September 2018 - Linux-stable-mirror

[PATCHv3 0/6] tty: Hold write ldisc sem in tty_reopen()

by Dmitry Safonov

Hi all, Three fixes that worth to have in the @stable, as we've hit them on v4.9 stable. And for linux-next - adding lockdep asserts for line discipline changing code, verifying that write ldisc sem will be held forthwith. The last patch is optional and probably, timeout can be dropped for read_lock(). I'll do it if everyone agrees. Rong Chen, could you kindly re-run this version to see if the lockup from v1 still happens? I wasn't able to reproduce it.. Thanks, Dima Changes since v2: - Added reviewed-by tags - Hopefully, fixed reported by 0-day issue. - Added optional fix for wait_readers decrement Changes since v1: - Added tested-by/reported-by tags - Dropped 3/4 (locking tty pair for lockdep sake), Because of that - not adding lockdep_assert_held() in tty_ldisc_open() - Added 4/4 cleanup to inc tty->count only on success of tty_ldisc_reinit() - lock ldisc without (5*HZ) timeout in tty_reopen() v1 link: lkml.kernel.org/r/<20180829022353.23568-1-dima(a)arista.com> Huuge cc list: Cc: Daniel Axtens <dja(a)axtens.net> Cc: Dmitry Vyukov <dvyukov(a)google.com> Cc: Michael Neuling <mikey(a)neuling.org> Cc: Mikulas Patocka <mpatocka(a)redhat.com> Cc: Nathan March <nathan(a)gt.net> Cc: Pasi Kärkkäinen <pasik(a)iki.fi> Cc: Peter Hurley <peter(a)hurleysoftware.com> Cc: "Rong, Chen" <rong.a.chen(a)intel.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work(a)gmail.com> Cc: Tan Xiaojun <tanxiaojun(a)huawei.com> Cc: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp> (please, ignore if I Cc'ed you mistakenly) Dmitry Safonov (6): tty: Drop tty->count on tty_reopen() failure tty/ldsem: Update waiter->task before waking up reader tty: Hold tty_ldisc_lock() during tty_reopen() tty/lockdep: Add ldisc_sem asserts tty: Simplify tty->count math in tty_reopen() tty/ldsem: Decrement wait_readers on timeouted down_read() drivers/tty/tty_io.c | 12 ++++++++---- drivers/tty/tty_ldisc.c | 5 +++++ drivers/tty/tty_ldsem.c | 5 ++++- 3 files changed, 17 insertions(+), 5 deletions(-) -- 2.13.6

6 years, 4 months

5
12
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[PATCH 04/26] drm/i915: Handle incomplete Z_FINISH for compressed error states

