[Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Laurent Vivier]

Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
fixes the problem for i386, do the same for ppc.

Running QEMU with
    qemu-system-ppc64 -M none -nographic -m 256
and executing
    dump-guest-memory /dev/null 0 8192
results in segfault

Fix by checking if we have CPU.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 target/ppc/arch_dump.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/target/ppc/arch_dump.c b/target/ppc/arch_dump.c
index 8e9397aa58..dcb7b19950 100644
--- a/target/ppc/arch_dump.c
+++ b/target/ppc/arch_dump.c
@@ -224,17 +224,22 @@ typedef struct NoteFuncDescStruct NoteFuncDesc;
 int cpu_get_dump_info(ArchDumpInfo *info,
                       const struct GuestPhysBlockList *guest_phys_blocks)
 {
-    PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
-    PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
-
     info->d_machine = PPC_ELF_MACHINE;
     info->d_class = ELFCLASS;
 
-    if ((*pcc->interrupts_big_endian)(cpu)) {
-        info->d_endian = ELFDATA2MSB;
+    if (first_cpu) {
+        PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
+        PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
+
+        if ((*pcc->interrupts_big_endian)(cpu)) {
+            info->d_endian = ELFDATA2MSB;
+        } else {
+            info->d_endian = ELFDATA2LSB;
+        }
     } else {
-        info->d_endian = ELFDATA2LSB;
+        info->d_endian = ELFDATA2MSB;
     }
+
     /* 64KB is the max page size for pseries kernel */
     if (strncmp(object_get_typename(qdev_get_machine()),
                 "pseries-", 8) == 0) {
-- 
2.13.5

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Daniel P. Berrange]

On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
> fixes the problem for i386, do the same for ppc.

What about all the other targets QEMU supports ?  Have you checked if they
are similarly affected, as we don't want to wait another 6 months to get a
bug report that s390 or aarch64 crash in exactly the same way too.

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
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Re: [Qemu-devel] [Qemu-ppc] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Greg Kurz]

[-- Attachment #1: Type: text/plain, Size: 1876 bytes --]

On Mon, 11 Sep 2017 13:00:37 +0200
Laurent Vivier <lvivier@redhat.com> wrote:

> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
> fixes the problem for i386, do the same for ppc.
> 
> Running QEMU with
>     qemu-system-ppc64 -M none -nographic -m 256
> and executing
>     dump-guest-memory /dev/null 0 8192
> results in segfault
> 
> Fix by checking if we have CPU.
> 
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---

Reviewed-by: Greg Kurz <groug@kaod.org>

>  target/ppc/arch_dump.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/target/ppc/arch_dump.c b/target/ppc/arch_dump.c
> index 8e9397aa58..dcb7b19950 100644
> --- a/target/ppc/arch_dump.c
> +++ b/target/ppc/arch_dump.c
> @@ -224,17 +224,22 @@ typedef struct NoteFuncDescStruct NoteFuncDesc;
>  int cpu_get_dump_info(ArchDumpInfo *info,
>                        const struct GuestPhysBlockList *guest_phys_blocks)
>  {
> -    PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
> -    PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
> -
>      info->d_machine = PPC_ELF_MACHINE;
>      info->d_class = ELFCLASS;
>  
> -    if ((*pcc->interrupts_big_endian)(cpu)) {
> -        info->d_endian = ELFDATA2MSB;
> +    if (first_cpu) {
> +        PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
> +        PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
> +
> +        if ((*pcc->interrupts_big_endian)(cpu)) {
> +            info->d_endian = ELFDATA2MSB;
> +        } else {
> +            info->d_endian = ELFDATA2LSB;
> +        }
>      } else {
> -        info->d_endian = ELFDATA2LSB;
> +        info->d_endian = ELFDATA2MSB;
>      }
> +
>      /* 64KB is the max page size for pseries kernel */
>      if (strncmp(object_get_typename(qdev_get_machine()),
>                  "pseries-", 8) == 0) {


[-- Attachment #2: OpenPGP digital signature --]
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Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Laurent Vivier]

On 11/09/2017 13:06, Daniel P. Berrange wrote:
> On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
>> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
>> fixes the problem for i386, do the same for ppc.
> 
> What about all the other targets QEMU supports ?  Have you checked if they
> are similarly affected, as we don't want to wait another 6 months to get a
> bug report that s390 or aarch64 crash in exactly the same way too.

s390 works fine, but aarch64 needs the same kind of fix.

