RFR: 8247732: validate user-input intrinsic_ids in ControlIntrinsic [v3]

[Xin Liu]

On Fri, 20 Nov 2020 08:48:28 GMT, Nils Eliasson <neliasso at openjdk.org> wrote:

>> Xin Liu has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains two commits:
>> 
>>  - 8247732: validate user-input intrinsic_ids in ControlIntrinsic
>>    
>>    avoid a warning of stringop-overflow
>>  - 8247732: validate user-input intrinsic_ids in ControlIntrinsic
>
> src/hotspot/share/compiler/compilerDirectives.hpp line 198:
> 
>> 196:       if (vmIntrinsics::_none == vmIntrinsics::find_id(*iter)) {
>> 197:         _bad = NEW_C_HEAP_ARRAY(char, strlen(*iter) + 1, mtCompiler);
>> 198:         strncpy(_bad, *iter, strlen(*iter) + 1);
> 
> This doesn't compile. Using strlen as an argument to strncpy is disallowed.
> 
>> "warning: 'char* __builtin_strncpy(char*, const char*, long unsigned int)' specified bound depends on the length of the source argument [-Wstringop-overflow=]"
> 
> Do a min between strlen and the maximum allowed length.
> 
> Fix this for both uses of the string length (row 197 and 198).

hi, @neliasso, 

I update my toolchain from g++-8 to g++-10 and successfully reproduce this issue. 
I have updated my code to fix it. Actually, only one line is modified. 
@@ -195,7 +195,7 @@ class ControlIntrinsicValidator {
     for (ControlIntrinsicIter iter(option, disabled_all); *iter != NULL && _valid; ++iter) {
       if (vmIntrinsics::_none == vmIntrinsics::find_id(*iter)) {
         _bad = NEW_C_HEAP_ARRAY(char, strlen(*iter) + 1, mtCompiler);
-        strncpy(_bad, *iter, strlen(*iter) + 1);
+        strcpy(_bad, *iter);
         _valid = false;
       }
     }

The change has passed all regression test. I don't know why the table above doesn't update. 
https://github.com/navyxliu/jdk/actions/runs/375913238

Could you take a look my patch, again?

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PR: https://git.openjdk.java.net/jdk/pull/1179