by Chris Wilson

The final call to zlib_deflate(Z_FINISH) may require more output space to be allocated and so needs to re-invoked. Failure to do so in the current code leads to incomplete zlib streams (albeit intact due to the use of Z_SYNC_FLUSH) resulting in the occasional short object capture. Testcase: igt/i915-error-capture.js Fixes: 0a97015d45ee ("drm/i915: Compress GPU objects in error state") Signed-off-by: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen(a)linux.intel.com> Cc: <stable(a)vger.kernel.org> # v4.10+ --- drivers/gpu/drm/i915/i915_gpu_error.c | 60 +++++++++++++++++++++------ 1 file changed, 47 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c index 2835cacd0d08..9789f4ff8c32 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.c +++ b/drivers/gpu/drm/i915/i915_gpu_error.c @@ -237,6 +237,7 @@ static int compress_page(struct compress *c, struct drm_i915_error_object *dst) { struct z_stream_s *zstream = &c->zstream; + int flush = Z_NO_FLUSH; zstream->next_in = src; if (c->tmp && i915_memcpy_from_wc(c->tmp, src, PAGE_SIZE)) @@ -257,8 +258,11 @@ static int compress_page(struct compress *c, zstream->avail_out = PAGE_SIZE; } - if (zlib_deflate(zstream, Z_SYNC_FLUSH) != Z_OK) + if (zlib_deflate(zstream, flush) != Z_OK) return -EIO; + + if (zstream->avail_out) + flush = Z_SYNC_FLUSH; } while (zstream->avail_in); /* Fallback to uncompressed if we increase size? */ @@ -268,19 +272,43 @@ static int compress_page(struct compress *c, return 0; } -static void compress_fini(struct compress *c, +static int compress_flush(struct compress *c, struct drm_i915_error_object *dst) { struct z_stream_s *zstream = &c->zstream; + unsigned long page; - if (dst) { - zlib_deflate(zstream, Z_FINISH); - dst->unused = zstream->avail_out; - } + do { + switch (zlib_deflate(zstream, Z_FINISH)) { + case Z_OK: /* more space requested */ + page = __get_free_page(GFP_ATOMIC | __GFP_NOWARN); + if (!page) + return -ENOMEM; + + dst->pages[dst->page_count++] = (void *)page; + zstream->next_out = (void *)page; + zstream->avail_out = PAGE_SIZE; + break; + case Z_STREAM_END: + goto end; + default: /* any error */ + return -EIO; + } + } while (1); + +end: + memset(zstream->next_out, 0, zstream->avail_out); + dst->unused = zstream->avail_out; + return 0; +} + +static void compress_fini(struct compress *c, + struct drm_i915_error_object *dst) +{ + struct z_stream_s *zstream = &c->zstream; zlib_deflateEnd(zstream); kfree(zstream->workspace); - if (c->tmp) free_page((unsigned long)c->tmp); } @@ -319,6 +347,12 @@ static int compress_page(struct compress *c, return 0; } +static int compress_flush(struct compress *c, + struct drm_i915_error_object *dst) +{ + return 0; +} + static void compress_fini(struct compress *c, struct drm_i915_error_object *dst) { @@ -951,15 +985,15 @@ i915_error_object_create(struct drm_i915_private *i915, if (ret) goto unwind; } - goto out; + if (compress_flush(&compress, dst)) { unwind: - while (dst->page_count--) - free_page((unsigned long)dst->pages[dst->page_count]); - kfree(dst); - dst = NULL; + while (dst->page_count--) + free_page((unsigned long)dst->pages[dst->page_count]); + kfree(dst); + dst = NULL; + } -out: compress_fini(&compress, dst); ggtt->vm.clear_range(&ggtt->vm, slot, PAGE_SIZE); return dst; -- 2.19.0.rc2

6 years, 4 months

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[PATCH v4 02/10] usb: roles: Handle driver reference counting

by Heikki Krogerus

This fixes potential "BUG: unable to handle kernel paging request at ..." from happening. Fixes: fde0aa6c175a ("usb: common: Small class for USB role switches") Cc: <stable(a)vger.kernel.org> Signed-off-by: Heikki Krogerus <heikki.krogerus(a)linux.intel.com> --- drivers/usb/common/roles.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/usb/common/roles.c b/drivers/usb/common/roles.c index 15cc76e22123..99116af07f1d 100644 --- a/drivers/usb/common/roles.c +++ b/drivers/usb/common/roles.c @@ -109,8 +109,15 @@ static void *usb_role_switch_match(struct device_connection *con, int ep, */ struct usb_role_switch *usb_role_switch_get(struct device *dev) { - return device_connection_find_match(dev, "usb-role-switch", NULL, - usb_role_switch_match); + struct usb_role_switch *sw; + + sw = device_connection_find_match(dev, "usb-role-switch", NULL, + usb_role_switch_match); + + if (!IS_ERR_OR_NULL(sw)) + WARN_ON(!try_module_get(sw->dev.parent->driver->owner)); + + return sw; } EXPORT_SYMBOL_GPL(usb_role_switch_get); @@ -122,8 +129,10 @@ EXPORT_SYMBOL_GPL(usb_role_switch_get); */ void usb_role_switch_put(struct usb_role_switch *sw) { - if (!IS_ERR_OR_NULL(sw)) + if (!IS_ERR_OR_NULL(sw)) { put_device(&sw->dev); + module_put(sw->dev.parent->driver->owner); + } } EXPORT_SYMBOL_GPL(usb_role_switch_put); -- 2.18.0

