subject:"Re\: \[PATCH\] vgaarb\: fix signal handling in vga

Re: [PATCH] vgaarb: fix signal handling in vga_get()

2015-12-14 Thread David Herrmann

Hi

On Mon, Dec 14, 2015 at 9:19 AM, Kirill A. Shutemov
 wrote:
> On Thu, Dec 10, 2015 at 11:28:58AM +0100, David Herrmann wrote:
>> Hi
>>
>> On Mon, Nov 30, 2015 at 3:17 AM, Kirill A. Shutemov
>>  wrote:
>> > There are few defects in vga_get() related to signal hadning:
>> >
>> >   - we shouldn't check for pending signals for TASK_UNINTERRUPTIBLE
>> > case;
>> >
>> >   - if we found pending signal we must remove ourself from wait queue
>> > and change task state back to running;
>> >
>> >   - -ERESTARTSYS is more appropriate, I guess.
>> >
>> > Signed-off-by: Kirill A. Shutemov 
>> > ---
>> >
>> > Alex, I try to get KVM with VGA passthrough working properly. I have i915
>> > (HD 4600) on the host and GTX 580 for the guest. The guest GPU is not
>> > capabale of EFI, so I have to use x-vga=on. It's kinda work with your
>> > patch for i915.enable_hd_vgaarb=1. But guest refuse to initialize the GPU
>> > after KVM was not shut down correctly, resulting in host crash like this:
>> >
>> > BUG: unable to handle kernel paging request at 880870187ed8
>> > IP: [] 0x880870187ed8
>> > PGD 2129067 PUD 800841e3
>> > Oops: 0011 [#1] PREEMPT SMP
>> > Modules linked in: iwlmvm iwlwifi
>> > CPU: 6 PID: 3983 Comm: qemu-system-x86 Not tainted 4.3.0-gentoo #6
>> > Hardware name: Gigabyte Technology Co., Ltd. Z87X-UD7 TH/Z87X-UD7 TH-CF, 
>> > BIOS F5a 06/12/2014
>> > task: 88087a91 ti: 8808632c task.ti: 8808632c
>> > RIP: 0010:[]  [] 0x880870187ed8
>> > RSP: 0018:8808632c3d08  EFLAGS: 00010006
>> > RAX: 880870187db0 RBX: 70187f58 RCX: 
>> > RDX:  RSI: 0003 RDI: 880870187db0
>> > RBP: 8808632c3d48 R08:  R09: 
>> > R10: 000103c0 R11: 0293 R12: 81ea03c8
>> > R13: 8104c7cb R14:  R15: 0003
>> > FS:  7f984f9b2700() GS:88089f38() 
>> > knlGS:
>> > CS:  0010 DS:  ES:  CR0: 80050033
>> > CR2: 880870187ed8 CR3: 0008645f8000 CR4: 001426e0
>> > Stack:
>> >  810cc83d 632c3d28  81ea03c0
>> >  0046 0003  
>> >  8808632c3d80 810cca44 88087af63800 0286
>> > Call Trace:
>> >  [] ? __wake_up_common+0x4d/0x80
>> >  [] __wake_up+0x34/0x50
>> >  [] __vga_put+0x73/0xd0
>> >  [] vga_put+0x54/0x80
>> >  [] vfio_pci_vga_rw+0x1d2/0x220
>> >  [] vfio_pci_rw+0x33/0x60
>> >  [] vfio_pci_write+0x17/0x20
>> >  [] vfio_device_fops_write+0x26/0x30
>> >  [] __vfs_write+0x23/0xe0
>> >  [] ? __vfs_read+0x23/0xd0
>> >  [] ? do_vfs_ioctl+0x2b5/0x490
>> >  [] vfs_write+0xa4/0x190
>> >  [] SyS_pwrite64+0x66/0xa0
>> >  [] entry_SYSCALL_64_fastpath+0x12/0x6a
>> > Code: 88 ff ff e0 7e 18 70 08 88 ff ff 00 8c 57 76 08 88 ff ff 20 7f 18 70 
>> > 08 88 ff ff 08 7f 18 70 08 88 ff ff 94 51 1a 81 ff ff ff ff <09> 00 00 00 
>> > 00 00 00 00 01 8c 57 76 08 88 ff ff 00 8c 57 76 08
>> > RIP  [] 0x880870187ed8
>> >  RSP 
>> > CR2: 880870187ed8
>> >
>> > The patch fixes the crash, but doesn't help with getting GPU in guest
>> > working again.
>> >
>> > Any ideas?
>> >
>> > ---
>> >  drivers/gpu/vga/vgaarb.c | 6 --
>> >  1 file changed, 4 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
>> > index 3166e4bc4eb6..9abcaa53bd25 100644
>> > --- a/drivers/gpu/vga/vgaarb.c
>> > +++ b/drivers/gpu/vga/vgaarb.c
>> > @@ -395,8 +395,10 @@ int vga_get(struct pci_dev *pdev, unsigned int rsrc, 
>> > int interruptible)
>> > set_current_state(interruptible ?
>> >   TASK_INTERRUPTIBLE :
>> >   TASK_UNINTERRUPTIBLE);
>> > -   if (signal_pending(current)) {
>> > -   rc = -EINTR;
>> > +   if (interruptible && signal_pending(current)) {
>> > +   __set_current_state(TASK_RUNNING);
>> > +   remove_wait_queue(_wait_queue, );
>> > +   rc = -ERESTARTSYS;
>> > break;
>>
>> All 3 points are valid, and the patch looks good to me:
>>
>> Reviewed-by: David Herrmann 
>>
>> However, there seems to be a race between vga_lock and putting the
>> thread asleep.
>
> I'm not sure I understand the race you're talking about.
> Could you elaborate?