Thanks,
Laurent

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Cornelia Huck]

On Mon, 11 Sep 2017 12:06:15 +0100
"Daniel P. Berrange" <berrange@redhat.com> wrote:

> On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
> > Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
> > fixes the problem for i386, do the same for ppc.  
> 
> What about all the other targets QEMU supports ?  Have you checked if they
> are similarly affected, as we don't want to wait another 6 months to get a
> bug report that s390 or aarch64 crash in exactly the same way too.

This patch actually prompted me to check s390, and the mentioned
command line works fine.

However, if we start a qemu with no guest memory defined and then call
dump-guest-memory without filtering, we get a core dump instead of a
guest dump (s390x or x86_64, machine none).

I can take a stab at fixing that, unless someone beats me to it.

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Daniel P. Berrange]

On Mon, Sep 11, 2017 at 01:41:58PM +0200, Cornelia Huck wrote:
> On Mon, 11 Sep 2017 12:06:15 +0100
> "Daniel P. Berrange" <berrange@redhat.com> wrote:
> 
> > On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
> > > Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
> > > fixes the problem for i386, do the same for ppc.  
> > 
> > What about all the other targets QEMU supports ?  Have you checked if they
> > are similarly affected, as we don't want to wait another 6 months to get a
> > bug report that s390 or aarch64 crash in exactly the same way too.
> 
> This patch actually prompted me to check s390, and the mentioned
> command line works fine.
> 
> However, if we start a qemu with no guest memory defined and then call
> dump-guest-memory without filtering, we get a core dump instead of a
> guest dump (s390x or x86_64, machine none).
> 
> I can take a stab at fixing that, unless someone beats me to it.

I wonder if someone wants to write a qtest job to run dump-guest-memory
across all machine types, on all targets. Seems we have enough crashiness
in this code to make it worthwhile to test

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
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Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Dr. David Alan Gilbert]

* Daniel P. Berrange (berrange@redhat.com) wrote:
> On Mon, Sep 11, 2017 at 01:41:58PM +0200, Cornelia Huck wrote:
> > On Mon, 11 Sep 2017 12:06:15 +0100
> > "Daniel P. Berrange" <berrange@redhat.com> wrote:
> > 
> > > On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
> > > > Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
> > > > fixes the problem for i386, do the same for ppc.  
> > > 
> > > What about all the other targets QEMU supports ?  Have you checked if they
> > > are similarly affected, as we don't want to wait another 6 months to get a
> > > bug report that s390 or aarch64 crash in exactly the same way too.
> > 
> > This patch actually prompted me to check s390, and the mentioned
> > command line works fine.
> > 
> > However, if we start a qemu with no guest memory defined and then call
> > dump-guest-memory without filtering, we get a core dump instead of a
> > guest dump (s390x or x86_64, machine none).
> > 
> > I can take a stab at fixing that, unless someone beats me to it.
> 
> I wonder if someone wants to write a qtest job to run dump-guest-memory
> across all machine types, on all targets. Seems we have enough crashiness
> in this code to make it worthwhile to test

We do have - that's how we found this case;  it's part of test-hmp.

