From patchwork Thu Nov 9 21:22:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 13451766 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 DABE538F87 for ; Thu, 9 Nov 2023 21:38:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="oivGQvGs" Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:242:246e::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5DF22139; Thu, 9 Nov 2023 13:38:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Content-Type:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=+DtEJdw1hoIddhRyJ2mVLtfdj8W1joudvJrs09mD3A4=; t=1699565905; x=1700775505; b=oivGQvGso84+xWyeMP70VawhLwOycZqLWhdWpejaMMlG5wr t3bfh8e+lk0W+TyCRSRE0wYsVW1/2k7MdFeWmtP5sYFFujM8n78IVFZxAr3s0/UNltKEsmMRm4ajq BEV/IfGn35NAWQgCR03GbQWIQhtbk8kVYuLAV7/sWCZsoimoz53TL9ceORr5l2fIWaYZsr8VxS+zD 506/boRHbvK1j7+kdHi2628msi1LGL+iOUJdks0ini9VGoLEXpN7/a+FOzs7f3T3WkUUsT/ARRMIx exqCWN4xV8PiEQ1vVwlTGE9Ruk65YaKP5jwHA+gVzTn9bk6lMuFIDZtpWsTcPdYA==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.97) (envelope-from ) id 1r1CjF-00000001znF-4871; Thu, 09 Nov 2023 22:38:22 +0100 From: Johannes Berg To: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, Greg Kroah-Hartman , "Rafael J. Wysocki" , Nicolai Stange , Ben Greear , Johannes Berg Subject: [RFC PATCH 6/6] wifi: mac80211: use wiphy locked debugfs for sdata/link Date: Thu, 9 Nov 2023 22:22:58 +0100 Message-ID: <20231109222251.f6f6241e2541.I99a21601e124f5ac4e161ad32b19949e7896e390@changeid> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231109212251.213873-7-johannes@sipsolutions.net> References: <20231109212251.213873-7-johannes@sipsolutions.net> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Johannes Berg The debugfs files for netdevs (sdata) and links are removed with the wiphy mutex held, which may deadlock. Use the new wiphy locked debugfs to avoid that. Signed-off-by: Johannes Berg --- net/mac80211/debugfs_netdev.c | 150 ++++++++++++++++++++++++---------- 1 file changed, 105 insertions(+), 45 deletions(-) diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c index ec91e131b29e..80aeb25f1b68 100644 --- a/net/mac80211/debugfs_netdev.c +++ b/net/mac80211/debugfs_netdev.c @@ -22,88 +22,148 @@ #include "debugfs_netdev.h" #include "driver-ops.h" +struct ieee80211_if_read_sdata_data { + ssize_t (*format)(const struct ieee80211_sub_if_data *, char *, int); + struct ieee80211_sub_if_data *sdata; +}; + +static ssize_t ieee80211_if_read_sdata_handler(struct wiphy *wiphy, + struct file *file, + char *buf, + size_t bufsize, + void *data) +{ + struct ieee80211_if_read_sdata_data *d = data; + + return d->format(d->sdata, buf, bufsize); +} + static ssize_t ieee80211_if_read_sdata( - struct ieee80211_sub_if_data *sdata, + struct file *file, char __user *userbuf, size_t count, loff_t *ppos, ssize_t (*format)(const struct ieee80211_sub_if_data *sdata, char *, int)) { + struct ieee80211_sub_if_data *sdata = file->private_data; + struct ieee80211_if_read_sdata_data data = { + .format = format, + .sdata = sdata, + }; char buf[200]; - ssize_t ret = -EINVAL; - wiphy_lock(sdata->local->hw.wiphy); - ret = (*format)(sdata, buf, sizeof(buf)); - wiphy_unlock(sdata->local->hw.wiphy); + return wiphy_locked_debugfs_read(sdata->local->hw.wiphy, + file, buf, sizeof(buf), + userbuf, count, ppos, + ieee80211_if_read_sdata_handler, + &data); +} - if (ret >= 0) - ret = simple_read_from_buffer(userbuf, count, ppos, buf, ret); +struct ieee80211_if_write_sdata_data { + ssize_t (*write)(struct ieee80211_sub_if_data *, const char *, int); + struct ieee80211_sub_if_data *sdata; +}; - return ret; +static ssize_t ieee80211_if_write_sdata_handler(struct wiphy *wiphy, + struct file *file, + char *buf, + size_t count, + void *data) +{ + struct ieee80211_if_write_sdata_data *d = data; + + return d->write(d->sdata, buf, count); } static ssize_t ieee80211_if_write_sdata( - struct ieee80211_sub_if_data *sdata, + struct file *file, const char __user *userbuf, size_t count, loff_t *ppos, ssize_t (*write)(struct ieee80211_sub_if_data *sdata, const char *, int)) { + struct ieee80211_sub_if_data *sdata = file->private_data; + struct ieee80211_if_write_sdata_data