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mac80211: reduce stack usage in debugfs

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We put a few large buffers on the stack here, but it's easy to
just allocate them on the heap, so do that.

Link: https://lore.kernel.org/r/20210920154009.1387f44e7382.Ife043c169e6a44edace516fea9f8311a5ca4282a@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Johannes Berg 2021-09-20 15:40:06 +02:00
parent 40f231e75a
commit 01f84f0ed3
1 changed files with 31 additions and 7 deletions
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38
net/mac80211/debugfs_sta.c
View File

@ -5,7 +5,7 @@
* Copyright 2007 Johannes Berg <johannes@sipsolutions.net> * Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
* Copyright 2013-2014 Intel Mobile Communications GmbH * Copyright 2013-2014 Intel Mobile Communications GmbH
* Copyright(c) 2016 Intel Deutschland GmbH * Copyright(c) 2016 Intel Deutschland GmbH
* Copyright (C) 2018 - 2020 Intel Corporation * Copyright (C) 2018 - 2021 Intel Corporation
*/ */
#include <linux/debugfs.h> #include <linux/debugfs.h>
@ -314,11 +314,17 @@ STA_OPS_RW(aql);
static ssize_t sta_agg_status_read(struct file *file, char __user *userbuf, static ssize_t sta_agg_status_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos) size_t count, loff_t *ppos)
{ {
char buf[71 + IEEE80211_NUM_TIDS * 40], *p = buf; char *buf, *p;
int i; int i;
struct sta_info *sta = file->private_data; struct sta_info *sta = file->private_data;
struct tid_ampdu_rx *tid_rx; struct tid_ampdu_rx *tid_rx;
struct tid_ampdu_tx *tid_tx; struct tid_ampdu_tx *tid_tx;
ssize_t ret;
buf = kzalloc(71 + IEEE80211_NUM_TIDS * 40, GFP_KERNEL);
if (!buf)
return -ENOMEM;
p = buf;
rcu_read_lock(); rcu_read_lock();
@ -352,7 +358,9 @@ static ssize_t sta_agg_status_read(struct file *file, char __user *userbuf,
} }
rcu_read_unlock(); rcu_read_unlock();
return simple_read_from_buffer(userbuf, count, ppos, buf, p - buf); ret = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
kfree(buf);
return ret;
} }
static ssize_t sta_agg_status_write(struct file *file, const char __user *userbuf, static ssize_t sta_agg_status_write(struct file *file, const char __user *userbuf,
@ -434,10 +442,16 @@ static ssize_t sta_ht_capa_read(struct file *file, char __user *userbuf,
if (_cond) \ if (_cond) \
p += scnprintf(p, sizeof(buf)+buf-p, "\t" _str "\n"); \ p += scnprintf(p, sizeof(buf)+buf-p, "\t" _str "\n"); \
} while (0) } while (0)
char buf[512], *p = buf; char *buf, *p;
int i; int i;
struct sta_info *sta = file->private_data; struct sta_info *sta = file->private_data;
struct ieee80211_sta_ht_cap *htc = &sta->sta.ht_cap; struct ieee80211_sta_ht_cap *htc = &sta->sta.ht_cap;
ssize_t ret;
buf = kzalloc(512, GFP_KERNEL);
if (!buf)
return -ENOMEM;
p = buf;
p += scnprintf(p, sizeof(buf) + buf - p, "ht %ssupported\n", p += scnprintf(p, sizeof(buf) + buf - p, "ht %ssupported\n",
htc->ht_supported ? "" : "not "); htc->ht_supported ? "" : "not ");
@ -504,16 +518,24 @@ static ssize_t sta_ht_capa_read(struct file *file, char __user *userbuf,
htc->mcs.tx_params); htc->mcs.tx_params);
} }
return simple_read_from_buffer(userbuf, count, ppos, buf, p - buf); ret = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
kfree(buf);
return ret;
} }
STA_OPS(ht_capa); STA_OPS(ht_capa);
static ssize_t sta_vht_capa_read(struct file *file, char __user *userbuf, static ssize_t sta_vht_capa_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos) size_t count, loff_t *ppos)
{ {
char buf[512], *p = buf; char *buf, *p;
struct sta_info *sta = file->private_data; struct sta_info *sta = file->private_data;
struct ieee80211_sta_vht_cap *vhtc = &sta->sta.vht_cap; struct ieee80211_sta_vht_cap *vhtc = &sta->sta.vht_cap;
ssize_t ret;
buf = kzalloc(512, GFP_KERNEL);
if (!buf)
return -ENOMEM;
p = buf;
p += scnprintf(p, sizeof(buf) + buf - p, "VHT %ssupported\n", p += scnprintf(p, sizeof(buf) + buf - p, "VHT %ssupported\n",
vhtc->vht_supported ? "" : "not "); vhtc->vht_supported ? "" : "not ");
@ -609,7 +631,9 @@ static ssize_t sta_vht_capa_read(struct file *file, char __user *userbuf,
#undef PFLAG #undef PFLAG
} }
return simple_read_from_buffer(userbuf, count, ppos, buf, p - buf); ret = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
kfree(buf);
return ret;
} }
STA_OPS(vht_capa); STA_OPS(vht_capa);