- Linux-kselftest-mirror - lists.linaro.org

[PATCH] kunit: tool: fix display of make errors

by Daniel Latypov

CalledProcessError stores the output of the failed process as `bytes`, not a `str`. So when we log it on build error, the make output is all crammed into one line with "\n" instead of actually printing new lines. After this change, we get readable output with new lines, e.g. > CC lib/kunit/kunit-example-test.o > In file included from ../lib/kunit/test.c:9: > ../include/kunit/test.h:22:1: error: unknown type name ‘invalid_type_that_causes_compile’ > 22 | invalid_type_that_causes_compile errors; > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > make[3]: *** [../scripts/Makefile.build:283: lib/kunit/test.o] Error 1 Secondly, trying to concat exceptions to strings will fail with > TypeError: can only concatenate str (not "OSError") to str so fix this with an explicit cast to str. Signed-off-by: Daniel Latypov <dlatypov(a)google.com> --- tools/testing/kunit/kunit_kernel.py | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py index e20e2056cb38..0e19089f62f0 100644 --- a/tools/testing/kunit/kunit_kernel.py +++ b/tools/testing/kunit/kunit_kernel.py @@ -36,9 +36,9 @@ class LinuxSourceTreeOperations(object): try: subprocess.check_output(['make', 'mrproper'], stderr=subprocess.STDOUT) except OSError as e: - raise ConfigError('Could not call make command: ' + e) + raise ConfigError('Could not call make command: ' + str(e)) except subprocess.CalledProcessError as e: - raise ConfigError(e.output) + raise ConfigError(e.output.decode()) def make_olddefconfig(self, build_dir, make_options): command = ['make', 'ARCH=um', 'olddefconfig'] @@ -49,9 +49,9 @@ class LinuxSourceTreeOperations(object): try: subprocess.check_output(command, stderr=subprocess.STDOUT) except OSError as e: - raise ConfigError('Could not call make command: ' + e) + raise ConfigError('Could not call make command: ' + str(e)) except subprocess.CalledProcessError as e: - raise ConfigError(e.output) + raise ConfigError(e.output.decode()) def make_allyesconfig(self): kunit_parser.print_with_timestamp( @@ -79,9 +79,9 @@ class LinuxSourceTreeOperations(object): try: subprocess.check_output(command, stderr=subprocess.STDOUT) except OSError as e: - raise BuildError('Could not call execute make: ' + e) + raise BuildError('Could not call execute make: ' + str(e)) except subprocess.CalledProcessError as e: - raise BuildError(e.output) + raise BuildError(e.output.decode()) def linux_bin(self, params, timeout, build_dir, outfile): """Runs the Linux UML binary. Must be named 'linux'.""" base-commit: ccc1d052eff9f3cfe59d201263903fe1d46c79a5 -- 2.28.0.709.gb0816b6eb0-goog

5 years

2
1
0 0

[PATCH bpf-next v2 4/4] selftest: bpf: Test copying a sockmap and sockhash

by Lorenz Bauer

Since we can now call map_update_elem(sockmap) from bpf_iter context it's possible to copy a sockmap or sockhash in the kernel. Add a selftest which exercises this. Signed-off-by: Lorenz Bauer <lmb(a)cloudflare.com> --- .../selftests/bpf/prog_tests/sockmap_basic.c | 14 +++++----- .../selftests/bpf/progs/bpf_iter_sockmap.c | 27 +++++++++++++++---- 2 files changed, 30 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c index e8a4bfb4d9f4..854a508e81ce 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c @@ -194,7 +194,7 @@ static void test_sockmap_invalid_update(void) test_sockmap_invalid_update__destroy(skel); } -static void test_sockmap_iter(enum bpf_map_type map_type) +static void test_sockmap_copy(enum bpf_map_type map_type) { DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts); int err, len, src_fd, iter_fd, duration = 0; @@ -242,7 +242,7 @@ static void test_sockmap_iter(enum bpf_map_type map_type) linfo.map.map_fd = src_fd; opts.link_info = &linfo; opts.link_info_len = sizeof(linfo); - link = bpf_program__attach_iter(skel->progs.count_elems, &opts); + link = bpf_program__attach_iter(skel->progs.copy, &opts); if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n")) goto out; @@ -265,6 +265,8 @@ static void test_sockmap_iter(enum bpf_map_type map_type) skel->bss->socks, num_sockets)) goto close_iter; + compare_cookies(src, skel->maps.dst); + close_iter: close(iter_fd); free_link: @@ -294,8 +296,8 @@ void test_sockmap_basic(void) test_sockmap_update(BPF_MAP_TYPE_SOCKHASH); if (test__start_subtest("sockmap update in unsafe context")) test_sockmap_invalid_update(); - if (test__start_subtest("sockmap iter")) - test_sockmap_iter(BPF_MAP_TYPE_SOCKMAP); - if (test__start_subtest("sockhash iter")) - test_sockmap_iter(BPF_MAP_TYPE_SOCKHASH); + if (test__start_subtest("sockmap copy")) + test_sockmap_copy(BPF_MAP_TYPE_SOCKMAP); + if (test__start_subtest("sockhash copy")) + test_sockmap_copy(BPF_MAP_TYPE_SOCKHASH); } diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c b/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c index 1af7555f6057..f3af0e30cead 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c @@ -22,21 +22,38 @@ struct { __type(value, __u64); } sockhash SEC(".maps"); +struct { + __uint(type, BPF_MAP_TYPE_SOCKHASH); + __uint(max_entries, 64); + __type(key, __u32); + __type(value, __u64); +} dst SEC(".maps"); + __u32 elems = 0; __u32 socks = 0; SEC("iter/sockmap") -int count_elems(struct bpf_iter__sockmap *ctx) +int copy(struct bpf_iter__sockmap *ctx) { struct sock *sk = ctx->sk; __u32 tmp, *key = ctx->key; int ret; - if (key) - elems++; + if (!key) + return 0; - if (sk) + elems++; + + /* We need a temporary buffer on the stack, since the verifier doesn't + * let us use the pointer from the context as an argument to the helper. + */ + tmp = *key; + + if (sk) { socks++; + return bpf_map_update_elem(&dst, &tmp, sk, 0) != 0; + } - return 0; + ret = bpf_map_delete_elem(&dst, &tmp); + return ret && ret != -ENOENT; } -- 2.25.1

