Bug#735202: speakup freezes system when trying to paste
Ben, I downloaded upstream kernel 3.12.17 and reproduced the issue. Then I patched it and using this patched kernel I see no ways to reproduce the issue. Pasting always works, even in scenario reported in bug #744015. Now I'll try to reproduce this other bug with and without the patch with kernel 3.14. Paul, thanks for the snapshot link. I couldn't find this useful archive by myself. I wanted to add that preparing a kernel from source works like a charm. I haven't seen any project that would be easier to build. It takes quite long, that's a different story. 11 hours. [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=744015 -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#735202: speakup freezes system when trying to paste
Ben, Recently I had a bunch of kernel's to choose from at boot time. But I must have done some accidental cleanup (apt-get autoremove maybe) and now from the 3.x series I have only 3.13. So it's what you were afraid of. If there is any doable scenario in which I could build and run 3.12 version and be able to apply your patches, I can still engage in that. But I would need some general preliminary guidance. I know were to find upstream kernel source package, but not sure if I can work on them. If there was a place to get deb files for 3.12, the rest should be easy. Jarek -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#735202: speakup freezes system when trying to paste
On 07-04-14 19:30, Jarek Czekalski wrote: If there was a place to get deb files for 3.12, the rest should be easy. http://snapshot.debian.org/ Paul signature.asc Description: OpenPGP digital signature
Bug#735202: speakup freezes system when trying to paste
On Tue, 2014-03-18 at 23:44 +0100, Jarek Czekalski wrote: [...] I can't freeze nor get scheduling on 3.13.1 kernel. So I confirm Jude's report, that this kernel version seems to be free of the bug. I can't freeze the kernel without a background task. Ben, is it still important to test your patches? I would have to do this hard job of compiling the kernel to test them, but if you need it, I'll do the job. It is not too difficult if you follow the instructions I linked to. But if you don't have a reliable way to reproduce the bug under 3.13, you won't be able to tell whether the patches fix it. Ben. -- Ben Hutchings Sturgeon's Law: Ninety percent of everything is crap. signature.asc Description: This is a digitally signed message part
Bug#735202: speakup freezes system when trying to paste
Hey Ben! After reading your findings I wanted to see if I can get at least these scheduling messages. So I started my 3.12.1 kernel and did some speakupping, while compiling glib in the background! Bingo, I got BUG ... scheduling ... message on console.. and an immediate freeze as well :( So these are my conditions for the freeze: 1. fire kernel 3.12.1 2. launch screen and a command while [[ 1 ]]; do find|wc; done and detach this screen (C-a d) 3. do some speakup pasting, cat is not necessary to experience the freeze after at most 3 pastes The BUG message also contained the word find. Something to do with my find command perhaps. I can't freeze nor get scheduling on 3.13.1 kernel. So I confirm Jude's report, that this kernel version seems to be free of the bug. I can't freeze the kernel without a background task. Ben, is it still important to test your patches? I would have to do this hard job of compiling the kernel to test them, but if you need it, I'll do the job. Jarek -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#735202: speakup freezes system when trying to paste
