From 1f2436229bf64ac040f2f5018df059c21fc5526a Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Sun, 7 Jun 2020 17:36:15 -0700 Subject: selftests/bpf: Fix ringbuf selftest sample counting undeterminism Fix test race, in which background poll can get either 5 or 6 samples, depending on timing of notification. Prevent this by open-coding sample triggering and forcing notification for the very last sample only. Also switch to using atomic increments and exchanges for more obviously reliable counting and checking. Additionally, check expected processed sample counters for single-threaded use cases as well. Fixes: 9a5f25ad30e5 ("selftests/bpf: Fix sample_cnt shared between two threads") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200608003615.3549991-1-andriin@fb.com --- tools/testing/selftests/bpf/prog_tests/ringbuf.c | 42 ++++++++++++++++++++---- 1 file changed, 35 insertions(+), 7 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf.c b/tools/testing/selftests/bpf/prog_tests/ringbuf.c index 2bba908dfa63..c1650548433c 100644 --- a/tools/testing/selftests/bpf/prog_tests/ringbuf.c +++ b/tools/testing/selftests/bpf/prog_tests/ringbuf.c @@ -25,13 +25,23 @@ struct sample { char comm[16]; }; -static volatile int sample_cnt; +static int sample_cnt; + +static void atomic_inc(int *cnt) +{ + __atomic_add_fetch(cnt, 1, __ATOMIC_SEQ_CST); +} + +static int atomic_xchg(int *cnt, int val) +{ + return __atomic_exchange_n(cnt, val, __ATOMIC_SEQ_CST); +} static int process_sample(void *ctx, void *data, size_t len) { struct sample *s = data; - sample_cnt++; + atomic_inc(&sample_cnt); switch (s->seq) { case 0: @@ -76,7 +86,7 @@ void test_ringbuf(void) const size_t rec_sz = BPF_RINGBUF_HDR_SZ + sizeof(struct sample); pthread_t thread; long bg_ret = -1; - int err; + int err, cnt; skel = test_ringbuf__open_and_load(); if (CHECK(!skel, "skel_open_load", "skeleton open&load failed\n")) @@ -116,11 +126,15 @@ void test_ringbuf(void) /* -EDONE is used as an indicator that we are done */ if (CHECK(err != -EDONE, "err_done", "done err: %d\n", err)) goto cleanup; + cnt = atomic_xchg(&sample_cnt, 0); + CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt); /* we expect extra polling to return nothing */ err = ring_buffer__poll(ringbuf, 0); if (CHECK(err != 0, "extra_samples", "poll result: %d\n", err)) goto cleanup; + cnt = atomic_xchg(&sample_cnt, 0); + CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt); CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n", 0L, skel->bss->dropped); @@ -136,6 +150,8 @@ void test_ringbuf(void) 3L * rec_sz, skel->bss->cons_pos); err = ring_buffer__poll(ringbuf, -1); CHECK(err <= 0, "poll_err", "err %d\n", err); + cnt = atomic_xchg(&sample_cnt, 0); + CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt); /* start poll in background w/ long timeout */ err = pthread_create(&thread, NULL, poll_thread, (void *)(long)10000); @@ -164,6 +180,8 @@ void test_ringbuf(void) 2L, skel->bss->total); CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n", 1L, skel->bss->discarded); + cnt = atomic_xchg(&sample_cnt, 0); + CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt); /* clear flags to return to "adaptive" notification mode */ skel->bss->flags = 0; @@ -178,10 +196,20 @@ void test_ringbuf(void) if (CHECK(err != EBUSY, "try_join", "err %d\n", err)) goto cleanup; + /* still no samples, because consumer is behind */ + cnt = atomic_xchg(&sample_cnt, 0); + CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt); + + skel->bss->dropped = 0; + skel->bss->total = 0; + skel->bss->discarded = 0; + + skel->bss->value = 333; + syscall(__NR_getpgid); /* now force notifications */ skel->bss->flags = BPF_RB_FORCE_WAKEUP; - sample_cnt = 0; - trigger_samples(); + skel->bss->value = 777; + syscall(__NR_getpgid); /* now we should get a pending notification */ usleep(50000); @@ -193,8 +221,8 @@ void test_ringbuf(void) goto cleanup; /* 3 rounds, 2 samples each */ - CHECK(sample_cnt != 