5 years

2
4
0 0

[PATCH bpf-next v3 0/6] bpf: BTF support for ksyms

by Hao Luo

v2 -> v3: - Rename functions and variables in verifier for better readability. - Stick to logging message convention in libbpf. - Move bpf_per_cpu_ptr and bpf_this_cpu_ptr from trace-specific helper set to base helper set. - More specific test in ksyms_btf. - Fix return type cast in bpf_*_cpu_ptr. - Fix btf leak in ksyms_btf selftest. - Fix return error code for kallsyms_find(). v1 -> v2: - Move check_pseudo_btf_id from check_ld_imm() to replace_map_fd_with_map_ptr() and rename the latter. - Add bpf_this_cpu_ptr(). - Use bpf_core_types_are_compat() in libbpf.c for checking type compatibility. - Rewrite typed ksym extern type in BTF with int to save space. - Minor revision of bpf_per_cpu_ptr()'s comments. - Avoid using long in tests that use skeleton. - Refactored test_ksyms.c by moving kallsyms_find() to trace_helpers.c - Fold the patches that sync include/linux/uapi and tools/include/linux/uapi. rfc -> v1: - Encode VAR's btf_id for PSEUDO_BTF_ID. - More checks in verifier. Checking the btf_id passed as PSEUDO_BTF_ID is valid VAR, its name and type. - Checks in libbpf on type compatibility of ksyms. - Add bpf_per_cpu_ptr() to access kernel percpu vars. Introduced new ARG and RET types for this helper. This patch series extends the previously added __ksym externs with btf support. Right now the __ksym externs are treated as pure 64-bit scalar value. Libbpf replaces ld_imm64 insn of __ksym by its kernel address at load time. This patch series extend those externs with their btf info. Note that btf support for __ksym must come with the kernel btf that has VARs encoded to work properly. The corresponding chagnes in pahole is available at [1] (with a fix at [2] for gcc 4.9+). The first 3 patches in this series add support for general kernel global variables, which include verifier checking (01/06), libpf support (02/06) and selftests for getting typed ksym extern's kernel address (03/06). The next 3 patches extends that capability further by introducing helpers bpf_per_cpu_ptr() and bpf_this_cpu_ptr(), which allows accessing kernel percpu variables correctly (04/06 and 05/06). The tests of this feature were performed against pahole that is extended with [1] and [2]. For kernel BTF that does not have VARs encoded, the selftests will be skipped. [1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=f3d9054ba… [2] https://www.spinics.net/lists/dwarves/msg00451.html Hao Luo (6): bpf: Introduce pseudo_btf_id bpf/libbpf: BTF support for typed ksyms selftests/bpf: ksyms_btf to test typed ksyms bpf: Introduce bpf_per_cpu_ptr() bpf: Introduce bpf_this_cpu_ptr() bpf/selftests: Test for bpf_per_cpu_ptr() and bpf_this_cpu_ptr() include/linux/bpf.h | 6 + include/linux/bpf_verifier.h | 7 + include/linux/btf.h | 26 +++ include/uapi/linux/bpf.h | 67 +++++- kernel/bpf/btf.c | 25 --- kernel/bpf/helpers.c | 32 +++ kernel/bpf/verifier.c | 190 ++++++++++++++++-- kernel/trace/bpf_trace.c | 4 + tools/include/uapi/linux/bpf.h | 67 +++++- tools/lib/bpf/libbpf.c | 112 +++++++++-- .../testing/selftests/bpf/prog_tests/ksyms.c | 38 ++-- .../selftests/bpf/prog_tests/ksyms_btf.c | 88 ++++++++ .../selftests/bpf/progs/test_ksyms_btf.c | 55 +++++ tools/testing/selftests/bpf/trace_helpers.c | 27 +++ tools/testing/selftests/bpf/trace_helpers.h | 4 + 15 files changed, 653 insertions(+), 95 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/ksyms_btf.c create mode 100644 tools/testing/selftests/bpf/progs/test_ksyms_btf.c -- 2.28.0.618.gf4bc123cb7-goog