Normal wake-up race. You have to check the condition you wait for
*after* linking your wait-queue and setting your thread-state. In the
current code, if the wake-up happens between spin_unlock_irqrestore()
and add_wait_queue(), you will never get woken up.

Thanks
David
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Re: [PATCH] vgaarb: fix signal handling in vga_get()

2015-12-14 Thread Kirill A. Shutemov

On Mon, Dec 14, 2015 at 11:20:00AM +0100, David Herrmann wrote:
> Hi
> 
> On Mon, Dec 14, 2015 at 9:19 AM, Kirill A. Shutemov
>  wrote:
> > On Thu, Dec 10, 2015 at 11:28:58AM +0100, David Herrmann wrote:
> >> Hi
> >>
> >> On Mon, Nov 30, 2015 at 3:17 AM, Kirill A. Shutemov
> >>  wrote:
> >> > There are few defects in vga_get() related to signal hadning:
> >> >
> >> >   - we shouldn't check for pending signals for TASK_UNINTERRUPTIBLE
> >> > case;
> >> >
> >> >   - if we found pending signal we must remove ourself from wait queue
> >> > and change task state back to running;
> >> >
> >> >   - -ERESTARTSYS is more appropriate, I guess.
> >> >
> >> > Signed-off-by: Kirill A. Shutemov 
> >> > ---
> >> >
> >> > Alex, I try to get KVM with VGA passthrough working properly. I have i915
> >> > (HD 4600) on the host and GTX 580 for the guest. The guest GPU is not
> >> > capabale of EFI, so I have to use x-vga=on. It's kinda work with your
> >> > patch for i915.enable_hd_vgaarb=1. But guest refuse to initialize the GPU
> >> > after KVM was not shut down correctly, resulting in host crash like this:
> >> >
> >> > BUG: unable to handle kernel paging request at 880870187ed8
> >> > IP: [] 0x880870187ed8
> >> > PGD 2129067 PUD 800841e3
> >> > Oops: 0011 [#1] PREEMPT SMP
> >> > Modules linked in: iwlmvm iwlwifi
> >> > CPU: 6 PID: 3983 Comm: qemu-system-x86 Not tainted 4.3.0-gentoo #6
> >> > Hardware name: Gigabyte Technology Co., Ltd. Z87X-UD7 TH/Z87X-UD7 TH-CF, 
> >> > BIOS F5a 06/12/2014
> >> > task: 88087a91 ti: 8808632c task.ti: 8808632c
> >> > RIP: 0010:[]  [] 0x880870187ed8
> >> > RSP: 0018:8808632c3d08  EFLAGS: 00010006
> >> > RAX: 880870187db0 RBX: 70187f58 RCX: 
> >> > RDX:  RSI: 0003 RDI: 880870187db0
> >> > RBP: 8808632c3d48 R08:  R09: 
> >> > R10: 000103c0 R11: 0293 R12: 81ea03c8
> >> > R13: 8104c7cb R14:  R15: 0003
> >> > FS:  7f984f9b2700() GS:88089f38() 
> >> > knlGS:
> >> > CS:  0010 DS:  ES:  CR0: 80050033
