Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2018-05-17

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Provide a new BPF helper for doing a FIB and neighbor lookup
   in the kernel tables from an XDP or tc BPF program. The helper
   provides a fast-path for forwarding packets. The API supports
   IPv4, IPv6 and MPLS protocols, but currently IPv4 and IPv6 are
   implemented in this initial work, from David (Ahern).

2) Just a tiny diff but huge feature enabled for nfp driver by
   extending the BPF offload beyond a pure host processing offload.
   Offloaded XDP programs are allowed to set the RX queue index and
   thus opening the door for defining a fully programmable RSS/n-tuple
   filter replacement. Once BPF decided on a queue already, the device
   data-path will skip the conventional RSS processing completely,
   from Jakub.

3) The original sockmap implementation was array based similar to
   devmap. However unlike devmap where an ifindex has a 1:1 mapping
   into the map there are use cases with sockets that need to be
   referenced using longer keys. Hence, sockhash map is added reusing
   as much of the sockmap code as possible, from John.

4) Introduce BTF ID. The ID is allocatd through an IDR similar as
   with BPF maps and progs. It also makes BTF accessible to user
   space via BPF_BTF_GET_FD_BY_ID and adds exposure of the BTF data
   through BPF_OBJ_GET_INFO_BY_FD, from Martin.

5) Enable BPF stackmap with build_id also in NMI context. Due to the
   up_read() of current->mm->mmap_sem build_id cannot be parsed.
   This work defers the up_read() via a per-cpu irq_work so that
   at least limited support can be enabled, from Song.

6) Various BPF JIT follow-up cleanups and fixups after the LD_ABS/LD_IND
   JIT conversion as well as implementation of an optimized 32/64 bit
   immediate load in the arm64 JIT that allows to reduce the number of
   emitted instructions; in case of tested real-world programs they
   were shrinking by three percent, from Daniel.

7) Add ifindex parameter to the libbpf loader in order to enable
   BPF offload support. Right now only iproute2 can load offloaded
   BPF and this will also enable libbpf for direct integration into
   other applications, from David (Beckett).

8) Convert the plain text documentation under Documentation/bpf/ into
   RST format since this is the appropriate standard the kernel is
   moving to for all documentation. Also add an overview README.rst,
   from Jesper.

9) Add __printf verification attribute to the bpf_verifier_vlog()
   helper. Though it uses va_list we can still allow gcc to check
   the format string, from Mathieu.

10) Fix a bash reference in the BPF selftest's Makefile. The '|& ...'
    is a bash 4.0+ feature which is not guaranteed to be available
    when calling out to shell, therefore use a more portable variant,
    from Joe.

11) Fix a 64 bit division in xdp_umem_reg() by using div_u64()
    instead of relying on the gcc built-in, from Björn.

12) Fix a sock hashmap kmalloc warning reported by syzbot when an
    overly large key size is used in hashmap then causing overflows
    in htab->elem_size. Reject bogus attr->key_size early in the
    sock_hash_alloc(), from Yonghong.

13) Ensure in BPF selftests when urandom_read is being linked that
    --build-id is always enabled so that test_stacktrace_build_id[_nmi]
    won't be failing, from Alexei.

14) Add bitsperlong.h as well as errno.h uapi headers into the tools
    header infrastructure which point to one of the arch specific
    uapi headers. This was needed in order to fix a build error on
    some systems for the BPF selftests, from Sirio.

15) Allow for short options to be used in the xdp_monitor BPF sample
    code. And also a bpf.h tools uapi header sync in order to fix a
    selftest build failure. Both from Prashant.

16) More formally clarify the meaning of ID in the direct packet access
    section of the BPF documentation, from Wang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 137 insertions, 3 deletions

diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index ed197eef1cfc..3ecf733330c1 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -1272,6 +1272,139 @@ out:
 	return;
 }
 