6, "wrong_sample_cnt", - "expected to see %d samples, got %d\n", 6, sample_cnt); + cnt = atomic_xchg(&sample_cnt, 0); + CHECK(cnt != 6, "cnt", "exp %d samples, got %d\n", 6, cnt); /* BPF side did everything right */ CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n", -- cgit v1.2.3 From 248e00ac47d64e153b9c50f45aad73cd61894a73 Mon Sep 17 00:00:00 2001 From: Lorenz Bauer Date: Mon, 8 Jun 2020 17:22:01 +0100 Subject: bpf: cgroup: Allow multi-attach program to replace itself When using BPF_PROG_ATTACH to attach a program to a cgroup in BPF_F_ALLOW_MULTI mode, it is not possible to replace a program with itself. This is because the check for duplicate programs doesn't take the replacement program into account. Replacing a program with itself might seem weird, but it has some uses: first, it allows resetting the associated cgroup storage. Second, it makes the API consistent with the non-ALLOW_MULTI usage, where it is possible to replace a program with itself. Third, it aligns BPF_PROG_ATTACH with bpf_link, where replacing itself is also supported. Sice this code has been refactored a few times this change will only apply to v5.7 and later. Adjustments could be made to commit 1020c1f24a94 ("bpf: Simplify __cgroup_bpf_attach") and commit d7bf2c10af05 ("bpf: allocate cgroup storage entries on attaching bpf programs") as well as commit 324bda9e6c5a ("bpf: multi program support for cgroup+bpf") Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program attachment") Signed-off-by: Lorenz Bauer Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200608162202.94002-1-lmb@cloudflare.com --- kernel/bpf/cgroup.c | 2 +- tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c | 7 +++++++ 2 files changed, 8 insertions(+), 1 deletion(-) (limited to 'tools') diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index fdf7836750a3..4d76f16524cc 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -378,7 +378,7 @@ static struct bpf_prog_list *find_attach_entry(struct list_head *progs, } list_for_each_entry(pl, progs, node) { - if (prog && pl->prog == prog) + if (prog && pl->prog == prog && prog != replace_prog) /* disallow attaching the same prog twice */ return ERR_PTR(-EINVAL); if (link && pl->link == link) diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c b/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c index 139f8e82c7c6..b549fcfacc0b 100644 --- a/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c @@ -230,6 +230,13 @@ void test_cgroup_attach_multi(void) "prog_replace", "errno=%d\n", errno)) goto err; + /* replace program with itself */ + attach_opts.replace_prog_fd = allow_prog[6]; + if (CHECK(bpf_prog_attach_xattr(allow_prog[6], cg1, + BPF_CGROUP_INET_EGRESS, &attach_opts), + "prog_replace", "errno=%d\n", errno)) + goto err; + value = 0; CHECK_FAIL(bpf_map_update_elem(map_fd, &key, &value, 0)); CHECK_FAIL(system(PING_CMD)); -- cgit v1.2.3 From 042b1545fe47788e734b0f074a8ae65856015cdf Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 9 Jun 2020 15:31:52 +0200 Subject: bpf: Selftests and tools use struct bpf_devmap_val from uapi Sync tools uapi bpf.h header file and update selftests that use struct bpf_devmap_val. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/159170951195.2102545.1833108712124273987.stgit@firesoul --- tools/include/uapi/linux/bpf.h | 13 +++++++++++++ tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c | 8 -------- tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c | 2 +- .../selftests/bpf/progs/test_xdp_with_devmap_helpers.c | 3 +-- 4 files changed, 15 insertions(+), 11 deletions(-) (limited to 'tools') diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index c65b374a5090..19684813faae 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3761,6 +3761,19 @@ struct xdp_md { __u32 egress_ifindex; /* txq->dev->ifindex */ }; +/* DEVMAP map-value layout + * + * The struct data-layout of map-value is a configuration interface. + * New members