From 26b4224d99615a19c002508c6e80bd3d1d783b64 Mon Sep 17 00:00:00 2001 From: Simon Guo Date: Fri, 7 Oct 2016 16:59:52 -0700 Subject: selftests: expanding more mlock selftest This patch will randomly perform mlock/mlock2 on a given memory region, and verify the RLIMIT_MEMLOCK limitation works properly. Suggested-by: David Rientjes Link: http://lkml.kernel.org/r/1473325970-11393-4-git-send-email-wei.guo.simon@gmail.com Signed-off-by: Simon Guo Cc: Shuah Khan Cc: Vlastimil Babka Cc: "Kirill A. Shutemov" Cc: Michal Hocko Cc: Eric B Munson Cc: Simon Guo Cc: Mel Gorman Cc: Alexey Klimov Cc: Andrea Arcangeli Cc: Thierry Reding Cc: Mike Kravetz Cc: Geert Uytterhoeven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- tools/testing/selftests/vm/Makefile | 4 +- tools/testing/selftests/vm/mlock-intersect-test.c | 76 ------ tools/testing/selftests/vm/mlock-random-test.c | 293 ++++++++++++++++++++++ 3 files changed, 295 insertions(+), 78 deletions(-) delete mode 100644 tools/testing/selftests/vm/mlock-intersect-test.c create mode 100644 tools/testing/selftests/vm/mlock-random-test.c (limited to 'tools/testing') diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index a0412a80b679..bbab7f4664ac 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -10,7 +10,7 @@ BINARIES += on-fault-limit BINARIES += thuge-gen BINARIES += transhuge-stress BINARIES += userfaultfd -BINARIES += mlock-intersect-test +BINARIES += mlock-random-test all: $(BINARIES) %: %.c @@ -18,7 +18,7 @@ all: $(BINARIES) userfaultfd: userfaultfd.c ../../../../usr/include/linux/kernel.h $(CC) $(CFLAGS) -O2 -o $@ $< -lpthread -mlock-intersect-test: mlock-intersect-test.c +mlock-random-test: mlock-random-test.c $(CC) $(CFLAGS) -o $@ $< -lcap ../../../../usr/include/linux/kernel.h: diff --git a/tools/testing/selftests/vm/mlock-intersect-test.c b/tools/testing/selftests/vm/mlock-intersect-test.c deleted file mode 100644 index f78e68a0967c..000000000000 --- a/tools/testing/selftests/vm/mlock-intersect-test.c +++ /dev/null @@ -1,76 +0,0 @@ -/* - * It tests the duplicate mlock result: - * - the ulimit of lock page is 64k - * - allocate address area 64k starting from p - * - mlock [p -- p + 30k] - * - Then mlock address [ p -- p + 40k ] - * - * It should succeed since totally we locked - * 40k < 64k limitation. - * - * It should not be run with CAP_IPC_LOCK. - */ -#include -#include -#include -#include -#include -#include -#include "mlock2.h" - -int main(int argc, char **argv) -{ - struct rlimit new; - char *p = NULL; - cap_t cap = cap_init(); - int i; - - /* drop capabilities including CAP_IPC_LOCK */ - if (cap_set_proc(cap)) - return -1; - - /* set mlock limits to 64k */ - new.rlim_cur = 65536; - new.rlim_max = 65536; - setrlimit(RLIMIT_MEMLOCK, &new); - - /* test VM_LOCK */ - p = malloc(1024 * 64); - if (mlock(p, 1024 * 30)) { - printf("mlock() 30k return failure.\n"); - return -1; - } - for (i = 0; i < 10; i++) { - if (mlock(p, 1024 * 40)) { - printf("mlock() #%d 40k returns failure.\n", i); - return -1; - } - } - for (i = 0; i < 10; i++) { - if (mlock2_(p, 1024 * 40, MLOCK_ONFAULT)) { - printf("mlock2_() #%d 40k returns failure.\n", i); - return -1; - } - } - free(p); - - /* Test VM_LOCKONFAULT */ - p = malloc(1024 * 64); - if (mlock2_(p, 1024 * 30, MLOCK_ONFAULT)) { - printf("mlock2_() 30k return failure.\n"); - return -1; - } - for (i = 0; i < 10; i++) { - if (mlock2_(p, 1024 * 40, MLOCK_ONFAULT)) { - printf("mlock2_() #%d 40k returns failure.