5 years

3
15
0 0

[RFC PATCH 4/4] selftest/x86/signal: Include test cases for validating sigaltstack

by Chang S. Bae

The test measures the kernel's signal delivery with different (enough vs. insufficient) stack sizes. Signed-off-by: Chang S. Bae <chang.seok.bae(a)intel.com> Reviewed-by: Len Brown <len.brown(a)intel.com> Cc: x86(a)kernel.org Cc: linux-kselftest(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org --- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/sigaltstack.c | 126 ++++++++++++++++++++++ 2 files changed, 127 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/sigaltstack.c diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 6703c7906b71..e0c52e5ab49e 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -13,7 +13,7 @@ CAN_BUILD_WITH_NOPIE := $(shell ./check_cc.sh $(CC) trivial_program.c -no-pie) TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \ check_initial_reg_state sigreturn iopl ioperm \ test_vdso test_vsyscall mov_ss_trap \ - syscall_arg_fault fsgsbase_restore + syscall_arg_fault fsgsbase_restore sigaltstack TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer diff --git a/tools/testing/selftests/x86/sigaltstack.c b/tools/testing/selftests/x86/sigaltstack.c new file mode 100644 index 000000000000..353679df6901 --- /dev/null +++ b/tools/testing/selftests/x86/sigaltstack.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#define _GNU_SOURCE +#include <signal.h> +#include <stdio.h> +#include <stdbool.h> +#include <string.h> +#include <err.h> +#include <errno.h> +#include <limits.h> +#include <sys/mman.h> +#include <sys/auxv.h> +#include <sys/prctl.h> +#include <sys/resource.h> +#include <setjmp.h> + +/* sigaltstack()-enforced minimum stack */ +#define ENFORCED_MINSIGSTKSZ 2048 + +#ifndef AT_MINSIGSTKSZ +# define AT_MINSIGSTKSZ 51 +#endif + +static int nerrs; + +static bool sigalrm_expected; + +static unsigned long at_minstack_size; + +static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), + int flags) +{ + struct sigaction sa; + + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO | flags; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static void clearhandler(int sig) +{ + struct sigaction sa; + + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static int setup_altstack(void *start, unsigned long size) +{ + stack_t ss; + + memset(&ss, 0, sizeof(ss)); + ss.ss_size = size; + ss.ss_sp = start; + + return sigaltstack(&ss, NULL); +} + +static jmp_buf jmpbuf; + +static void sigsegv(int sig, siginfo_t *info, void *ctx_void) +{ + if (sigalrm_expected) { + printf("[FAIL]\tSIGSEGV signal delivered.\n"); + nerrs++; + } else { + printf("[OK]\tSIGSEGV signal expectedly delivered.\n"); + } + + siglongjmp(jmpbuf, 1); +} + +static void sigalrm(int sig, siginfo_t *info, void *ctx_void) +{ + if (!sigalrm_expected) { + printf("[FAIL]\tSIGALRM sigal delivered.\n"); + nerrs++; + } else { + printf("[OK]\tSIGALRM signal expectedly delivered.\n"); + } +} + +static void test_sigaltstack(void *altstack, unsigned long size) +{ + if (setup_altstack(altstack, size)) + err(1, "sigaltstack()"); + + sigalrm_expected = (size > at_minstack_size) ? true : false; + + sethandler(SIGSEGV, sigsegv, 0); + sethandler(SIGALRM, sigalrm, SA_ONSTACK); + + if (sigsetjmp(jmpbuf, 1) == 0) { + printf("[RUN]\tTest an %s sigaltstack\n", + sigalrm_expected ? "enough" : "insufficient"); + raise(SIGALRM); + } + + clearhandler(SIGALRM); + clearhandler(SIGSEGV); +} + +int main(void) +{ + void *altstack; + + at_minstack_size = getauxval(AT_MINSIGSTKSZ); + + altstack = mmap(NULL, at_minstack_size + SIGSTKSZ, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); + if (altstack == MAP_FAILED) + err(1, "mmap()"); + + if ((ENFORCED_MINSIGSTKSZ + 1) < at_minstack_size) + test_sigaltstack(altstack, ENFORCED_MINSIGSTKSZ + 1); + + test_sigaltstack(altstack, at_minstack_size + SIGSTKSZ); + + return nerrs == 0 ? 0 : 1; +} -- 2.17.1

