* FAILED: patch "[PATCH] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU" failed to apply to 4.14-stable tree
@ 2019-01-27 15:09 gregkh
2019-01-28 13:21 ` [PATCH] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU David Hildenbrand
0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2019-01-27 15:09 UTC (permalink / raw)
To: david, cohuck, schwidefsky; +Cc: stable
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 60f1bf29c0b2519989927cae640cd1f50f59dc7f Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@redhat.com>
Date: Fri, 11 Jan 2019 15:18:22 +0100
Subject: [PATCH] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU
When calling smp_call_ipl_cpu() from the IPL CPU, we will try to read
from pcpu_devices->lowcore. However, due to prefixing, that will result
in reading from absolute address 0 on that CPU. We have to go via the
actual lowcore instead.
This means that right now, we will read lc->nodat_stack == 0 and
therfore work on a very wrong stack.
This BUG essentially broke rebooting under QEMU TCG (which will report
a low address protection exception). And checking under KVM, it is
also broken under KVM. With 1 VCPU it can be easily triggered.
:/# echo 1 > /proc/sys/kernel/sysrq
:/# echo b > /proc/sysrq-trigger
[ 28.476745] sysrq: SysRq : Resetting
[ 28.476793] Kernel stack overflow.
[ 28.476817] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13
[ 28.476820] Hardware name: IBM 2964 NE1 716 (KVM/Linux)
[ 28.476826] Krnl PSW : 0400c00180000000 0000000000115c0c (pcpu_delegate+0x12c/0x140)
[ 28.476861] R:0 T:1 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
[ 28.476863] Krnl GPRS: ffffffffffffffff 0000000000000000 000000000010dff8 0000000000000000
[ 28.476864] 0000000000000000 0000000000000000 0000000000ab7090 000003e0006efbf0
[ 28.476864] 000000000010dff8 0000000000000000 0000000000000000 0000000000000000
[ 28.476865] 000000007fffc000 0000000000730408 000003e0006efc58 0000000000000000
[ 28.476887] Krnl Code: 0000000000115bfe: 4170f000 la %r7,0(%r15)
[ 28.476887] 0000000000115c02: 41f0a000 la %r15,0(%r10)
[ 28.476887] #0000000000115c06: e370f0980024 stg %r7,152(%r15)
[ 28.476887] >0000000000115c0c: c0e5fffff86e brasl %r14,114ce8
[ 28.476887] 0000000000115c12: 41f07000 la %r15,0(%r7)
[ 28.476887] 0000000000115c16: a7f4ffa8 brc 15,115b66
[ 28.476887] 0000000000115c1a: 0707 bcr 0,%r7
[ 28.476887] 0000000000115c1c: 0707 bcr 0,%r7
[ 28.476901] Call Trace:
[ 28.476902] Last Breaking-Event-Address:
[ 28.476920] [<0000000000a01c4a>] arch_call_rest_init+0x22/0x80
[ 28.476927] Kernel panic - not syncing: Corrupt kernel stack, can't continue.
[ 28.476930] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13
[ 28.476932] Hardware name: IBM 2964 NE1 716 (KVM/Linux)
[ 28.476932] Call Trace:
Fixes: 2f859d0dad81 ("s390/smp: reduce size of struct pcpu")
Cc: stable@vger.kernel.org # 4.0+
Reported-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 307a1c86ea21..b198ece2aad6 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -381,8 +381,13 @@ void smp_call_online_cpu(void (*func)(void *), void *data)
*/
void smp_call_ipl_cpu(void (*func)(void *), void *data)
{
+ struct lowcore *lc = pcpu_devices->lowcore;
+
+ if (pcpu_devices[0].address == stap())
+ lc = &S390_lowcore;
+
pcpu_delegate(&pcpu_devices[0], func, data,
- pcpu_devices->lowcore->nodat_stack);
+ lc->nodat_stack);
}
int smp_find_processor_id(u16 address)
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU
2019-01-27 15:09 FAILED: patch "[PATCH] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU" failed to apply to 4.14-stable tree gregkh
@ 2019-01-28 13:21 ` David Hildenbrand
2019-01-29 9:49 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: David Hildenbrand @ 2019-01-28 13:21 UTC (permalink / raw)
To: stable; +Cc: gregkh, cohuck, schwidefsky, David Hildenbrand
This is the backport of 60f1bf29c0b2 ("s390/smp: Fix calling
smp_call_ipl_cpu() from ipl CPU") for 4.14-stable.