can only be added to the end of this structure. + */ +struct bpf_devmap_val { + __u32 ifindex; /* device index */ + union { + int fd; /* prog fd on map write */ + __u32 id; /* prog id on map read */ + } bpf_prog; +}; + enum sk_action { SK_DROP = 0, SK_PASS, diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c index d19dbd668f6a..88ef3ec8ac4c 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c @@ -8,14 +8,6 @@ #define IFINDEX_LO 1 -struct bpf_devmap_val { - u32 ifindex; /* device index */ - union { - int fd; /* prog fd on map write */ - u32 id; /* prog id on map read */ - } bpf_prog; -}; - void test_xdp_with_devmap_helpers(void) { struct test_xdp_with_devmap_helpers *skel; diff --git a/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c index e5c0f131c8a7..b360ba2bd441 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c @@ -2,7 +2,7 @@ /* fails to load without expected_attach_type = BPF_XDP_DEVMAP * because of access to egress_ifindex */ -#include "vmlinux.h" +#include #include SEC("xdp_dm_log") diff --git a/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c index deef0e050863..330811260123 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c @@ -1,6 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 - -#include "vmlinux.h" +#include #include struct { -- cgit v1.2.3 From 8ca8d4a841730c02e77bf3c87bf658cc44f364b9 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Tue, 9 Jun 2020 18:16:53 -0300 Subject: libbpf: Define __WORDSIZE if not available Some systems, such as Android, don't have a define for __WORDSIZE, do it in terms of __SIZEOF_LONG__, as done in perf since 2012: http://git.kernel.org/torvalds/c/3f34f6c0233ae055b5 For reference: https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html I build tested it here and Andrii did some Travis CI build tests too. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200608161150.GA3073@kernel.org --- tools/lib/bpf/hashmap.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/hashmap.h b/tools/lib/bpf/hashmap.h index e823b35e7371..df59fd4fc95b 100644 --- a/tools/lib/bpf/hashmap.h +++ b/tools/lib/bpf/hashmap.h @@ -10,10 +10,9 @@ #include #include -#ifdef __GLIBC__ -#include -#else -#include +#include +#ifndef __WORDSIZE +#define __WORDSIZE (__SIZEOF_LONG__ * 8) #endif static inline size_t hash_bits(size_t h, int bits) -- cgit v1.2.3 From 32022fd97ed34f6812802bf1288db27c313576f4 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Tue, 9 Jun 2020 22:23:35 -0700 Subject: libbpf: Handle GCC noreturn-turned-volatile quirk Handle a GCC quirk of emitting extra volatile modifier in DWARF (and subsequently preserved in BTF by pahole) for function pointers marked as __attribute__((noreturn)). This was the way to mark such functions before GCC 2.5 added noreturn attribute. Drop such func_proto modifiers, similarly to how it's done for array (also to handle GCC quirk/bug). Such volatile attribute is emitted by GCC only, so existing selftests can't express such test. Simple repro is like this (compiled with GCC + BTF generated by pahole): struct my_struct { void __attribute__((noreturn)) (*fn)(int); }; struct my_struct a; Without this fix, output will be: struct my_struct { voidvolatile (*fn)(int); }; With the fix: struct my_struct { void (*fn)(int); }; Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") Reported-by: Jean-Philippe Brucker Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Tested-by: Jean-Philippe Brucker Link: https://lore.kernel.org/bpf/20200610052335.2862559-1-andriin@fb.com --- tools/lib/bpf/btf_dump.c | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index de07e559a11d..bbb430317260 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -1137,6 +1137,20 @@ static void btf_dump_emit_mods(struct btf_dump *d, struct id_stack *decl_stack) } } +static void btf_dump_drop_mods(struct btf_dump *d, struct id_stack *decl_stack) +{ + const struct btf_type *t; + __u32 id; + + while (decl_stack->cnt) { + id = decl_stack->ids[decl_stack->cnt - 1]; + t = btf__type_by_id(d->btf, id); + if (!btf_is_mod(t)) + return; + decl_stack->cnt--; + } +} + static void btf_dump_emit_name(const struct btf_dump *d, const char *name, bool last_was_ptr) { @@ -1235,14 +1249,7 @@ static void btf_dump_emit_type_chain(struct btf_dump *d, * a const/volatile modifier for array, so we are * going to silently skip them here. */ - while (decls->cnt) { - next_id = decls->ids[decls->cnt - 1]; - next_t = btf__type_by_id(d->btf, next_id); - if (btf_is_mod(next_t)) - decls->cnt--; - else - break; - } + btf_dump_drop_mods(d, decls); if (decls->cnt == 0) { btf_dump_emit_name(d, fname, last_was_ptr); @@ -1270,7 +1277,15 @@ static void btf_dump_emit_type_chain(struct btf_dump *d, __u16 vlen = btf_vlen(t); int i; - btf_dump_emit_mods(d, decls); + /* + * GCC emits extra volatile qualifier for + * __attribute__((noreturn)) function pointers. Clang + * doesn't do it. It's a GCC quirk for backwards + * compatibility with code written for GCC <2.5. So, + * similarly to extra qualifiers for array, just drop + * them, instead of handling them. + */ + btf_dump_drop_mods(d, decls); if (decls->cnt) { btf_dump_printf(d, " ("); btf_dump_emit_type_chain(d, decls, fname, lvl); -- cgit v1.2.3 From 47f6bc4ce1ff70d7ba0924c2f1c218c96cd585fb Mon Sep 17 00:00:00 2001 From: Brett Mastbergen Date: Tue, 9 Jun 2020 17:35:06 -0400 Subject: tools, bpf: Do not force gcc as CC This allows transparent cross-compilation with CROSS_COMPILE by relying on 7ed1c1901fe5 ("tools: fix cross-compile var clobbering"). Same change was applied to tools/bpf/bpftool/Makefile in 9e88b9312acb ("tools: bpftool: do not force gcc as CC"). Signed-off-by: Brett Mastbergen Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200609213506.3299-1-brett.mastbergen@gmail.com --- tools/bpf/Makefile | 1 - 1 file changed, 1 deletion(-) (limited to 'tools') diff --git a/tools/bpf/Makefile b/tools/bpf/Makefile index 77472e28c8fd..6df1850f8353 100644 --- a/tools/bpf/Makefile +++ b/tools/bpf/Makefile @@ -3,7 +3,6 @@ include ../scripts/Makefile.include prefix ?= /usr/local -CC = gcc LEX = flex YACC = bison MAKE = make -- cgit v1.2.3 From bd6fecb9a99cceb949271c1821cfbad2b2db97c6 Mon Sep 17 00:00:00 2001 From: YiFei Zhu Date: Wed, 10 Jun 2020 13:41:40 -0500 Subject: selftests/bpf: Add cgroup_skb/egress test for load_bytes_relative When cgroup_skb/egress triggers the MAC header is not set. Added a test that asserts reading MAC header is a -EFAULT but NET header succeeds. The test result from within the eBPF program is stored in an 1-element array map that the userspace then reads and asserts on. Another assertion is added that reading from a large offset, past the end of packet, returns -EFAULT. Signed-off-by: YiFei Zhu Signed-off-by: Daniel Borkmann Reviewed-by: Stanislav Fomichev Link: https://lore.kernel.org/bpf/9028ccbea4385a620e69c0a104f469ffd655c01e.1591812755.git.zhuyifei@google.com --- .../selftests/bpf/prog_tests/load_bytes_relative.c | 71 ++++++++++++++++++++++ .../selftests/bpf/progs/load_bytes_relative.c | 48 +++++++++++++++ 2 files changed, 119 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/load_bytes_relative.c create mode 100644 tools/testing/selftests/bpf/progs/load_bytes_relative.c (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/load_bytes_relative.c b/tools/testing/selftests/bpf/prog_tests/load_bytes_relative.c new file mode 100644 index 000000000000..c1168e4a9036 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/load_bytes_relative.