5 years

1
0
0 0

[PATCH 0/8] selftests/vm: gup_test, hmm-tests, assorted improvements

by John Hubbard

This is based on the latest mmotm. Summary: This series provides two main things, and a number of smaller supporting goodies. The two main points are: 1) Add a new sub-test to gup_test, which in turn is a renamed version of gup_benchmark. This sub-test allows nicer testing of dump_pages(), at least on user-space pages. For quite a while, I was doing a quick hack to gup_test.c whenever I wanted to try out changes to dump_page(). Then Matthew Wilcox asked me what I meant when I said "I used my dump_page() unit test", and I realized that it might be nice to check in a polished up version of that. Details about how it works and how to use it are in the commit description for patch #6. 2) Fixes a limitation of hmm-tests: these tests are incredibly useful, but only if people actually build and run them. And it turns out that libhugetlbfs is a little too effective at throwing a wrench in the works, there. So I've added a little configuration check that removes just two of the 21 hmm-tests, if libhugetlbfs is not available. Further details in the commit description of patch #8. Other smaller things that this series does: a) Remove code duplication by creating gup_test.h. b) Clear up the sub-test organization, and their invocation within run_vmtests.sh. c) Other minor assorted improvements. John Hubbard (8): mm/gup_benchmark: rename to mm/gup_test selftests/vm: use a common gup_test.h selftests/vm: rename run_vmtests --> run_vmtests.sh selftests/vm: minor cleanup: Makefile and gup_test.c selftests/vm: only some gup_test items are really benchmarks selftests/vm: gup_test: introduce the dump_pages() sub-test selftests/vm: run_vmtest.sh: update and clean up gup_test invocation selftests/vm: hmm-tests: remove the libhugetlbfs dependency Documentation/core-api/pin_user_pages.rst | 6 +- arch/s390/configs/debug_defconfig | 2 +- arch/s390/configs/defconfig | 2 +- mm/Kconfig | 21 +- mm/Makefile | 2 +- mm/{gup_benchmark.c => gup_test.c} | 109 ++++++---- mm/gup_test.h | 32 +++ tools/testing/selftests/vm/.gitignore | 3 +- tools/testing/selftests/vm/Makefile | 38 +++- tools/testing/selftests/vm/check_config.sh | 30 +++ tools/testing/selftests/vm/config | 2 +- tools/testing/selftests/vm/gup_benchmark.c | 137 ------------- tools/testing/selftests/vm/gup_test.c | 188 ++++++++++++++++++ tools/testing/selftests/vm/hmm-tests.c | 10 +- .../vm/{run_vmtests => run_vmtest.sh} | 24 ++- 15 files changed, 403 insertions(+), 203 deletions(-) rename mm/{gup_benchmark.c => gup_test.c} (59%) create mode 100644 mm/gup_test.h create mode 100755 tools/testing/selftests/vm/check_config.sh delete mode 100644 tools/testing/selftests/vm/gup_benchmark.c create mode 100644 tools/testing/selftests/vm/gup_test.c rename tools/testing/selftests/vm/{run_vmtests => run_vmtest.sh} (91%) -- 2.28.0

5 years

4
27
0 0

Re: [patch 00/13] preempt: Make preempt count unconditional

by Thomas Gleixner

On Mon, Sep 14 2020 at 15:24, Linus Torvalds wrote: > On Mon, Sep 14, 2020 at 2:55 PM Thomas Gleixner <tglx(a)linutronix.de> wrote: >> >> Yes it does generate better code, but I tried hard to spot a difference >> in various metrics exposed by perf. It's all in the noise and I only >> can spot a difference when the actual preemption check after the >> decrement > > I'm somewhat more worried about the small-device case. I just checked on one of my old UP ARM toys which I run at home. The .text increase is about 2% (75k) and none of the tests I ran showed any significant difference. Couldn't verify with perf though as the PMU on that piece of art is unusable. > That said, the diffstat certainly has its very clear charm, and I do > agree that it makes things simpler. > > I'm just not convinced people should ever EVER do things like that "if > (preemptible())" garbage. It sounds like somebody is doing seriously > bad things. OTOH, having a working 'preemptible()' or maybe better named 'can_schedule()' check makes tons of sense to make decisions about allocation modes or other things. We're currently looking through all of in_atomic(), in_interrupt() etc. usage sites and quite some of them are historic and have the clear intent of checking whether the code is called from task context or hard/softirq context. Lots of them are completely broken or just work by chance. But there is clearly historic precendence that context checks are useful, but they only can be useful if we have a consistent mechanism which works everywhere. Of course we could mandate that every interface which might be called from one or the other context has a context argument or provides two variants of the same thing. But I'm not really convinced whether that's a win over having a consistent and reliable set of checks. Thanks, tglx

