From nobody Wed Dec 17 07:41:48 2025 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.4]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 565F272623; Sat, 23 Aug 2025 06:50:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755931844; cv=none; b=bRL6NqMMfonzit7VX9ZFR/txXfovwCbzXv60tZaLuYHqvzvXjLT+1C5roLNkQ5sH1CVYNgVMrPg1qyWZS9CbueC7Sacn3/F1cJV0j/mCYIIqM6ZNlcra5OeoCski/BxyA3deGuuZT/xT+CViTOiQOv7biJESI3LQsbcBbkFNOjE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755931844; c=relaxed/simple; bh=kJuiIR8rVDpwqGIPF1nQuAY6c7Z+h+ZunUtTbQE0708=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jg9zYrbAgUbVHXIm1zjwXbq/UB7St60yGnxBB20KpluPGQLq+HF8AhxjBorQS68mFJEN1t77QNbO2frNnDTT6htfMR233+J77vHp60hZtPaGh9Y3R/1JbUEeSzrPlhP4EYUQIlhtkzBiHBd2bhSxtyj8jsIxW49Xh7BgxpR7iKs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=AFcirxRv; arc=none smtp.client-ip=220.197.31.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="AFcirxRv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=hY 0bVfXVCvwSkvV8zWlb3tUSiMgvkV/DiRGEg8n7LL0=; b=AFcirxRv0R09F0Vfue aULqevP0VSXHTaGvyLfG2kj5PoVmoi6tp9Hid02afbyst90ZUq8xsANafPRSio5z lEAfsR5uQ8p8MNySSfsO/Eram1EVPLeuI8y0TTAxBAfm9u4yvCQBCBsmz47KzxyM BO3NmAODG5HZRH+SeEXduYJsM= Received: from phoenix.. (unknown []) by gzga-smtp-mtada-g0-2 (Coremail) with SMTP id _____wAn8USdZKlohCriDQ--.20793S3; Sat, 23 Aug 2025 14:50:08 +0800 (CST) From: Jiawei Zhao To: ast@kernel.org Cc: daniel@iogearbox.net, andrii@kernel.org, yonghong.song@linux.dev, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf-next v14 1/2] libbpf: fix USDT SIB argument handling causing unrecognized register error Date: Sat, 23 Aug 2025 06:50:03 +0000 Message-ID: <20250823065005.1187181-2-phoenix500526@163.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250823065005.1187181-1-phoenix500526@163.com> References: <20250823065005.1187181-1-phoenix500526@163.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wAn8USdZKlohCriDQ--.20793S3 X-Coremail-Antispam: 1Uf129KBjvJXoWxtryfArWkXF4kJr48Xw47urg_yoWxXrWfpa y09rnayryrJw4Sva1fXF40y343CFs7Gr4rZrWkta45ZFWxWr4UJrySkF1Yyrn8JFW2yF43 ZF4YvrWxG3W3ur7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jzlksUUUUU= X-CM-SenderInfo: pskrv0dl0viiqvswqiywtou0bp/1tbiFAqyiGipWPbE8QABs- Content-Type: text/plain; charset="utf-8" On x86-64, USDT arguments can be specified using Scale-Index-Base (SIB) addressing, e.g. "1@-96(%rbp,%rax,8)". The current USDT implementation in libbpf cannot parse this format, causing `bpf_program__attach_usdt()` to fail with -ENOENT (unrecognized register). This patch fixes this by implementing the necessary changes: - add correct handling for SIB-addressed arguments in `bpf_usdt_arg`. - add adaptive support to `__bpf_usdt_arg_type` and `__bpf_usdt_arg_spec` to represent SIB addressing parameters. Signed-off-by: Jiawei Zhao --- tools/lib/bpf/usdt.bpf.h | 44 +++++++++++++++++++++++++++++-- tools/lib/bpf/usdt.c | 57 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 94 insertions(+), 7 deletions(-) diff --git a/tools/lib/bpf/usdt.bpf.h b/tools/lib/bpf/usdt.bpf.h index 2a7865c8e3fe..aaa584a4f4f9 100644 --- a/tools/lib/bpf/usdt.bpf.h +++ b/tools/lib/bpf/usdt.bpf.h @@ -34,13 +34,32 @@ enum __bpf_usdt_arg_type { BPF_USDT_ARG_CONST, BPF_USDT_ARG_REG, BPF_USDT_ARG_REG_DEREF, + BPF_USDT_ARG_SIB, }; =20 +/* + * This