From e8f1f34a344d060eaf1918089369c4c1172a153b Mon Sep 17 00:00:00 2001 From: Zi Shen Lim Date: Sun, 19 Mar 2017 23:03:14 -0700 Subject: selftests/bpf: fix broken build, take 2 Merge of 'linux-kselftest-4.11-rc1': 1. Partially removed use of 'test_objs' target, breaking force rebuild of BPFOBJ, introduced in commit d498f8719a09 ("bpf: Rebuild bpf.o for any dependency update"). Update target so dependency on BPFOBJ is restored. 2. Introduced commit 2047f1d8ba28 ("selftests: Fix the .c linking rule") which fixes order of LDLIBS. Commit d02d8986a768 ("bpf: Always test unprivileged programs") added libcap dependency into CFLAGS. Use LDLIBS instead to fix linking of test_verifier. 3. Introduced commit d83c3ba0b926 ("selftests: Fix selftests build to just build, not run tests"). Reordering the Makefile allows us to remove the 'all' target. Tested both: selftests/bpf$ make and selftests$ make TARGETS=bpf on Ubuntu 16.04.2. Signed-off-by: Zi Shen Lim Acked-by: Daniel Borkmann Tested-by: Daniel Borkmann Acked-by: Alexei Starovoitov Tested-by: Alexei Starovoitov Acked-by: Shuah Khan Signed-off-by: David S. Miller --- tools/testing/selftests/bpf/Makefile | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 67531f4..6a1ad58 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -1,22 +1,23 @@ LIBDIR := ../../../lib -BPFOBJ := $(LIBDIR)/bpf/bpf.o +BPFDIR := $(LIBDIR)/bpf -CFLAGS += -Wall -O2 -lcap -I../../../include/uapi -I$(LIBDIR) $(BPFOBJ) +CFLAGS += -Wall -O2 -I../../../include/uapi -I$(LIBDIR) +LDLIBS += -lcap TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map TEST_PROGS := test_kmod.sh -all: $(TEST_GEN_PROGS) +include ../lib.mk + +BPFOBJ := $(OUTPUT)/bpf.o + +$(TEST_GEN_PROGS): $(BPFOBJ) -.PHONY: all clean force +.PHONY: force # force a rebuild of BPFOBJ when its dependencies are updated force: $(BPFOBJ): force - $(MAKE) -C $(dir $(BPFOBJ)) - -$(test_objs): $(BPFOBJ) - -include ../lib.mk + $(MAKE) -C $(BPFDIR) OUTPUT=$(OUTPUT)/ -- cgit v1.1 From 8c290e60fa2a51806159522331c9ed41252a8fb3 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Tue, 21 Mar 2017 19:05:04 -0700 Subject: bpf: fix hashmap extra_elems logic In both kmalloc and prealloc mode the bpf_map_update_elem() is using per-cpu extra_elems to do atomic update when the map is full. There are two issues with it. The logic can be misused, since it allows max_entries+num_cpus elements to be present in the map. And alloc_extra_elems() at map creation time can fail percpu alloc for large map values with a warn: WARNING: CPU: 3 PID: 2752 at ../mm/percpu.c:892 pcpu_alloc+0x119/0xa60 illegal size (32824) or align (8) for percpu allocation The fixes for both of these issues are different for kmalloc and prealloc modes. For prealloc mode allocate extra num_possible_cpus elements and store their pointers into extra_elems array instead of actual elements. Hence we can use these hidden(spare) elements not only when the map is full but during bpf_map_update_elem() that replaces existing element too. That also improves performance, since pcpu_freelist_pop/push is avoided. Unfortunately this approach cannot be used for kmalloc mode which needs to kfree elements after rcu grace period. Therefore switch it back to normal kmalloc even when full and old element exists like it was prior to commit 6c9059817432 ("bpf: pre-allocate hash map elements"). Add tests to check for over max_entries and large map values. Reported-by: Dave Jones Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements") Signed-off-by: Alexei Starovoitov Acked-by: Daniel Borkmann Acked-by: Martin KaFai Lau Signed-off-by: David S. Miller --- tools/testing/selftests/bpf/test_maps.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c index cada17a..a0aa200 100644 --- a/tools/testing/selftests/bpf/test_maps.c +++ b/tools/testing/selftests/bpf/test_maps.c @@ -80,8 +80,9 @@ static void test_hashmap(int task, void *data) assert(bpf_map_update_elem(fd, &key, &value, BPF_EXIST) == 0); key = 2; assert(bpf_map_update_elem(fd, &key, &value, BPF_ANY) == 0); - key = 1; - assert(bpf_map_update_elem(fd, &key, &value, BPF_ANY) == 0); + key = 3; + assert(bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST) == -1 && + errno == E2BIG); /* Check that key = 0 doesn't exist. */ key = 0; @@ -110,6 +111,24 @@ static void test_hashmap(int task, void *data) close(fd); } +static void test_hashmap_sizes(int task, void *data) +{ + int fd, i, j; + + for (i = 1; i <= 512; i <<= 1) + for (j = 1; j <= 1 << 18; j <<= 1) { + fd = bpf_create_map(BPF_MAP_TYPE_HASH, i, j, + 2, map_flags); + if (fd < 0) { + printf("Failed to create hashmap key=%d value=%d '%s'\n", + i, j, strerror(errno)); + exit(1); + } + close(fd); + usleep(10); /* give kernel time to destroy */ + } +} + static void test_hashmap_percpu(int task, void *data) { unsigned int nr_cpus = bpf_num_possible_cpus(); @@ -317,7 +336,10 @@ static void test_arraymap_percpu(int task, void *data) static void test_arraymap_percpu_many_keys(void) { unsigned int nr_cpus = bpf_num_possible_cpus(); - unsigned int nr_keys = 20000; + /* nr_keys is not too large otherwise the test stresses percpu + * allocator more than anything else + */ + unsigned int nr_keys = 2000; long values[nr_cpus]; int key, fd, i; @@ -419,6 +441,7 @@ static void test_map_stress(void) { run_parallel(100, test_hashmap, NULL); run_parallel(100, test_hashmap_percpu, NULL); + run_parallel(100, test_hashmap_sizes, NULL); run_parallel(100, test_arraymap, NULL); run_parallel(100, test_arraymap_percpu, NULL); -- cgit v1.1