[Qemu-devel] [PATCH] qemu-system-tricore: segfault when entering "x 0" on the monitor

[Qemu-devel] [PATCH] qemu-system-tricore: segfault when entering "x 0" on the monitor

[Eduardo Otubo]

Starting Qemu with "qemu-system-tricore -nographic -M tricore_testboard -S"
and entering "x 0" at the monitor prompt leads to Segmentation fault. This happens
because tricore_cpu_get_phys_page_debug() is not implemented yet, this
is a temporary workaround to avoid the crash.

Signed-off-by: Eduardo Otubo <otubo@redhat.com>
---
 target/tricore/cpu.c | 10 ++++++++++
 target/tricore/cpu.h |  1 +
 2 files changed, 11 insertions(+)

diff --git a/target/tricore/cpu.c b/target/tricore/cpu.c
index 08f50e2ba7..5ab5b56454 100644
--- a/target/tricore/cpu.c
+++ b/target/tricore/cpu.c
@@ -22,6 +22,15 @@
 #include "cpu.h"
 #include "qemu-common.h"
 #include "exec/exec-all.h"
+#include "qemu/error-report.h"
+
+static hwaddr tricore_cpu_get_phys_page_attrs_debug(CPUState *cpu, vaddr addr,
+                                         MemTxAttrs *attrs)
+{
+    error_report("function cpu_get_phys_page_attrs_debug not "
+                    "implemented, aborting");
+    return -1;
+}
 
 static inline void set_feature(CPUTriCoreState *env, int feature)
 {
@@ -176,6 +185,7 @@ static void tricore_cpu_class_init(ObjectClass *c, void *data)
     cc->dump_state = tricore_cpu_dump_state;
     cc->set_pc = tricore_cpu_set_pc;
     cc->synchronize_from_tb = tricore_cpu_synchronize_from_tb;
+    cc->get_phys_page_attrs_debug = tricore_cpu_get_phys_page_attrs_debug;
 }
 
 static void cpu_register(const TriCoreCPUInfo *info)
diff --git a/target/tricore/cpu.h b/target/tricore/cpu.h
index a3493a123c..2663723955 100644
--- a/target/tricore/cpu.h
+++ b/target/tricore/cpu.h
@@ -224,6 +224,7 @@ static inline TriCoreCPU *tricore_env_get_cpu(CPUTriCoreState *env)
 #define ENV_OFFSET offsetof(TriCoreCPU, env)
 
 hwaddr tricore_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
+
 void tricore_cpu_dump_state(CPUState *cpu, FILE *f,
                             fprintf_function cpu_fprintf, int flags);
 
-- 
2.13.3

Re: [Qemu-devel] [PATCH] qemu-system-tricore: segfault when entering "x 0" on the monitor

[Thomas Huth]

On 27.07.2017 16:30, Eduardo Otubo wrote:
> Starting Qemu with "qemu-system-tricore -nographic -M tricore_testboard -S"
> and entering "x 0" at the monitor prompt leads to Segmentation fault. This happens
> because tricore_cpu_get_phys_page_debug() is not implemented yet, this
> is a temporary workaround to avoid the crash.
> 
> Signed-off-by: Eduardo Otubo <otubo@redhat.com>
> ---
>  target/tricore/cpu.c | 10 ++++++++++
>  target/tricore/cpu.h |  1 +
>  2 files changed, 11 insertions(+)
> 
> diff --git a/target/tricore/cpu.c b/target/tricore/cpu.c
> index 08f50e2ba7..5ab5b56454 100644
> --- a/target/tricore/cpu.c
> +++ b/target/tricore/cpu.c
> @@ -22,6 +22,15 @@
>  #include "cpu.h"
>  #include "qemu-common.h"
>  #include "exec/exec-all.h"
> +#include "qemu/error-report.h"
> +
> +static hwaddr tricore_cpu_get_phys_page_attrs_debug(CPUState *cpu, vaddr addr,
> +                                         MemTxAttrs *attrs)
> +{
> +    error_report("function cpu_get_phys_page_attrs_debug not "
> +                    "implemented, aborting");
> +    return -1;
> +}
>  
>  static inline void set_feature(CPUTriCoreState *env, int feature)
>  {
> @@ -176,6 +185,7 @@ static void tricore_cpu_class_init(ObjectClass *c, void *data)
>      cc->dump_state = tricore_cpu_dump_state;
>      cc->set_pc = tricore_cpu_set_pc;
>      cc->synchronize_from_tb = tricore_cpu_synchronize_from_tb;
> +    cc->get_phys_page_attrs_debug = tricore_cpu_get_phys_page_attrs_debug;
>  }
>  
>  static void cpu_register(const TriCoreCPUInfo *info)
> diff --git a/target/tricore/cpu.h b/target/tricore/cpu.h
> index a3493a123c..2663723955 100644
> --- a/target/tricore/cpu.h
> +++ b/target/tricore/cpu.h
> @@ -224,6 +224,7 @@ static inline TriCoreCPU *tricore_env_get_cpu(CPUTriCoreState *env)
>  #define ENV_OFFSET offsetof(TriCoreCPU, env)
>  
>  hwaddr tricore_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
> +

Unnecessary white-space change ... rather remove the
tricore_cpu_get_phys_page_debug() line instead?

