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* [PATCH v3] Only print debug message when failed to serach for kernel symbol from /proc/kallsyms
@ 2017-03-03  3:52 Baoquan He
  2017-03-03  4:05 ` Pratyush Anand
  2017-03-06  1:46 ` Dave Young
  0 siblings, 2 replies; 7+ messages in thread
From: Baoquan He @ 2017-03-03  3:52 UTC (permalink / raw)
  To: horms; +Cc: panand, dyoung, kexec, Baoquan He

Kernel symbol page_offset_base could be unavailable when mm KASLR code is
not compiled in kernel. It's unappropriate to print out error message
when failed to search for page_offset_base from /proc/kallsyms. Seems now
there is not a way to find out if mm KASLR is compiled in or not. An
alternative approach is only printing out debug message in get_kernel_sym
if failed to search a expected kernel symbol.

Do it in this patch, a simple fix.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
 kexec/arch/i386/crashdump-x86.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
index 88aeee3..c4cf201 100644
--- a/kexec/arch/i386/crashdump-x86.c
+++ b/kexec/arch/i386/crashdump-x86.c
@@ -127,7 +127,7 @@ static unsigned long long get_kernel_sym(const char *symbol)
 		}
 	}
 
-	fprintf(stderr, "Cannot get kernel %s symbol address\n", symbol);
+	dbgprintf("Cannot get kernel %s symbol address\n", symbol);
 	return 0;
 }
 
-- 
2.5.5


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^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH v3] Only print debug message when failed to serach for kernel symbol from /proc/kallsyms
  2017-03-03  3:52 [PATCH v3] Only print debug message when failed to serach for kernel symbol from /proc/kallsyms Baoquan He
@ 2017-03-03  4:05 ` Pratyush Anand
  2017-03-06  1:46 ` Dave Young
  1 sibling, 0 replies; 7+ messages in thread
From: Pratyush Anand @ 2017-03-03  4:05 UTC (permalink / raw)
  To: Baoquan He, horms; +Cc: dyoung, kexec



On Friday 03 March 2017 09:22 AM, Baoquan He wrote:
> Kernel symbol page_offset_base could be unavailable when mm KASLR code is
> not compiled in kernel. It's unappropriate to print out error message
> when failed to search for page_offset_base from /proc/kallsyms. Seems now
> there is not a way to find out if mm KASLR is compiled in or not. An
> alternative approach is only printing out debug message in get_kernel_sym
> if failed to search a expected kernel symbol.
>
> Do it in this patch, a simple fix.
>
> Signed-off-by: Baoquan He <bhe@redhat.com>

Yes, a particular symbol can be kernel version dependent and may not be 
available in all the kernel version.

Reviewed-by: Pratyush Anand <panand@redhat.com>

> ---
>  kexec/arch/i386/crashdump-x86.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
> index 88aeee3..c4cf201 100644
> --- a/kexec/arch/i386/crashdump-x86.c
> +++ b/kexec/arch/i386/crashdump-x86.c
> @@ -127,7 +127,7 @@ static unsigned long long get_kernel_sym(const char *symbol)
>  		}
>  	}
>
> -	fprintf(stderr, "Cannot get kernel %s symbol address\n", symbol);
> +	dbgprintf("Cannot get kernel %s symbol address\n", symbol);
>  	return 0;
>  }
>
>

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v3] Only print debug message when failed to serach for kernel symbol from /proc/kallsyms
  2017-03-03  3:52 [PATCH v3] Only print debug message when failed to serach for kernel symbol from /proc/kallsyms Baoquan He
  2017-03-03  4:05 ` Pratyush Anand
@ 2017-03-06  1:46 ` Dave Young
  2017-03-09  4:13   ` Philip Prindeville
  1 sibling, 1 reply; 7+ messages in thread
From: Dave Young @ 2017-03-06  1:46 UTC (permalink / raw)
  To: Baoquan He; +Cc: panand, horms, kexec, thgarnie

