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 885632C11D5; Tue, 21 Apr 2026 09:54:52 +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=1776765292; cv=none; b=jYwOVAd9ywYr5kIq/jgmEUIh0zo0ukE7tGK3K9HsltTQcUAU6fJy0xoPHF98i1MI6XnVPKm8E8xnMnTCkxA5rSYj0ULtV3sf5KZw4DTtyxETpJ8ZxOT8lVP0BSa2HGmsJJEmMfbHyEaeBPBwt7aDJ2xlOSrR5qJFhwxSxUqQRTk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776765292; c=relaxed/simple; bh=005nSr9PcwcpWMrkMnnLw5KzGHpwsyQmbaNI4ETSzOI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=ZuhPTsloM8CfR5p34LhDBnuWVv3fQRtpHo/ISwcpOz/J7sKESFkmDVF3H/LoKHqFy4dH6QACc0vJ8djJv5jxYyueLEnizRESUi6QgW0IckzueP56ahuZXT2V3Duom7mD7P5NMTg4S42cGPyTT+UyXh3cv/ni/JjtjwKtFKit1nY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JlHQavFR; 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="JlHQavFR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32A36C2BCB0; Tue, 21 Apr 2026 09:54:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776765292; bh=005nSr9PcwcpWMrkMnnLw5KzGHpwsyQmbaNI4ETSzOI=; h=From:To:Cc:Subject:Date:From; b=JlHQavFR7vQNlGyJp7mtx9//PUxdrDZHk+LJOVN0FG8mlDMEqmeZP5cFRkyPcA0rt jE1HfcDyVsTc/zWGZdnpnjEyNjblvo3QUO09Xyfi3SoTj6zrIrOboukX+IYtPzjAoY Dcc0YSC5rSCvNVltb6VxhYFCEiZkpIGxOyOZ1qwipAlrAvJJWmvtW31n/Q1D/ydM67 fHz1UKyOQ8Nte7Fihp5S5V9Yomdfyb526jt4lUV6p39A77uw5oc1+pQXcJ2BcES8UU WDjL4ZDvmsv6yLTCMtLjZ0KeVrCrFZLjx7d2j2SF4tIzYxiU/CqNpBYG4p7kJ4Aub/ mQkZlHXxHACHg== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1wF7of-0000000DNJ6-3Sf8; Tue, 21 Apr 2026 09:54:49 +0000 From: Marc Zyngier To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Linus Torvalds , Paolo Bonzini , Vincent Donnefort , Nathan Chancellor , Steven Rostedt , Arnd Bergmann Subject: [PATCH] tracing: Make undefsyms_base.c a first-class citizen Date: Tue, 21 Apr 2026 10:54:46 +0100 Message-ID: <20260421095446.2951646-1-maz@kernel.org> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.linux.dev, torvalds@linux-foundation.org, pbonzini@redhat.com, vdonnefort@google.com, nathan@kernel.org, rostedt@goodmis.org, arnd@arndb.de X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Linus points out that dumping undefsyms_base.c form the Makefile is rather ugly, and that a much better course of action would be to have this file as a first-class citizen in the git tree. This allows some extra cleanup in the Makefile, and the removal of the .gitignore file in kernel/trace. Link: https://lore.kernel.org/r/CAHk-=wieqGd_XKpu8UxDoyADZx8TDe8CF3RmkUXt5N_9t5Pf_w@mail.gmail.com Signed-off-by: Marc Zyngier Cc: Linus Torvalds Cc: Paolo Bonzini Cc: Vincent Donnefort Cc: Nathan Chancellor Cc: Steven Rostedt Cc: Arnd Bergmann --- kernel/trace/.gitignore | 1 - kernel/trace/Makefile | 23 ----------------------- kernel/trace/undefsyms_base.c | 14 ++++++++++++++ 3 files changed, 14 insertions(+), 24 deletions(-) delete mode 100644 kernel/trace/.gitignore create mode 100644 kernel/trace/undefsyms_base.c diff --git a/kernel/trace/.gitignore b/kernel/trace/.gitignore deleted file mode 100644 index 6adbb09d6deb0..0000000000000 --- a/kernel/trace/.gitignore +++ /dev/null @@ -1 +0,0 @@ -/undefsyms_base.c diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 4d4229e5eec4b..0b0b8f5b9d2bf 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -140,29 +140,6 @@ obj-$(CONFIG_TRACE_REMOTE_TEST) += remote_test.o # undefsyms_base generates a set of compiler and tooling-generated symbols that can # safely be ignored for simple_ring_buffer. # -filechk_undefsyms_base = \ - echo '$(pound)include '; \ - echo '$(pound)include '; \ - echo '$(pound)include '; \ - echo 'static char page[PAGE_SIZE] __aligned(PAGE_SIZE);'; \ - echo 'void undefsyms_base(void *p, int n);'; \ - echo 'void undefsyms_base(void *p, int n) {'; \ - echo ' char buffer[256] = { 0 };'; \ - echo ' u32 u = 0;'; \ - echo ' memset((char * volatile)page, 8, PAGE_SIZE);'; \ - echo ' memset((char * volatile)buffer, 8, sizeof(buffer));'; \ - echo ' memcpy((void * volatile)p, buffer, sizeof(buffer));'; \ - echo ' cmpxchg((u32 * volatile)&u, 0, 8);'; \ - echo ' WARN_ON(n == 0xdeadbeef);'; \ - echo '}' - -$(obj)/undefsyms_base.c: FORCE - $(call filechk,undefsyms_base) - -clean-files += undefsyms_base.c - -$(obj)/undefsyms_base.o: $(obj)/undefsyms_base.c - targets += undefsyms_base.o # Ensure KASAN is enabled to avoid logic that may disable FORTIFY_SOURCE when diff --git a/kernel/trace/undefsyms_base.c b/kernel/trace/undefsyms_base.c new file mode 100644 index 0000000000000..3db5adf918cce --- /dev/null +++ b/kernel/trace/undefsyms_base.c @@ -0,0 +1,14 @@ +#include +#include +#include +static char page[PAGE_SIZE] __aligned(PAGE_SIZE); +void undefsyms_base(void *p, int n); +void undefsyms_base(void *p, int n) { + char buffer[256] = { 0 }; + u32 u = 0; + memset((char * volatile)page, 8, PAGE_SIZE); + memset((char * volatile)buffer, 8, sizeof(buffer)); + memcpy((void * volatile)p, buffer, sizeof(buffer)); + cmpxchg((u32 * volatile)&u, 0, 8); + WARN_ON(n == 0xdeadbeef); +} -- 2.47.3