From: Mathieu Chouquet-Stringer <mchouque-GANU6spQydw@public.gmane.org>
To: j@w1.fi
Cc: linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: [PATCH] hostap: procfs fix for hostap_fw.c
Date: Tue, 6 May 2008 17:23:54 +0200 [thread overview]
Message-ID: <20080506152354.GA3680@mobydick> (raw)
Hello,
I've been toying with hostap_pci and found a bug that is triggered when
you unload/reload the module.
If you don't have PRISM2_NO_PROCFS_DEBUG defined (which is the default,
as per hostap_config.h), the driver creates a "registers" file in /proc
used to dump PRISM registers (function prism2_init_local_data):
#ifndef PRISM2_NO_PROCFS_DEBUG
create_proc_read_entry("registers", 0, local->proc,
prism2_registers_proc_read, local);
#endif /* PRISM2_NO_PROCFS_DEBUG */
Note that create_proc_read_entry is being called with local->proc which
isn't defined at the time: "registers" ends up being created as
/proc/registers.
When hostap_pci is done initializing the hardware, it calls
hostap_hw_ready which in turns creates all the files in /proc through
hostap_init_proc (hostap_proc.c):
local->proc = NULL;
if (hostap_proc == NULL) {
printk(KERN_WARNING "%s: hostap proc directory not created\n",
local->dev->name);
return;
}
local->proc = proc_mkdir(local->ddev->name, hostap_proc);
So far so good, well sort of... When you unload the module,
prism2_free_local_data does this:
#ifndef PRISM2_NO_PROCFS_DEBUG
if (local->proc != NULL)
remove_proc_entry("registers", local->proc);
#endif /* PRISM2_NO_PROCFS_DEBUG */
hostap_remove_proc(local);
Problem is local->proc has now been overwritten by hostap_init_proc
meaning "registers" isn't removed. When you reload the module you get
an error telling you "registers" already exists (and you then get
duplicate "registers" files in /proc).
So in a nutshell "registers" should be created after calling
hostap_init_proc (this way it'll be created where it belongs -
/proc/net/hostap/%s) making it removable at module unload.
Please apply the patch below which does just that: it creates "register"
in hostap_hw_ready right after creating all the proc entries.
Best,
Mathieu
Signed-off-by: Mathieu Chouquet-Stringer <mchouque-GANU6spQydw@public.gmane.org>
diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c
index 7be68db..454fcb4 100644
--- a/drivers/net/wireless/hostap/hostap_hw.c
+++ b/drivers/net/wireless/hostap/hostap_hw.c
@@ -3276,11 +3276,6 @@ while (0)
}
printk(KERN_INFO "%s: Registered netdevice %s\n", dev_info, dev->name);
-#ifndef PRISM2_NO_PROCFS_DEBUG
- create_proc_read_entry("registers", 0, local->proc,
- prism2_registers_proc_read, local);
-#endif /* PRISM2_NO_PROCFS_DEBUG */
reply other threads:[~2008-05-06 15:23 UTC|newest]
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