When calling smp_call_ipl_cpu() from the IPL CPU, we will try to read
from pcpu_devices->lowcore. However, due to prefixing, that will result
in reading from absolute address 0 on that CPU. We have to go via the
actual lowcore instead.
This means that right now, we will read lc->nodat_stack == 0 and
therfore work on a very wrong stack.
This BUG essentially broke rebooting under QEMU TCG (which will report
a low address protection exception). And checking under KVM, it is
also broken under KVM. With 1 VCPU it can be easily triggered.
:/# echo 1 > /proc/sys/kernel/sysrq
:/# echo b > /proc/sysrq-trigger
[ 28.476745] sysrq: SysRq : Resetting
[ 28.476793] Kernel stack overflow.
[ 28.476817] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13
[ 28.476820] Hardware name: IBM 2964 NE1 716 (KVM/Linux)
[ 28.476826] Krnl PSW : 0400c00180000000 0000000000115c0c (pcpu_delegate+0x12c/0x140)
[ 28.476861] R:0 T:1 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
[ 28.476863] Krnl GPRS: ffffffffffffffff 0000000000000000 000000000010dff8 0000000000000000
[ 28.476864] 0000000000000000 0000000000000000 0000000000ab7090 000003e0006efbf0
[ 28.476864] 000000000010dff8 0000000000000000 0000000000000000 0000000000000000
[ 28.476865] 000000007fffc000 0000000000730408 000003e0006efc58 0000000000000000
[ 28.476887] Krnl Code: 0000000000115bfe: 4170f000 la %r7,0(%r15)
[ 28.476887] 0000000000115c02: 41f0a000 la %r15,0(%r10)
[ 28.476887] #0000000000115c06: e370f0980024 stg %r7,152(%r15)
[ 28.476887] >0000000000115c0c: c0e5fffff86e brasl %r14,114ce8
[ 28.476887] 0000000000115c12: 41f07000 la %r15,0(%r7)
[ 28.476887] 0000000000115c16: a7f4ffa8 brc 15,115b66
[ 28.476887] 0000000000115c1a: 0707 bcr 0,%r7
[ 28.476887] 0000000000115c1c: 0707 bcr 0,%r7
[ 28.476901] Call Trace:
[ 28.476902] Last Breaking-Event-Address:
[ 28.476920] [<0000000000a01c4a>] arch_call_rest_init+0x22/0x80
[ 28.476927] Kernel panic - not syncing: Corrupt kernel stack, can't continue.
[ 28.476930] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13
[ 28.476932] Hardware name: IBM 2964 NE1 716 (KVM/Linux)
[ 28.476932] Call Trace:
Fixes: 2f859d0dad81 ("s390/smp: reduce size of struct pcpu")
Cc: stable@vger.kernel.org # 4.0+
Reported-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/kernel/smp.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index ae5df4177803..81e8e93376a7 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -387,9 +387,13 @@ void smp_call_online_cpu(void (*func)(void *), void *data)
*/
void smp_call_ipl_cpu(void (*func)(void *), void *data)
{
+ struct lowcore *lc = pcpu_devices->lowcore;
+
+ if (pcpu_devices[0].address == stap())
+ lc = &S390_lowcore;
+
pcpu_delegate(&pcpu_devices[0], func, data,
- pcpu_devices->lowcore->panic_stack -
- PANIC_FRAME_OFFSET + PAGE_SIZE);
+ lc->panic_stack - PANIC_FRAME_OFFSET + PAGE_SIZE);
}
int smp_find_processor_id(u16 address)
--
2.17.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU
2019-01-28 13:21 ` [PATCH] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU David Hildenbrand
@ 2019-01-29 9:49 ` Greg KH
0 siblings, 0 replies; 3+ messages in thread
From: Greg KH @ 2019-01-29 9:49 UTC (permalink / raw)
To: David Hildenbrand; +Cc: stable, cohuck, schwidefsky
On Mon, Jan 28, 2019 at 02:21:41PM +0100, David Hildenbrand wrote:
> This is the backport of 60f1bf29c0b2 ("s390/smp: Fix calling
> smp_call_ipl_cpu() from ipl CPU") for 4.14-stable.