struct layout is designed specifically to be backwards/forward + * compatible between libbpf versions for ARG_CONST, ARG_REG, and + * ARG_REG_DEREF modes. ARG_SIB requires libbpf v1.7+. + */ struct __bpf_usdt_arg_spec { /* u64 scalar interpreted depending on arg_type, see below */ __u64 val_off; +#if __BYTE_ORDER__ =3D=3D __ORDER_LITTLE_ENDIAN__ /* arg location case, see bpf_usdt_arg() for details */ - enum __bpf_usdt_arg_type arg_type; + enum __bpf_usdt_arg_type arg_type: 8; + /* index register offset within struct pt_regs */ + __u16 idx_reg_off: 12, + /* scale factor for index register (1, 2, 4, or 8) */ + __u16 scale: 4; + /* reserved for future use, keeps reg_off offset stable */ + __u8 __reserved: 8; +#else + __u8 __reserved: 8; + __u16 idx_reg_off: 12; + __u16 scale: 4; + enum __bpf_usdt_arg_type arg_type: 8; +#endif /* offset of referenced register within struct pt_regs */ short reg_off; /* whether arg should be interpreted as signed value */ @@ -149,7 +168,7 @@ int bpf_usdt_arg(struct pt_regs *ctx, __u64 arg_num, lo= ng *res) { struct __bpf_usdt_spec *spec; struct __bpf_usdt_arg_spec *arg_spec; - unsigned long val; + unsigned long val, idx; int err, spec_id; =20 *res =3D 0; @@ -202,6 +221,27 @@ int bpf_usdt_arg(struct pt_regs *ctx, __u64 arg_num, l= ong *res) return err; #if __BYTE_ORDER__ =3D=3D __ORDER_BIG_ENDIAN__ val >>=3D arg_spec->arg_bitshift; +#endif + break; + case BPF_USDT_ARG_SIB: + /* Arg is in memory addressed by SIB (Scale-Index-Base) mode + * (e.g., "-1@-96(%rbp,%rax,8)" in USDT arg spec). We first + * fetch the base register contents and the index register + * contents from pt_regs. Then we calculate the final address + * as base + (index * scale) + offset, and do a user-space + * probe read to fetch the argument value. + */ + err =3D bpf_probe_read_kernel(&val, sizeof(val), (void *)ctx + arg_spec-= >reg_off); + if (err) + return err; + err =3D bpf_probe_read_kernel(&idx, sizeof(idx), (void *)ctx + arg_spec-= >idx_reg_off); + if (err) + return err; + err =3D bpf_probe_read_user(&val, sizeof(val), (void *)(val + (idx * arg= _spec->scale) + arg_spec->val_off)); + if (err) + return err; +#if __BYTE_ORDER__ =3D=3D __ORDER_BIG_ENDIAN__ + val >>=3D arg_spec->arg_bitshift; #endif break; default: diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c index 3373b9d45ac4..d90e0b694134 100644 --- a/tools/lib/bpf/usdt.c +++ b/tools/lib/bpf/usdt.c @@ -200,12 +200,23 @@ enum usdt_arg_type { USDT_ARG_CONST, USDT_ARG_REG, USDT_ARG_REG_DEREF, + USDT_ARG_SIB, }; =20 /* should match exactly struct __bpf_usdt_arg_spec from usdt.bpf.h */ struct usdt_arg_spec { __u64 val_off; - enum usdt_arg_type arg_type; +#if __BYTE_ORDER__ =3D=3D __ORDER_LITTLE_ENDIAN__ + enum usdt_arg_type arg_type: 8; + __u16 idx_reg_off: 12; + __u16 scale: 4; + __u8 __reserved: 8; /* keep reg_off offset stable */ +#else + __u8 __reserved: 8; /* keep reg_off offset stable */ + __u16 idx_reg_off: 12; + __u16 scale: 4; + enum usdt_arg_type arg_type: 8; +#endif short reg_off; bool arg_signed; char arg_bitshift; @@ -1283,11 +1294,46 @@ static int calc_pt_regs_off(const char *reg_name) =20 static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_ar= g_spec *arg, int *arg_sz) { - char reg_name[16]; - int len, reg_off; - long off; + char reg_name[16] =3D {0}, idx_reg_name[16] =3D {0}; + int len, reg_off, idx_reg_off, scale =3D 1; + long off =3D 0; + + if (sscanf(arg_str, " %d @ %ld ( %%%15[^,] , %%%15[^,] , %d ) %n", + arg_sz, &off, reg_name, idx_reg_name, &scale, &len) =3D=3D 5 || + sscanf(arg_str, " %d @ ( %%%15[^,] , %%%15[^,] , %d ) %n", + arg_sz, reg_name, idx_reg_name, &scale, &len) =3D=3D 4 || + sscanf(arg_str, " %d @ %ld ( %%%15[^,] , %%%15[^)] ) %n", + arg_sz, &off, reg_name, idx_reg_name, &len) =3D=3D 4 || + sscanf(arg_str, " %d @ ( %%%15[^,] , %%%15[^)] ) %n", + arg_sz, reg_name, idx_reg_name, &len) =3D=3D 3 + ) { + /* + * Scale Index Base case: + * 1@-96(%rbp,%rax,8) + * 1@(%rbp,%rax,8) + * 1@-96(%rbp,%rax) + * 1@(%rbp,%rax) + */ + arg->arg_type =3D USDT_ARG_SIB; + arg->val_off =3D off; =20 - if (sscanf(arg_str, " %d @ %ld ( %%%15[^)] ) %n", arg_sz, &off, reg_name,= &len) =3D=3D 3) { + reg_off =3D calc_pt_regs_off(reg_name); + if (reg_off < 0) + return reg_off; + arg->reg_off =3D reg_off; + + idx_reg_off =3D calc_pt_regs_off(idx_reg_name); + if (idx_reg_off < 0) + return idx_reg_off; + /* validate scale factor and set fields directly */ + if (scale !=3D 1 && scale !=3D 2 && scale !=3D 4 && scale !=3D 8) { + pr_warn("usdt: invalid SIB scale %d, expected 1, 2, 4, 8\n", scale); + return -EINVAL; + } + arg->idx_reg_off =3D idx_reg_off; + arg->scale =3D scale; + } else if (sscanf(arg_str, " %d @ %ld ( %%%15[^)] ) %n", + arg_sz, &off, reg_name, &len) =3D=3D 3) { /* Memory dereference case, e.g., -4@-20(%rbp) */ arg->arg_type =3D USDT_ARG_REG_DEREF; arg->val_off =3D off; @@ -1306,6 +1352,7 @@ static int parse_usdt_arg(const char *arg_str, int ar= g_num, struct usdt_arg_spec } else if (sscanf(arg_str, " %d @ %%%15s %n", arg_sz, reg_name, &len) =3D= =3D 2) { /* Register read case, e.g., -4@%eax */ arg->arg_type =3D USDT_ARG_REG; + /* register read has no memory offset */ arg->val_off =3D 0; =20 reg_off =3D calc_pt_regs_off(reg_name); --=20 2.43.0 From nobody Wed Dec 17 07:41:48 2025 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.2]) by smtp.subspace.kernel.org (Postfix) with ESMTP id F0D5122259D; Sat, 23 Aug 2025 06:50:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.2 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755931847; cv=none; b=iiNwFMn+AohWBj5Mwpb3wILp7IQTIJswgJulJubxBG4XtRYvBHbFfQMEk5+yx9vwZ2qV5Gb6T/lK7y7Sid8MKaIfQTGO4560/eFxFAhV/e+QT2+IkVocp13HBW56x1G4qrY3XCk1Po7X9t/A+Wb9X7ChSHZ6+rFEzxZZ/d762rk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755931847; c=relaxed/simple; bh=QukoYCtjW4waH+Id5rp8ZqCUjlvR6HYBYHosM6VD1LU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cbv2HUR3tP13qAQYOit5CXaXWQCMx6n3ZnRCxe5Wq7M98BpQnEfqQndK2k3tA0sYNg9bWOCTLCGI989gtc6ZGPUPViUk9/IA537szb9nUoTeHJRY/wnN0ivPn0+/0E4O+bGwF1JYmXJruQvqF8cmA7GW1QFeIzcR+gXwwdqnJdM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=CKa9ISHX; arc=none smtp.client-ip=117.135.210.2 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="CKa9ISHX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=8p O9xe2lXuwQ1Fp2+vvEgmLZFoddmipbcHTTsOk6d3k=; b=CKa9ISHXtmcnlv3F+W UMOn1SFFm77WO2mGKq7FwKICcnoyau1qxZkYyjgcu7Qq2ZVQRPRszXgcjnxN8l+l h8tG8O8HZAinubNF2qJ5xrzjCE9d/2Tl1VXB8iik0pNC420WjWuLOU8CNYl4u4fb Fb1CakZNFUBo4R6zcVPrnU/Ck= Received: from phoenix.. (unknown []) by gzga-smtp-mtada-g0-2 (Coremail) with SMTP id _____wAn8USdZKlohCriDQ--.20793S4; Sat, 23 Aug 2025 14:50:09 +0800 (CST) From: Jiawei Zhao To: ast@kernel.org Cc: daniel@iogearbox.net, andrii@kernel.org, yonghong.song@linux.dev, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf-next v14 2/2] selftests/bpf: Enrich subtest_basic_usdt case in selftests to cover SIB handling logic Date: Sat, 23 Aug 2025 06:50:04 +0000 Message-ID: <20250823065005.1187181-3-phoenix500526@163.