[PATCH] sandbox: disable tracing before unmapping RAM

[PATCH] sandbox: disable tracing before unmapping RAM

[Pavel Skripkin]

Currently doing 'reset' command in sandbox with tracing enabled causes
SIGSEV

```
Hit any key to stop autoboot:  0
=>
=>
=> reset
resetting ...
Segmentation fault (core dumped)

```

Tracing callback uses RAM buffer for storing tracing reports, but
state_uninit() function unmaps whole RAM, which causes SIGSEV on umapped
memory inside tracing subsystem.

Fix it by disabling tracing before unmapping memory

Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 arch/sandbox/cpu/state.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/sandbox/cpu/state.c b/arch/sandbox/cpu/state.c
index 69da378ab5..d8d5da25b1 100644
--- a/arch/sandbox/cpu/state.c
+++ b/arch/sandbox/cpu/state.c
@@ -10,6 +10,7 @@
 #include <fdtdec.h>
 #include <log.h>
 #include <os.h>
+#include <trace.h>
 #include <asm/malloc.h>
 #include <asm/state.h>
 #include <asm/test.h>
@@ -525,6 +526,9 @@ int state_uninit(void)
 	if (state->jumped_fname)
 		os_unlink(state->jumped_fname);
 
+	/* Disable tracing before unmapping RAM */
+	trace_set_enabled(0);
+
 	os_free(state->state_fdt);
 	os_free(state->ram_buf);
 	memset(state, '\0', sizeof(*state));
-- 
2.39.2

Re: [PATCH] sandbox: disable tracing before unmapping RAM

[Simon Glass]

On Wed, 12 Apr 2023 at 12:55, Pavel Skripkin <paskripkin@gmail.com> wrote:
>
> Currently doing 'reset' command in sandbox with tracing enabled causes
> SIGSEV
>
> ```
> Hit any key to stop autoboot:  0
> =>
> =>
> => reset
> resetting ...
> Segmentation fault (core dumped)
>
> ```
>
> Tracing callback uses RAM buffer for storing tracing reports, but
> state_uninit() function unmaps whole RAM, which causes SIGSEV on umapped
> memory inside tracing subsystem.
>
> Fix it by disabling tracing before unmapping memory
>
> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> ---
>  arch/sandbox/cpu/state.c | 4 ++++
>  1 file changed, 4 insertions(+)

Reviewed-by: Simon Glass <sjg@chromium.org>

Re: [PATCH] sandbox: disable tracing before unmapping RAM

[Pavel Skripkin]

Hi Simon,

Simon Glass <sjg@chromium.org> says:
> On Wed, 12 Apr 2023 at 12:55, Pavel Skripkin <paskripkin@gmail.com> wrote:
>>
>> Currently doing 'reset' command in sandbox with tracing enabled causes
>> SIGSEV
>>
>> ```
>> Hit any key to stop autoboot:  0
>> =>
>> =>
>> => reset
>> resetting ...
>> Segmentation fault (core dumped)
>>
>> ```
>>
>> Tracing callback uses RAM buffer for storing tracing reports, but
>> state_uninit() function unmaps whole RAM, which causes SIGSEV on umapped
>> memory inside tracing subsystem.
>>
>> Fix it by disabling tracing before unmapping memory
>>
>> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
>> ---
>>  arch/sandbox/cpu/state.c | 4 ++++
>>  1 file changed, 4 insertions(+)
> 
> Reviewed-by: Simon Glass <sjg@chromium.org>

Thank you for review!

+Tom, I guess?

@Tom, could you, please, pick following patch?


https://lists.denx.de/pipermail/u-boot/2023-April/515192.html




With regards,
Pavel Skripkin

Re: [PATCH] sandbox: disable tracing before unmapping RAM

[Tom Rini]

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On Tue, Apr 25, 2023 at 04:43:19PM +0300, Pavel Skripkin wrote:
> Hi Simon,
> 
> Simon Glass <sjg@chromium.org> says:
> > On Wed, 12 Apr 2023 at 12:55, Pavel Skripkin <paskripkin@gmail.com> wrote:
> > > 
> > > Currently doing 'reset' command in sandbox with tracing enabled causes
> > > SIGSEV
> > > 
> > > ```
> > > Hit any key to stop autoboot:  0
> > > =>
> > > =>
> > > => reset
> > > resetting ...
> > > Segmentation fault (core dumped)
> > > 
> > > ```
> > > 
> > > Tracing callback uses RAM buffer for storing tracing reports, but
> > > state_uninit() function unmaps whole RAM, which causes SIGSEV on umapped
> > > memory inside tracing subsystem.
> > > 
> > > Fix it by disabling tracing before unmapping memory
> > > 
> > > Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> > > ---
> > >  arch/sandbox/cpu/state.c | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > 
> > Reviewed-by: Simon Glass <sjg@chromium.org>
> 
> Thank you for review!
> 
> +Tom, I guess?
> 
> @Tom, could you, please, pick following patch?
> 
> 
> https://lists.denx.de/pipermail/u-boot/2023-April/515192.html

Simon takes sandbox patches himself and I've assigned this to him in
patchwork, thanks for submitting the patch.

-- 
Tom

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Re: [PATCH] sandbox: disable tracing before unmapping RAM

[Pavel Skripkin]

Hi Tom,

Tom Rini <trini@konsulko.com> says:
> Simon takes sandbox patches himself and I've assigned this to him in
> patchwork, thanks for submitting the patch.
> 

Ah, sorry for noise then. I am just unfamiliar with u-boot development 
process.

Thank you!


With regards,
Pavel Skripkin

Re: [PATCH] sandbox: disable tracing before unmapping RAM

[Simon Glass]

Hi Tom,

Tom Rini <trini@konsulko.com> says:
> Simon takes sandbox patches himself and I've assigned this to him in
> patchwork, thanks for submitting the patch.
>

Ah, sorry for noise then. I am just unfamiliar with u-boot development
process.

Thank you!


With regards,
Pavel Skripkin

Applied to u-boot-dm, thanks!

Re: [PATCH] sandbox: disable tracing before unmapping RAM

[Simon Glass]

Hi Pavel,

On Fri, 28 Apr 2023 at 13:20, Simon Glass <sjg@chromium.org> wrote:
>
> Hi Tom,
>
> Tom Rini <trini@konsulko.com> says:
> > Simon takes sandbox patches himself and I've assigned this to him in
> > patchwork, thanks for submitting the patch.
> >
>
> Ah, sorry for noise then. I am just unfamiliar with u-boot development
> process.
>
> Thank you!

Note, I had to add a check for tracing being enabled, to avoid build errors.

Regards,
SImon