Dave

> Regards,
> Daniel
> -- 
> |: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org         -o-            https://fstop138.berrange.com :|
> |: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Laurent Vivier]

On 11/09/2017 14:04, Dr. David Alan Gilbert wrote:
> * Daniel P. Berrange (berrange@redhat.com) wrote:
>> On Mon, Sep 11, 2017 at 01:41:58PM +0200, Cornelia Huck wrote:
>>> On Mon, 11 Sep 2017 12:06:15 +0100
>>> "Daniel P. Berrange" <berrange@redhat.com> wrote:
>>>
>>>> On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
>>>>> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
>>>>> fixes the problem for i386, do the same for ppc.  
>>>>
>>>> What about all the other targets QEMU supports ?  Have you checked if they
>>>> are similarly affected, as we don't want to wait another 6 months to get a
>>>> bug report that s390 or aarch64 crash in exactly the same way too.
>>>
>>> This patch actually prompted me to check s390, and the mentioned
>>> command line works fine.
>>>
>>> However, if we start a qemu with no guest memory defined and then call
>>> dump-guest-memory without filtering, we get a core dump instead of a
>>> guest dump (s390x or x86_64, machine none).
>>>
>>> I can take a stab at fixing that, unless someone beats me to it.
>>
>> I wonder if someone wants to write a qtest job to run dump-guest-memory
>> across all machine types, on all targets. Seems we have enough crashiness
>> in this code to make it worthwhile to test
> 
> We do have - that's how we found this case;  it's part of test-hmp.

The test-hmp runs by default with 0 MB of memory, the problem can only
be found with some memory added to the machine.

Perhaps we can simply update the test to add memory?

BTW, I'm not sure it is really useful to dump memory of a machine
without CPU.

Laurent

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Daniel P. Berrange]

On Mon, Sep 11, 2017 at 02:10:14PM +0200, Laurent Vivier wrote:
> On 11/09/2017 14:04, Dr. David Alan Gilbert wrote:
> > * Daniel P. Berrange (berrange@redhat.com) wrote:
> >> On Mon, Sep 11, 2017 at 01:41:58PM +0200, Cornelia Huck wrote:
> >>> On Mon, 11 Sep 2017 12:06:15 +0100
> >>> "Daniel P. Berrange" <berrange@redhat.com> wrote:
> >>>
> >>>> On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
> >>>>> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
> >>>>> fixes the problem for i386, do the same for ppc.  
> >>>>
> >>>> What about all the other targets QEMU supports ?  Have you checked if they
> >>>> are similarly affected, as we don't want to wait another 6 months to get a
> >>>> bug report that s390 or aarch64 crash in exactly the same way too.
> >>>
> >>> This patch actually prompted me to check s390, and the mentioned
> >>> command line works fine.
> >>>
> >>> However, if we start a qemu with no guest memory defined and then call
> >>> dump-guest-memory without filtering, we get a core dump instead of a
> >>> guest dump (s390x or x86_64, machine none).
> >>>
> >>> I can take a stab at fixing that, unless someone beats me to it.
> >>
> >> I wonder if someone wants to write a qtest job to run dump-guest-memory
> >> across all machine types, on all targets. Seems we have enough crashiness
> >> in this code to make it worthwhile to test
> > 
> > We do have - that's how we found this case;  it's part of test-hmp.
> 
> The test-hmp runs by default with 0 MB of memory, the problem can only
> be found with some memory added to the machine.
> 
> Perhaps we can simply update the test to add memory?

Probably best to run it twice, 0MB and with say 2MB, as they're both
fairly magic values.

Regards,
Daniel
-- 
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Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Laurent Vivier]

