From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1519773784; cv=none; d=google.com; s=arc-20160816; b=mg+8eUuUvIj13m7jTl9bxHcLgghNf5c+Iy4ZYrth418uxoFpCKTLlUD4OSMqQGSJzX M5i4c0hexEPVjUrytvpB0KuR1vAcYLtbZ23vAojLrVmdYvfmPtnZUFbTS5SstQez9Sod DCwLOKKYa9auZUmgd+bHWgchdAXz0yFYlKI0hj0P1brB/ts3FW8fy7GFX7YYx4MexKX6 a2fsU7gjcq6Qy3cMtloZKtHjdIxeKKsN5lLjHyUN2YmLU3mbrVboKXMJCjIc+TZ1beJY du6ZrqxPAiwsctZqP77fy/29oF0rqtedymwBiSMZxHThxs+ENnOtLe1kZnp/s22wPCsk eyow== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=cc:to:subject:message-id:date:from:references:in-reply-to:sender :mime-version:dkim-signature:dkim-signature :arc-authentication-results; bh=tGDi/70heOUovRST6lROw/JMYgjYh9dezyoUHJ8A/30=; b=UiAJlcgVT+iFcMwsC8rF1euohCUVa4kcXvT/pldezhLuVJMGAy38plDvrntCCR321u wQH8If3lVo1kEsnXnXFhGuN4jiyElzx0Mr2ntgDOjEYbOukYNfcGhOGrvpvmY7pqp/Wl +lM4FWbYI9y2x9DuGX1jPm6+LZ3v8WLyC9Z9Mm5GlEmTUx1IbhUguK8JSWob1Wn2Fh2P GjU5lNduDJhDjmiIunJD8Z82T72lTlLm162Q01myG9b144EV/+5MZCUXBslQg/MoNxzJ SqMCDZeMOMOHVKp5dmulWAcGLOio9Qec5VpaiiYpEZMM+i+ML3SY6F1PgkvVfQBbv5UF A3/Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=mfviC+8p; dkim=pass header.i=@chromium.org header.s=google header.b=dKLF2sLS; spf=pass (google.com: domain of keescook@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=keescook@google.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=mfviC+8p; dkim=pass header.i=@chromium.org header.s=google header.b=dKLF2sLS; spf=pass (google.com: domain of keescook@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=keescook@google.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org X-Google-Smtp-Source: AG47ELu/AVDFAjiw41a6Jy6HPz7lGPziEH4r6c8fZqv60TFdy5YKhcMcf5hk7rV9D4GQK4s7zfLa4Odr7cr/d5h5SJA= MIME-Version: 1.0 Sender: keescook@google.com In-Reply-To: <20180224024613.24078-10-mcgrof@kernel.org> References: <20180224024613.24078-1-mcgrof@kernel.org> <20180224024613.24078-10-mcgrof@kernel.org> From: Kees Cook Date: Tue, 27 Feb 2018 15:23:03 -0800 X-Google-Sender-Auth: ZYScVxCijSRqqBUqwBYIrCLPuvc Message-ID: Subject: Re: [PATCH v2 09/11] firmware: enable to force disable the fallback mechanism at run time To: "Luis R. Rodriguez" Cc: Greg KH , Andrew Morton , Shuah Khan , Martin Fuzzey , Mimi Zohar , David Howells , pali.rohar@gmail.com, Takashi Iwai , arend.vanspriel@broadcom.com, =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= , nbroeking@me.com, Vikram Mulukutla , stephen.boyd@linaro.org, Mark Brown , Dmitry Torokhov , David Woodhouse , Linus Torvalds , Abhay_Salunke@dell.com, bjorn.andersson@linaro.org, jewalt@lgsinnovations.com, LKML , "linux-fsdevel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1593248722155111296?= X-GMAIL-MSGID: =?utf-8?q?1593598316273048748?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Fri, Feb 23, 2018 at 6:46 PM, Luis R. Rodriguez wrote: > You currently need four different kernel builds to test the firmware > API fully. By adding a proc knob to force disable the fallback mechanism > completely we are able to reduce the amount of kernels you need built > to test the firmware API down to two. > > Signed-off-by: Luis R. Rodriguez Acked-by: Kees Cook -Kees > --- > drivers/base/firmware_fallback.c | 5 +++++ > drivers/base/firmware_fallback.h | 4 ++++ > drivers/base/firmware_fallback_table.c | 9 +++++++++ > 3 files changed, 18 insertions(+) > > diff --git a/drivers/base/firmware_fallback.c b/drivers/base/firmware_fallback.c > index cbce9a950cd8..13fa5ff2b46c 100644 > --- a/drivers/base/firmware_fallback.c > +++ b/drivers/base/firmware_fallback.c > @@ -643,6 +643,11 @@ static bool fw_force_sysfs_fallback(unsigned int opt_flags) > > static bool fw_run_sysfs_fallback(unsigned int opt_flags) > { > + if (fw_fallback_config.ignore_sysfs_fallback) { > + pr_info_once("Ignoring firmware sysfs fallback due to debugfs knob\n"); > + return false; > + } > + > if ((opt_flags & FW_OPT_NOFALLBACK)) > return false; > > diff --git a/drivers/base/firmware_fallback.h b/drivers/base/firmware_fallback.h > index ca7e69a8417b..dfebc644ed35 100644 > --- a/drivers/base/firmware_fallback.h > +++ b/drivers/base/firmware_fallback.h > @@ -14,12 +14,16 @@ > * as if one had enabled CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y. > * Useful to help debug a CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y > * functionality on a kernel where that config entry has been disabled. > + * @ignore_sysfs_fallback: force to disable the sysfs fallback mechanism. > + * This emulates the behaviour as if we had set the kernel > + * config CONFIG_FW_LOADER_USER_HELPER=n. > * @old_timeout: for internal use > * @loading_timeout: the timeout to wait for the fallback mechanism before > * giving up, in seconds. > */ > struct firmware_fallback_config { > unsigned int force_sysfs_fallback; > + unsigned int ignore_sysfs_fallback; > int old_timeout; > int loading_timeout; > }; > diff --git a/drivers/base/firmware_fallback_table.c b/drivers/base/firmware_fallback_table.c > index 77300d5e9c52..5e990b0330c7 100644 > --- a/drivers/base/firmware_fallback_table.c > +++ b/drivers/base/firmware_fallback_table.c > @@ -39,6 +39,15 @@ struct ctl_table firmware_config_table[] = { > .extra1 = &zero, > .extra2 = &one, > }, > + { > + .procname = "ignore_sysfs_fallback", > + .data = &fw_fallback_config.ignore_sysfs_fallback, > + .maxlen = sizeof(unsigned int), > + .mode = 0644, > + .proc_handler = proc_douintvec_minmax, > + .extra1 = &zero, > + .extra2 = &one, > + }, > { } > }; > EXPORT_SYMBOL_GPL(firmware_config_table); > -- > 2.16.2 > -- Kees Cook Pixel Security