5 years

6
17
0 0

[PATCH bpf-next v3 4/4] selftest: bpf: Test copying a sockmap and sockhash

by Lorenz Bauer

Since we can now call map_update_elem(sockmap) from bpf_iter context it's possible to copy a sockmap or sockhash in the kernel. Add a selftest which exercises this. Signed-off-by: Lorenz Bauer <lmb(a)cloudflare.com> --- .../selftests/bpf/prog_tests/sockmap_basic.c | 14 +++++----- .../selftests/bpf/progs/bpf_iter_sockmap.c | 27 +++++++++++++++---- 2 files changed, 30 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c index 316c4e271b36..4c4224e3e10a 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c @@ -194,7 +194,7 @@ static void test_sockmap_invalid_update(void) test_sockmap_invalid_update__destroy(skel); } -static void test_sockmap_iter(enum bpf_map_type map_type) +static void test_sockmap_copy(enum bpf_map_type map_type) { DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts); int err, len, src_fd, iter_fd, duration = 0; @@ -242,7 +242,7 @@ static void test_sockmap_iter(enum bpf_map_type map_type) linfo.map.map_fd = src_fd; opts.link_info = &linfo; opts.link_info_len = sizeof(linfo); - link = bpf_program__attach_iter(skel->progs.count_elems, &opts); + link = bpf_program__attach_iter(skel->progs.copy, &opts); if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n")) goto out; @@ -265,6 +265,8 @@ static void test_sockmap_iter(enum bpf_map_type map_type) skel->bss->socks, num_sockets)) goto close_iter; + compare_cookies(src, skel->maps.dst); + close_iter: close(iter_fd); free_link: @@ -294,8 +296,8 @@ void test_sockmap_basic(void) test_sockmap_update(BPF_MAP_TYPE_SOCKHASH); if (test__start_subtest("sockmap update in unsafe context")) test_sockmap_invalid_update(); - if (test__start_subtest("sockmap iter")) - test_sockmap_iter(BPF_MAP_TYPE_SOCKMAP); - if (test__start_subtest("sockhash iter")) - test_sockmap_iter(BPF_MAP_TYPE_SOCKHASH); + if (test__start_subtest("sockmap copy")) + test_sockmap_copy(BPF_MAP_TYPE_SOCKMAP); + if (test__start_subtest("sockhash copy")) + test_sockmap_copy(BPF_MAP_TYPE_SOCKHASH); } diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c b/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c index 1af7555f6057..f3af0e30cead 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c @@ -22,21 +22,38 @@ struct { __type(value, __u64); } sockhash SEC(".maps"); +struct { + __uint(type, BPF_MAP_TYPE_SOCKHASH); + __uint(max_entries, 64); + __type(key, __u32); + __type(value, __u64); +} dst SEC(".maps"); + __u32 elems = 0; __u32 socks = 0; SEC("iter/sockmap") -int count_elems(struct bpf_iter__sockmap *ctx) +int copy(struct bpf_iter__sockmap *ctx) { struct sock *sk = ctx->sk; __u32 tmp, *key = ctx->key; int ret; - if (key) - elems++; + if (!key) + return 0; - if (sk) + elems++; + + /* We need a temporary buffer on the stack, since the verifier doesn't + * let us use the pointer from the context as an argument to the helper. + */ + tmp = *key; + + if (sk) { socks++; + return bpf_map_update_elem(&dst, &tmp, sk, 0) != 0; + } - return 0; + ret = bpf_map_delete_elem(&dst, &tmp); + return ret && ret != -ENOENT; } -- 2.25.1

5 years

1
0
0 0

[PATCH bpf-next v3 3/4] selftests: bpf: remove shared header from sockmap iter test

by Lorenz Bauer

The shared header to define SOCKMAP_MAX_ENTRIES is a bit overkill. Dynamically allocate the sock_fd array based on bpf_map__max_entries instead. Suggested-by: Yonghong Song <yhs(a)fb.com> Signed-off-by: Lorenz Bauer <lmb(a)cloudflare.com> Acked-by: Yonghong Song <yhs(a)fb.com> --- .../selftests/bpf/prog_tests/sockmap_basic.c | 36 +++++++++---------- .../selftests/bpf/progs/bpf_iter_sockmap.c | 5 ++- .../selftests/bpf/progs/bpf_iter_sockmap.h | 3 -- 3 files changed, 20 insertions(+), 24 deletions(-) delete mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_sockmap.h diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c index 3596d3f3039f..316c4e271b36 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c @@ -8,8 +8,6 @@ #include "test_sockmap_invalid_update.skel.h" #include "bpf_iter_sockmap.skel.h" -#include "progs/bpf_iter_sockmap.h" - #define TCP_REPAIR 19 /* TCP sock is under repair right now */ #define TCP_REPAIR_ON 1 @@ -201,9 +199,9 @@ static void test_sockmap_iter(enum bpf_map_type map_type) DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts); int err, len, src_fd, iter_fd, duration = 0; union bpf_iter_link_info linfo = {0}; - __s64 sock_fd[SOCKMAP_MAX_ENTRIES]; - __u32 i, num_sockets, max_elems; + __u32 i, num_sockets, num_elems; struct bpf_iter_sockmap *skel; + __s64 *sock_fd = NULL; struct bpf_link *link; struct bpf_map *src; char buf[64]; @@ -212,22 +210,23 @@ static void test_sockmap_iter(enum bpf_map_type map_type) if (CHECK(!skel, "bpf_iter_sockmap__open_and_load", "skeleton open_and_load failed\n")) return; - for (i = 0; i < ARRAY_SIZE(sock_fd); i++) - sock_fd[i] = -1; - - /* Make sure we have at least one "empty" entry to test iteration of - * an empty slot. - */ - num_sockets = ARRAY_SIZE(sock_fd) - 1; - if (map_type == BPF_MAP_TYPE_SOCKMAP) { src = skel->maps.sockmap; - max_elems = bpf_map__max_entries(src); + num_elems = bpf_map__max_entries(src); + num_sockets = num_elems - 1; } else { src = skel->maps.sockhash; - max_elems = num_sockets; + num_elems = bpf_map__max_entries(src) - 1; + num_sockets = num_elems; } + sock_fd = calloc(num_sockets, sizeof(*sock_fd)); + if (CHECK(!sock_fd, "calloc(sock_fd)", "failed to allocate\n")) + goto out; + + for (i = 0; i < num_sockets; i++) + sock_fd[i] = -1; + src_fd = bpf_map__fd(src); for (i = 0; i < num_sockets; i++) { @@ -258,8 +257,8 @@ static void test_sockmap_iter(enum bpf_map_type map_type) goto close_iter; /* test results */ - if (CHECK(skel->bss->elems != max_elems, "elems", "got %u expected %u\n", - skel->bss->elems, max_elems)) + if (CHECK(skel->bss->elems != num_elems, "elems", "got %u expected %u\n", + skel->bss->elems, num_elems)) goto close_iter; if (CHECK(skel->bss->socks != num_sockets, "socks", "got %u expected %u\n", @@ -271,10 +270,11 @@ static void test_sockmap_iter(enum bpf_map_type map_type) free_link: bpf_link__destroy(link); out: - for (i = 0; i < num_sockets; i++) { + for (i = 0; sock_fd && i < num_sockets; i++) if (sock_fd[i] >= 0) close(sock_fd[i]); - } + if (sock_fd) + free(sock_fd); bpf_iter_sockmap__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c b/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c index 0e27f73dd803..1af7555f6057 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c @@ -2,7 +2,6 @@ /* Copyright (c) 2020 Cloudflare */ #include "bpf_iter.h" #include "bpf_tracing_net.h" -#include "bpf_iter_sockmap.h" #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include <errno.h> @@ -11,14 +10,14 @@ char _license[] SEC("license") = "GPL"; struct { __uint(type, BPF_MAP_TYPE_SOCKMAP); - __uint(max_entries, SOCKMAP_MAX_ENTRIES); + __uint(max_entries, 64); __type(key, __u32); __type(value, __u64); } sockmap SEC(".maps"); struct { __uint(type, BPF_MAP_TYPE_SOCKHASH); - __uint(max_entries, SOCKMAP_MAX_ENTRIES); + __uint(max_entries, 64); __type(key, __u32); __type(value, __u64); } sockhash SEC(".maps"); diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.h b/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.h deleted file mode 100644 index 35a675d13c0f..000000000000 --- a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.h +++ /dev/null @@ -1,3 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ - -#define SOCKMAP_MAX_ENTRIES (64) -- 2.25.1