data = { + .write = write, + .sdata = sdata, + }; char buf[64]; - ssize_t ret; - if (count >= sizeof(buf)) - return -E2BIG; + return wiphy_locked_debugfs_write(sdata->local->hw.wiphy, + file, buf, sizeof(buf), + userbuf, count, + ieee80211_if_write_sdata_handler, + &data); +} - if (copy_from_user(buf, userbuf, count)) - return -EFAULT; - buf[count] = '\0'; +struct ieee80211_if_read_link_data { + ssize_t (*format)(const struct ieee80211_link_data *, char *, int); + struct ieee80211_link_data *link; +}; - wiphy_lock(sdata->local->hw.wiphy); - ret = (*write)(sdata, buf, count); - wiphy_unlock(sdata->local->hw.wiphy); +static ssize_t ieee80211_if_read_link_handler(struct wiphy *wiphy, + struct file *file, + char *buf, + size_t bufsize, + void *data) +{ + struct ieee80211_if_read_link_data *d = data; - return ret; + return d->format(d->link, buf, bufsize); } static ssize_t ieee80211_if_read_link( - struct ieee80211_link_data *link, + struct file *file, char __user *userbuf, size_t count, loff_t *ppos, ssize_t (*format)(const struct ieee80211_link_data *link, char *, int)) { + struct ieee80211_link_data *link = file->private_data; + struct ieee80211_if_read_link_data data = { + .format = format, + .link = link, + }; char buf[200]; - ssize_t ret = -EINVAL; - wiphy_lock(link->sdata->local->hw.wiphy); - ret = (*format)(link, buf, sizeof(buf)); - wiphy_unlock(link->sdata->local->hw.wiphy); + return wiphy_locked_debugfs_read(link->sdata->local->hw.wiphy, + file, buf, sizeof(buf), + userbuf, count, ppos, + ieee80211_if_read_link_handler, + &data); +} - if (ret >= 0) - ret = simple_read_from_buffer(userbuf, count, ppos, buf, ret); +struct ieee80211_if_write_link_data { + ssize_t (*write)(struct ieee80211_link_data *, const char *, int); + struct ieee80211_link_data *link; +}; - return ret; +static ssize_t ieee80211_if_write_link_handler(struct wiphy *wiphy, + struct file *file, + char *buf, + size_t count, + void *data) +{ + struct ieee80211_if_write_sdata_data *d = data; + + return d->write(d->sdata, buf, count); } static ssize_t ieee80211_if_write_link( - struct ieee80211_link_data *link, + struct file *file, const char __user *userbuf, size_t count, loff_t *ppos, ssize_t (*write)(struct ieee80211_link_data *link, const char *, int)) { + struct ieee80211_link_data *link = file->private_data; + struct ieee80211_if_write_link_data data = { + .write = write, + .link = link, + }; char buf[64]; - ssize_t ret; - if (count >= sizeof(buf)) - return -E2BIG; - - if (copy_from_user(buf, userbuf, count)) - return -EFAULT; - buf[count] = '\0'; - - wiphy_lock(link->sdata->local->hw.wiphy); - ret = (*write)(link, buf, count); - wiphy_unlock(link->sdata->local->hw.wiphy); - - return ret; + return wiphy_locked_debugfs_write(link->sdata->local->hw.wiphy, + file, buf, sizeof(buf), + userbuf, count, + ieee80211_if_write_link_handler, + &data); } #define IEEE80211_IF_FMT(name, type, field, format_string) \ @@ -173,7 +233,7 @@ static ssize_t ieee80211_if_read_##name(struct file *file, \ char __user *userbuf, \ size_t count, loff_t *ppos) \ { \ - return ieee80211_if_read_sdata(file->private_data, \ + return ieee80211_if_read_sdata(file, \ userbuf, count, ppos, \ ieee80211_if_fmt_##name); \ } @@ -183,7 +243,7 @@ static ssize_t ieee80211_if_write_##name(struct file *file, \ const char __user *userbuf, \ size_t count, loff_t *ppos) \ { \ - return ieee80211_if_write_sdata(file->private_data, userbuf, \ + return ieee80211_if_write_sdata(file, userbuf, \ count, ppos, \ ieee80211_if_parse_##name); \ } @@ -211,7 +271,7 @@ static ssize_t ieee80211_if_read_##name(struct file *file, \ char __user *userbuf, \ size_t count, loff_t *ppos) \ { \ - return ieee80211_if_read_link(file->private_data, \ + return ieee80211_if_read_link(file, \ userbuf, count, ppos, \ ieee80211_if_fmt_##name); \ } @@ -221,7 +281,7 @@ static ssize_t ieee80211_if_write_##name(struct file *file, \ const char __user *userbuf, \ size_t count, loff_t *ppos) \ { \ - return ieee80211_if_write_link(file->private_data, userbuf, \ + return ieee80211_if_write_link(file, userbuf, \ count, ppos, \ ieee80211_if_parse_##name); \ }