On Fri, 18 Mar 2022 02:39:23 GMT, Mikael Vidstedt <mik...@openjdk.org> wrote:
>> Note: this PR replaces the one I messed up earlier. >> >> Background, from JBS: >> >> src/java.base/share/native/libverify/check_code.c: In function >> 'read_all_code': >> src/java.base/share/native/libverify/check_code.c:942:5: error: 'lengths' >> may be used uninitialized [-Werror=maybe-uninitialized] >> 942 | check_and_push(context, lengths, VM_MALLOC_BLK); >> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> src/java.base/share/native/libverify/check_code.c:4145:13: note: by argument >> 2 of type 'const void *' to 'check_and_push' declared here >> 4145 | static void check_and_push(context_type *context, const void *ptr, >> int kind) >> | ^~~~~~~~~~~~~~ >> >> Because the second argument of check_and_push is "const void*" GCC assumes >> that the malloc:ed data, which has not yet been initialized, will not be/can >> not be modified later which in turn suggests it may be used without ever >> being initialized. >> >> The same general issue was addressed in JDK-8266168, presumably for GCC 11.1. >> >> Details: >> >> Instead of sprinkling more calloc calls around or using pragmas/gcc >> attributes I chose to change the check_and_push function to take a >> (non-const) void* argument, and provide a new wrapper function >> check_and_push_const which handles the const argument case. For the >> (non-const) VM_MALLOC_BKP that means the pointer never needs to go through a >> const conversion. >> >> To avoid having multiple ways of solving the same problem I also chose to >> revert the change made in JDK-8266168, reverting the calloc back to a malloc >> call. >> >> Testing: >> >> tier1 + builds-tier{2,3,4,5} > > Mikael Vidstedt has updated the pull request incrementally with one > additional commit since the last revision: > > Use const char for check_and_push_string_utf Looks good! ------------- Marked as reviewed by dholmes (Reviewer). PR: https://git.openjdk.java.net/jdk/pull/7859