On 03/03/17 at 11:52am, Baoquan He wrote:
> Kernel symbol page_offset_base could be unavailable when mm KASLR code is
> not compiled in kernel. It's unappropriate to print out error message
> when failed to search for page_offset_base from /proc/kallsyms. Seems now
> there is not a way to find out if mm KASLR is compiled in or not. An
> alternative approach is only printing out debug message in get_kernel_sym
> if failed to search a expected kernel symbol.
> 
> Do it in this patch, a simple fix.
> 
> Signed-off-by: Baoquan He <bhe@redhat.com>
> ---
>  kexec/arch/i386/crashdump-x86.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
> index 88aeee3..c4cf201 100644
> --- a/kexec/arch/i386/crashdump-x86.c
> +++ b/kexec/arch/i386/crashdump-x86.c
> @@ -127,7 +127,7 @@ static unsigned long long get_kernel_sym(const char *symbol)
>  		}
>  	}
>  
> -	fprintf(stderr, "Cannot get kernel %s symbol address\n", symbol);
> +	dbgprintf("Cannot get kernel %s symbol address\n", symbol);
>  	return 0;
>  }
>  
> -- 
> 2.5.5
> 

It looks reasonable to me:

Acked-by: Dave Young <dyoung@redhat.com>

Thanks
Dave

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http://lists.infradead.org/mailman/listinfo/kexec

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v3] Only print debug message when failed to serach for kernel symbol from /proc/kallsyms
  2017-03-06  1:46 ` Dave Young
@ 2017-03-09  4:13   ` Philip Prindeville
  2017-03-09  7:29     ` Baoquan He
  0 siblings, 1 reply; 7+ messages in thread
From: Philip Prindeville @ 2017-03-09  4:13 UTC (permalink / raw)
  To: Dave Young; +Cc: panand, horms, kexec, thgarnie, Baoquan He

Inline…


> On Mar 5, 2017, at 6:46 PM, Dave Young <dyoung@redhat.com> wrote:
> 
> On 03/03/17 at 11:52am, Baoquan He wrote:
>> Kernel symbol page_offset_base could be unavailable when mm KASLR code is
>> not compiled in kernel. It's unappropriate to print out error message

I subscribed to the list the day after this patch went out…  Anyway, change to “inappropriate”.

-Philip


>> when failed to search for page_offset_base from /proc/kallsyms. Seems now
>> there is not a way to find out if mm KASLR is compiled in or not. An
>> alternative approach is only printing out debug message in get_kernel_sym
>> if failed to search a expected kernel symbol.
>> 
>> Do it in this patch, a simple fix.
>> 
>> Signed-off-by: Baoquan He <bhe@redhat.com>
>> ---
>> kexec/arch/i386/crashdump-x86.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
>> index 88aeee3..c4cf201 100644
>> --- a/kexec/arch/i386/crashdump-x86.c
>> +++ b/kexec/arch/i386/crashdump-x86.c
>> @@ -127,7 +127,7 @@ static unsigned long long get_kernel_sym(const char *symbol)
>> 		}
>> 	}
>> 
>> -	fprintf(stderr, "Cannot get kernel %s symbol address\n", symbol);
>> +	dbgprintf("Cannot get kernel %s symbol address\n", symbol);
>> 	return 0;
>> }
>> 
>> -- 
>> 2.5.5
>> 
> 
> It looks reasonable to me:
> 
> Acked-by: Dave Young <dyoung@redhat.com>
> 
> Thanks
> Dave


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kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v3] Only print debug message when failed to serach for kernel symbol from /proc/kallsyms
  2017-03-09  4:13   ` Philip Prindeville
@ 2017-03-09  7:29     ` Baoquan He
  2017-03-10  9:14       ` Simon Horman
  0 siblings, 1 reply; 7+ messages in thread
From: Baoquan He @ 2017-03-09  7:29 UTC (permalink / raw)
  To: Philip Prindeville; +Cc: panand, kexec, horms, Dave Young, thgarnie

On 03/08/17 at 09:13pm, Philip Prindeville wrote:
> Inline…
> 
> 
> > On Mar 5, 2017, at 6:46 PM, Dave Young <dyoung@redhat.com> wrote:
> > 
> > On 03/03/17 at 11:52am, Baoquan He wrote:
> >> Kernel symbol page_offset_base could be unavailable when mm KASLR code is
> >> not compiled in kernel. It's unappropriate to print out error message
> 
> I subscribed to the list the day after this patch went out…  Anyway, change to “inappropriate”.

Indeed, not sure if Simon want a repost.

Thanks, nice catch!