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[PATCH bpf-next v3 2/4] selftests: bpf: Add helper to compare socket cookies

by Lorenz Bauer

We compare socket cookies to ensure that insertion into a sockmap worked. Pull this out into a helper function for use in other tests. Signed-off-by: Lorenz Bauer <lmb(a)cloudflare.com> --- .../selftests/bpf/prog_tests/sockmap_basic.c | 50 +++++++++++++------ 1 file changed, 36 insertions(+), 14 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c index 4b7a527e7e82..3596d3f3039f 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c @@ -50,6 +50,37 @@ static int connected_socket_v4(void) return -1; } +static void compare_cookies(struct bpf_map *src, struct bpf_map *dst) +{ + __u32 i, max_entries = bpf_map__max_entries(src); + int err, duration = 0, src_fd, dst_fd; + + src_fd = bpf_map__fd(src); + dst_fd = bpf_map__fd(dst); + + for (i = 0; i < max_entries; i++) { + __u64 src_cookie, dst_cookie; + + err = bpf_map_lookup_elem(src_fd, &i, &src_cookie); + if (err && errno == ENOENT) { + err = bpf_map_lookup_elem(dst_fd, &i, &dst_cookie); + CHECK(!err, "map_lookup_elem(dst)", "element %u not deleted\n", i); + CHECK(err && errno != ENOENT, "map_lookup_elem(dst)", "%s\n", + strerror(errno)); + continue; + } + if (CHECK(err, "lookup_elem(src)", "%s\n", strerror(errno))) + continue; + + err = bpf_map_lookup_elem(dst_fd, &i, &dst_cookie); + if (CHECK(err, "lookup_elem(dst)", "%s\n", strerror(errno))) + continue; + + CHECK(dst_cookie != src_cookie, "cookie mismatch", + "%llu != %llu (pos %u)\n", dst_cookie, src_cookie, i); + } +} + /* Create a map, populate it with one socket, and free the map. */ static void test_sockmap_create_update_free(enum bpf_map_type map_type) { @@ -109,9 +140,9 @@ static void test_skmsg_helpers(enum bpf_map_type map_type) static void test_sockmap_update(enum bpf_map_type map_type) { struct bpf_prog_test_run_attr tattr; - int err, prog, src, dst, duration = 0; + int err, prog, src, duration = 0; struct test_sockmap_update *skel; - __u64 src_cookie, dst_cookie; + struct bpf_map *dst_map; const __u32 zero = 0; char dummy[14] = {0}; __s64 sk; @@ -127,18 +158,14 @@ static void test_sockmap_update(enum bpf_map_type map_type) prog = bpf_program__fd(skel->progs.copy_sock_map); src = bpf_map__fd(skel->maps.src); if (map_type == BPF_MAP_TYPE_SOCKMAP) - dst = bpf_map__fd(skel->maps.dst_sock_map); + dst_map = skel->maps.dst_sock_map; else - dst = bpf_map__fd(skel->maps.dst_sock_hash); + dst_map = skel->maps.dst_sock_hash; err = bpf_map_update_elem(src, &zero, &sk, BPF_NOEXIST); if (CHECK(err, "update_elem(src)", "errno=%u\n", errno)) goto out; - err = bpf_map_lookup_elem(src, &zero, &src_cookie); - if (CHECK(err, "lookup_elem(src, cookie)", "errno=%u\n", errno)) - goto out; - tattr = (struct bpf_prog_test_run_attr){ .prog_fd = prog, .repeat = 1, @@ -151,12 +178,7 @@ static void test_sockmap_update(enum bpf_map_type map_type) "errno=%u retval=%u\n", errno, tattr.retval)) goto out; - err = bpf_map_lookup_elem(dst, &zero, &dst_cookie); - if (CHECK(err, "lookup_elem(dst, cookie)", "errno=%u\n", errno)) - goto out; - - CHECK(dst_cookie != src_cookie, "cookie mismatch", "%llu != %llu\n", - dst_cookie, src_cookie); + compare_cookies(skel->maps.src, dst_map); out: test_sockmap_update__destroy(skel); -- 2.25.1

