From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-189.mta1.migadu.com (out-189.mta1.migadu.com [95.215.58.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 289D428B51F for ; Wed, 6 Aug 2025 18:17:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754504274; cv=none; b=jbV+fSntnftunJYzoyKrtlExWOQutqMQGhxRiuYF87Btk3wYNHJIJim4QZ64cNuhXniQrIUbnnLaorKVwbT5SrItiXCwSqmiItGG7EF1pcBVLhhF6XbNuSQxBxFpNhDSWkNKjjCNY3KECShYl/clsLkN11EqF8lrWcRl60QTEZQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754504274; c=relaxed/simple; bh=3FKNH/2j/7yu+W35gTHHG3ks/5yRV+BkQeegHY/jpjU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=bNRo6a6W4cIe6B7w8l1v8Rks6PByPI+9K17XZB9xTP/6Up7hBB7j72IZMxR1xN7YKf19hPUZ8yHdRJIVJ3e/fA36xFkS69Fkj4rtzItVajoHeY9tebK3FwPL85mfuP5FJc/ty+pGa/tKRCUVYV05X8UnKeefhLh4JxbYjD+IqEI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=EOSBM5z3; arc=none smtp.client-ip=95.215.58.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="EOSBM5z3" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1754504259; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OhCFOoWcGKQbx95VvRl2b6bWCAnvya8JVL9ii3cAoDE=; b=EOSBM5z3ZJOmEo9Ixd9QAEvaEPUKcZfPlRtc+NfPXufXiYchRCLelhonbA7+Q6stWN31n3 L6cY8LibCK76zwAVQXfYFdmVXcZ9kbQ5hP+H96hD4EDn7giULPUOG8jDB7jgxCoqA3VU43 tmZvRZoTMZos8h5DeBY6UiA5YqbntRM= Date: Wed, 6 Aug 2025 11:17:34 -0700 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v7 2/2] selftests/bpf: Force -O2 for USDT selftests to cover SIB handling logic Content-Language: en-GB To: Jiawei Zhao , ast@kernel.org Cc: daniel@iogearbox.net, andrii@kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250806092458.111972-1-phoenix500526@163.com> <20250806092458.111972-3-phoenix500526@163.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yonghong Song In-Reply-To: <20250806092458.111972-3-phoenix500526@163.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 8/6/25 2:24 AM, Jiawei Zhao wrote: > When using GCC on x86-64 to compile an usdt prog with -O1 or higher > optimization, the compiler will generate SIB addressing mode for global > array and PC-relative addressing mode for global variable, > e.g. "1@-96(%rbp,%rax,8)" and "-1@4+t1(%rip)". > > In this patch: > - add usdt_o2 test case to cover SIB addressing usdt argument spec > handling logic > > Signed-off-by: Jiawei Zhao > --- > tools/testing/selftests/bpf/Makefile | 8 +++ > .../selftests/bpf/prog_tests/usdt_o2.c | 71 +++++++++++++++++++ > .../selftests/bpf/progs/test_usdt_o2.c | 37 ++++++++++ > 3 files changed, 116 insertions(+) > create mode 100644 tools/testing/selftests/bpf/prog_tests/usdt_o2.c > create mode 100644 tools/testing/selftests/bpf/progs/test_usdt_o2.c > > diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile > index 910d8d6402ef..68cf6a9cf05f 100644 > --- a/tools/testing/selftests/bpf/Makefile > +++ b/tools/testing/selftests/bpf/Makefile > @@ -759,6 +759,14 @@ TRUNNER_BPF_BUILD_RULE := $$(error no BPF objects should be built) > TRUNNER_BPF_CFLAGS := > $(eval $(call DEFINE_TEST_RUNNER,test_maps)) > > +# Use -O2 optimization to generate SIB addressing usdt argument spec > +# Only apply on x86 architecture where SIB addressing is relevant > +ifeq ($(ARCH), x86) > +$(OUTPUT)/usdt_o2.test.o: CFLAGS:=$(subst O0,O2,$(CFLAGS)) > +$(OUTPUT)/cpuv4/usdt_o2.test.o: CFLAGS:=$(subst O0,O2,$(CFLAGS)) > +$(OUTPUT)/no_alu32/usdt_o2.test.o: CFLAGS:=$(subst O0,O2,$(CFLAGS)) > +endif I tried your selftest with gcc14 and llvm20 in my environment. See below: llvm20: Displaying notes found in: .note.stapsdt Owner Data size Description stapsdt 0x0000002f NT_STAPSDT (SystemTap probe descriptors) Provider: test Name: usdt1 Location: 0x00000000000003ac, Base: 0x0000000000000000, Semaphore: 0x0000000000000000 Arguments: 8@-64(%rbp) gcc14: Displaying notes found in: .note.stapsdt Owner Data size Description stapsdt 0x00000034 NT_STAPSDT (SystemTap probe descriptors) Provider: test Name: usdt1 Location: 0x0000000000000334, Base: 0x0000000000000000, Semaphore: 0x0000000000000000 Arguments: 8@array(,%rax,8) llvm20 and gcc14 generate different usdt patterns. '8@-64(%rbp)' already supports so with SIB support, the test should pass CI, I think. > + > # Define test_verifier test runner. > # It is much simpler than test_maps/test_progs and sufficiently different from > # them (e.g., test.h is using completely pattern), that it's worth just > diff --git a/tools/testing/selftests/bpf/prog_tests/usdt_o2.c b/tools/testing/selftests/bpf/prog_tests/usdt_o2.c > new file mode 100644 > index 000000000000..f04b756b3640 > --- /dev/null > +++ b/tools/testing/selftests/bpf/prog_tests/usdt_o2.c > @@ -0,0 +1,71 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* Copyright (c) 2025 Jiawei Zhao . */ > +#include > + > +#define _SDT_HAS_SEMAPHORES 1 > +#include "../sdt.h" > +#include "test_usdt_o2.skel.h" > + > +int lets_test_this(int); > + > +#define test_value 0xFEDCBA9876543210ULL > +#define SEC(name) __attribute__((section(name), used)) > + > + > +static volatile __u64 array[1] = {test_value}; > +unsigned short test_usdt1_semaphore SEC(".probes"); > + > +static __always_inline void trigger_func(void) > +{ > + /* Base address + offset + (index * scale) */ > + if (test_usdt1_semaphore) { > + for (volatile int i = 0; i <= 0; i++) > + STAP_PROBE1(test, usdt1, array[i]); > + } > +} > + > +static void basic_sib_usdt(void) > +{ > + LIBBPF_OPTS(bpf_usdt_opts, opts); > + struct test_usdt_o2 *skel; > + struct test_usdt_o2__bss *bss; > + int err; > + > + skel = test_usdt_o2__open_and_load(); > + if (!ASSERT_OK_PTR(skel, "skel_open")) > + return; > + > + bss = skel->bss; > + bss->my_pid = getpid(); > + > + err = test_usdt_o2__attach(skel); > + if (!ASSERT_OK(err, "skel_attach")) > + goto cleanup; > + > + /* usdt1 won't be auto-attached */ > + opts.usdt_cookie = 0xcafedeadbeeffeed; > + skel->links.usdt1 = bpf_program__attach_usdt(skel->progs.usdt1, > + 0 /*self*/, "/proc/self/exe", > + "test", "usdt1", &opts); > + if (!ASSERT_OK_PTR(skel->links.usdt1, "usdt1_link")) > + goto cleanup; > + > + trigger_func(); > + > + ASSERT_EQ(bss->usdt1_called, 1, "usdt1_called"); > + ASSERT_EQ(bss->usdt1_cookie, 0xcafedeadbeeffeed, "usdt1_cookie"); > + ASSERT_EQ(bss->usdt1_arg_cnt, 1, "usdt1_arg_cnt"); > + ASSERT_EQ(bss->usdt1_arg, test_value, "usdt1_arg"); > + ASSERT_EQ(bss->usdt1_arg_ret, 0, "usdt1_arg_ret"); > + ASSERT_EQ(bss->usdt1_arg_size, sizeof(array[0]), "usdt1_arg_size"); > + > +cleanup: > + test_usdt_o2__destroy(skel); > +} > + > + > + > +void test_usdt_o2(void) > +{ > + basic_sib_usdt(); > +} > diff --git a/tools/testing/selftests/bpf/progs/test_usdt_o2.c b/tools/testing/selftests/bpf/progs/test_usdt_o2.c > new file mode 100644 > index 000000000000..14602aa54578 > --- /dev/null > +++ b/tools/testing/selftests/bpf/progs/test_usdt_o2.c > @@ -0,0 +1,37 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ > + > +#include "vmlinux.h" > +#include > +#include > + > +int my_pid; > + > +int usdt1_called; > +u64 usdt1_cookie; > +int usdt1_arg_cnt; > +int usdt1_arg_ret; > +u64 usdt1_arg; > +int usdt1_arg_size; > + > +SEC("usdt") > +int usdt1(struct pt_regs *ctx) > +{ > + long tmp; > + > + if (my_pid != (bpf_get_current_pid_tgid() >> 32)) > + return 0; > + > + __sync_fetch_and_add(&usdt1_called, 1); > + > + usdt1_cookie = bpf_usdt_cookie(ctx); > + usdt1_arg_cnt = bpf_usdt_arg_cnt(ctx); > + > + usdt1_arg_ret = bpf_usdt_arg(ctx, 0, &tmp); > + usdt1_arg = (u64)tmp; > + usdt1_arg_size = bpf_usdt_arg_size(ctx, 0); > + > + return 0; > +} > + > +char _license[] SEC("license") = "GPL";