On 11/09/2017 14:13, Daniel P. Berrange wrote:
> On Mon, Sep 11, 2017 at 02:10:14PM +0200, Laurent Vivier wrote:
>> On 11/09/2017 14:04, Dr. David Alan Gilbert wrote:
>>> * Daniel P. Berrange (berrange@redhat.com) wrote:
>>>> On Mon, Sep 11, 2017 at 01:41:58PM +0200, Cornelia Huck wrote:
>>>>> On Mon, 11 Sep 2017 12:06:15 +0100
>>>>> "Daniel P. Berrange" <berrange@redhat.com> wrote:
>>>>>
>>>>>> On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
>>>>>>> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
>>>>>>> fixes the problem for i386, do the same for ppc.  
>>>>>>
>>>>>> What about all the other targets QEMU supports ?  Have you checked if they
>>>>>> are similarly affected, as we don't want to wait another 6 months to get a
>>>>>> bug report that s390 or aarch64 crash in exactly the same way too.
>>>>>
>>>>> This patch actually prompted me to check s390, and the mentioned
>>>>> command line works fine.
>>>>>
>>>>> However, if we start a qemu with no guest memory defined and then call
>>>>> dump-guest-memory without filtering, we get a core dump instead of a
>>>>> guest dump (s390x or x86_64, machine none).
>>>>>
>>>>> I can take a stab at fixing that, unless someone beats me to it.
>>>>
>>>> I wonder if someone wants to write a qtest job to run dump-guest-memory
>>>> across all machine types, on all targets. Seems we have enough crashiness
>>>> in this code to make it worthwhile to test
>>>
>>> We do have - that's how we found this case;  it's part of test-hmp.
>>
>> The test-hmp runs by default with 0 MB of memory, the problem can only
>> be found with some memory added to the machine.
>>
>> Perhaps we can simply update the test to add memory?
> 
> Probably best to run it twice, 0MB and with say 2MB, as they're both
> fairly magic values.

OK, I'm going to update the test.

Laurent

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Cornelia Huck]

On Mon, 11 Sep 2017 14:10:14 +0200
Laurent Vivier <lvivier@redhat.com> wrote:

> On 11/09/2017 14:04, Dr. David Alan Gilbert wrote:
> > * Daniel P. Berrange (berrange@redhat.com) wrote:  
> >> On Mon, Sep 11, 2017 at 01:41:58PM +0200, Cornelia Huck wrote:  

> >>> However, if we start a qemu with no guest memory defined and then call
> >>> dump-guest-memory without filtering, we get a core dump instead of a
> >>> guest dump (s390x or x86_64, machine none).
> >>>
> >>> I can take a stab at fixing that, unless someone beats me to it.  
> >>
> >> I wonder if someone wants to write a qtest job to run dump-guest-memory
> >> across all machine types, on all targets. Seems we have enough crashiness
> >> in this code to make it worthwhile to test  
> > 
> > We do have - that's how we found this case;  it's part of test-hmp.  
> 
> The test-hmp runs by default with 0 MB of memory, the problem can only
> be found with some memory added to the machine.
> 
> Perhaps we can simply update the test to add memory?

We have several combinations that can fail here... (cf. the problem
with no memory and no filter above).

> 
> BTW, I'm not sure it is really useful to dump memory of a machine
> without CPU.

Even so, it should not segfault (and neither should dumping a guest
with no memory, even if it doesn't make sense).

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Laurent Vivier]

On 11/09/2017 13:41, Cornelia Huck wrote:
> On Mon, 11 Sep 2017 12:06:15 +0100
> "Daniel P. Berrange" <berrange@redhat.com> wrote:
> 
>> On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
>>> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
>>> fixes the problem for i386, do the same for ppc.  
>>
>> What about all the other targets QEMU supports ?  Have you checked if they
>> are similarly affected, as we don't want to wait another 6 months to get a
>> bug report that s390 or aarch64 crash in exactly the same way too.
> 
> This patch actually prompted me to check s390, and the mentioned
> command line works fine.
> 
> However, if we start a qemu with no guest memory defined and then call
> dump-guest-memory without filtering, we get a core dump instead of a
> guest dump (s390x or x86_64, machine none).
> 
> I can take a stab at fixing that, unless someone beats me to it.
> 

I will update the test with this test case too.