On Sat, 2014-03-01 at 17:23 +0100, Jarek Czekalski wrote: I have Debian unstable with kernel 3.12.8-1 and cannot reproduce the issue. What should I change in my system to make it reproduce? Here are my steps: 1. boot debian into console prompt 2. login as root 3. modprobe speakup_soft 4. service espeakup start 5. type test 6. mark tes using speakup hot keys 7. paste tes using Ins-/ 7. execute cat 8. paste tes using Ins-/ Thanks for the hints. All works, nothing hangs. The only strange thing is that inside cat it does not show the text until I press enter. Does the issue reproduce with any speakup synthesizer? Including dummy, none and soft? I can't reproduce the hang, but when I do the above the kernel does report 'scheduling while atomic' (full log below) and that means there is the potential for a hang. I'm working on a patch for this. Ben. [ 553.085884] BUG: scheduling while atomic: swapper/0/0/0x1001 [ 553.087285] Modules linked in: speakup_soft(C) speakup(C) ip6table_filter ip6_tables iptable_filter ip_tables ebtable_nat ebtables x_tables parport_pc ppdev lp bnep parport rfcomm bluetooth snd_hrtimer cpufreq_powersave cpu freq_conservative cpufreq_stats cpufreq_userspace binfmt_misc nfsv3 nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc fuse nls_utf8 nls_cp437 vfat fat loop x86_pkg_temp_thermal intel_powerclamp joydev snd_hda_code c_hdmi coretemp kvm_intel snd_hda_codec_realtek kvm snd_hda_intel snd_hda_codec snd_hwdep i915 iTCO_wdt iTCO_vendor_support crct10dif_pclmul crc32_pclmul lpc_ich crc32c_intel snd_pcm mfd_core ghash_clmulni_intel drm_kms_helper drm efi_pstore i2c_algo_bit i2c_i801 i2c_core efivars eeepc_wmi aesni_intel asus_wmi aes_x86_64 snd_page_alloc pcspkr psmouse snd_seq snd_seq_device snd_timer snd mei_me lrw sparse_keymap mei rfkill soundcore gf128mul process or glue_helper video serio_raw evdev ablk_helper wmi button cryptd ext4 crc16 mbcache jbd2 dm_mod sr_mod cdrom hid_generic hid_lenovo_tpkbd usbhid hid usb_storage sg sd_mod crc_t10dif crct10dif_common aic7xxx scsi_transport_sp i ahci libahci ehci_pci ehci_hcd xhci_hcd libata scsi_mod fan usbcore usb_common thermal thermal_sys r8169 mii [ 553.087367] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G C 3.12-0.bpo.1-amd64 #1 Debian 3.12.9-1~bpo70+1 [ 553.087369] Hardware name: System manufacturer System Product Name/P8Z68-V LX, BIOS 4003 08/22/2012 [ 553.087371] 81813480 814be0b3 88021f214300 [ 553.087375] 814baf3b 814c1c78 88021f203a96 [ 553.087378] 81801fd8 81801fd8 81801fd8 [ 553.087381] Call Trace: [ 553.087383] IRQ [814be0b3] ? dump_stack+0x41/0x51 [ 553.087392] [814baf3b] ? __schedule_bug+0x45/0x55 [ 553.087396] [814c1c78] ? __schedule+0x768/0x780 [ 553.087401] [8108ef5d] ? __cond_resched+0x1d/0x30 [ 553.087404] [814c1d10] ? _cond_resched+0x30/0x40 [ 553.087407] [814c1169] ? down_read+0x9/0x19 [ 553.087411] [813347b8] ? n_tty_receive_buf+0x28/0xa0 [ 553.087417] [a076f09e] ? speakup_paste_selection+0x13e/0x160 [speakup] [ 553.087421] [810913b0] ? try_to_wake_up+0x280/0x280 [ 553.087425] [a076c5b0] ? speakup_win_set+0x230/0x230 [speakup] [ 553.087429] [a076ba1d] ? keyboard_notifier_call+0x2ed/0xc50 [speakup] [ 553.087432] [811981e5] ? pollwake+0x65/0x70 [ 553.087436] [814c7895] ? notifier_call_chain+0x45/0x60 [ 553.087440] [814c78e5] ? atomic_notifier_call_chain+0x15/0x20 [ 553.087444] [8133fa37] ? kbd_event+0x2b7/0x710 [ 553.087448] [8138a7a3] ? input_to_handler+0xd3/0xe0 [ 553.087453] [8138c880] ? input_pass_values+0x150/0x160 [ 553.087457] [8138d190] ? input_handle_event+0x140/0x540 [ 553.087460] [8138d6c2] ? input_event+0x72/0x90 [ 553.087470] [a0098318] ? scsi_run_queue+0xc8/0x260 [scsi_mod] [ 553.087473] [81392c9a] ? atkbd_interrupt+0x5fa/0x6b0 [ 553.087478] [8101c195] ? sched_clock+0x5/0x10 [ 553.087481] [81387edd] ? serio_interrupt+0x4d/0xa0 [ 553.087484] [81388e4c] ? i8042_interrupt+0x18c/0x3a0 [ 553.087488] [810b648b] ? do_timer+0x1eb/0x620 [ 553.087492] [8106521d] ? __do_softirq+0x14d/0x280 [ 553.087496] [810ad294] ? handle_irq_event_percpu+0x54/0x210 [ 553.087500] [810ad491] ? handle_irq_event+0x41/0x70 [ 553.087503] [810aff65] ? handle_edge_irq+0x75/0x110 [ 553.087507] [81016648] ? handle_irq+0x18/0x30 [ 553.087510] [81016163] ? do_IRQ+0x53/0xd0 [ 553.087514] [814c3d2d] ? common_interrupt+0x6d/0x6d [ 553.087515] EOI [813a012b] ? cpuidle_enter_state+0x5b/0xf0 [ 553.087522] [813a0124] ? cpuidle_enter_state+0x54/0xf0 [ 553.087526] [813a028b] ? cpuidle_idle_call+0xcb/0x240 [
Bug#735202: speakup freezes system when trying to paste
On Sat, 2014-03-15 at 23:03 +, Ben Hutchings wrote:
[...]
I can't reproduce the hang, but when I do the above the kernel does
report 'scheduling while atomic' (full log below) and that means there
is the potential for a hang.
I'm working on a patch for this.
[...]
I'm attaching two patches, one which should directly address this and a
second which fixes further locking bugs in the same area. They fixed
the 'scheduling while atomic' error for me. Please test them, following
the directions at
http://kernel-handbook.alioth.debian.org/ch-common-tasks.html#s-common-official.
If necessary, I can provide new packages for you to test, but this does
take more of my time.
Ben.
--
Ben Hutchings
When you say `I wrote a program that crashed Windows', people just stare ...
and say `Hey, I got those with the system, *for free*'. - Linus Torvalds
From e5951c042f47f8c12810984453ef66920b422e71 Mon Sep 17 00:00:00 2001
From: Ben Hutchings b...@decadent.org.uk
Date: Sat, 15 Mar 2014 22:34:09 +
Subject: [PATCH 1/2] Staging: speakup: Move pasting into a work item
Input is handled in softirq context, but when pasting we may
need to sleep. speakup_paste_selection() currently tries to
bodge this by busy-waiting if in_atomic(), but that doesn't
help because the ldisc may also sleep.
For bonus breakage, speakup_paste_selection() changes the
state of current, even though it's not running in process
context.
Move it into a work item and make sure to cancel it on exit.
