* [PATCH] powerpc/powernv: Fix idle state allocation corruption
@ 2015-05-20 17:13 Jack Miller
2015-05-20 17:28 ` Shreyas B Prabhu
0 siblings, 1 reply; 3+ messages in thread
From: Jack Miller @ 2015-05-20 17:13 UTC (permalink / raw)
To: linuxppc-dev; +Cc: preeti, shreyas, jk
pnv_alloc_idle_core_states is iterating over PACAs based on the
configured maximum number of CPUs (NR_CPUS), but PACAs are only
initialized up to nr_cpu_ids, so rein in loops to keep from overwriting
adjacent memory.
Signed-off-by: Jack Miller <millerjo@us.ibm.com>
---
arch/powerpc/platforms/powernv/setup.c | 26 +++++++++++---------------
1 file changed, 11 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index ad0e32e..8e794b6 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -356,9 +356,8 @@ int pnv_save_sprs_for_winkle(void)
static void pnv_alloc_idle_core_states(void)
{
- int i, j;
- int nr_cores = cpu_nr_cores();
- u32 *core_idle_state;
+ u32 *core_idle_state = NULL;
+ int i, thread;
/*
* core_idle_state - First 8 bits track the idle state of each thread
@@ -371,20 +370,17 @@ static void pnv_alloc_idle_core_states(void)
* b. While the last thread in the core is saving the core state, it
* prevents a different thread from waking up.
*/
- for (i = 0; i < nr_cores; i++) {
- int first_cpu = i * threads_per_core;
- int node = cpu_to_node(first_cpu);
+ for (i = 0; i < nr_cpu_ids; i++) {
+ thread = i % threads_per_core;
- core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node);
- *core_idle_state = PNV_CORE_IDLE_THREAD_BITS;
-
- for (j = 0; j < threads_per_core; j++) {
- int cpu = first_cpu + j;
-
- paca[cpu].core_idle_state_ptr = core_idle_state;
- paca[cpu].thread_idle_state = PNV_THREAD_RUNNING;
- paca[cpu].thread_mask = 1 << j;
+ if (thread == 0) {
+ core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, cpu_to_node(i));
+ *core_idle_state = PNV_CORE_IDLE_THREAD_BITS;
}
+
+ paca[i].core_idle_state_ptr = core_idle_state;
+ paca[i].thread_idle_state = PNV_THREAD_RUNNING;
+ paca[i].thread_mask = 1 << thread;
}
update_subcore_sibling_mask();
--
2.4.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] powerpc/powernv: Fix idle state allocation corruption
2015-05-20 17:13 [PATCH] powerpc/powernv: Fix idle state allocation corruption Jack Miller
@ 2015-05-20 17:28 ` Shreyas B Prabhu
2015-05-20 19:02 ` Jack Miller
0 siblings, 1 reply; 3+ messages in thread
From: Shreyas B Prabhu @ 2015-05-20 17:28 UTC (permalink / raw)
To: Jack Miller, linuxppc-dev; +Cc: Preeti U Murthy, jk, jstancek
On Wednesday 20 May 2015 10:43 PM, Jack Miller wrote:
> pnv_alloc_idle_core_states is iterating over PACAs based on the
> configured maximum number of CPUs (NR_CPUS), but PACAs are only
> initialized up to nr_cpu_ids, so rein in loops to keep from overwriting
> adjacent memory.
>
Hi Jack,
Jan Stancek has a patch fixing this (d52356e7f powerpc: fix memory
corruption by pnv_alloc_idle_core_states).
Thanks,
Shreyas
> Signed-off-by: Jack Miller <millerjo@us.ibm.com>
> ---
> arch/powerpc/platforms/powernv/setup.c | 26 +++++++++++---------------
> 1 file changed, 11 insertions(+), 15 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
> index ad0e32e..8e794b6 100644
> --- a/arch/powerpc/platforms/powernv/setup.c
> +++ b/arch/powerpc/platforms/powernv/setup.c
> @@ -356,9 +356,8 @@ int pnv_save_sprs_for_winkle(void)
>
> static void pnv_alloc_idle_core_states(void)
> {
> - int i, j;
> - int nr_cores = cpu_nr_cores();
> - u32 *core_idle_state;
> + u32 *core_idle_state = NULL;
> + int i, thread;
>
> /*
> * core_idle_state - First 8 bits track the idle state of each thread
> @@ -371,20 +370,17 @@ static void pnv_alloc_idle_core_states(void)
> * b. While the last thread in the core is saving the core state, it
> * prevents a different thread from waking up.
> */
> - for (i = 0; i < nr_cores; i++) {
> - int first_cpu = i * threads_per_core;
> - int node = cpu_to_node(first_cpu);
> + for (i = 0; i < nr_cpu_ids; i++) {
> + thread = i % threads_per_core;
>
> - core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node);
> - *core_idle_state = PNV_CORE_IDLE_THREAD_BITS;
> -
> - for (j = 0; j < threads_per_core; j++) {
> - int cpu = first_cpu + j;
> -
> - paca[cpu].core_idle_state_ptr = core_idle_state;
> - paca[cpu].thread_idle_state = PNV_THREAD_RUNNING;
> - paca[cpu].thread_mask = 1 << j;
> + if (thread == 0) {
> + core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, cpu_to_node(i));
> + *core_idle_state = PNV_CORE_IDLE_THREAD_BITS;
> }
> +
> + paca[i].core_idle_state_ptr = core_idle_state;
> + paca[i].thread_idle_state = PNV_THREAD_RUNNING;
> + paca[i].thread_mask = 1 << thread;
> }
>
> update_subcore_sibling_mask();
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] powerpc/powernv: Fix idle state allocation corruption
2015-05-20 17:28 ` Shreyas B Prabhu
@ 2015-05-20 19:02 ` Jack Miller
0 siblings, 0 replies; 3+ messages in thread
From: Jack Miller @ 2015-05-20 19:02 UTC (permalink / raw)
To: Shreyas B Prabhu; +Cc: Preeti U Murthy, linuxppc-dev, jk, jstancek
On Wed, May 20, 2015 at 10:58:42PM +0530, Shreyas B Prabhu wrote:
>
>
> On Wednesday 20 May 2015 10:43 PM, Jack Miller wrote:
> > pnv_alloc_idle_core_states is iterating over PACAs based on the
> > configured maximum number of CPUs (NR_CPUS), but PACAs are only
> > initialized up to nr_cpu_ids, so rein in loops to keep from overwriting
> > adjacent memory.
> >
>
> Hi Jack,
>
> Jan Stancek has a patch fixing this (d52356e7f powerpc: fix memory
> corruption by pnv_alloc_idle_core_states).
Must've missed it, just ran into the issue and didn't see a fix upstream.
Just found it in the April list archive.
Thanks,
- Jack
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-05-20 19:03 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-05-20 17:13 [PATCH] powerpc/powernv: Fix idle state allocation corruption Jack Miller
2015-05-20 17:28 ` Shreyas B Prabhu
2015-05-20 19:02 ` Jack Miller
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.