From nobody Mon Feb 9 21:18:41 2026 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 34650289811 for ; Wed, 12 Nov 2025 14:21:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762957277; cv=none; b=k+8ohqRLYtGFdE6hNt8iu6Q+KRbY4esbNpSXN2joIzPZo+BYYJIE1tPGiZaBd93rOpLYg4w3hxCiNMSWxay7q+Ovb+kNbobMo9gQmfjPabMnjchWqhjIWUa1ShvYQP4nh+oVG2U0qvxjrOmfmMvXuNPxF2ddEdh4KA1J5pAHgGA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762957277; c=relaxed/simple; bh=u3JhEMeaHqCCm3K2TgktQ2sf6pbkWpeo3IYBAWNLKUE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tvWfsCb27zLNQpBKIL5WeROExeJ5OJyzfz3JjDCi+L3VonAMywBqMzLi9qgkfaY8+sBsLsduKVZZPAfW5r5b4X9LRl28zMfCYR+EXZmIfCfJZS5EADEfaFMl3n6EqgMNBFk21yq1858ULAMfDBIoSt4CwKIQI4LMZms2sDVCcQ0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b=BnLRB4F5; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b=nfE6lf8+; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="BnLRB4F5"; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="nfE6lf8+" Received: from pathway.suse.cz (unknown [10.100.208.146]) by smtp-out2.suse.de (Postfix) with ESMTP id E55921F807; Wed, 12 Nov 2025 14:21:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1762957274; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BqiSBpirJiJgacOo4S6qpog2Igj/FxV7fepY1Ud1yj0=; b=BnLRB4F5kJvWwq0uNFeHowmv1KnJLRD/SadwOgmpAPdbqJwMwnI2r67nMU7639gySQO1fw JaE3y0NsrSLvGGxVw9iHHz7i8Z+lbkGWc/CDpNdA3Gh0MkYEUAQPXr76+w/l+22E8RAm8m 7M67Qyji0EBagdLVxL6cWqvJYII5ebM= Authentication-Results: smtp-out2.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1762957273; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BqiSBpirJiJgacOo4S6qpog2Igj/FxV7fepY1Ud1yj0=; b=nfE6lf8+xSB8X6uMB6MAvfX9g5LM0PTktLSW/TjYc8aWLCrkOH2loOODKkGAZ7ffflRX/g 7JGH4bmjSV1stI5Nvw5xWQD+yt0coyQ5lnK9Q4yzEhFYwkTC8fOw+OPXGP7/DtyrDJG0+E ynBOFl4UpXHJAr2iReFapL95pgRSQZY= From: Petr Mladek To: Petr Pavlu , Steven Rostedt , Alexei Starovoitov , Andrew Morton , Kees Cook Cc: Aaron Tomlin , Daniel Borkmann , John Fastabend , Masami Hiramatsu , Mark Rutland , Luis Chamberlain , Daniel Gomez , Sami Tolvanen , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-modules@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Petr Mladek Subject: [PATCH v2 4/7] kallsyms: Cleanup code for appending the module buildid Date: Wed, 12 Nov 2025 15:20:00 +0100 Message-ID: <20251112142003.182062-5-pmladek@suse.com> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251112142003.182062-1-pmladek@suse.com> References: <20251112142003.182062-1-pmladek@suse.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-Spamd-Result: default: False [-5.30 / 50.00]; REPLY(-4.00)[]; BAYES_HAM(-3.00)[100.00%]; SUSPICIOUS_RECIPS(1.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MID_CONTAINS_FROM(1.00)[]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; ARC_NA(0.00)[]; FUZZY_RATELIMITED(0.00)[rspamd.com]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCPT_COUNT_TWELVE(0.00)[18]; MIME_TRACE(0.00)[0:+]; TO_DN_SOME(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; FREEMAIL_CC(0.00)[atomlin.com,iogearbox.net,gmail.com,kernel.org,arm.com,google.com,vger.kernel.org,suse.com]; RCVD_COUNT_ZERO(0.00)[0]; FROM_HAS_DN(0.00)[]; TAGGED_RCPT(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:mid,suse.com:email,pathway.suse.cz:helo]; R_RATELIMIT(0.00)[to_ip_from(RLw9bydq1j5bti46rxed9sjz7y)]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; FREEMAIL_ENVRCPT(0.00)[gmail.com] X-Spam-Flag: NO X-Spam-Score: -5.30 X-Spam-Level: Content-Type: text/plain; charset="utf-8" Put the code for appending the optional "buildid" into a helper function, It makes __sprint_symbol() better readable. Also print a warning when the "modname" is set and the "buildid" isn't. It might catch a situation when some lookup function in kallsyms_lookup_buildid() does not handle the "buildid". Use pr_*_once() to avoid an infinite recursion when the function is called from printk(). The recursion is rather theoretical but better be on the safe side. Signed-off-by: Petr Mladek --- kernel/kallsyms.c | 42 +++++++++++++++++++++++++++++++++--------- 1 file changed, 33 insertions(+), 9 deletions(-) diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index ffb64eaa0505..f25b122397ce 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -432,6 +432,37 @@ int lookup_symbol_name(unsigned long addr, char *symna= me) return lookup_module_symbol_name(addr, symname); } =20 +#ifdef CONFIG_STACKTRACE_BUILD_ID + +static int append_buildid(char *buffer, const char *modname, + const unsigned char *buildid) +{ + if (!modname) + return 0; + + if (!buildid) { + pr_warn_once("Undefined buildid for the module %s\n", modname); + return 0; + } + + /* build ID should match length of sprintf */ +#ifdef CONFIG_MODULES + static_assert(sizeof(typeof_member(struct module, build_id)) =3D=3D 20); +#endif + + return sprintf(buffer, " %20phN", buildid); +} + +#else /* CONFIG_STACKTRACE_BUILD_ID */ + +static int append_buildid(char *buffer, const char *modname, + const unsigned char *buildid) +{ + return 0; +} + +#endif /* CONFIG_STACKTRACE_BUILD_ID */ + /* Look up a kernel symbol and return it in a text buffer. */ static int __sprint_symbol(char *buffer, unsigned long address, int symbol_offset, int add_offset, int add_buildid) @@ -454,15 +485,8 @@ static int __sprint_symbol(char *buffer, unsigned long= address, =20 if (modname) { len +=3D sprintf(buffer + len, " [%s", modname); -#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) - if (add_buildid && buildid) { - /* build ID should match length of sprintf */ -#if IS_ENABLED(CONFIG_MODULES) - static_assert(sizeof(typeof_member(struct module, build_id)) =3D=3D 20); -#endif - len +=3D sprintf(buffer + len, " %20phN", buildid); - } -#endif + if (add_buildid) + len +=3D append_buildid(buffer + len, modname, buildid); len +=3D sprintf(buffer + len, "]"); } =20 --=20 2.51.1