> >> > CR2: 880870187ed8 CR3: 0008645f8000 CR4: 001426e0
> >> > Stack:
> >> >  810cc83d 632c3d28  81ea03c0
> >> >  0046 0003  
> >> >  8808632c3d80 810cca44 88087af63800 0286
> >> > Call Trace:
> >> >  [] ? __wake_up_common+0x4d/0x80
> >> >  [] __wake_up+0x34/0x50
> >> >  [] __vga_put+0x73/0xd0
> >> >  [] vga_put+0x54/0x80
> >> >  [] vfio_pci_vga_rw+0x1d2/0x220
> >> >  [] vfio_pci_rw+0x33/0x60
> >> >  [] vfio_pci_write+0x17/0x20
> >> >  [] vfio_device_fops_write+0x26/0x30
> >> >  [] __vfs_write+0x23/0xe0
> >> >  [] ? __vfs_read+0x23/0xd0
> >> >  [] ? do_vfs_ioctl+0x2b5/0x490
> >> >  [] vfs_write+0xa4/0x190
> >> >  [] SyS_pwrite64+0x66/0xa0
> >> >  [] entry_SYSCALL_64_fastpath+0x12/0x6a
> >> > Code: 88 ff ff e0 7e 18 70 08 88 ff ff 00 8c 57 76 08 88 ff ff 20 7f 18 
> >> > 70 08 88 ff ff 08 7f 18 70 08 88 ff ff 94 51 1a 81 ff ff ff ff <09> 00 
> >> > 00 00 00 00 00 00 01 8c 57 76 08 88 ff ff 00 8c 57 76 08
> >> > RIP  [] 0x880870187ed8
> >> >  RSP 
> >> > CR2: 880870187ed8
> >> >
> >> > The patch fixes the crash, but doesn't help with getting GPU in guest
> >> > working again.
> >> >
> >> > Any ideas?
> >> >
> >> > ---
> >> >  drivers/gpu/vga/vgaarb.c | 6 --
> >> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >> >
> >> > diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
> >> > index 3166e4bc4eb6..9abcaa53bd25 100644
> >> > --- a/drivers/gpu/vga/vgaarb.c
> >> > +++ b/drivers/gpu/vga/vgaarb.c
> >> > @@ -395,8 +395,10 @@ int vga_get(struct pci_dev *pdev, unsigned int 
> >> > rsrc, int interruptible)
> >> > set_current_state(interruptible ?
> >> >   TASK_INTERRUPTIBLE :
> >> >   TASK_UNINTERRUPTIBLE);
> >> > -   if (signal_pending(current)) {
> >> > -   rc = -EINTR;
> >> > +   if (interruptible && signal_pending(current)) {
> >> > +   __set_current_state(TASK_RUNNING);
> >> > +   remove_wait_queue(_wait_queue, );
> >> > +   rc = -ERESTARTSYS;
> >> > break;
> >>
> >> All 3 points are valid, and the patch looks good to me:
> >>
> >> Reviewed-by: David Herrmann 
> >>
> >> However, there seems to be a race between vga_lock and putting the
> >> thread asleep.
> >
> > I'm not sure I understand the race you're talking about.
> > Could you elaborate?
> 
> Normal wake-up race. You have to check the condition you wait for
> *after* linking your wait-queue and setting your thread-state. In the
>

