[Crash-utility] [PATCH] x86_64: Add support for new divide_error name

[Nikolay Borisov]

On 6.11.20 г. 6:48 ч., HAGIO KAZUHITO(萩尾 一仁) wrote:
> -----Original Message-----
>> Upstream kernel commit 9d06c4027f21 ("x86/entry: Convert Divide Error to IDTENTRY")
>> renamed divide_error handler to asm_exc_divide_error. This breaks kaslr
>> offser derivation when we crash tries to open a qemu image dump. Fix it
>> by also checking symbols for the presence of the new name.
>>
>> Signed-off-by: Nikolay Borisov <nborisov at suse.com>
> 
> Thank you for catching this.
> 
> The divide_error way would be rarely used with Alexey's patchset, but
> it's still there.  I've tested this patch with a 5.9 kernel.

FWIW Even with Alexey's patches I was still not able to open qemu's
memory dump.

> 
> Acked-by: Kazuhito Hagio <k-hagio-ab at nec.com>
> 
> (I will add "Linux 5.8 and later" to the commit message.)
> 
> Thanks,
> Kazu
> 
>> ---
>>  symbols.c | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/symbols.c b/symbols.c
>> index 70b1455750ee..e3594ce0ed48 100644
>> --- a/symbols.c
>> +++ b/symbols.c
>> @@ -12711,9 +12711,11 @@ numeric_forward(const void *P_x, const void *P_y)
>>
>>  	if (SADUMP_DUMPFILE() || QEMU_MEM_DUMP_NO_VMCOREINFO() || VMSS_DUMPFILE()) {
>>  		/* Need for kaslr_offset and phys_base */
>> -		if (STREQ(x->name, "divide_error"))
>> +		if (STREQ(x->name, "divide_error") ||
>> +		    STREQ(x->name, "asm_exc_divide_error"))
>>  			st->divide_error_vmlinux = valueof(x);
>> -		else if (STREQ(y->name, "divide_error"))
>> +		else if (STREQ(y->name, "divide_error") ||
>> +			 STREQ(y->name, "asm_exc_divide_error"))
>>  			st->divide_error_vmlinux = valueof(y);
>>
>>  		if (STREQ(x->name, "idt_table"))
>> --
>> 2.25.1
>>
>>
>> --
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>