>  void tricore_cpu_dump_state(CPUState *cpu, FILE *f,
>                              fprintf_function cpu_fprintf, int flags);

Apart from the nit above, looks like this fixes the crash indeed:

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

Re: [Qemu-devel] qemu-system-tricore: segfault when entering "x 0" on the monitor

[Michael Tokarev]

27.07.2017 17:30, Eduardo Otubo wrote:
> Starting Qemu with "qemu-system-tricore -nographic -M tricore_testboard -S"
> and entering "x 0" at the monitor prompt leads to Segmentation fault. This happens
> because tricore_cpu_get_phys_page_debug() is not implemented yet, this
> is a temporary workaround to avoid the crash.

Applied to -trivial, without the extra newline in target/tricore/cpu.h

/mjt

Re: [Qemu-devel] qemu-system-tricore: segfault when entering "x 0" on the monitor

[Bastian Koppelmann]

On 07/28/2017 01:19 PM, Michael Tokarev wrote:
> 27.07.2017 17:30, Eduardo Otubo wrote:
>> Starting Qemu with "qemu-system-tricore -nographic -M tricore_testboard -S"
>> and entering "x 0" at the monitor prompt leads to Segmentation fault. This happens
>> because tricore_cpu_get_phys_page_debug() is not implemented yet, this
>> is a temporary workaround to avoid the crash.
> 
> Applied to -trivial, without the extra newline in target/tricore/cpu.h
> 
> /mjt
> 

Thanks for picking this up :)

Cheers,
Bastian

Re: [Qemu-devel] [PATCH] qemu-system-tricore: segfault when entering "x 0" on the monitor

[Thomas Huth]

 Hi Eduardo,

Meta comment: Please always put the maintainer(s) and qemu-devel on CC:

On 27.07.2017 14:37, Eduardo Otubo wrote:
> Starting Qemu with "qemu-system-tricore -nographic -M tricore_testboard
> -S" and entering "x 0" at the monitor prompt leads to Segmentation
> fault. This happens because tricore_cpu_get_phys_page_debug() is not
> implemented yet, this is a temporary workaround to avoid the crash do
> just abort the execution with exit(1).
> 
> Signed-off-by: Eduardo Otubo <otubo@redhat.com>
> ---
>  target/tricore/cpu.c | 10 ++++++++++
>  target/tricore/cpu.h |  3 +++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/target/tricore/cpu.c b/target/tricore/cpu.c
> index 08f50e2ba7..822c7f4092 100644
> --- a/target/tricore/cpu.c
> +++ b/target/tricore/cpu.c
> @@ -22,6 +22,15 @@
>  #include "cpu.h"
>  #include "qemu-common.h"
>  #include "exec/exec-all.h"
> +#include "qemu/error-report.h"
> +
> +hwaddr tricore_cpu_get_phys_page_attrs_debug(CPUState *cpu, vaddr addr,
> +                                         MemTxAttrs *attrs)
> +{
> +    error_report("function cpu_get_phys_page_attrs_debug not"
> +                    "implemented, aborting");
> +    exit(1);

Looking at the description in include/qom/cpu.h and the callers in
exec.c, it seems like it is OK if these functions return -1 if the page
could not be found. I think you should do that here, too, instead of
exiting - it's always a little bit annoying for the users if QEMU exits
unexpectedly, so we should try to avoid that if possible.

> +}
>  
>  static inline void set_feature(CPUTriCoreState *env, int feature)
>  {
> @@ -176,6 +185,7 @@ static void tricore_cpu_class_init(ObjectClass *c, void *data)
>      cc->dump_state = tricore_cpu_dump_state;
>      cc->set_pc = tricore_cpu_set_pc;
>      cc->synchronize_from_tb = tricore_cpu_synchronize_from_tb;
> +    cc->get_phys_page_attrs_debug = tricore_cpu_get_phys_page_attrs_debug;
>  }
>  
>  static void cpu_register(const TriCoreCPUInfo *info)
> diff --git a/target/tricore/cpu.h b/target/tricore/cpu.h
> index a3493a123c..c374ed3213 100644
> --- a/target/tricore/cpu.h
> +++ b/target/tricore/cpu.h
> @@ -224,6 +224,9 @@ static inline TriCoreCPU *tricore_env_get_cpu(CPUTriCoreState *env)
>  #define ENV_OFFSET offsetof(TriCoreCPU, env)
>  
>  hwaddr tricore_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);

I think you could also remove that prototype above now - since there is
no implementation for this.

> +hwaddr tricore_cpu_get_phys_page_attrs_debug(CPUState *cpu, vaddr addr,
> +                                         MemTxAttrs *attrs);
> +
>  void tricore_cpu_dump_state(CPUState *cpu, FILE *f,
>                              fprintf_function cpu_fprintf, int flags);
>  
> 

 Thomas