5 years

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[PATCH v7 bpf-next 0/8] bpf: add helpers to support BTF-based kernel data display

by Alan Maguire

This series attempts to provide a simple way for BPF programs (and in future other consumers) to utilize BPF Type Format (BTF) information to display kernel data structures in-kernel. The use case this functionality is applied to here is to support a snprintf()-like helper to copy a BTF representation of kernel data to a string, and a BPF seq file helper to display BTF data for an iterator. There is already support in kernel/bpf/btf.c for "show" functionality; the changes here generalize that support from seq-file specific verifier display to the more generic case and add another specific use case; rather than seq_printf()ing the show data, it is copied to a supplied string using a snprintf()-like function. Other future consumers of the show functionality could include a bpf_printk_btf() function which printk()ed the data instead. Oops messaging in particular would be an interesting application for such functionality. The above potential use case hints at a potential reply to a reasonable objection that such typed display should be solved by tracing programs, where the in-kernel tracing records data and the userspace program prints it out. While this is certainly the recommended approach for most cases, I believe having an in-kernel mechanism would be valuable also. Critically in BPF programs it greatly simplifies debugging and tracing of such data to invoking a simple helper. One challenge raised in an earlier iteration of this work - where the BTF printing was implemented as a printk() format specifier - was that the amount of data printed per printk() was large, and other format specifiers were far simpler. Here we sidestep that concern by printing components of the BTF representation as we go for the seq file case, and in the string case the snprintf()-like operation is intended to be a basis for perf event or ringbuf output. The reasons for avoiding bpf_trace_printk are that 1. bpf_trace_printk() strings are restricted in size and cannot display anything beyond trivial data structures; and 2. bpf_trace_printk() is for debugging purposes only. As Alexei suggested, a bpf_trace_puts() helper could solve this in the future but it still would be limited by the 1000 byte limit for traced strings. Default output for an sk_buff looks like this (zeroed fields are omitted): (struct sk_buff){ .transport_header = (__u16)65535, .mac_header = (__u16)65535, .end = (sk_buff_data_t)192, .head = (unsigned char *)0x000000007524fd8b, .data = (unsigned char *)0x000000007524fd8b, .truesize = (unsigned int)768, .users = (refcount_t){ .refs = (atomic_t){ .counter = (int)1, }, }, } Flags can modify aspects of output format; see patch 3 for more details. Changes since v6: - Updated safe data size to 32, object name size to 80. This increases the number of safe copies done, but performance is not a key goal here. WRT name size the largest type name length in bpf-next according to "pahole -s" is 64 bytes, so that still gives room for additional type qualifiers, parens etc within the name limit (Alexei, patch 2) - Remove inlines and converted as many #defines to functions as was possible. In a few cases - btf_show_type_value[s]() specifically - I left these as macros as btf_show_type_value[s]() prepends and appends format strings to the format specifier (in order to include indentation, delimiters etc so a macro makes that simpler (Alexei, patch 2) - Handle btf_resolve_size() error in btf_show_obj_safe() (Alexei, patch 2) - Removed clang loop unroll in BTF snprintf test (Alexei) - switched to using bpf_core_type_id_kernel(type) as suggested by Andrii, and Alexei noted that __builtin_btf_type_id(,1) should be used (patch 4) - Added skip logic if __builtin_btf_type_id is not available (patches 4,8) - Bumped limits on bpf iters to support printing larger structures (Alexei, patch 5) - Updated overflow bpf_iter tests to reflect new iter max size (patch 6) - Updated seq helper to use type id only (Alexei, patch 7) - Updated BTF task iter test to use task struct instead of struct fs_struct since new limits allow a task_struct to be displayed (patch 8) - Fixed E2BIG handling in iter task (Alexei, patch 8) Changes since v5: - Moved btf print prepare into patch 3, type show seq with flags into patch 2 (Alexei, patches 2,3) - Fixed build bot warnings around static declarations and printf attributes - Renamed functions to snprintf_btf/seq_printf_btf (Alexei, patches 3-6) Changes since v4: - Changed approach from a BPF trace event-centric design to one utilizing a snprintf()-like helper and an iter helper (Alexei, patches 3,5) - Added tests to verify BTF output (patch 4) - Added support to tests for verifying BTF type_id-based display as well as type name via __builtin_btf_type_id (Andrii, patch 4). - Augmented task iter tests to cover the BTF-based seq helper. Because a task_struct's BTF-based representation would overflow the PAGE_SIZE limit on iterator data, the "struct fs_struct" (task->fs) is displayed for each task instead (Alexei, patch 6). Changes since v3: - Moved to RFC since the approach is different (and bpf-next is closed) - Rather than using a printk() format specifier as the means of invoking BTF-enabled display, a dedicated BPF helper is used. This solves the issue of printk() having to output large amounts of data using a complex mechanism such as BTF traversal, but still provides a way for the display of such data to be achieved via BPF programs. Future work could include a bpf_printk_btf() function to invoke display via printk() where the elements of a data structure are printk()ed one