On Fri, 24 Jan 2025 09:53:43 GMT, SendaoYan <s...@openjdk.org> wrote:
> Hi all,
> This PR fix a undefined behaviour in 'CollisionsReceiveDifferentIndexes'
> testcase
> locate in 'test/hotspot/gtest/nmt/test_nmt_nativecallstackstorage.cpp' file
> when call `NativeCallStack::NativeCallStack` function. Before this PR,
> 'CollisionsReceiveDifferentIndexes' test allocate 4 type variable `i` and
> then pass the address `&i`, but in 'NativeCallStack' function read the
> pointer as 8 types, so the AddressSanitizer report "Memory access partially
> overflows variable i". This PR change the variable `i` to `size_t` to avoid
> this undefined behaviour.
> Change has been verified locally, test-fix only, no risk.
>
> Below code snippet can reproduce the same issue:
>
>
> #include <stdio.h>
> typedef unsigned char u_char;
> typedef u_char* address;
> int main()
> {
> int i = 0;
> address* pc = (address*)(&i);
> address _stack = pc[0];
> printf("_stack = %p\n", _stack);
> return 0;
> }
>
>
> Reproduce command:
>
> clang -g3 -Wall -Wextra -fsanitize=address -fsanitize=leak
> -fsanitize=undefined partially-overflows.c && ./a.out
Thanks all for the reviews.
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PR Comment: https://git.openjdk.org/jdk/pull/23294#issuecomment-2623885264