>
> When calling smp_call_ipl_cpu() from the IPL CPU, we will try to read
> from pcpu_devices->lowcore. However, due to prefixing, that will result
> in reading from absolute address 0 on that CPU. We have to go via the
> actual lowcore instead.
>
> This means that right now, we will read lc->nodat_stack == 0 and
> therfore work on a very wrong stack.
>
> This BUG essentially broke rebooting under QEMU TCG (which will report
> a low address protection exception). And checking under KVM, it is
> also broken under KVM. With 1 VCPU it can be easily triggered.
>
> :/# echo 1 > /proc/sys/kernel/sysrq
> :/# echo b > /proc/sysrq-trigger
> [ 28.476745] sysrq: SysRq : Resetting
> [ 28.476793] Kernel stack overflow.
> [ 28.476817] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13
> [ 28.476820] Hardware name: IBM 2964 NE1 716 (KVM/Linux)
> [ 28.476826] Krnl PSW : 0400c00180000000 0000000000115c0c (pcpu_delegate+0x12c/0x140)
> [ 28.476861] R:0 T:1 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
> [ 28.476863] Krnl GPRS: ffffffffffffffff 0000000000000000 000000000010dff8 0000000000000000
> [ 28.476864] 0000000000000000 0000000000000000 0000000000ab7090 000003e0006efbf0
> [ 28.476864] 000000000010dff8 0000000000000000 0000000000000000 0000000000000000
> [ 28.476865] 000000007fffc000 0000000000730408 000003e0006efc58 0000000000000000
> [ 28.476887] Krnl Code: 0000000000115bfe: 4170f000 la %r7,0(%r15)
> [ 28.476887] 0000000000115c02: 41f0a000 la %r15,0(%r10)
> [ 28.476887] #0000000000115c06: e370f0980024 stg %r7,152(%r15)
> [ 28.476887] >0000000000115c0c: c0e5fffff86e brasl %r14,114ce8
> [ 28.476887] 0000000000115c12: 41f07000 la %r15,0(%r7)
> [ 28.476887] 0000000000115c16: a7f4ffa8 brc 15,115b66
> [ 28.476887] 0000000000115c1a: 0707 bcr 0,%r7
> [ 28.476887] 0000000000115c1c: 0707 bcr 0,%r7
> [ 28.476901] Call Trace:
> [ 28.476902] Last Breaking-Event-Address:
> [ 28.476920] [<0000000000a01c4a>] arch_call_rest_init+0x22/0x80
> [ 28.476927] Kernel panic - not syncing: Corrupt kernel stack, can't continue.
> [ 28.476930] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13
> [ 28.476932] Hardware name: IBM 2964 NE1 716 (KVM/Linux)
> [ 28.476932] Call Trace:
>
> Fixes: 2f859d0dad81 ("s390/smp: reduce size of struct pcpu")
> Cc: stable@vger.kernel.org # 4.0+
> Reported-by: Cornelia Huck <cohuck@redhat.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
> arch/s390/kernel/smp.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
All now queued up, thanks.
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-01-29 9:49 UTC | newest]
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2019-01-27 15:09 FAILED: patch "[PATCH] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU" failed to apply to 4.14-stable tree gregkh
2019-01-28 13:21 ` [PATCH] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU David Hildenbrand
2019-01-29 9:49 ` Greg KH
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