Re: [PATCH] vgaarb: fix signal handling in vga_get()

2015-12-14 Thread Kirill A. Shutemov

On Thu, Dec 10, 2015 at 11:28:58AM +0100, David Herrmann wrote:
> Hi
> 
> On Mon, Nov 30, 2015 at 3:17 AM, Kirill A. Shutemov
>  wrote:
> > There are few defects in vga_get() related to signal hadning:
> >
> >   - we shouldn't check for pending signals for TASK_UNINTERRUPTIBLE
> > case;
> >
> >   - if we found pending signal we must remove ourself from wait queue
> > and change task state back to running;
> >
> >   - -ERESTARTSYS is more appropriate, I guess.
> >
> > Signed-off-by: Kirill A. Shutemov 
> > ---
> >
> > Alex, I try to get KVM with VGA passthrough working properly. I have i915
> > (HD 4600) on the host and GTX 580 for the guest. The guest GPU is not
> > capabale of EFI, so I have to use x-vga=on. It's kinda work with your
> > patch for i915.enable_hd_vgaarb=1. But guest refuse to initialize the GPU
> > after KVM was not shut down correctly, resulting in host crash like this:
> >
> > BUG: unable to handle kernel paging request at 880870187ed8
> > IP: [] 0x880870187ed8
> > PGD 2129067 PUD 800841e3
> > Oops: 0011 [#1] PREEMPT SMP
> > Modules linked in: iwlmvm iwlwifi
> > CPU: 6 PID: 3983 Comm: qemu-system-x86 Not tainted 4.3.0-gentoo #6
> > Hardware name: Gigabyte Technology Co., Ltd. Z87X-UD7 TH/Z87X-UD7 TH-CF, 
> > BIOS F5a 06/12/2014
> > task: 88087a91 ti: 8808632c task.ti: 8808632c
> > RIP: 0010:[]  [] 0x880870187ed8
> > RSP: 0018:8808632c3d08  EFLAGS: 00010006
> > RAX: 880870187db0 RBX: 70187f58 RCX: 
> > RDX:  RSI: 0003 RDI: 880870187db0
> > RBP: 8808632c3d48 R08:  R09: 
> > R10: 000103c0 R11: 0293 R12: 81ea03c8
> > R13: 8104c7cb R14:  R15: 0003
> > FS:  7f984f9b2700() GS:88089f38() knlGS:
> > CS:  0010 DS:  ES:  CR0: 80050033
> > CR2: 880870187ed8 CR3: 0008645f8000 CR4: 001426e0
> > Stack:
> >  810cc83d 632c3d28  81ea03c0
> >  0046 0003  
> >  8808632c3d80 810cca44 88087af63800 0286
> > Call Trace:
> >  [] ? __wake_up_common+0x4d/0x80
> >  [] __wake_up+0x34/0x50
> >  [] __vga_put+0x73/0xd0
> >  [] vga_put+0x54/0x80
> >  [] vfio_pci_vga_rw+0x1d2/0x220
> >  [] vfio_pci_rw+0x33/0x60
> >  [] vfio_pci_write+0x17/0x20
> >  [] vfio_device_fops_write+0x26/0x30
> >  [] __vfs_write+0x23/0xe0
> >  [] ? __vfs_read+0x23/0xd0
> >  [] ? do_vfs_ioctl+0x2b5/0x490
> >  [] vfs_write+0xa4/0x190
> >  [] SyS_pwrite64+0x66/0xa0
> >  [] entry_SYSCALL_64_fastpath+0x12/0x6a
> > Code: 88 ff ff e0 7e 18 70 08 88 ff ff 00 8c 57 76 08 88 ff ff 20 7f 18 70 
> > 08 88 ff ff 08 7f 18 70 08 88 ff ff 94 51 1a 81 ff ff ff ff <09> 00 00 00 
> > 00 00 00 00 01 8c 57 76 08 88 ff ff 00 8c 57 76 08
> > RIP  [] 0x880870187ed8
> >  RSP 
> > CR2: 880870187ed8
> >
> > The patch fixes the crash, but doesn't help with getting GPU in guest
> > working again.
> >
> > Any ideas?
> >
> > ---
> >  drivers/gpu/vga/vgaarb.c | 6 --
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
> > index 3166e4bc4eb6..9abcaa53bd25 100644
> > --- a/drivers/gpu/vga/vgaarb.c
> > +++ b/drivers/gpu/vga/vgaarb.c
> > @@ -395,8 +395,10 @@ int vga_get(struct pci_dev *pdev, unsigned int rsrc, 
> > int interruptible)
> > set_current_state(interruptible ?
> >   TASK_INTERRUPTIBLE :
> >   TASK_UNINTERRUPTIBLE);
> > -   if (signal_pending(current)) {
> > -   rc = -EINTR;
> > +   if (interruptible && signal_pending(current)) {
> > +   __set_current_state(TASK_RUNNING);
> > +   remove_wait_queue(_wait_queue, );
> > +   rc = -ERESTARTSYS;
> > break;
> 
> All 3 points are valid, and the patch looks good to me:
> 
> Reviewed-by: David Herrmann 
> 
> However, there seems to be a race between vga_lock and putting the
> thread asleep.