Thanks,
Laurent

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Thomas Huth]

On 11.09.2017 13:00, Laurent Vivier wrote:
> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
> fixes the problem for i386, do the same for ppc.
> 
> Running QEMU with
>     qemu-system-ppc64 -M none -nographic -m 256
> and executing
>     dump-guest-memory /dev/null 0 8192
> results in segfault
> 
> Fix by checking if we have CPU.
> 
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---
>  target/ppc/arch_dump.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/target/ppc/arch_dump.c b/target/ppc/arch_dump.c
> index 8e9397aa58..dcb7b19950 100644
> --- a/target/ppc/arch_dump.c
> +++ b/target/ppc/arch_dump.c
> @@ -224,17 +224,22 @@ typedef struct NoteFuncDescStruct NoteFuncDesc;
>  int cpu_get_dump_info(ArchDumpInfo *info,
>                        const struct GuestPhysBlockList *guest_phys_blocks)
>  {
> -    PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
> -    PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
> -
>      info->d_machine = PPC_ELF_MACHINE;
>      info->d_class = ELFCLASS;
>  
> -    if ((*pcc->interrupts_big_endian)(cpu)) {
> -        info->d_endian = ELFDATA2MSB;
> +    if (first_cpu) {
> +        PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
> +        PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
> +
> +        if ((*pcc->interrupts_big_endian)(cpu)) {
> +            info->d_endian = ELFDATA2MSB;
> +        } else {
> +            info->d_endian = ELFDATA2LSB;
> +        }
>      } else {
> -        info->d_endian = ELFDATA2LSB;
> +        info->d_endian = ELFDATA2MSB;
>      }
> +
>      /* 64KB is the max page size for pseries kernel */
>      if (strncmp(object_get_typename(qdev_get_machine()),
>                  "pseries-", 8) == 0) {
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Thomas Huth]

On 11.09.2017 14:15, Laurent Vivier wrote:
> On 11/09/2017 14:13, Daniel P. Berrange wrote:
>> On Mon, Sep 11, 2017 at 02:10:14PM +0200, Laurent Vivier wrote:
>>> On 11/09/2017 14:04, Dr. David Alan Gilbert wrote:
>>>> * Daniel P. Berrange (berrange@redhat.com) wrote:
>>>>> On Mon, Sep 11, 2017 at 01:41:58PM +0200, Cornelia Huck wrote:
>>>>>> On Mon, 11 Sep 2017 12:06:15 +0100
>>>>>> "Daniel P. Berrange" <berrange@redhat.com> wrote:
>>>>>>
>>>>>>> On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
>>>>>>>> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
>>>>>>>> fixes the problem for i386, do the same for ppc.  
>>>>>>>
>>>>>>> What about all the other targets QEMU supports ?  Have you checked if they
>>>>>>> are similarly affected, as we don't want to wait another 6 months to get a
>>>>>>> bug report that s390 or aarch64 crash in exactly the same way too.
>>>>>>
>>>>>> This patch actually prompted me to check s390, and the mentioned
>>>>>> command line works fine.
>>>>>>
>>>>>> However, if we start a qemu with no guest memory defined and then call
>>>>>> dump-guest-memory without filtering, we get a core dump instead of a
>>>>>> guest dump (s390x or x86_64, machine none).
>>>>>>
>>>>>> I can take a stab at fixing that, unless someone beats me to it.
>>>>>
>>>>> I wonder if someone wants to write a qtest job to run dump-guest-memory
>>>>> across all machine types, on all targets. Seems we have enough crashiness
>>>>> in this code to make it worthwhile to test
>>>>
>>>> We do have - that's how we found this case;  it's part of test-hmp.
>>>
>>> The test-hmp runs by default with 0 MB of memory, the problem can only
>>> be found with some memory added to the machine.
>>>
>>> Perhaps we can simply update the test to add memory?
>>
>> Probably best to run it twice, 0MB and with say 2MB, as they're both
>> fairly magic values.
> 
> OK, I'm going to update the test.

Thanks! But please note that it is only the "none" machine which is
started without memory and CPU by default - all the other boards should
have a default set of memory and at least one CPU. So we should only add
an additional tests for the "none" machine here.

