attr, mem_snapshot_fn, map1); + set_pthread_cpu(mem_snapshot_thread, start_cpu + i); + + + pthread_join(mem_snapshot_thread, NULL); + for (i = 0; i < nrthreads; i++) { + pthread_join(rim_threads[i], NULL); + } + + if (!timeout) { + time(&now); + printf("=================================\n"); + printf(" Data Corruption Detected\n"); + printf(" %s", ctime(&now)); + printf(" See logfiles in %s\n", logdir); + printf("=================================\n"); + return 1; + } + return 0; +}