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0-only + +/* + * Copyright 2020 Google LLC. + */ + +#include +#include + +void test_load_bytes_relative(void) +{ + int server_fd, cgroup_fd, prog_fd, map_fd, client_fd; + int err; + struct bpf_object *obj; + struct bpf_program *prog; + struct bpf_map *test_result; + __u32 duration = 0; + + __u32 map_key = 0; + __u32 map_value = 0; + + cgroup_fd = test__join_cgroup("/load_bytes_relative"); + if (CHECK_FAIL(cgroup_fd < 0)) + return; + + server_fd = start_server(AF_INET, SOCK_STREAM); + if (CHECK_FAIL(server_fd < 0)) + goto close_cgroup_fd; + + err = bpf_prog_load("./load_bytes_relative.o", BPF_PROG_TYPE_CGROUP_SKB, + &obj, &prog_fd); + if (CHECK_FAIL(err)) + goto close_server_fd; + + test_result = bpf_object__find_map_by_name(obj, "test_result"); + if (CHECK_FAIL(!test_result)) + goto close_bpf_object; + + map_fd = bpf_map__fd(test_result); + if (map_fd < 0) + goto close_bpf_object; + + prog = bpf_object__find_program_by_name(obj, "load_bytes_relative"); + if (CHECK_FAIL(!prog)) + goto close_bpf_object; + + err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_INET_EGRESS, + BPF_F_ALLOW_MULTI); + if (CHECK_FAIL(err)) + goto close_bpf_object; + + client_fd = connect_to_fd(AF_INET, SOCK_STREAM, server_fd); + if (CHECK_FAIL(client_fd < 0)) + goto close_bpf_object; + close(client_fd); + + err = bpf_map_lookup_elem(map_fd, &map_key, &map_value); + if (CHECK_FAIL(err)) + goto close_bpf_object; + + CHECK(map_value != 1, "bpf", "bpf program returned failure"); + +close_bpf_object: + bpf_object__close(obj); + +close_server_fd: + close(server_fd); + +close_cgroup_fd: + close(cgroup_fd); +} diff --git a/tools/testing/selftests/bpf/progs/load_bytes_relative.c b/tools/testing/selftests/bpf/progs/load_bytes_relative.c new file mode 100644 index 000000000000..dc1d04a7a3d6 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/load_bytes_relative.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0-only + +/* + * Copyright 2020 Google LLC. + */ + +#include +#include +#include +#include +#include + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u32); +} test_result SEC(".maps"); + +SEC("cgroup_skb/egress") +int load_bytes_relative(struct __sk_buff *skb) +{ + struct ethhdr eth; + struct iphdr iph; + + __u32 map_key = 0; + __u32 test_passed = 0; + + /* MAC header is not set by the time cgroup_skb/egress triggers */ + if (bpf_skb_load_bytes_relative(skb, 0, ð, sizeof(eth), + BPF_HDR_START_MAC) != -EFAULT) + goto fail; + + if (bpf_skb_load_bytes_relative(skb, 0, &iph, sizeof(iph), + BPF_HDR_START_NET)) + goto fail; + + if (bpf_skb_load_bytes_relative(skb, 0xffff, &iph, sizeof(iph), + BPF_HDR_START_NET) != -EFAULT) + goto fail; + + test_passed = 1; + +fail: + bpf_map_update_elem(&test_result, &map_key, &test_passed, BPF_ANY); + + return 1; +} -- cgit v1.2.3 From d4060ac969563113101c79433f2ae005feca1c29 Mon Sep 17 00:00:00 2001 From: Tobias Klauser Date: Wed, 10 Jun 2020 15:08:04 +0200 Subject: tools, bpftool: Fix memory leak in codegen error cases Free the memory allocated for the template on error paths in function codegen. Signed-off-by: Tobias Klauser Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200610130804.21423-1-tklauser@distanz.ch --- tools/bpf/bpftool/gen.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'tools') diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index a3c4bb86c05a..ecbae47e66b8 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -224,6 +224,7 @@ static int codegen(const char *template, ...) } else { p_err("unrecognized character at pos %td in template '%s'", src - template - 1, template); + free(s); return -EINVAL; } } @@ -234,6 +235,7 @@ static int codegen(const char *template, ...) if (*src != '\t') { p_err("not enough tabs at pos %td in template '%s'", src - template - 1, template); + free(s); return -EINVAL; } } -- cgit v1.2.3 From 2c4779eff837f1035f6f9650d246905daadd9528 Mon Sep 17 00:00:00 2001 From: Tobias Klauser Date: Thu, 11 Jun 2020 12:33:41 +0200 Subject: tools, bpftool: Exit on error in function codegen Currently, the codegen function might fail and return an error. But its callers continue without checking its return value. Since codegen can fail only in the unlikely case of the system running out of memory or the static template being malformed, just exit(-1) directly from codegen and make it void-returning. Suggested-by: Andrii Nakryiko Signed-off-by: Tobias Klauser Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200611103341.21532-1-tklauser@distanz.ch --- tools/bpf/bpftool/gen.