> 
> -Philip
> 
> 
> >> when failed to search for page_offset_base from /proc/kallsyms. Seems now
> >> there is not a way to find out if mm KASLR is compiled in or not. An
> >> alternative approach is only printing out debug message in get_kernel_sym
> >> if failed to search a expected kernel symbol.
> >> 
> >> Do it in this patch, a simple fix.
> >> 
> >> Signed-off-by: Baoquan He <bhe@redhat.com>
> >> ---
> >> kexec/arch/i386/crashdump-x86.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >> 
> >> diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
> >> index 88aeee3..c4cf201 100644
> >> --- a/kexec/arch/i386/crashdump-x86.c
> >> +++ b/kexec/arch/i386/crashdump-x86.c
> >> @@ -127,7 +127,7 @@ static unsigned long long get_kernel_sym(const char *symbol)
> >> 		}
> >> 	}
> >> 
> >> -	fprintf(stderr, "Cannot get kernel %s symbol address\n", symbol);
> >> +	dbgprintf("Cannot get kernel %s symbol address\n", symbol);
> >> 	return 0;
> >> }
> >> 
> >> -- 
> >> 2.5.5
> >> 
> > 
> > It looks reasonable to me:
> > 
> > Acked-by: Dave Young <dyoung@redhat.com>
> > 
> > Thanks
> > Dave
> 

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v3] Only print debug message when failed to serach for kernel symbol from /proc/kallsyms
  2017-03-09  7:29     ` Baoquan He
@ 2017-03-10  9:14       ` Simon Horman
  2017-03-10  9:23         ` Baoquan He
  0 siblings, 1 reply; 7+ messages in thread
From: Simon Horman @ 2017-03-10  9:14 UTC (permalink / raw)
  To: Baoquan He; +Cc: panand, kexec, Philip Prindeville, Dave Young, thgarnie

On Thu, Mar 09, 2017 at 03:29:45PM +0800, Baoquan He wrote:
> On 03/08/17 at 09:13pm, Philip Prindeville wrote:
> > Inline…
> > 
> > 
> > > On Mar 5, 2017, at 6:46 PM, Dave Young <dyoung@redhat.com> wrote:
> > > 
> > > On 03/03/17 at 11:52am, Baoquan He wrote:
> > >> Kernel symbol page_offset_base could be unavailable when mm KASLR code is
> > >> not compiled in kernel. It's unappropriate to print out error message
> > 
> > I subscribed to the list the day after this patch went out…  Anyway, change to “inappropriate”.
> 
> Indeed, not sure if Simon want a repost.

No need, I have fixed up the change log and applied the patch.

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http://lists.infradead.org/mailman/listinfo/kexec

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v3] Only print debug message when failed to serach for kernel symbol from /proc/kallsyms
  2017-03-10  9:14       ` Simon Horman
@ 2017-03-10  9:23         ` Baoquan He
  0 siblings, 0 replies; 7+ messages in thread
From: Baoquan He @ 2017-03-10  9:23 UTC (permalink / raw)
  To: Simon Horman; +Cc: panand, kexec, Philip Prindeville, Dave Young, thgarnie

On 03/10/17 at 10:14am, Simon Horman wrote:
> On Thu, Mar 09, 2017 at 03:29:45PM +0800, Baoquan He wrote:
> > On 03/08/17 at 09:13pm, Philip Prindeville wrote:
> > > Inline…
> > > 
> > > 
> > > > On Mar 5, 2017, at 6:46 PM, Dave Young <dyoung@redhat.com> wrote:
> > > > 
> > > > On 03/03/17 at 11:52am, Baoquan He wrote:
> > > >> Kernel symbol page_offset_base could be unavailable when mm KASLR code is
> > > >> not compiled in kernel. It's unappropriate to print out error message
> > > 
> > > I subscribed to the list the day after this patch went out…  Anyway, change to “inappropriate”.
> > 
> > Indeed, not sure if Simon want a repost.
> 
> No need, I have fixed up the change log and applied the patch.

Thanks, Simon!

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^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2017-03-10  9:23 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-03-03  3:52 [PATCH v3] Only print debug message when failed to serach for kernel symbol from /proc/kallsyms Baoquan He
2017-03-03  4:05 ` Pratyush Anand
2017-03-06  1:46 ` Dave Young
2017-03-09  4:13   ` Philip Prindeville
2017-03-09  7:29     ` Baoquan He
2017-03-10  9:14       ` Simon Horman
2017-03-10  9:23         ` Baoquan He

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