Signed-off-by: Ben Hutchings b...@decadent.org.uk
---
drivers/staging/speakup/main.c | 1 +
drivers/staging/speakup/selection.c | 38 +++--
drivers/staging/speakup/speakup.h | 1 +
3 files changed, 34 insertions(+), 6 deletions(-)
diff --git a/drivers/staging/speakup/main.c b/drivers/staging/speakup/main.c
index 14079c4..2239fdd 100644
--- a/drivers/staging/speakup/main.c
+++ b/drivers/staging/speakup/main.c
@@ -2220,6 +2220,7 @@ static void __exit speakup_exit(void)
unregister_keyboard_notifier(keyboard_notifier_block);
unregister_vt_notifier(vt_notifier_block);
speakup_unregister_devsynth();
+ speakup_cancel_paste();
del_timer(cursor_timer);
kthread_stop(speakup_task);
speakup_task = NULL;
diff --git a/drivers/staging/speakup/selection.c b/drivers/staging/speakup/selection.c
index f0fb003..f67941e 100644
--- a/drivers/staging/speakup/selection.c
+++ b/drivers/staging/speakup/selection.c
@@ -4,6 +4,8 @@
#include linux/sched.h
#include linux/device.h /* for dev_warn */
#include linux/selection.h
+#include linux/workqueue.h
+#include asm/cmpxchg.h
#include speakup.h
@@ -121,20 +123,24 @@ int speakup_set_selection(struct tty_struct *tty)
return 0;
}
-/* TODO: move to some helper thread, probably. That'd fix having to check for
- * in_atomic(). */
-int speakup_paste_selection(struct tty_struct *tty)
+struct speakup_paste_work {
+ struct work_struct work;
+ struct tty_struct *tty;
+};
+
+static void __speakup_paste_selection(struct work_struct *work)
{
+ struct speakup_paste_work *spw =
+ container_of(work, struct speakup_paste_work, work);
+ struct tty_struct *tty = xchg(spw-tty, NULL);
struct vc_data *vc = (struct vc_data *) tty-driver_data;
int pasted = 0, count;
DECLARE_WAITQUEUE(wait, current);
+
add_wait_queue(vc-paste_wait, wait);
while (sel_buffer sel_buffer_lth pasted) {
set_current_state(TASK_INTERRUPTIBLE);
if (test_bit(TTY_THROTTLED, tty-flags)) {
- if (in_atomic())
-/* if we are in an interrupt handler, abort */
-break;
schedule();
continue;
}
@@ -146,6 +152,26 @@ int speakup_paste_selection(struct tty_struct *tty)
}
remove_wait_queue(vc-paste_wait, wait);
current-state = TASK_RUNNING;
+ tty_kref_put(tty);
+}
+
+static struct speakup_paste_work speakup_paste_work = {
+ .work = __WORK_INITIALIZER(speakup_paste_work.work,
+ __speakup_paste_selection)
+};
+
+int speakup_paste_selection(struct tty_struct *tty)
+{
+ if (cmpxchg(speakup_paste_work.tty, NULL, tty) != NULL)
+ return -EBUSY;
+
+ tty_kref_get(tty);
+ schedule_work_on(WORK_CPU_UNBOUND, speakup_paste_work.work);
return 0;
}
+void speakup_cancel_paste(void)
+{
+ cancel_work_sync(speakup_paste_work.work);
+ tty_kref_put(speakup_paste_work.tty);
+}
diff --git a/drivers/staging/speakup/speakup.h b/drivers/staging/speakup/speakup.h
index 0126f71..74fe724 100644
--- a/drivers/staging/speakup/speakup.h
+++ b/drivers/staging/speakup/speakup.h
@@ -77,6 +77,7 @@ extern void synth_buffer_clear(void);
extern void speakup_clear_selection(void);
extern int speakup_set_selection(struct tty_struct *tty);
extern int speakup_paste_selection(struct tty_struct *tty);
+extern void speakup_cancel_paste(void);
extern void speakup_register_devsynth(void);
extern void speakup_unregister_devsynth(void);
extern void synth_write(const char *buf, size_t count);
From fa970267e33f95f96ff44febe3cfa0ff08817167 Mon Sep 17 00:00:00 2001
From: Ben Hutchings b...@decadent.org.uk
Date:
Bug#735202: speakup freezes system when trying to paste
I have Debian unstable with kernel 3.12.8-1 and cannot reproduce the issue. What should I change in my system to make it reproduce? Here are my steps: 1. boot debian into console prompt 2. login as root 3. modprobe speakup_soft 4. service espeakup start 5. type test 6. mark tes using speakup hot keys 7. paste tes using Ins-/ 7. execute cat 8. paste tes using Ins-/ All works, nothing hangs. The only strange thing is that inside cat it does not show the text until I press enter. Does the issue reproduce with any speakup synthesizer? Including dummy, none and soft? Jarek -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
