From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 41E2B3DD869; Thu, 14 May 2026 13:54:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778766846; cv=none; b=ebItvXnbLMRi/Sz4IdX6O8EN0fcEDGP8jzI7OQ3rbFW7Si7jd9mFO6K20LAIXYRGmuWej7jh5v6AJ0mCGSLwxkPZnoiTrUOo1cf65N2i8yw5cea4zmPgdbFZwveQWf5YmhYFN2kC9BbERfOWxZQJeeestTOcdD8K/X1VZLvZwbk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778766846; c=relaxed/simple; bh=HqwVdCDQ5PT4T0eOwYDAP/Ngm6gJlwORb493qxmzn5w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fzrzxp24OCkOVx80/ypekHBHWhy+zAPAk5zOG5qC+HN/TLn1eTPCk7RmKuBWBDZDJI7kCxHiWTX0XrutrVC70daOQPvj6+hB6BxGq6+9zKQ2jD7xi9rM1aonbNcY0GSJPHR/N7oCRLgexDbGeu1Jf6ibITsUUV2/31TXlRChDhE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a2oJuChD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a2oJuChD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC873C2BCB3; Thu, 14 May 2026 13:54:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778766845; bh=HqwVdCDQ5PT4T0eOwYDAP/Ngm6gJlwORb493qxmzn5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a2oJuChDzeQnRFD8lpKzwqrVggp4DPJ2ybLs0VzfCXr0xKxuWsTA+PBsYsRo+YdRU 3/9i2P/BQ/4nri3+QfsFi5h2KlFK/zqcLwoAS8AzOblhvQOksXmpXX4cLsWQdh0oAj c8JKi8ZJ2Sw2WVozu6G0dhHab0eBRXt3JzYN+CWhpcPMyM78c/94U/DtlOZTIWLQ28 QuZzmq6PXPWMkuPQ+aVEm3NlgaWkZnIRQ9Pz0gRlnpKiol/QE7JMAXdb0MFMA+kZRi FSfJCzXE6np2yDSH0rGi9CT0xM2x8JNZudgDUl/lfplG4RI19zYULdi7DaV4DbUN8y tLu5YX0VsLaSg== From: Jiri Olsa To: Oleg Nesterov , Peter Zijlstra , Ingo Molnar , Masami Hiramatsu , Andrii Nakryiko Cc: bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH 2/7] libbpf: Change has_nop_combo to work on top of nop10 Date: Thu, 14 May 2026 15:53:37 +0200 Message-ID: <20260514135342.22130-3-jolsa@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260514135342.22130-1-jolsa@kernel.org> References: <20260514135342.22130-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit We now expect nop combo with 10 bytes nop instead of 5 bytes nop, fixing has_nop_combo to reflect that. Signed-off-by: Jiri Olsa --- tools/lib/bpf/usdt.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c index e3710933fd52..7e62e4d5bedd 100644 --- a/tools/lib/bpf/usdt.c +++ b/tools/lib/bpf/usdt.c @@ -305,7 +305,7 @@ struct usdt_manager *usdt_manager_new(struct bpf_object *obj) /* * Detect kernel support for uprobe() syscall, it's presence means we can - * take advantage of faster nop5 uprobe handling. + * take advantage of faster nop10 uprobe handling. * Added in: 56101b69c919 ("uprobes/x86: Add uprobe syscall to speed up uprobe") */ man->has_uprobe_syscall = kernel_supports(obj, FEAT_UPROBE_SYSCALL); @@ -596,14 +596,14 @@ static int parse_usdt_spec(struct usdt_spec *spec, const struct usdt_note *note, #if defined(__x86_64__) static bool has_nop_combo(int fd, long off) { - unsigned char nop_combo[6] = { - 0x90, 0x0f, 0x1f, 0x44, 0x00, 0x00 /* nop,nop5 */ + unsigned char nop_combo[11] = { + 0x90, 0x66, 0x66, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00, }; - unsigned char buf[6]; + unsigned char buf[11]; - if (pread(fd, buf, 6, off) != 6) + if (pread(fd, buf, 11, off) != 11) return false; - return memcmp(buf, nop_combo, 6) == 0; + return memcmp(buf, nop_combo, 11) == 0; } #else static bool has_nop_combo(int fd, long off) @@ -814,8 +814,8 @@ static int collect_usdt_targets(struct usdt_manager *man, struct elf_fd *elf_fd, memset(target, 0, sizeof(*target)); /* - * We have uprobe syscall and usdt with nop,nop5 instructions combo, - * so we can place the uprobe directly on nop5 (+1) and get this probe + * We have uprobe syscall and usdt with nop,nop10 instructions combo, + * so we can place the uprobe directly on nop10 (+1) and get this probe * optimized. */ if (man->has_uprobe_syscall && has_nop_combo(elf_fd->fd, usdt_rel_ip)) { -- 2.53.0