\n", i); - return -1; - } - } - for (i = 0; i < 10; i++) { - if (mlock(p, 1024 * 40)) { - printf("mlock() #%d 40k returns failure.\n", i); - return -1; - } - } - return 0; -} diff --git a/tools/testing/selftests/vm/mlock-random-test.c b/tools/testing/selftests/vm/mlock-random-test.c new file mode 100644 index 000000000000..83de4f58d262 --- /dev/null +++ b/tools/testing/selftests/vm/mlock-random-test.c @@ -0,0 +1,293 @@ +/* + * It tests the mlock/mlock2() when they are invoked + * on randomly memory region. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "mlock2.h" + +#define CHUNK_UNIT (128 * 1024) +#define MLOCK_RLIMIT_SIZE (CHUNK_UNIT * 2) +#define MLOCK_WITHIN_LIMIT_SIZE CHUNK_UNIT +#define MLOCK_OUTOF_LIMIT_SIZE (CHUNK_UNIT * 3) + +#define TEST_LOOP 100 +#define PAGE_ALIGN(size, ps) (((size) + ((ps) - 1)) & ~((ps) - 1)) + +int set_cap_limits(rlim_t max) +{ + struct rlimit new; + cap_t cap = cap_init(); + + new.rlim_cur = max; + new.rlim_max = max; + if (setrlimit(RLIMIT_MEMLOCK, &new)) { + perror("setrlimit() returns error\n"); + return -1; + } + + /* drop capabilities including CAP_IPC_LOCK */ + if (cap_set_proc(cap)) { + perror("cap_set_proc() returns error\n"); + return -2; + } + + return 0; +} + +int get_proc_locked_vm_size(void) +{ + FILE *f; + int ret = -1; + char line[1024] = {0}; + unsigned long lock_size = 0; + + f = fopen("/proc/self/status", "r"); + if (!f) { + perror("fopen"); + return -1; + } + + while (fgets(line, 1024, f)) { + if (strstr(line, "VmLck")) { + ret = sscanf(line, "VmLck:\t%8lu kB", &lock_size); + if (ret <= 0) { + printf("sscanf() on VmLck error: %s: %d\n", + line, ret); + fclose(f); + return -1; + } + fclose(f); + return (int)(lock_size << 10); + } + } + + perror("cann't parse VmLck in /proc/self/status\n"); + fclose(f); + return -1; +} + +/* + * Get the MMUPageSize of the memory region including input + * address from proc file. + * + * return value: on error case, 0 will be returned. + * Otherwise the page size(in bytes) is returned. + */ +int get_proc_page_size(unsigned long addr) +{ + FILE *smaps; + char *line; + unsigned long mmupage_size = 0; + size_t size; + + smaps = seek_to_smaps_entry(addr); + if (!smaps) { + printf("Unable to parse /proc/self/smaps\n"); + return 0; + } + + while (getline(&line, &size, smaps) > 0) { + if (!strstr(line, "MMUPageSize")) { + free(line); + line = NULL; + size = 0; + continue; + } + + /* found the MMUPageSize of this section */ + if (sscanf(line, "MMUPageSize: %8lu kB", + &mmupage_size) < 1) { + printf("Unable to parse smaps entry for Size:%s\n", + line); + break; + } + + } + free(line); + if (smaps) + fclose(smaps); + return mmupage_size << 10; +} + +/* + * Test mlock/mlock2() on provided memory chunk. + * It expects the mlock/mlock2() to be successful (within rlimit) + * + * With allocated memory chunk [p, p + alloc_size), this + * test will choose start/len randomly to perform mlock/mlock2 + * [start, start + len] memory range. The range is within range + * of the allocated chunk. + * + * The memory region size alloc_size is within the rlimit. + * So we always expect a success of mlock/mlock2. + * + * VmLck is assumed to be 0 before this test. + * + * return value: 0 - success + * else: failure + */ +int test_mlock_within_limit(char *p, int alloc_size) +{ + int i; + int ret = 0; + int locked_vm_size = 0; + struct rlimit cur; + int page_size = 0; + + getrlimit(RLIMIT_MEMLOCK, &cur); + if (cur.rlim_cur < alloc_size) { + printf("alloc_size[%d] < %u rlimit,lead to mlock failure\n", + alloc_size, (unsigned int)cur.rlim_cur); + return -1; + } + + srand(time(NULL)); + for (i = 0; i < TEST_LOOP; i++) { + /* + * - choose mlock/mlock2 randomly + * - choose lock_size randomly but lock_size < alloc_size + * - choose start_offset randomly but p+start_offset+lock_size + * < p+alloc_size + */ + int is_mlock = !!