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250823065005.1187181-1-phoenix500526@163.com> References: <20250823065005.1187181-1-phoenix500526@163.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wAn8USdZKlohCriDQ--.20793S4 X-Coremail-Antispam: 1Uf129KBjvJXoWxKF15Cry3JFW7ZFWkWw4DArb_yoWxGFyUpa ykZ34xtFy5t3WxGw4xJr4jqw4rKFn2yrW5AFZrXry2yrWkGrs7Xrn7K3W3KFnIqaykX3W5 ArZ0kan5tw4xXF7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jqeHDUUUUU= X-CM-SenderInfo: pskrv0dl0viiqvswqiywtou0bp/1tbiFAqyiGipWPbE8QACs8 Content-Type: text/plain; charset="utf-8" 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: - enrich subtest_basic_usdt test case to cover SIB addressing usdt argument= spec handling logic Signed-off-by: Jiawei Zhao --- tools/testing/selftests/bpf/prog_tests/usdt.c | 62 ++++++++++++++++++- tools/testing/selftests/bpf/progs/test_usdt.c | 32 ++++++++++ 2 files changed, 92 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/usdt.c b/tools/testing/= selftests/bpf/prog_tests/usdt.c index 9057e983cc54..0d5e40eca0d4 100644 --- a/tools/testing/selftests/bpf/prog_tests/usdt.c +++ b/tools/testing/selftests/bpf/prog_tests/usdt.c @@ -10,6 +10,26 @@ =20 int lets_test_this(int); =20 +#if defined(__x86_64__) || defined(__i386__) +/* + * SIB (Scale-Index-Base) addressing format: + * "size@(base_reg, index_reg, scale)" + * - 'size' is the size in bytes of the array element, and its sign indica= tes + * whether the type is signed (negative) or unsigned (positive). + * - 'base_reg' is the register holding the base address, normally rdx or = edx + * - 'index_reg' is the register holding the index, normally rax or eax + * - 'scale' is the scaling factor (typically 1, 2, 4, or 8), which matche= s the + * size of the element type. + * + * For example, for an array of 'short' (signed 2-byte elements), the SIB = spec would be: + * - size: -2 (negative because 'short' is signed) + * - scale: 2 (since sizeof(short) =3D=3D 2) + * The resulting SIB format: "-2@(%%rdx,%%rax,2)" + */ +static volatile short array[] =3D {-1, -2, -3, -4}; +#define USDT_SIB_ARG_SPEC -2@(%%rdx,%%rax,2) +#endif + static volatile int idx =3D 2; static volatile __u64 bla =3D 0xFEDCBA9876543210ULL; static volatile short nums[] =3D {-1, -2, -3, -4}; @@ -25,6 +45,10 @@ unsigned short test_usdt0_semaphore SEC(".probes"); unsigned short test_usdt3_semaphore SEC(".probes"); unsigned short test_usdt12_semaphore SEC(".probes"); =20 +#if defined(__x86_64__) || defined(__i386__) +unsigned short test_usdt_sib_semaphore SEC(".probes"); +#endif + static void __always_inline trigger_func(int x) { long y =3D 42; =20 @@ -40,12 +64,27 @@ static void __always_inline trigger_func(int x) { } } =20 +#if defined(__x86_64__) || defined(__i386__) +static void trigger_sib_spec(void) +{ + /* Base address + offset + (index * scale) */ + /* Force SIB addressing with inline assembly */ + asm