On Thu, 1 Nov 2012, Jiri Kosina wrote:
> > Commit 4fe9f8e203fdad1524c04beb390f3c6099781ed9 upstream
> > Commit 57a38d925e665fcd729cd9ad4a75c84e11bd95c9 linux-stable
> >
> > This commit "HID: hidraw: don't deallocate memory when it is in use"
> > prevents users to rmmod then insmod any hid special driver without
> > either physically unplugging the device or without rmmod-ing the hid
> > bus itself.
> >
> > When the user does a rmmod, hidinput_disconnect is called before
> > hidraw_disconnect, thus, the hidraw device is still there, but the
> > input one not. It leads to the fact that the device is not working
> > anymore even if you call modprobe.
> >
> > Any idea to solve that?
>
> Guys, how about this?
>
>
> ---
> drivers/hid/hidraw.c | 5 +++--
> 1 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
> index 17d15bb..fce4256 100644
> --- a/drivers/hid/hidraw.c
> +++ b/drivers/hid/hidraw.c
> @@ -560,10 +560,11 @@ static void drop_ref(struct hidraw *hidraw, int exists_bit)
> {
> mutex_lock(&minors_lock);
> if (exists_bit) {
> - hid_hw_close(hidraw->hid);
> hidraw->exist = 0;
> - if (hidraw->open)
> + if (hidraw->open) {
> + hid_hw_close(hidraw->hid);
> wake_up_interruptible(&hidraw->wait);
> + }
> } else {
> --hidraw->open;
> }
So this seems to fix the problem with rmmod/modprobe, but the patch has
apparently other problems. rmmoding special driver while reading from
hidraw interface causes this:
------------[ cut here ]------------
WARNING: at lib/list_debug.c:59 __list_del_entry+0xa4/0xd0()
Hardware name: 7470BN2
list_del corruption. prev->next should be ffff880036f97178, but was 6b6b6b6b6b6b6b6b
Modules linked in: af_packet rfcomm bnep tun iptable_mangle xt_DSCP nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables xt
e nf_conntrack iptable_filter ip_tables x_tables cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf dm_mod
m_intel kvm iwldvm mac80211 snd_hda_codec_conexant microcode usbhid sg iwlwifi pcspkr snd_hda_intel cfg80211 lpc_ich i2c_i801 mfd_c
imer snd_page_alloc thinkpad_acpi rfkill wmi snd ac soundcore battery tpm_tis tpm tpm_bios autofs4 uhci_hcd ehci_hcd usbcore usb_co
button edd fan processor ata_generic thermal thermal_sys [last unloaded: hid_cypress]
Pid: 4725, comm: hexdump Not tainted 3.7.0-rc3-00008-g35fd3dc #157
Call Trace:
[<ffffffff812f95c4>] ? __list_del_entry+0xa4/0xd0
[<ffffffff812f95c4>] ? __list_del_entry+0xa4/0xd0
[<ffffffff810452fa>] warn_slowpath_common+0x7a/0xb0
[<ffffffff810453d1>] warn_slowpath_fmt+0x41/0x50
[<ffffffff812f95c4>] __list_del_entry+0xa4/0xd0
[<ffffffff812f9601>] list_del+0x11/0x40
[<ffffffff81454a23>] hidraw_release+0x33/0x50
[<ffffffff8118cd0a>] __fput+0xca/0x2b0
[<ffffffff8118cf49>] ____fput+0x9/0x10
[<ffffffff8106b7a1>] task_work_run+0xb1/0xe0
[<ffffffff8104c81e>] do_exit+0x1ee/0x4c0
[<ffffffff810adcad>] ? trace_hardirqs_on_caller+0x12d/0x1b0
[<ffffffff8104cb37>] do_group_exit+0x47/0xc0
[<ffffffff8104cbc2>] sys_exit_group+0x12/0x20
[<ffffffff8158a529>] system_call_fastpath+0x16/0x1b
---[ end trace 3bec13493e086171 ]---
As Ratan doesn't seem to be responsive and I don't have time to debug it
as the moment, I'll just be reverting Ratan's patch for 3.7 completely.
--
Jiri Kosina
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
