Re: [PATCH v2 1/8] makedumpfile: Add '--config' option to specify filterconfig file.

[Mahesh Jagannath Salgaonkar <mahesh@linux.vnet.ibm.com>]

On 05/23/2011 02:39 PM, tachibana@mxm.nes.nec.co.jp wrote:
> Hi Mahesh
> 
> 
> On 2011/05/18 01:30:07 +0530, Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com> wrote:
>> From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
>>
>> This patch adds '--config' option to specify config file that contains filter
>> commands to filter out desired kernel data and it's members.
>>
>> Updated makedumpfile man page with '--config' option info.
>>
>> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
>> Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
>> ---
>>
>>  makedumpfile.8 |   20 +++++++++++++++++++-
>>  makedumpfile.c |   17 +++++++++++++++++
>>  makedumpfile.h |    7 +++++++
>>  3 files changed, 43 insertions(+), 1 deletions(-)
>>
>> diff --git a/makedumpfile.8 b/makedumpfile.8
>> index 4a0271d..a1aaa3e 100644
>> --- a/makedumpfile.8
>> +++ b/makedumpfile.8
>> @@ -6,6 +6,8 @@ makedumpfile \- make a small dumpfile of kdump
>>  .br
>>  \fBmakedumpfile\fR \-F [\fIOPTION\fR] [\-x \fIVMLINUX\fR|\-i \fIVMCOREINFO\fR] \fIVMCORE\fR
>>  .br
>> +\fBmakedumpfile\fR   [\fIOPTION\fR] \-x \fIVMLINUX\fR \-\-config \fIFILTERCONFIGFILE\fR \fIVMCORE\fR \fIDUMPFILE\fR
>> +.br
>>  \fBmakedumpfile\fR \-R \fIDUMPFILE\fR
>>  .br
>>  \fBmakedumpfile\fR \-\-split [\fIOPTION\fR] [\-x \fIVMLINUX\fR|\-i \fIVMCOREINFO\fR] \fIVMCORE\fR \fIDUMPFILE1\fR \fI
> DUMPFILE2\fR [\fIDUMPFILE3\fR ..]
>> @@ -55,6 +57,15 @@ compression support. The ELF format is readable with GDB and the crash utility.
>>  If a user wants to use GDB, \fIDUMPFILE\fR format has to be explicitly
>>  specified to be the ELF format.
>>  .PP
>> +Apart from the exclusion of unnecessary pages mentioned above, makedumpfile
>> +allows user to filter out targeted kernel data. The filter config file can
>> +be used to specify kernel/module symbols and its members that need to be
>> +filtered out through the erase command syntax. makedumpfile reads the filter
>> +config and builds the list of memory addresses and its sizes after processing
>> +filter commands. The memory locations that require to be filtered out are
>> +then poisoned with character 'X' (58 in Hex). Refer to \fBfilter.conf(8)\fR
>> +for file format.
>> +.PP
>>  To analyze the first kernel's memory usage, makedumpfile can refer to
>>  \fIVMCOREINFO\fR instead of \fIVMLINUX\fR. \fIVMCOREINFO\fR contains the first
>>  kernel's information (structure size, field offset, etc.), and \fIVMCOREINFO\fR
>> @@ -232,6 +243,13 @@ specified.
>>  # makedumpfile \-g vmcoreinfo \-x vmlinux
>>  
>>  .TP
>> +\fB\-\-config\fR \fIFILTERCONFIGFILE\fR
>> +Used in conjunction with \-x \fIVMLINUX\fR option, to specify the filter
>> +config file \fIFILTERCONFIGFILE\fR that contains erase commands to filter out
>> +desired kernel data from vmcore while creating \fIDUMPFILE\fR. For filter
>> +command syntax please refer to \fBfilter.conf(8)\fR.
>> +
>> +.TP
>>  \fB\-F\fR
>>  Output the dump data in the flattened format to the standard output for
>>  transporting the dump data by SSH.
>> @@ -482,5 +500,5 @@ Written by Masaki Tachibana, and Ken'ichi Ohmichi.