6 years, 4 months

1
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[PATCH v4 01/10] usb: typec: Take care of driver module reference counting

by Heikki Krogerus

Functions typec_mux_get() and typec_switch_get() already make sure that the mux device reference count is incremented, but the same must be done to the driver module as well to prevent the drivers from being unloaded in the middle of operation. This fixes a potential "BUG: unable to handle kernel paging request at ..." from happening. Fixes: 93dd2112c7b2 ("usb: typec: mux: Get the mux identifier from function parameter") Cc: <stable(a)vger.kernel.org> Signed-off-by: Heikki Krogerus <heikki.krogerus(a)linux.intel.com> --- drivers/usb/typec/mux.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c index ddaac63ecf12..d990aa510fab 100644 --- a/drivers/usb/typec/mux.c +++ b/drivers/usb/typec/mux.c @@ -9,6 +9,7 @@ #include <linux/device.h> #include <linux/list.h> +#include <linux/module.h> #include <linux/mutex.h> #include <linux/usb/typec_mux.h> @@ -49,8 +50,10 @@ struct typec_switch *typec_switch_get(struct device *dev) mutex_lock(&switch_lock); sw = device_connection_find_match(dev, "typec-switch", NULL, typec_switch_match); - if (!IS_ERR_OR_NULL(sw)) + if (!IS_ERR_OR_NULL(sw)) { + WARN_ON(!try_module_get(sw->dev->driver->owner)); get_device(sw->dev); + } mutex_unlock(&switch_lock); return sw; @@ -65,8 +68,10 @@ EXPORT_SYMBOL_GPL(typec_switch_get); */ void typec_switch_put(struct typec_switch *sw) { - if (!IS_ERR_OR_NULL(sw)) + if (!IS_ERR_OR_NULL(sw)) { + module_put(sw->dev->driver->owner); put_device(sw->dev); + } } EXPORT_SYMBOL_GPL(typec_switch_put); @@ -136,8 +141,10 @@ struct typec_mux *typec_mux_get(struct device *dev, const char *name) mutex_lock(&mux_lock); mux = device_connection_find_match(dev, name, NULL, typec_mux_match); - if (!IS_ERR_OR_NULL(mux)) + if (!IS_ERR_OR_NULL(mux)) { + WARN_ON(!try_module_get(mux->dev->driver->owner)); get_device(mux->dev); + } mutex_unlock(&mux_lock); return mux; @@ -152,8 +159,10 @@ EXPORT_SYMBOL_GPL(typec_mux_get); */ void typec_mux_put(struct typec_mux *mux) { - if (!IS_ERR_OR_NULL(mux)) + if (!IS_ERR_OR_NULL(mux)) { + module_put(mux->dev->driver->owner); put_device(mux->dev); + } } EXPORT_SYMBOL_GPL(typec_mux_put); -- 2.18.0

6 years, 4 months

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[PATCHES] Networking

by David Miller

Please queue up the following networking bug fixes for v4.17 and v4.18 -stable, respectively. Thanks!

6 years, 4 months

2
1
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Editing 5

by Aaron

Hi, If you have photos for editing, please send email to: hansrekan(a)outlook.com We have 12 in house image editors and we can help you for cutting out your photos, or path the photos. Includes retouching if needed. Used for products photos or portrait photos, catalog photos. You may drop us one photo, we can send you the testing work. Thanks, Aaron Williams Email: hansrekan(a)outlook.com

6 years, 4 months

1
0
0 0

Editing 4

by Aaron

Hi, If you have photos for editing, please send email to: hansrekan(a)outlook.com We have 12 in house image editors and we can help you for cutting out your photos, or path the photos. Includes retouching if needed. Used for products photos or portrait photos, catalog photos. You may drop us one photo, we can send you the testing work. Thanks, Aaron Williams Email: hansrekan(a)outlook.com

