[8u] RFR 8180032 Unaligned pointer dereference in ClassFileParser

[Aleksey Shipilev]

Hi Dmitry,

On 2/28/20 7:11 PM, Dmitry Cherepanov wrote:
> Please review the following backport for 8u.
> 
> JBS: https://bugs.openjdk.java.net/browse/JDK-8180032
> Original: http://hg.openjdk.java.net/jdk10/jdk10/hotspot/rev/4b93e1b1d5b7
> Webrev: http://cr.openjdk.java.net/~dcherepanov/openjdk8u/8180032/webrev.v0/

*) In classFileParser.hpp, I think the indents are a bit mismatched, should be indented under the
opening parenthesis?

 259   void* parse_exception_table(u4 code_length, u4 exception_table_length,
 260                             TRAPS);

 264   void* parse_localvariable_table(u4 code_length, u2 max_locals, u4 code_attribute_length,
 265                                 u2* localvariable_table_length,
 266                                 bool isLVTT, TRAPS);

 267   void* parse_checked_exceptions(u2* checked_exceptions_length, u4 method_attribute_length,
 268                                TRAPS);

*) In bytecodeInterpreter.hpp, you removed the bytes*.hpp include block, but have not added #include
for bytes.hpp?


> There was a cleanup in the hotspot files. It's done by 
> https://bugs.openjdk.java.net/browse/JDK-8140485 which seems to be too 
> massive to be backported and seems redundant. The patch for JDK-8140485 
> changed the context in 10 (e.g. added const modifier) so I manually 
> re-applied the changes.

That makes sense to me.

> This umbrella header was added in 9 by 
> https://bugs.openjdk.java.net/browse/JDK-8049325. This patch also seems 
> optional for this backport. So I backport'ed only relevant parts (added 
> bytes.hpp and updated #include directives in affected files) to 8u as a 
> part of this change.

Ugh. So we need this to get shared Endian utility that is now in bytes.hpp. Seems like the lesser
evil than backporting JDK-8049325. Maintainers might think differently, though.

-- 
Thanks,
-Aleksey