Re: [PATCH] random: Fix early crash in credit_entropy_bits

2016-10-06 Thread Jiri Olsa 
On Wed, Oct 05, 2016 at 04:27:35PM -0400, Theodore Ts'o wrote:
> This was discussed and Linus wanted to fix it a different way.  Please
> see this thread:
> 
> http://www.gossamer-threads.com/lists/linux/kernel/2525929
> 
> Cheers,

ook, thanks for info

jirka

Re: [PATCH] random: Fix early crash in credit_entropy_bits

2016-10-06 Thread Jiri Olsa 
On Wed, Oct 05, 2016 at 04:27:35PM -0400, Theodore Ts'o wrote:
> This was discussed and Linus wanted to fix it a different way.  Please
> see this thread:
> 
> http://www.gossamer-threads.com/lists/linux/kernel/2525929
> 
> Cheers,

ook, thanks for info

jirka

Re: [PATCH] random: Fix early crash in credit_entropy_bits

2016-10-05 Thread Theodore Ts'o 
This was discussed and Linus wanted to fix it a different way.  Please
see this thread:

http://www.gossamer-threads.com/lists/linux/kernel/2525929

Cheers,

- Ted

Re: [PATCH] random: Fix early crash in credit_entropy_bits

2016-10-05 Thread Theodore Ts'o 
This was discussed and Linus wanted to fix it a different way.  Please
see this thread:

http://www.gossamer-threads.com/lists/linux/kernel/2525929

Cheers,

- Ted

Re: [PATCH] random: Fix early crash in credit_entropy_bits

2016-10-05 Thread Jiri Olsa 
ping

thanks,
jirka

On Wed, Sep 21, 2016 at 05:07:11PM +0200, Jiri Olsa wrote:
> From: Jiri Olsa 
> 
> When printing out some early acpi messages I hit bug in
> work queue code. The system_wq is not initialized at the
> time acpi_early_init is called and causes irq storm that
> makes credit_entropy_bits call schedule_work and crash:
> 
>   BUG: unable to handle kernel NULL pointer dereference at 0102^M
>   IP: [] __queue_work+0x32/0x450^M
>   PGD 0 ^M
>   Oops:  [#1] SMP^M
>   ...
>   Call Trace:^M
> [  286.521689]  [] ? 
> _raw_write_unlock_irqrestore+0x16/0x20^M
>[] ? add_interrupt_randomness+0x1c2/0x200^M
>[] queue_work_on+0x27/0x40^M
>[] credit_entropy_bits+0x219/0x280^M
>[] ? __mix_pool_bytes+0x36/0x90^M
>[] add_interrupt_randomness+0x1c2/0x200^M
>[] handle_irq_event_percpu+0x40/0x80^M
>[] handle_irq_event+0x2c/0x50^M
>[] handle_level_irq+0x83/0x100^M
>[] handle_irq+0x73/0x120^M
>[] ? _local_bh_enable+0x21/0x50^M
>[] do_IRQ+0x4b/0xd0^M
>[] common_interrupt+0x8c/0x8c^M
> [  286.521717]  [] ? native_restore_fl+0x6/0x10^M
>[] console_unlock+0x3ef/0x5d0^M
>[] ? update_sample+0x6e/0xe0^M
>[] vprintk_emit+0x2aa/0x520^M
>[] vprintk_default+0x1f/0x30^M
>[] printk+0x57/0x73^M
>[] acpi_os_vprintf+0x3f/0x41^M
>[] acpi_os_printf+0x52/0x6e^M
>...
>[] acpi_load_tables+0x6c/0xf4^M
>[] acpi_early_init+0x7a/0xf0^M
>[] start_kernel+0x3be/0x472^M
> 
> Preventing this by checking the system_wq has been initialized already.
> 
> Signed-off-by: Jiri Olsa 
> ---
>  drivers/char/random.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/char/random.c b/drivers/char/random.c
> index 3efb3bf0ab83..f4dec86c2e25 100644
> --- a/drivers/char/random.c
> +++ b/drivers/char/random.c
> @@ -725,7 +725,8 @@ retry:
>   /* If the input pool is getting full, send some
>* entropy to the blocking pool until it is 75% full.
>*/
> - if (entropy_bits > random_write_wakeup_bits &&
> + if (keventd_up() &&
> + entropy_bits > random_write_wakeup_bits &&
>   r->initialized &&
>   r->entropy_total >= 2*random_read_wakeup_bits) {
>   struct entropy_store *other = _pool;
> -- 
> 2.7.4
>