(rand() % 2); + int lock_size = rand() % alloc_size; + int start_offset = rand() % (alloc_size - lock_size); + + if (is_mlock) + ret = mlock(p + start_offset, lock_size); + else + ret = mlock2_(p + start_offset, lock_size, + MLOCK_ONFAULT); + + if (ret) { + printf("%s() failure at |%p(%d)| mlock:|%p(%d)|\n", + is_mlock ? "mlock" : "mlock2", + p, alloc_size, + p + start_offset, lock_size); + return ret; + } + } + + /* + * Check VmLck left by the tests. + */ + locked_vm_size = get_proc_locked_vm_size(); + page_size = get_proc_page_size((unsigned long)p); + if (page_size == 0) { + printf("cannot get proc MMUPageSize\n"); + return -1; + } + + if (locked_vm_size > PAGE_ALIGN(alloc_size, page_size) + page_size) { + printf("test_mlock_within_limit() left VmLck:%d on %d chunk\n", + locked_vm_size, alloc_size); + return -1; + } + + return 0; +} + + +/* + * We expect the mlock/mlock2() to be fail (outof limitation) + * + * With allocated memory chunk [p, p + alloc_size), this + * test will randomly choose start/len and perform mlock/mlock2 + * on [start, start+len] range. + * + * The memory region size alloc_size is above the rlimit. + * And the len to be locked is higher than rlimit. + * So we always expect a failure of mlock/mlock2. + * No locked page number should be increased as a side effect. + * + * return value: 0 - success + * else: failure + */ +int test_mlock_outof_limit(char *p, int alloc_size) +{ + int i; + int ret = 0; + int locked_vm_size = 0, old_locked_vm_size = 0; + struct rlimit cur; + + getrlimit(RLIMIT_MEMLOCK, &cur); + if (cur.rlim_cur >= alloc_size) { + printf("alloc_size[%d] >%u rlimit, violates test condition\n", + alloc_size, (unsigned int)cur.rlim_cur); + return -1; + } + + old_locked_vm_size = get_proc_locked_vm_size(); + srand(time(NULL)); + for (i = 0; i < TEST_LOOP; i++) { + int is_mlock = !!(rand() % 2); + int lock_size = (rand() % (alloc_size - cur.rlim_cur)) + + cur.rlim_cur; + int start_offset = rand() % (alloc_size - lock_size); + + if (is_mlock) + ret = mlock(p + start_offset, lock_size); + else + ret = mlock2_(p + start_offset, lock_size, + MLOCK_ONFAULT); + if (ret == 0) { + printf("%s() succeeds? on %p(%d) mlock%p(%d)\n", + is_mlock ? "mlock" : "mlock2", + p, alloc_size, + p + start_offset, lock_size); + return -1; + } + } + + locked_vm_size = get_proc_locked_vm_size(); + if (locked_vm_size != old_locked_vm_size) { + printf("tests leads to new mlocked page: old[%d], new[%d]\n", + old_locked_vm_size, + locked_vm_size); + return -1; + } + + return 0; +} + +int main(int argc, char **argv) +{ + char *p = NULL; + int ret = 0; + + if (set_cap_limits(MLOCK_RLIMIT_SIZE)) + return -1; + + p = malloc(MLOCK_WITHIN_LIMIT_SIZE); + if (p == NULL) { + perror("malloc() failure\n"); + return -1; + } + ret = test_mlock_within_limit(p, MLOCK_WITHIN_LIMIT_SIZE); + if (ret) + return ret; + munlock(p, MLOCK_WITHIN_LIMIT_SIZE); + free(p); + + + p = malloc(MLOCK_OUTOF_LIMIT_SIZE); + if (p == NULL) { + perror("malloc() failure\n"); + return -1; + } + ret = test_mlock_outof_limit(p, MLOCK_OUTOF_LIMIT_SIZE); + if (ret) + return ret; + munlock(p, MLOCK_OUTOF_LIMIT_SIZE); + free(p); + + return 0; +} -- cgit v1.2.3