volatile( + STAP_PROBE_ASM(test, usdt_sib, USDT_SIB_ARG_SPEC) + : + : "d"(array), "a"(0) + : "memory" + ); +} +#endif + static void subtest_basic_usdt(void) { LIBBPF_OPTS(bpf_usdt_opts, opts); struct test_usdt *skel; struct test_usdt__bss *bss; int err, i; + const __u64 expected_cookie =3D 0xcafedeadbeeffeed; =20 skel =3D test_usdt__open_and_load(); if (!ASSERT_OK_PTR(skel, "skel_open")) @@ -59,20 +98,29 @@ static void subtest_basic_usdt(void) goto cleanup; =20 /* usdt0 won't be auto-attached */ - opts.usdt_cookie =3D 0xcafedeadbeeffeed; + opts.usdt_cookie =3D expected_cookie; skel->links.usdt0 =3D bpf_program__attach_usdt(skel->progs.usdt0, 0 /*self*/, "/proc/self/exe", "test", "usdt0", &opts); if (!ASSERT_OK_PTR(skel->links.usdt0, "usdt0_link")) goto cleanup; =20 +#if defined(__x86_64__) || defined(__i386__) + opts.usdt_cookie =3D expected_cookie; + skel->links.usdt_sib =3D bpf_program__attach_usdt(skel->progs.usdt_sib, + 0 /*self*/, "/proc/self/exe", + "test", "usdt_sib", &opts); + if (!ASSERT_OK_PTR(skel->links.usdt_sib, "usdt_sib_link")) + goto cleanup; +#endif + trigger_func(1); =20 ASSERT_EQ(bss->usdt0_called, 1, "usdt0_called"); ASSERT_EQ(bss->usdt3_called, 1, "usdt3_called"); ASSERT_EQ(bss->usdt12_called, 1, "usdt12_called"); =20 - ASSERT_EQ(bss->usdt0_cookie, 0xcafedeadbeeffeed, "usdt0_cookie"); + ASSERT_EQ(bss->usdt0_cookie, expected_cookie, "usdt0_cookie"); ASSERT_EQ(bss->usdt0_arg_cnt, 0, "usdt0_arg_cnt"); ASSERT_EQ(bss->usdt0_arg_ret, -ENOENT, "usdt0_arg_ret"); ASSERT_EQ(bss->usdt0_arg_size, -ENOENT, "usdt0_arg_size"); @@ -156,6 +204,16 @@ static void subtest_basic_usdt(void) ASSERT_EQ(bss->usdt3_args[1], 42, "usdt3_arg2"); ASSERT_EQ(bss->usdt3_args[2], (uintptr_t)&bla, "usdt3_arg3"); =20 +#if defined(__x86_64__) || defined(__i386__) + trigger_sib_spec(); + ASSERT_EQ(bss->usdt_sib_called, 1, "usdt_sib_called"); + ASSERT_EQ(bss->usdt_sib_cookie, expected_cookie, "usdt_sib_cookie"); + ASSERT_EQ(bss->usdt_sib_arg_cnt, 1, "usdt_sib_arg_cnt"); + ASSERT_EQ(bss->usdt_sib_arg, nums[0], "usdt_sib_arg"); + ASSERT_EQ(bss->usdt_sib_arg_ret, 0, "usdt_sib_arg_ret"); + ASSERT_EQ(bss->usdt_sib_arg_size, sizeof(nums[0]), "usdt_sib_arg_size"); +#endif + cleanup: test_usdt__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/test_usdt.c b/tools/testing/= selftests/bpf/progs/test_usdt.c index 096488f47fbc..63db72253316 100644 --- a/tools/testing/selftests/bpf/progs/test_usdt.c +++ b/tools/testing/selftests/bpf/progs/test_usdt.c @@ -107,4 +107,36 @@ int BPF_USDT(usdt12, int a1, int a2, long a3, long a4,= unsigned a5, return 0; } =20 + +int usdt_sib_called; +u64 usdt_sib_cookie; +int usdt_sib_arg_cnt; +int usdt_sib_arg_ret; +u64 usdt_sib_arg; +int usdt_sib_arg_size; + +/* + * usdt_sib is only tested on x86-related architectures, so it requires + * manual attach since auto-attach will panic tests under other architectu= res + */ +SEC("usdt") +int usdt_sib(struct pt_regs *ctx) +{ + long tmp; + + if (my_pid !=3D (bpf_get_current_pid_tgid() >> 32)) + return 0; + + __sync_fetch_and_add(&usdt_sib_called, 1); + + usdt_sib_cookie =3D bpf_usdt_cookie(ctx); + usdt_sib_arg_cnt =3D bpf_usdt_arg_cnt(ctx); + + usdt_sib_arg_ret =3D bpf_usdt_arg(ctx, 0, &tmp); + usdt_sib_arg =3D (short)tmp; + usdt_sib_arg_size =3D bpf_usdt_arg_size(ctx, 0); + + return 0; +} + char _license[] SEC("license") =3D "GPL"; --=20 2.43.0