I'm not sure I understand the race you're talking about.
Could you elaborate?

-- 
 Kirill A. Shutemov
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Re: [PATCH] vgaarb: fix signal handling in vga_get()

2015-12-10 Thread David Herrmann

Hi

On Mon, Nov 30, 2015 at 3:17 AM, Kirill A. Shutemov
 wrote:
> There are few defects in vga_get() related to signal hadning:
>
>   - we shouldn't check for pending signals for TASK_UNINTERRUPTIBLE
> case;
>
>   - if we found pending signal we must remove ourself from wait queue
> and change task state back to running;
>
>   - -ERESTARTSYS is more appropriate, I guess.
>
> Signed-off-by: Kirill A. Shutemov 
> ---
>
> Alex, I try to get KVM with VGA passthrough working properly. I have i915
> (HD 4600) on the host and GTX 580 for the guest. The guest GPU is not
> capabale of EFI, so I have to use x-vga=on. It's kinda work with your
> patch for i915.enable_hd_vgaarb=1. But guest refuse to initialize the GPU
> after KVM was not shut down correctly, resulting in host crash like this:
>
> BUG: unable to handle kernel paging request at 880870187ed8
> IP: [] 0x880870187ed8
> PGD 2129067 PUD 800841e3
> Oops: 0011 [#1] PREEMPT SMP
> Modules linked in: iwlmvm iwlwifi
> CPU: 6 PID: 3983 Comm: qemu-system-x86 Not tainted 4.3.0-gentoo #6
> Hardware name: Gigabyte Technology Co., Ltd. Z87X-UD7 TH/Z87X-UD7 TH-CF, BIOS 
> F5a 06/12/2014
> task: 88087a91 ti: 8808632c task.ti: 8808632c
> RIP: 0010:[]  [] 0x880870187ed8
> RSP: 0018:8808632c3d08  EFLAGS: 00010006
> RAX: 880870187db0 RBX: 70187f58 RCX: 
> RDX:  RSI: 0003 RDI: 880870187db0
> RBP: 8808632c3d48 R08:  R09: 
> R10: 000103c0 R11: 0293 R12: 81ea03c8
> R13: 8104c7cb R14:  R15: 0003
> FS:  7f984f9b2700() GS:88089f38() knlGS:
> CS:  0010 DS:  ES:  CR0: 80050033
> CR2: 880870187ed8 CR3: 0008645f8000 CR4: 001426e0
> Stack:
>  810cc83d 632c3d28  81ea03c0
>  0046 0003  
>  8808632c3d80 810cca44 88087af63800 0286
> Call Trace:
>  [] ? __wake_up_common+0x4d/0x80
>  [] __wake_up+0x34/0x50
>  [] __vga_put+0x73/0xd0
>  [] vga_put+0x54/0x80
>  [] vfio_pci_vga_rw+0x1d2/0x220
>  [] vfio_pci_rw+0x33/0x60
>  [] vfio_pci_write+0x17/0x20
>  [] vfio_device_fops_write+0x26/0x30
>  [] __vfs_write+0x23/0xe0
>  [] ? __vfs_read+0x23/0xd0
>  [] ? do_vfs_ioctl+0x2b5/0x490
>  [] vfs_write+0xa4/0x190
>  [] SyS_pwrite64+0x66/0xa0
>  [] entry_SYSCALL_64_fastpath+0x12/0x6a
> Code: 88 ff ff e0 7e 18 70 08 88 ff ff 00 8c 57 76 08 88 ff ff 20 7f 18 70 08 
> 88 ff ff 08 7f 18 70 08 88 ff ff 94 51 1a 81 ff ff ff ff <09> 00 00 00 00 00 
> 00 00 01 8c 57 76 08 88 ff ff 00 8c 57 76 08
> RIP  [] 0x880870187ed8
>  RSP 
> CR2: 880870187ed8
>
> The patch fixes the crash, but doesn't help with getting GPU in guest
> working again.
>
> Any ideas?
>
> ---
>  drivers/gpu/vga/vgaarb.c | 6 --
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
> index 3166e4bc4eb6..9abcaa53bd25 100644
> --- a/drivers/gpu/vga/vgaarb.c
> +++ b/drivers/gpu/vga/vgaarb.c
> @@ -395,8 +395,10 @@ int vga_get(struct pci_dev *pdev, unsigned int rsrc, int 
> interruptible)
> set_current_state(interruptible ?
>   TASK_INTERRUPTIBLE :
>   TASK_UNINTERRUPTIBLE);
> -   if (signal_pending(current)) {
> -   rc = -EINTR;
> +   if (interruptible && signal_pending(current)) {
> +   __set_current_state(TASK_RUNNING);
> +   remove_wait_queue(_wait_queue, );
> +   rc = -ERESTARTSYS;
> break;