 Thomas

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Miroslav Rezanina]

----- Original Message -----
> From: "Thomas Huth" <thuth@redhat.com>
> To: "Laurent Vivier" <lvivier@redhat.com>, qemu-devel@nongnu.org
> Cc: "David Gibson" <david@gibson.dropbear.id.au>, qemu-ppc@nongnu.org, "Dr . David Alan Gilbert"
> <dgilbert@redhat.com>, "Miroslav Rezanina" <mrezanin@redhat.com>
> Sent: Monday, September 11, 2017 4:36:01 PM
> Subject: Re: [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)
> 
> On 11.09.2017 13:00, Laurent Vivier wrote:
> > Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
> > fixes the problem for i386, do the same for ppc.
> > 
> > Running QEMU with
> >     qemu-system-ppc64 -M none -nographic -m 256
> > and executing
> >     dump-guest-memory /dev/null 0 8192
> > results in segfault
> > 
> > Fix by checking if we have CPU.
> > 
> > Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> > ---
> >  target/ppc/arch_dump.c | 17 +++++++++++------
> >  1 file changed, 11 insertions(+), 6 deletions(-)
> > 
> > diff --git a/target/ppc/arch_dump.c b/target/ppc/arch_dump.c
> > index 8e9397aa58..dcb7b19950 100644
> > --- a/target/ppc/arch_dump.c
> > +++ b/target/ppc/arch_dump.c
> > @@ -224,17 +224,22 @@ typedef struct NoteFuncDescStruct NoteFuncDesc;
> >  int cpu_get_dump_info(ArchDumpInfo *info,
> >                        const struct GuestPhysBlockList *guest_phys_blocks)
> >  {
> > -    PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
> > -    PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
> > -
> >      info->d_machine = PPC_ELF_MACHINE;
> >      info->d_class = ELFCLASS;
> >  
> > -    if ((*pcc->interrupts_big_endian)(cpu)) {
> > -        info->d_endian = ELFDATA2MSB;
> > +    if (first_cpu) {
> > +        PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
> > +        PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
> > +
> > +        if ((*pcc->interrupts_big_endian)(cpu)) {
> > +            info->d_endian = ELFDATA2MSB;
> > +        } else {
> > +            info->d_endian = ELFDATA2LSB;
> > +        }
> >      } else {
> > -        info->d_endian = ELFDATA2LSB;
> > +        info->d_endian = ELFDATA2MSB;
> >      }
> > +
> >      /* 64KB is the max page size for pseries kernel */
> >      if (strncmp(object_get_typename(qdev_get_machine()),
> >                  "pseries-", 8) == 0) {
> > 
> 
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> 

We need similar fix for aarch64 too.

Mirek
-- 
Miroslav Rezanina
Software Engineer - Virtualization Team

Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Thomas Huth]

On 12.09.2017 06:52, Miroslav Rezanina wrote:
> 
> 
> ----- Original Message -----
>> From: "Thomas Huth" <thuth@redhat.com>
>> To: "Laurent Vivier" <lvivier@redhat.com>, qemu-devel@nongnu.org
>> Cc: "David Gibson" <david@gibson.dropbear.id.au>, qemu-ppc@nongnu.org, "Dr . David Alan Gilbert"
>> <dgilbert@redhat.com>, "Miroslav Rezanina" <mrezanin@redhat.com>
>> Sent: Monday, September 11, 2017 4:36:01 PM
>> Subject: Re: [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)
>>
>> On 11.09.2017 13:00, Laurent Vivier wrote:
>>> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
>>> fixes the problem for i386, do the same for ppc.
>>>
>>> Running QEMU with
>>>     qemu-system-ppc64 -M none -nographic -m 256
>>> and executing
>>>     dump-guest-memory /dev/null 0 8192
>>> results in segfault
>>>
>>> Fix by checking if we have CPU.
[...]
> 
> We need similar fix for aarch64 too.

Yes, Laurent already posted a v2 which includes a patch for ARM, too:

https://lists.gnu.org/archive/html/qemu-devel/2017-09/msg02586.html

 Thomas