RFR: 8240956: SEGV in DwarfParser::process_dwarf after JDK-8234624

[David Holmes]

On 16/03/2020 12:17 pm, David Holmes wrote:
> Hi Yasumasa,
> 
> I can't review this as I know nothing about the code, but I'm putting 
> the patch through our internal testing.

Sorry but the crashes still exist:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007fcdd403894e, pid=16948, tid=16949
#
# JRE version: Java(TM) SE Runtime Environment (15.0) (fastdebug build 
15-internal+0-2020-03-16-0214474.david.holmes.jdk-dev)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 
15-internal+0-2020-03-16-0214474.david.holmes.jdk-dev, mixed mode, 
sharing, tiered, compressed oops, g1 gc, linux-amd64)
# Problematic frame:
# C  [libsaproc.so+0x494e]  DwarfParser::process_dwarf(unsigned long)+0x4e

in fact they seem worse as the test seems to always crash now.

David

> David
> 
> On 14/03/2020 11:35 am, Yasumasa Suenaga wrote:
>> Hi all,
>>
>> Please review this change:
>>
>>    JBS: https://bugs.openjdk.java.net/browse/JDK-8240956
>>    webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8240956/webrev.00/
>>
>> JDK-8234624 introduced DWARF parser in SA for unwinding native frames 
>> in jstack mixed mode.
>> However some error has seen intermittently after that.
>>
>> I investigated the cause of this, I found two concerns:
>>
>>    A: lack of buffer (.eh_frame section data) range check
>>    B: Language personality routine and Language Specific Data Area 
>> (LSDA) are not considered
>>
>> I addd range check for .eh_frame processing, and ignore personality 
>> routine and LSDA in this webrev.
>> Also I added bailout code if DWARF processing is failed due to these 
>> concerns.
>>
>> This change has passed all tests on submit repo 
>> (mach5-one-ysuenaga-JDK-8240956-20200313-1518-9434671),
>> also I tested it on my Fedora 31 box and Oracle Linux 7.7 container.
>>
>>
>> Thanks,
>>
>> Yasumasa