at a time. Thanks to Petr Mladek, Andy Shevchenko and Rasmus Villemoes who took time to look at the earlier printk() format-specifier-focused version of this and provided feedback clarifying the problems with that approach. - Added trace id to the bpf_trace_printk events as a means of separating output from standard bpf_trace_printk() events, ensuring it can be easily parsed by the reader. - Added bpf_trace_btf() helper tests which do simple verification of the various display options. Changes since v2: - Alexei and Yonghong suggested it would be good to use probe_kernel_read() on to-be-shown data to ensure safety during operation. Safe copy via probe_kernel_read() to a buffer object in "struct btf_show" is used to support this. A few different approaches were explored including dynamic allocation and per-cpu buffers. The downside of dynamic allocation is that it would be done during BPF program execution for bpf_trace_printk()s using %pT format specifiers. The problem with per-cpu buffers is we'd have to manage preemption and since the display of an object occurs over an extended period and in printk context where we'd rather not change preemption status, it seemed tricky to manage buffer safety while considering preemption. The approach of utilizing stack buffer space via the "struct btf_show" seemed like the simplest approach. The stack size of the associated functions which have a "struct btf_show" on their stack to support show operation (btf_type_snprintf_show() and btf_type_seq_show()) stays under 500 bytes. The compromise here is the safe buffer we use is small - 256 bytes - and as a result multiple probe_kernel_read()s are needed for larger objects. Most objects of interest are smaller than this (e.g. "struct sk_buff" is 224 bytes), and while task_struct is a notable exception at ~8K, performance is not the priority for BTF-based display. (Alexei and Yonghong, patch 2). - safe buffer use is the default behaviour (and is mandatory for BPF) but unsafe display - meaning no safe copy is done and we operate on the object itself - is supported via a 'u' option. - pointers are prefixed with 0x for clarity (Alexei, patch 2) - added additional comments and explanations around BTF show code, especially around determining whether objects such zeroed. Also tried to comment safe object scheme used. (Yonghong, patch 2) - added late_initcall() to initialize vmlinux BTF so that it would not have to be initialized during printk operation (Alexei, patch 5) - removed CONFIG_BTF_PRINTF config option as it is not needed; CONFIG_DEBUG_INFO_BTF can be used to gate test behaviour and determining behaviour of type-based printk can be done via retrieval of BTF data; if it's not there BTF was unavailable or broken (Alexei, patches 4,6) - fix bpf_trace_printk test to use vmlinux.h and globals via skeleton infrastructure, removing need for perf events (Andrii, patch 8) Changes since v1: - changed format to be more drgn-like, rendering indented type info along with type names by default (Alexei) - zeroed values are omitted (Arnaldo) by default unless the '0' modifier is specified (Alexei) - added an option to print pointer values without obfuscation. The reason to do this is the sysctls controlling pointer display are likely to be irrelevant in many if not most tracing contexts. Some questions on this in the outstanding questions section below... - reworked printk format specifer so that we no longer rely on format %pT<type> but instead use a struct * which contains type information (Rasmus). This simplifies the printk parsing, makes use more dynamic and also allows specification by BTF id as well as name. - removed incorrect patch which tried to fix dereferencing of resolved BTF info for vmlinux; instead we skip modifiers for the relevant case (array element type determination) (Alexei). - fixed issues with negative snprintf format length (Rasmus) - added test cases for various data structure formats; base types, typedefs, structs, etc. - tests now iterate through all typedef, enum, struct and unions defined for vmlinux BTF and render a version of the target dummy value which is either all zeros or all 0xff values; the idea is this exercises the "skip if zero" and "print everything" cases. - added support in BPF for using the %pT format specifier in bpf_trace_printk() - added BPF tests which ensure %pT format specifier use works (Alexei). Alan Maguire (8): bpf: provide function to get vmlinux BTF information bpf: move to generic BTF show support, apply it to seq files/strings bpf: add bpf_snprintf_btf helper selftests/bpf: add bpf_snprintf_btf helper tests bpf: bump iter seq size to support BTF representation of large data structures selftests/bpf: fix overflow tests to reflect iter size increase bpf: add bpf_seq_printf_btf helper selftests/bpf: add test for bpf_seq_printf_btf helper include/linux/bpf.h | 3 + include/linux/btf.h | 39 + include/uapi/linux/bpf.h | 76 ++ kernel/bpf/bpf_iter.c | 4 +- kernel/bpf/btf.c | 1007 ++++++++++++++++++-- kernel/bpf/core.c | 2 + kernel/bpf/helpers.c | 4 + kernel/bpf/verifier.c | 18 +- kernel/trace/bpf_trace.c | 98 ++ scripts/bpf_helpers_doc.py | 2 + tools/include/uapi/linux/bpf.h | 76 ++ tools/testing/selftests/bpf/prog_tests/bpf_iter.c | 88 +- .../selftests/bpf/prog_tests/snprintf_btf.c | 60 ++ .../selftests/bpf/progs/bpf_iter_task_btf.c | 50 + .../selftests/bpf/progs/netif_receive_skb.c | 249 +++++ 15 files changed, 1659 insertions(+), 117 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/snprintf_btf.c create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_task_btf.c create mode 100644 tools/testing/selftests/bpf/progs/netif_receive_skb.c -- 1.8.3.1

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