From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-177.mta0.migadu.com (out-177.mta0.migadu.com [91.218.175.177]) (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 BFAFE9444 for ; Sat, 10 May 2025 21:01:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746910900; cv=none; b=umfpE1hdvPscz8NCGXnsH3LDxpiHRc3shfAHswekoeCvEeFs9KZ2S94n1mqbAOiCRJIsum8E2egOw9SJEXN/hpovG733nEprJAN5LNT10CZegW9GPKUogQWkhrwICObLX8XiGY4H4/GB8I4AAxQrHpVM/y4/nyfR/ZcxozF9tcQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746910900; c=relaxed/simple; bh=CqyaO56/um0r7+07UnuOVscO2huajZ+XOTAMEA9PjAs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=HCc98RF2DXjlhCYeEVBXMvIXrb0WpWteDb7sBUBhwIYzlypeRQPtFcM0mwTZm3aDsa3QhkzOHMGEq3Z0M832N7VlINtZtCRr+0XUKEkA5uX53efHlfaVpTD8cu6MXkCEvtVXhZLHAdFWP2hhA1VraG7vDB4mYpp5r6rlyt27zMQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Tba9+g+h; arc=none smtp.client-ip=91.218.175.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Tba9+g+h" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1746910894; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=SbT4EkS9jDwls1/MWPzR6fUxNMkTZUGDTe7h7TpT/ko=; b=Tba9+g+hj5ohfWOFe9qq5iXS40bSZ7Tj2ikBvDOSHh6Fe+fLHL18HEe/hpl+yKriILmQrn dtWpOGN+mFOEOG1DAXVSNqjoBpU/B0U1PVmuaU4llaGy+J7UUtpM5Aju1jpCdrxsWGXmmj VyKBjKpvlwL+rUHfcVW64oG6C8VyaQQ= From: Kent Overstreet To: linux-kernel@vger.kernel.org Cc: Kent Overstreet , Luis Chamberlain , Petr Pavlu , Sami Tolvanen , Daniel Gomez , linux-modules@vger.kernel.org Subject: [PATCH] params: Add support for static keys Date: Sat, 10 May 2025 17:01:26 -0400 Message-ID: <20250510210126.4032840-1-kent.overstreet@linux.dev> Precedence: bulk X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Static keys can now be a module parameter, e.g. module_param_named(foo, foo.key, static_key_t, 0644) bcachefs is now using this. Cc: Luis Chamberlain Cc: Petr Pavlu Cc: Sami Tolvanen Cc: Daniel Gomez Cc: linux-modules@vger.kernel.org Signed-off-by: Kent Overstreet --- include/linux/jump_label.h | 2 ++ include/linux/moduleparam.h | 6 ++++++ kernel/params.c | 35 +++++++++++++++++++++++++++++++++++ 3 files changed, 43 insertions(+) diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index fdb79dd1ebd8..0fc9b71db56f 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -107,6 +107,8 @@ struct static_key { #endif /* CONFIG_JUMP_LABEL */ }; +typedef struct static_key static_key_t; + #endif /* __ASSEMBLY__ */ #ifdef CONFIG_JUMP_LABEL diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index bfb85fd13e1f..2494e7e67453 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -488,6 +488,12 @@ extern int param_set_bint(const char *val, const struct kernel_param *kp); #define param_get_bint param_get_int #define param_check_bint param_check_int +/* A static key, which can only be set like a bool */ +extern const struct kernel_param_ops param_ops_static_key_t; +extern int param_set_static_key_t(const char *val, const struct kernel_param *kp); +extern int param_get_static_key_t(char *buffer, const struct kernel_param *kp); +#define param_check_static_key_t(name, p) __param_check(name, p, struct static_key) + /** * module_param_array - a parameter which is an array of some type * @name: the name of the array variable diff --git a/kernel/params.c b/kernel/params.c index 2509f216c9f3..991f49e138e7 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #ifdef CONFIG_SYSFS @@ -412,6 +413,40 @@ const struct kernel_param_ops param_ops_bint = { }; EXPORT_SYMBOL(param_ops_bint); +int param_set_static_key_t(const char *val, const struct kernel_param *kp) +{ + /* Match bool exactly, by re-using it. */ + struct kernel_param boolkp = *kp; + bool v; + int ret; + + boolkp.arg = &v; + + ret = param_set_bool(val, &boolkp); + if (ret) + return ret; + if (v) + static_key_enable(kp->arg); + else + static_key_disable(kp->arg); + return 0; +} +EXPORT_SYMBOL(param_set_static_key_t); + +int param_get_static_key_t(char *buffer, const struct kernel_param *kp) +{ + struct static_key *key = kp->arg; + return sprintf(buffer, "%c\n", static_key_enabled(key) ? 'N' : 'Y'); +} +EXPORT_SYMBOL(param_get_static_key_t); + +const struct kernel_param_ops param_ops_static_key_t = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = param_set_static_key_t, + .get = param_get_static_key_t, +}; +EXPORT_SYMBOL(param_ops_static_key_t); + /* We break the rule and mangle the string. */ static int param_array(struct module *mod, const char *name, -- 2.49.0