All 3 points are valid, and the patch looks good to me:

Reviewed-by: David Herrmann 

However, there seems to be a race between vga_lock and putting the
thread asleep. We should fix that as well. See the hunk below
(completely untested.. why is VGA still in use? *sigh*).

Thanks
David

diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index a0b4334..82cf1e3 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -359,8 +359,8 @@ static void __vga_put
 int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
 {
struct vga_device *vgadev, *conflict;
+   DECLARE_WAITQUEUE(wait, current);
unsigned long flags;
-   wait_queue_t wait;
int rc = 0;

vga_check_first_use();
@@ -371,6 +371,11 @@ int vga_get
return 0;

for (;;) {
+   add_wait_queue(_wait_queue, );
+   set_current_state(interruptible ?
+ TASK_INTERRUPTIBLE :
+ TASK_UNINTERRUPTIBLE);
+
spin_lock_irqsave(_lock, flags);
vgadev =

Re: [PATCH] vgaarb: fix signal handling in vga_get()

2015-12-09 Thread Kirill A. Shutemov

On Mon, Nov 30, 2015 at 04:17:31AM +0200, Kirill A. Shutemov wrote:
> There are few defects in vga_get() related to signal hadning:
> 
>   - we shouldn't check for pending signals for TASK_UNINTERRUPTIBLE
> case;
> 
>   - if we found pending signal we must remove ourself from wait queue
> and change task state back to running;
> 
>   - -ERESTARTSYS is more appropriate, I guess.
> 
> Signed-off-by: Kirill A. Shutemov 

Ping?

David, this patch fixes crash. It would be nice to get it into 4.4.