>>  
>>  .SH SEE ALSO
>>  .PP
>> -crash(8), gdb(1), kexec(8)
>> +crash(8), gdb(1), kexec(8), filter.conf(8)
>>  
>> diff --git a/makedumpfile.c b/makedumpfile.c
>> index 7d0c663..f136eba 100644
>> --- a/makedumpfile.c
>> +++ b/makedumpfile.c
>> @@ -636,6 +636,11 @@ print_usage(void)
>>  	MSG("  Creating DUMPFILE:\n");
>>  	MSG("  # makedumpfile    [-c|-E] [-d DL] [-x VMLINUX|-i VMCOREINFO] VMCORE DUMPFILE\n");
>>  	MSG("\n");
>> +	MSG("  Creating DUMPFILE with filtered kernel data specified through filter config\n");
>> +	MSG("  file:\n");
>> +	MSG("  # makedumpfile    [-c|-E] [-d DL] -x VMLINUX --config FILTERCONFIGFILE VMCORE\n");
>> +	MSG("    DUMPFILE\n");
>> +	MSG("\n");
>>  	MSG("  Outputting the dump data in the flattened format to the standard output:\n");
>>  	MSG("  # makedumpfile -F [-c|-E] [-d DL] [-x VMLINUX|-i VMCOREINFO] VMCORE\n");
>>  	MSG("\n");
>> @@ -714,6 +719,11 @@ print_usage(void)
>>  	MSG("      other system that is running the same first kernel. [-x VMLINUX] must\n");
>>  	MSG("      be specified.\n");
>>  	MSG("\n");
>> +	MSG("  [--config FILTERCONFIGFILE]:\n");
>> +	MSG("      Used in conjunction with -x VMLINUX option, to specify the filter config\n");
>> +	MSG("      file that contains filter commands to filter out desired kernel data\n");
>> +	MSG("      from vmcore while creating DUMPFILE.\n");
>> +	MSG("\n");
>>  	MSG("  [-F]:\n");
>>  	MSG("      Output the dump data in the flattened format to the standard output\n");
>>  	MSG("      for transporting the dump data by SSH.\n");
>> @@ -7729,6 +7739,9 @@ check_param_for_creating_dumpfile(int argc, char *argv[])
>>  	if (info->flag_flatten && info->flag_split)
>>  		return FALSE;
>>  
> 
> 
>> +	if (info->name_filterconfig && !info->name_vmlinux)
>> +		return FALSE;
> 
> A new option '--config makedumpfile.conf' always needs an option 
> '-x debug_info_file', doesn't it?
Yes, '-x' is mandatory while using '--config' option.
> Once I heard that a debug_info file(i.e. vmlinux) was too large 
> to be included in 2nd kernel's initrd.
> So instead of a debug_info_file, small text files generated by 
> '-g debug_info_file' were introduced.
> Now a debug information is read from /proc/vmcore.
> Do you want to use '--config' while 2nd kernel is running?
> But I think it's impossible on usual distributers' environment, because
> vmlinux is not included in 2nd kernel's initrd.
> So I suppose you use this option as follows:
> 1.Panic occurs.
> 2.2nd kernel is activated.
> 3.makedumpfile makes a dump file from /proc/vmcore without '--config'.
> 4.1st kernel is reactivated.
> 5.makedumpfile makes a masked dump file from the above dump file 
>   with '--config'.
> 
> Am I right?
Yes.
> 
> 
> Thanks
> tachibana
> 
> 
>> +
>>  	if ((argc == optind + 2) && !info->flag_flatten
>>  				 && !info->flag_split) {
>>  		/*
>> @@ -7821,6 +7834,7 @@ static struct option longopts[] = {
>>  	{"message-level", required_argument, NULL, 'm'},
>>  	{"vtop", required_argument, NULL, 'V'},
>>  	{"dump-dmesg", no_argument, NULL, 'M'}, 
>> +	{"config", required_argument, NULL, 'C'},
>>  	{"help", no_argument, NULL, 'h'},
>>  	{0, 0, 0, 0}
>>  };
>> @@ -7851,6 +7865,9 @@ main(int argc, char *argv[])
>>  		case 'b':
>>  			info->block_order = atoi(optarg);
>>  			break;
>> +		case 'C':
>> +			info->name_filterconfig = optarg;
>> +			break;
>>  		case 'c':
>>  			info->flag_compress = 1;
>>  			break;
>> diff --git a/makedumpfile.h b/makedumpfile.h
>> index 4ec77b7..e037f12 100644
>> --- a/makedumpfile.h
>> +++ b/makedumpfile.h
>> @@ -888,6 +888,13 @@ struct DumpInfo {
>>  	unsigned long	vmemmap_end;
>>  
>>  	/*
>> +	 * Filter config file containing filter commands to filter out kernel
>> +	 * data from vmcore.
>> +	 */
>> +	char		*name_filterconfig;
>> +	FILE		*file_filterconfig;
>> +
>> +	/*
>>  	 * diskdimp info:
>>  	 */
>>  	int		block_order;
>>
>>
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> 
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