On Wed, 4 Nov 2026 17:33:21 GMT, Ashay Rane <[email protected]> wrote:
> Without this patch, HotSpot uses `VirtualAlloc()` with `MEM_COMMIT` to > make Windows convert stack pages from "reserved" to "committed", but > doing so does not update the `StackLimit` field in the Thread > Environment Block (TEB) tracked by Windows. Subsequent use of the stack > by HotSpot can cause the stack pointer to be _below_ `StackLimit`, which > breaks the invariant expected by the Win32 API functions like > `__chkstk()`. > > To fix this problem, this patch touches pages one by one, starting from > `StackLimit` down to the target address. This has the intended effect > of commiting the pages, but it also correctly updates `StackLimit`. > > The included test reliably fails without this patch, and it passes with > this patch. I validated this patch using Tier 1 through 3 tests in the > JDK, HotSpot, and LangTools test groups. > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). This pull request has now been integrated. Changeset: eb4e83bd Author: Ashay Rane <[email protected]> URL: https://git.openjdk.org/jdk/commit/eb4e83bddc6961d165b3eeca5fa1d2cf6bfcf622 Stats: 134 lines in 4 files changed: 127 ins; 2 del; 5 mod 8394484: C2 stack bang on Windows can lead to non-recoverable crash Reviewed-by: kvn, dlong, macarte ------------- PR: https://git.openjdk.org/jdk/pull/33729