> ---
> 
> Alex, I try to get KVM with VGA passthrough working properly. I have i915
> (HD 4600) on the host and GTX 580 for the guest. The guest GPU is not
> capabale of EFI, so I have to use x-vga=on. It's kinda work with your
> patch for i915.enable_hd_vgaarb=1. But guest refuse to initialize the GPU
> after KVM was not shut down correctly, resulting in host crash like this:
> 
> BUG: unable to handle kernel paging request at 880870187ed8
> IP: [] 0x880870187ed8
> PGD 2129067 PUD 800841e3
> Oops: 0011 [#1] PREEMPT SMP
> Modules linked in: iwlmvm iwlwifi
> CPU: 6 PID: 3983 Comm: qemu-system-x86 Not tainted 4.3.0-gentoo #6
> Hardware name: Gigabyte Technology Co., Ltd. Z87X-UD7 TH/Z87X-UD7 TH-CF, BIOS 
> F5a 06/12/2014
> task: 88087a91 ti: 8808632c task.ti: 8808632c
> RIP: 0010:[]  [] 0x880870187ed8
> RSP: 0018:8808632c3d08  EFLAGS: 00010006
> RAX: 880870187db0 RBX: 70187f58 RCX: 
> RDX:  RSI: 0003 RDI: 880870187db0
> RBP: 8808632c3d48 R08:  R09: 
> R10: 000103c0 R11: 0293 R12: 81ea03c8
> R13: 8104c7cb R14:  R15: 0003
> FS:  7f984f9b2700() GS:88089f38() knlGS:
> CS:  0010 DS:  ES:  CR0: 80050033
> CR2: 880870187ed8 CR3: 0008645f8000 CR4: 001426e0
> Stack:
>  810cc83d 632c3d28  81ea03c0
>  0046 0003  
>  8808632c3d80 810cca44 88087af63800 0286
> Call Trace:
>  [] ? __wake_up_common+0x4d/0x80
>  [] __wake_up+0x34/0x50
>  [] __vga_put+0x73/0xd0
>  [] vga_put+0x54/0x80
>  [] vfio_pci_vga_rw+0x1d2/0x220
>  [] vfio_pci_rw+0x33/0x60
>  [] vfio_pci_write+0x17/0x20
>  [] vfio_device_fops_write+0x26/0x30
>  [] __vfs_write+0x23/0xe0
>  [] ? __vfs_read+0x23/0xd0
>  [] ? do_vfs_ioctl+0x2b5/0x490
>  [] vfs_write+0xa4/0x190
>  [] SyS_pwrite64+0x66/0xa0
>  [] entry_SYSCALL_64_fastpath+0x12/0x6a
> Code: 88 ff ff e0 7e 18 70 08 88 ff ff 00 8c 57 76 08 88 ff ff 20 7f 18 70 08 
> 88 ff ff 08 7f 18 70 08 88 ff ff 94 51 1a 81 ff ff ff ff <09> 00 00 00 00 00 
> 00 00 01 8c 57 76 08 88 ff ff 00 8c 57 76 08
> RIP  [] 0x880870187ed8
>  RSP 
> CR2: 880870187ed8
> 
> The patch fixes the crash, but doesn't help with getting GPU in guest
> working again.
> 
> Any ideas?
> 
> ---
>  drivers/gpu/vga/vgaarb.c | 6 --
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
> index 3166e4bc4eb6..9abcaa53bd25 100644
> --- a/drivers/gpu/vga/vgaarb.c
> +++ b/drivers/gpu/vga/vgaarb.c
> @@ -395,8 +395,10 @@ int vga_get(struct pci_dev *pdev, unsigned int rsrc, int 
> interruptible)
>   set_current_state(interruptible ?
> TASK_INTERRUPTIBLE :
> TASK_UNINTERRUPTIBLE);
> - if (signal_pending(current)) {
> - rc = -EINTR;
> + if (interruptible && signal_pending(current)) {
> + __set_current_state(TASK_RUNNING);
> + remove_wait_queue(_wait_queue, );
> + rc = -ERESTARTSYS;
>   break;
>   }
>   schedule();
> -- 
> 2.6.3
> 

-- 
 Kirill A. Shutemov
--
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Re: [PATCH] vgaarb: fix signal handling in vga_get()

Re: [PATCH] vgaarb: fix signal handling in vga_get()

Re: [PATCH] vgaarb: fix signal handling in vga_get()

Re: [PATCH] vgaarb: fix signal handling in vga_get()

Re: [PATCH] vgaarb: fix signal handling in vga_get()

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