6 years, 4 months

1
0
0 0

Editing 6

by Aaron

Hi, If you have photos for editing, please send email to: hansrekan(a)outlook.com We have 12 in house image editors and we can help you for cutting out your photos, or path the photos. Includes retouching if needed. Used for products photos or portrait photos, catalog photos. You may drop us one photo, we can send you the testing work. Thanks, Aaron Williams Email: hansrekan(a)outlook.com

6 years, 4 months

1
0
0 0

[PATCH 0/4] tty: Hold write ldisc sem in tty_reopen()

by Dmitry Safonov

Two fixes for potential and real issues. Looks worth to have in stables as we've hit it on v4.9 stable. And for linux-next - adding lockdep asserts for line discipline changing code, verifying that write ldisc sem will be held forthwith. I couldn't verify that holding write lock fixes the issue as we've hit it only once and I've failed in reproducing it. But searching in lkml, Cc'ing here people who probably had the same crash (and in hope someone of them could give tested-by): Cc: Daniel Axtens <dja(a)axtens.net> Cc: Dmitry Vyukov <dvyukov(a)google.com> Cc: Michael Neuling <mikey(a)neuling.org> Cc: Mikulas Patocka <mpatocka(a)redhat.com> Cc: Pasi Kärkkäinen <pasik(a)iki.fi> Cc: Peter Hurley <peter(a)hurleysoftware.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work(a)gmail.com> Cc: Tan Xiaojun <tanxiaojun(a)huawei.com> (please, ignore if I Cc'ed you mistakenly) Dmitry Safonov (4): tty: Drop tty->count on tty_reopen() failure tty: Hold tty_ldisc_lock() during tty_reopen() tty: Lock tty pair in tty_init_dev() tty/lockdep: Add ldisc_sem asserts drivers/tty/tty_io.c | 21 +++++++++++++++------ drivers/tty/tty_ldisc.c | 12 ++++++++---- include/linux/tty.h | 4 ++++ 3 files changed, 27 insertions(+), 10 deletions(-) -- 2.13.6

6 years, 4 months

9
23
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patch "Revert "cdc-acm: implement put_char() and flush_chars()"" added to usb-linus