+static void test_stacktrace_build_id_nmi(void)
+{
+	int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
+	const char *file = "./test_stacktrace_build_id.o";
+	int err, pmu_fd, prog_fd;
+	struct perf_event_attr attr = {
+		.sample_freq = 5000,
+		.freq = 1,
+		.type = PERF_TYPE_HARDWARE,
+		.config = PERF_COUNT_HW_CPU_CYCLES,
+	};
+	__u32 key, previous_key, val, duration = 0;
+	struct bpf_object *obj;
+	char buf[256];
+	int i, j;
+	struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
+	int build_id_matches = 0;
+
+	err = bpf_prog_load(file, BPF_PROG_TYPE_PERF_EVENT, &obj, &prog_fd);
+	if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
+		return;
+
+	pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
+			 0 /* cpu 0 */, -1 /* group id */,
+			 0 /* flags */);
+	if (CHECK(pmu_fd < 0, "perf_event_open",
+		  "err %d errno %d. Does the test host support PERF_COUNT_HW_CPU_CYCLES?\n",
+		  pmu_fd, errno))
+		goto close_prog;
+
+	err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
+	if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n",
+		  err, errno))
+		goto close_pmu;
+
+	err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
+	if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n",
+		  err, errno))
+		goto disable_pmu;
+
+	/* find map fds */
+	control_map_fd = bpf_find_map(__func__, obj, "control_map");
+	if (CHECK(control_map_fd < 0, "bpf_find_map control_map",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	stackid_hmap_fd = bpf_find_map(__func__, obj, "stackid_hmap");
+	if (CHECK(stackid_hmap_fd < 0, "bpf_find_map stackid_hmap",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	stackmap_fd = bpf_find_map(__func__, obj, "stackmap");
+	if (CHECK(stackmap_fd < 0, "bpf_find_map stackmap", "err %d errno %d\n",
+		  err, errno))
+		goto disable_pmu;
+
+	stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap");
+	if (CHECK(stack_amap_fd < 0, "bpf_find_map stack_amap",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	assert(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null")
+	       == 0);
+	assert(system("taskset 0x1 ./urandom_read 100000") == 0);
+	/* disable stack trace collection */
+	key = 0;
+	val = 1;
+	bpf_map_update_elem(control_map_fd, &key, &val, 0);
+
+	/* for every element in stackid_hmap, we can find a corresponding one
+	 * in stackmap, and vise versa.
+	 */
+	err = compare_map_keys(stackid_hmap_fd, stackmap_fd);
+	if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	err = compare_map_keys(stackmap_fd, stackid_hmap_fd);
+	if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	err = extract_build_id(buf, 256);
+
+	if (CHECK(err, "get build_id with readelf",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
+	err = bpf_map_get_next_key(stackmap_fd, NULL, &key);
+	if (CHECK(err, "get_next_key from stackmap",
+		  "err %d, errno %d\n", err, errno))
+		goto disable_pmu;
+
+	do {
+		char build_id[64];
+
+		err = bpf_map_lookup_elem(stackmap_fd, &key, id_offs);
+		if (CHECK(err, "lookup_elem from stackmap",
+			  "err %d, errno %d\n", err, errno))
+			goto disable_pmu;
+		for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i)
+			if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID &&
+			    id_offs[i].offset != 0) {
+				for (j = 0; j < 20; ++j)
+					sprintf(build_id + 2 * j, "%02x",
+						id_offs[i].build_id[j] & 0xff);
+				if (strstr(buf, build_id) != NULL)
+					build_id_matches = 1;
+			}
+		previous_key = key;
+	} while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0);
+
+	if (CHECK(build_id_matches < 1, "build id match",
+		  "Didn't find expected build ID from the map\n"))
+		goto disable_pmu;
+
+	/*
+	 * We intentionally skip compare_stack_ips(). This is because we
+	 * only support one in_nmi() ips-to-build_id translation per cpu
+	 * at any time, thus stack_amap here will always fallback to
+	 * BPF_STACK_BUILD_ID_IP;
+	 */
+
+disable_pmu:
+	ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
+
+close_pmu:
+	close(pmu_fd);
+
+close_prog:
+	bpf_object__close(obj);
+}
+
 #define MAX_CNT_RAWTP	10ull
 #define MAX_STACK_RAWTP	100
 struct get_stack_trace_t {
@@ -1337,12 +1470,12 @@ static int get_stack_print_output(void *data, int size)
 			good_user_stack = true;
 	}
 	if (!good_kern_stack || !good_user_stack)
-		return PERF_EVENT_ERROR;
+		return LIBBPF_PERF_EVENT_ERROR;
 
 	if (cnt == MAX_CNT_RAWTP)
-		return PERF_EVENT_DONE;
+		return LIBBPF_PERF_EVENT_DONE;
 
-	return PERF_EVENT_CONT;
+	return LIBBPF_PERF_EVENT_CONT;
 }
 
 static void test_get_stack_raw_tp(void)
@@ -1425,6 +1558,7 @@ int main(void)
 	test_tp_attach_query();
 	test_stacktrace_map();
 	test_stacktrace_build_id();
+	test_stacktrace_build_id_nmi();
 	test_stacktrace_map_raw_tp();
 	test_get_stack_raw_tp();