Re: [PATCH] random: Fix early crash in credit_entropy_bits

2016-10-05 Thread Jiri Olsa 
ping

thanks,
jirka

On Wed, Sep 21, 2016 at 05:07:11PM +0200, Jiri Olsa wrote:
> From: Jiri Olsa 
> 
> When printing out some early acpi messages I hit bug in
> work queue code. The system_wq is not initialized at the
> time acpi_early_init is called and causes irq storm that
> makes credit_entropy_bits call schedule_work and crash:
> 
>   BUG: unable to handle kernel NULL pointer dereference at 0102^M
>   IP: [] __queue_work+0x32/0x450^M
>   PGD 0 ^M
>   Oops:  [#1] SMP^M
>   ...
>   Call Trace:^M
> [  286.521689]  [] ? 
> _raw_write_unlock_irqrestore+0x16/0x20^M
>[] ? add_interrupt_randomness+0x1c2/0x200^M
>[] queue_work_on+0x27/0x40^M
>[] credit_entropy_bits+0x219/0x280^M
>[] ? __mix_pool_bytes+0x36/0x90^M
>[] add_interrupt_randomness+0x1c2/0x200^M
>[] handle_irq_event_percpu+0x40/0x80^M
>[] handle_irq_event+0x2c/0x50^M
>[] handle_level_irq+0x83/0x100^M
>[] handle_irq+0x73/0x120^M
>[] ? _local_bh_enable+0x21/0x50^M
>[] do_IRQ+0x4b/0xd0^M
>[] common_interrupt+0x8c/0x8c^M
> [  286.521717]  [] ? native_restore_fl+0x6/0x10^M
>[] console_unlock+0x3ef/0x5d0^M
>[] ? update_sample+0x6e/0xe0^M
>[] vprintk_emit+0x2aa/0x520^M
>[] vprintk_default+0x1f/0x30^M
>[] printk+0x57/0x73^M
>[] acpi_os_vprintf+0x3f/0x41^M
>[] acpi_os_printf+0x52/0x6e^M
>...
>[] acpi_load_tables+0x6c/0xf4^M
>[] acpi_early_init+0x7a/0xf0^M
>[] start_kernel+0x3be/0x472^M
> 
> Preventing this by checking the system_wq has been initialized already.
> 
> Signed-off-by: Jiri Olsa 
> ---
>  drivers/char/random.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/char/random.c b/drivers/char/random.c
> index 3efb3bf0ab83..f4dec86c2e25 100644
> --- a/drivers/char/random.c
> +++ b/drivers/char/random.c
> @@ -725,7 +725,8 @@ retry:
>   /* If the input pool is getting full, send some
>* entropy to the blocking pool until it is 75% full.
>*/
> - if (entropy_bits > random_write_wakeup_bits &&
> + if (keventd_up() &&
> + entropy_bits > random_write_wakeup_bits &&
>   r->initialized &&
>   r->entropy_total >= 2*random_read_wakeup_bits) {
>   struct entropy_store *other = _pool;
> -- 
> 2.7.4
>

[PATCH] random: Fix early crash in credit_entropy_bits

2016-09-21 Thread Jiri Olsa 
From: Jiri Olsa 

When printing out some early acpi messages I hit bug in
work queue code. The system_wq is not initialized at the
time acpi_early_init is called and causes irq storm that
makes credit_entropy_bits call schedule_work and crash:

  BUG: unable to handle kernel NULL pointer dereference at 0102^M
  IP: [] __queue_work+0x32/0x450^M
  PGD 0 ^M
  Oops:  [#1] SMP^M
  ...
  Call Trace:^M
[  286.521689]  [] ? 
_raw_write_unlock_irqrestore+0x16/0x20^M
   [] ? add_interrupt_randomness+0x1c2/0x200^M
   [] queue_work_on+0x27/0x40^M
   [] credit_entropy_bits+0x219/0x280^M
   [] ? __mix_pool_bytes+0x36/0x90^M
   [] add_interrupt_randomness+0x1c2/0x200^M
   [] handle_irq_event_percpu+0x40/0x80^M
   [] handle_irq_event+0x2c/0x50^M
   [] handle_level_irq+0x83/0x100^M
   [] handle_irq+0x73/0x120^M
   [] ? _local_bh_enable+0x21/0x50^M
   [] do_IRQ+0x4b/0xd0^M
   [] common_interrupt+0x8c/0x8c^M
[  286.521717]  [] ? native_restore_fl+0x6/0x10^M
   [] console_unlock+0x3ef/0x5d0^M
   [] ? update_sample+0x6e/0xe0^M
   [] vprintk_emit+0x2aa/0x520^M
   [] vprintk_default+0x1f/0x30^M
   [] printk+0x57/0x73^M
   [] acpi_os_vprintf+0x3f/0x41^M
   [] acpi_os_printf+0x52/0x6e^M
   ...
   [] acpi_load_tables+0x6c/0xf4^M
   [] acpi_early_init+0x7a/0xf0^M
   [] start_kernel+0x3be/0x472^M

Preventing this by checking the system_wq has been initialized already.

Signed-off-by: Jiri Olsa 
---
 drivers/char/random.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 3efb3bf0ab83..f4dec86c2e25 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -725,7 +725,8 @@ retry:
/* If the input pool is getting full, send some
 * entropy to the blocking pool until it is 75% full.
 */
-   if (entropy_bits > random_write_wakeup_bits &&
+   if (keventd_up() &&
+   entropy_bits > random_write_wakeup_bits &&
r->initialized &&
r->entropy_total >= 2*random_read_wakeup_bits) {
struct entropy_store *other = _pool;
-- 
2.7.4

[PATCH] random: Fix early crash in credit_entropy_bits

2016-09-21 Thread Jiri Olsa 
From: Jiri Olsa 

When printing out some early acpi messages I hit bug in
work queue code. The system_wq is not initialized at the
time acpi_early_init is called and causes irq storm that
makes credit_entropy_bits call schedule_work and crash:

  BUG: unable to handle kernel NULL pointer dereference at 0102^M
  IP: [] __queue_work+0x32/0x450^M
  PGD 0 ^M
  Oops:  [#1] SMP^M
  ...
  Call Trace:^M
[  286.521689]  [] ? 
_raw_write_unlock_irqrestore+0x16/0x20^M
   [] ? add_interrupt_randomness+0x1c2/0x200^M
   [] queue_work_on+0x27/0x40^M
   [] credit_entropy_bits+0x219/0x280^M
   [] ? __mix_pool_bytes+0x36/0x90^M
   [] add_interrupt_randomness+0x1c2/0x200^M
   [] handle_irq_event_percpu+0x40/0x80^M
   [] handle_irq_event+0x2c/0x50^M
   [] handle_level_irq+0x83/0x100^M
   [] handle_irq+0x73/0x120^M
   [] ? _local_bh_enable+0x21/0x50^M
   [] do_IRQ+0x4b/0xd0^M
   [] common_interrupt+0x8c/0x8c^M
[  286.521717]  [] ? native_restore_fl+0x6/0x10^M
   [] console_unlock+0x3ef/0x5d0^M
   [] ? update_sample+0x6e/0xe0^M
   [] vprintk_emit+0x2aa/0x520^M
   [] vprintk_default+0x1f/0x30^M
   [] printk+0x57/0x73^M
   [] acpi_os_vprintf+0x3f/0x41^M
   [] acpi_os_printf+0x52/0x6e^M
   ...
   [] acpi_load_tables+0x6c/0xf4^M
   [] acpi_early_init+0x7a/0xf0^M
   [] start_kernel+0x3be/0x472^M

Preventing this by checking the system_wq has been initialized already.

Signed-off-by: Jiri Olsa 
---
 drivers/char/random.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 3efb3bf0ab83..f4dec86c2e25 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -725,7 +725,8 @@ retry:
/* If the input pool is getting full, send some
 * entropy to the blocking pool until it is 75% full.
 */
-   if (entropy_bits > random_write_wakeup_bits &&
+   if (keventd_up() &&
+   entropy_bits > random_write_wakeup_bits &&
r->initialized &&
r->entropy_total >= 2*random_read_wakeup_bits) {
struct entropy_store *other = _pool;
-- 
2.7.4