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'tools') diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index ecbae47e66b8..7443879e87af 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -200,7 +200,7 @@ out: return err; } -static int codegen(const char *template, ...) +static void codegen(const char *template, ...) { const char *src, *end; int skip_tabs = 0, n; @@ -211,7 +211,7 @@ static int codegen(const char *template, ...) n = strlen(template); s = malloc(n + 1); if (!s) - return -ENOMEM; + exit(-1); src = template; dst = s; @@ -225,7 +225,7 @@ static int codegen(const char *template, ...) p_err("unrecognized character at pos %td in template '%s'", src - template - 1, template); free(s); - return -EINVAL; + exit(-1); } } @@ -236,7 +236,7 @@ static int codegen(const char *template, ...) p_err("not enough tabs at pos %td in template '%s'", src - template - 1, template); free(s); - return -EINVAL; + exit(-1); } } /* trim trailing whitespace */ @@ -257,7 +257,8 @@ static int codegen(const char *template, ...) va_end(args); free(s); - return n; + if (n) + exit(-1); } static int do_skeleton(int argc, char **argv) -- cgit v1.2.3 From 22eb78792e07a4dfb63c85f34950d4e58eb90326 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 12 Jun 2020 13:16:03 -0700 Subject: tools/bpftool: Fix skeleton codegen Remove unnecessary check at the end of codegen() routine which makes codegen() to always fail and exit bpftool with error code. Positive value of variable n is not an indicator of a failure. Fixes: 2c4779eff837 ("tools, bpftool: Exit on error in function codegen") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Reviewed-by: Tobias Klauser Link: https://lore.kernel.org/bpf/20200612201603.680852-1-andriin@fb.com --- tools/bpf/bpftool/gen.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'tools') diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index 7443879e87af..10de76b296ba 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -257,8 +257,6 @@ static void codegen(const char *template, ...) va_end(args); free(s); - if (n) - exit(-1); } static int do_skeleton(int argc, char **argv) -- cgit v1.2.3 From caf62492f479585296e9d636c798d5ac256b7b04 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 12 Jun 2020 12:45:04 -0700 Subject: libbpf: Support pre-initializing .bss global variables Remove invalid assumption in libbpf that .bss map doesn't have to be updated in kernel. With addition of skeleton and memory-mapped initialization image, .bss doesn't have to be all zeroes when BPF map is created, because user-code might have initialized those variables from user-space. Fixes: eba9c5f498a1 ("libbpf: Refactor global data map initialization") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200612194504.557844-1-andriin@fb.com --- tools/lib/bpf/libbpf.c | 4 -- tools/testing/selftests/bpf/prog_tests/skeleton.c | 45 ++++++++++++++++++++--- tools/testing/selftests/bpf/progs/test_skeleton.c | 19 ++++++++-- 3 files changed, 55 insertions(+), 13 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 7f01be2b88b8..477c679ed945 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3564,10 +3564,6 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map) char *cp, errmsg[STRERR_BUFSIZE]; int err, zero = 0; - /* kernel already zero-initializes .bss map. */ - if (map_type == LIBBPF_MAP_BSS) - return 0; - err = bpf_map_update_elem(map->fd, &zero, map->mmaped, 0); if (err) { err = -errno; diff --git a/tools/testing/selftests/bpf/prog_tests/skeleton.c b/tools/testing/selftests/bpf/prog_tests/skeleton.c index 9264a2736018..fa153cf67b1b 100644 --- a/tools/testing/selftests/bpf/prog_tests/skeleton.c +++ b/tools/testing/selftests/bpf/prog_tests/skeleton.c @@ -15,6 +15,8 @@ void test_skeleton(void) int duration = 0, err; struct test_skeleton* skel; struct test_skeleton__bss *bss; + struct test_skeleton__data *data; + struct test_skeleton__rodata *rodata; struct test_skeleton__kconfig *kcfg; skel = test_skeleton__open(); @@ -24,13 +26,45 @@ void test_skeleton(void) if (CHECK(skel->kconfig, "skel_kconfig", "kconfig is mmaped()!