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled Revert "cdc-acm: implement put_char() and flush_chars()" to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From df3aa13c7bbb307e172c37f193f9a7aa058d4739 Mon Sep 17 00:00:00 2001 From: Oliver Neukum <oneukum(a)suse.com> Date: Wed, 5 Sep 2018 17:56:46 +0200 Subject: Revert "cdc-acm: implement put_char() and flush_chars()" This reverts commit a81cf9799ad7299b03a4dff020d9685f9ac5f3e0. The patch causes a regression, which I cannot find the reason for. So let's revert for now, as a revert hurts only performance. Original report: I was trying to resolve the problem with Oliver but we don't get any conclusion for 5 months, so I am now sending this to mail list and cdc_acm authors. I am using simple request-response protocol to obtain the boiller parameters in constant intervals. A simple one transaction is: 1. opening the /dev/ttyACM0 2. sending the following 10-bytes request to the device: unsigned char req[] = {0x02, 0xfe, 0x01, 0x05, 0x08, 0x02, 0x01, 0x69, 0xab, 0x03}; 3. reading response (frame of 74 bytes length). 4. closing the descriptor I am doing this transaction with 5 seconds intervals. Before the bad commit everything was working correctly: I've got a requests and a responses in a timely manner. After the bad commit more time I am using the kernel module, more problems I have. The graph [2] is showing the problem. As you can see after module load all seems fine but after about 30 minutes I've got a plenty of EAGAINs when doing read()'s and trying to read back the data. When I rmmod and insmod the cdc_acm module again, then the situation is starting over again: running ok shortly after load, and more time it is running, more EAGAINs I have when calling read(). As a bonus I can see the problem on the device itself: The device is configured as you can see here on this screen [3]. It has two transmision LEDs: TX and RX. Blink duration is set for 100ms. This is a recording before the bad commit when all is working fine: [4] And this is with the bad commit: [5] As you can see the TX led is blinking wrongly long (indicating transmission?) and I have problems doing read() calls (EAGAIN). Reported-by: Mariusz Bialonczyk <manio(a)skyboo.net> Signed-off-by: Oliver Neukum <oneukum(a)suse.com> Fixes: a81cf9799ad7 ("cdc-acm: implement put_char() and flush_chars()") Cc: stable <stable(a)vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/usb/class/cdc-acm.c | 73 ------------------------------------- drivers/usb/class/cdc-acm.h | 1 - 2 files changed, 74 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 27346d69f393..f9b40a9dc4d3 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -780,20 +780,9 @@ static int acm_tty_write(struct tty_struct *tty, } if (acm->susp_count) { - if (acm->putbuffer) { - /* now to preserve order */ - usb_anchor_urb(acm->putbuffer->urb, &acm->delayed); - acm->putbuffer = NULL; - } usb_anchor_urb(wb->urb, &acm->delayed); spin_unlock_irqrestore(&acm->write_lock, flags); return count; - } else { - if (acm->putbuffer) { - /* at this point there is no good way to handle errors */ - acm_start_wb(acm, acm->putbuffer); - acm->putbuffer = NULL; - } } stat = acm_start_wb(acm, wb); @@ -804,66 +793,6 @@ static int acm_tty_write(struct tty_struct *tty, return count; } -static void acm_tty_flush_chars(struct tty_struct *tty) -{ - struct acm *acm = tty->driver_data; - struct acm_wb *cur; - int err; - unsigned long flags; - - spin_lock_irqsave(&acm->write_lock, flags); - - cur = acm->putbuffer; - if (!cur) /* nothing to do */ - goto out; - - acm->putbuffer = NULL; - err = usb_autopm_get_interface_async(acm->control); - if (err < 0) { - cur->use = 0; - acm->putbuffer = cur; - goto out; - } - - if (acm->susp_count) - usb_anchor_urb(cur->urb, &acm->delayed); - else - acm_start_wb(acm, cur); -out: - spin_unlock_irqrestore(&acm->write_lock, flags); - return; -} - -static int acm_tty_put_char(struct tty_struct *tty, unsigned char ch) -{ - struct acm *acm = tty->driver_data; - struct acm_wb *cur; - int wbn; - unsigned long flags; - -overflow: - cur = acm->putbuffer; - if (!cur) { - spin_lock_irqsave(&acm->write_lock, flags); - wbn = acm_wb_alloc(acm); - if (wbn >= 0) { - cur = &acm->wb[wbn]; - acm->putbuffer = cur; - } - spin_unlock_irqrestore(&acm->write_lock, flags); - if (!cur) - return 0; - } - - if (cur->len == acm->writesize) { - acm_tty_flush_chars(tty); - goto overflow; - } - - cur->buf[cur->len++] = ch; - return 1; -} - static int acm_tty_write_room(struct tty_struct *tty) { struct acm *acm = tty->driver_data; @@ -1987,8 +1916,6 @@ static const struct tty_operations acm_ops = { .cleanup = acm_tty_cleanup, .hangup = acm_tty_hangup, .write = acm_tty_write, - .put_char = acm_tty_put_char, - .flush_chars = acm_tty_flush_chars, .write_room = acm_tty_write_room, .ioctl = acm_tty_ioctl, .throttle = acm_tty_throttle, diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h index eacc116e83da..ca06b20d7af9 100644 --- a/drivers/usb/class/cdc-acm.h +++ b/drivers/usb/class/cdc-acm.h @@ -96,7 +96,6 @@ struct acm { unsigned long read_urbs_free; struct urb *read_urbs[ACM_NR]; struct acm_rb read_buffers[ACM_NR]; - struct acm_wb *putbuffer; /* for acm_tty_put_char() */ int rx_buflimit; spinlock_t read_lock; u8 *notification_buffer; /* to reassemble fragmented notifications */ -- 2.18.0

6 years, 4 months

1
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Linux-stable-mirror September 2018