From nobody Mon Oct 6 15:19:42 2025 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5C74923DE; Sun, 20 Jul 2025 10:55:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753008958; cv=none; b=j3nBW5ob1t4jYPWMo+mfkzCH5IiN+IMwUX8kVL5fTZJKQyubBoCmrANWy2ikYTK99CFNqFL1TV55+YptOtGPPlIv4dmxSYSi7NUC5DgGsvfX0OS8KKr3ANCCZb3y2lYOtDvhqH4ddApkTzr1gDqpeocbiVjmritmaONZ4GOAGls= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753008958; c=relaxed/simple; bh=yTaoxejXwNQCn++pllekPZVksUSS8z4GbWq3pO1U1H8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=L3nMHLkcQndAleYCNEsqwpmRUoKEPVKsWdS1j1bYTHuK07CZw9Vrqf/dZ1rEwmNGozWWtJ0hKU5BeJ5lhrHShWkFmLvRvTeXzEydqAgrLY+5V58mNw52jbU17Q8Pu0TF1JN0g9otYkiKQinYuBfRuz2OR3tNfbZMPz/yzawJD6k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [223.64.68.193]) by gateway (Coremail) with SMTP id _____8Bx22owy3xoUSkuAQ--.59383S3; Sun, 20 Jul 2025 18:55:44 +0800 (CST) Received: from localhost.localdomain (unknown [223.64.68.193]) by front1 (Coremail) with SMTP id qMiowJDxscIYy3xoyY8eAA--.18430S2; Sun, 20 Jul 2025 18:55:42 +0800 (CST) From: Huacai Chen To: Huacai Chen , Andrew Morton Cc: linux-mm@kvack.org, Alexander Viro , Christian Brauner , Jan Kara , linux-kernel@vger.kernel.org, Huacai Chen , stable@vger.kernel.org Subject: [PATCH V2] init: Handle bootloader identifier in kernel parameters Date: Sun, 20 Jul 2025 18:55:09 +0800 Message-ID: <20250720105509.2914898-1-chenhuacai@loongson.cn> 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: quoted-printable X-CM-TRANSID: qMiowJDxscIYy3xoyY8eAA--.18430S2 X-CM-SenderInfo: hfkh0x5xdftxo6or00hjvr0hdfq/ X-Coremail-Antispam: 1Uk129KBj93XoW7tw4fCr1rCFW3GF1xXr17XFc_yoW8uw43pF s2qryrW3ykGw45Cr4kWrWvgrySvwnxZa17GanxWan8XFn8tFy0qrWFkF4aga4Dtr4fKF42 qFnrZF18CF17CFXCm3ZEXasCq-sJn29KB7ZKAUJUUUUr529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUU9Yb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_JFI_Gr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Jr0_Gr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2kKe7AKxVWUXVWUAwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWU XVWUAwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7V AKI48JMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMxCIbckI1I0E14v2 6r1Y6r17MI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17 CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF 0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIx AIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWUJVW8JbIYCTnIWIev Ja73UjIFyTuYvjxU2MKZDUUUU Content-Type: text/plain; charset="utf-8" BootLoader (Grub, LILO, etc) may pass an identifier such as "BOOT_IMAGE=3D /boot/vmlinuz-x.y.z" to kernel parameters. But these identifiers are not recognized by the kernel itself so will be passed to user space. However user space init program also doesn't recognized it. KEXEC may also pass an identifier such as "kexec" on some architectures. We cannot change BootLoader's behavior, because this behavior exists for many years, and there are already user space programs search BOOT_IMAGE=3D in /proc/cmdline to obtain the kernel image locations: https://github.com/linuxdeepin/deepin-ab-recovery/blob/master/util.go (search getBootOptions) https://github.com/linuxdeepin/deepin-ab-recovery/blob/master/main.go (search getKernelReleaseWithBootOption) So the the best way is handle (ignore) it by the kernel itself, which can avoid such boot warnings (if we use something like init=3D/bin/bash, bootloader identifier can even cause a crash): Kernel command line: BOOT_IMAGE=3D(hd0,1)/vmlinuz-6.x root=3D/dev/sda3 ro c= onsole=3Dtty Unknown kernel command line parameters "BOOT_IMAGE=3D(hd0,1)/vmlinuz-6.x", = will be passed to user space. Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen --- V2: Update comments and commit messages. init/main.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/init/main.c b/init/main.c index 225a58279acd..c53863e5ad82 100644 --- a/init/main.c +++ b/init/main.c @@ -545,6 +545,7 @@ static int __init unknown_bootoption(char *param, char = *val, const char *unused, void *arg) { size_t len =3D strlen(param); + const char *bootloader[] =3D { "BOOT_IMAGE=3D", "kexec", NULL }; =20 /* Handle params aliased to sysctls */ if (sysctl_is_alias(param)) @@ -552,6 +553,12 @@ static int __init unknown_bootoption(char *param, char= *val, =20 repair_env_string(param, val); =20 + /* Handle bootloader identifier */ + for (int i =3D 0; bootloader[i]; i++) { + if (!strncmp(param, bootloader[i], strlen(bootloader[i]))) + return 0; + } + /* Handle obsolete-style parameters */ if (obsolete_checksetup(param)) return 0; --=20 2.47.3