\n")) goto cleanup; + bss = skel->bss; + data = skel->data; + rodata = skel->rodata; + + /* validate values are pre-initialized correctly */ + CHECK(data->in1 != -1, "in1", "got %d != exp %d\n", data->in1, -1); + CHECK(data->out1 != -1, "out1", "got %d != exp %d\n", data->out1, -1); + CHECK(data->in2 != -1, "in2", "got %lld != exp %lld\n", data->in2, -1LL); + CHECK(data->out2 != -1, "out2", "got %lld != exp %lld\n", data->out2, -1LL); + + CHECK(bss->in3 != 0, "in3", "got %d != exp %d\n", bss->in3, 0); + CHECK(bss->out3 != 0, "out3", "got %d != exp %d\n", bss->out3, 0); + CHECK(bss->in4 != 0, "in4", "got %lld != exp %lld\n", bss->in4, 0LL); + CHECK(bss->out4 != 0, "out4", "got %lld != exp %lld\n", bss->out4, 0LL); + + CHECK(rodata->in6 != 0, "in6", "got %d != exp %d\n", rodata->in6, 0); + CHECK(bss->out6 != 0, "out6", "got %d != exp %d\n", bss->out6, 0); + + /* validate we can pre-setup global variables, even in .bss */ + data->in1 = 10; + data->in2 = 11; + bss->in3 = 12; + bss->in4 = 13; + rodata->in6 = 14; + err = test_skeleton__load(skel); if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err)) goto cleanup; - bss = skel->bss; - bss->in1 = 1; - bss->in2 = 2; + /* validate pre-setup values are still there */ + CHECK(data->in1 != 10, "in1", "got %d != exp %d\n", data->in1, 10); + CHECK(data->in2 != 11, "in2", "got %lld != exp %lld\n", data->in2, 11LL); + CHECK(bss->in3 != 12, "in3", "got %d != exp %d\n", bss->in3, 12); + CHECK(bss->in4 != 13, "in4", "got %lld != exp %lld\n", bss->in4, 13LL); + CHECK(rodata->in6 != 14, "in6", "got %d != exp %d\n", rodata->in6, 14); + + /* now set new values and attach to get them into outX variables */ + data->in1 = 1; + data->in2 = 2; bss->in3 = 3; bss->in4 = 4; bss->in5.a = 5; @@ -44,14 +78,15 @@ void test_skeleton(void) /* trigger tracepoint */ usleep(1); - CHECK(bss->out1 != 1, "res1", "got %d != exp %d\n", bss->out1, 1); - CHECK(bss->out2 != 2, "res2", "got %lld != exp %d\n", bss->out2, 2); + CHECK(data->out1 != 1, "res1", "got %d != exp %d\n", data->out1, 1); + CHECK(data->out2 != 2, "res2", "got %lld != exp %d\n", data->out2, 2); CHECK(bss->out3 != 3, "res3", "got %d != exp %d\n", (int)bss->out3, 3); CHECK(bss->out4 != 4, "res4", "got %lld != exp %d\n", bss->out4, 4); CHECK(bss->handler_out5.a != 5, "res5", "got %d != exp %d\n", bss->handler_out5.a, 5); CHECK(bss->handler_out5.b != 6, "res6", "got %lld != exp %d\n", bss->handler_out5.b, 6); + CHECK(bss->out6 != 14, "res7", "got %d != exp %d\n", bss->out6, 14); CHECK(bss->bpf_syscall != kcfg->CONFIG_BPF_SYSCALL, "ext1", "got %d != exp %d\n", bss->bpf_syscall, kcfg->CONFIG_BPF_SYSCALL); diff --git a/tools/testing/selftests/bpf/progs/test_skeleton.c b/tools/testing/selftests/bpf/progs/test_skeleton.c index de03a90f78ca..77ae86f44db5 100644 --- a/tools/testing/selftests/bpf/progs/test_skeleton.c +++ b/tools/testing/selftests/bpf/progs/test_skeleton.c @@ -10,16 +10,26 @@ struct s { long long b; } __attribute__((packed)); -int in1 = 0; -long long in2 = 0; +/* .data section */ +int in1 = -1; +long long in2 = -1; + +/* .bss section */ char in3 = '\0'; long long in4 __attribute__((aligned(64))) = 0; struct s in5 = {}; -long long out2 = 0; +/* .rodata section */ +const volatile int in6 = 0; + +/* .data section */ +int out1 = -1; +long long out2 = -1; + +/* .bss section */ char out3 = 0; long long out4 = 0; -int out1 = 0; +int out6 = 0; extern bool CONFIG_BPF_SYSCALL __kconfig; extern int LINUX_KERNEL_VERSION __kconfig; @@ -36,6 +46,7 @@ int handler(const void *ctx) out3 = in3; out4 = in4; out5 = in5; + out6 = in6; bpf_syscall = CONFIG_BPF_SYSCALL; kern_ver = LINUX_KERNEL_VERSION; -- cgit v1.2.3