From c39d1cd6161101e6cbe42b7f08634abca9a052d9 Mon Sep 17 00:00:00 2001 From: Rohan Kumar Date: Mon, 17 Apr 2023 00:07:50 -0700 Subject: [PATCH] syndicate --- content/notes/clang-supports-wiping-call-used-registers.md | 3 +++ 1 file changed, 3 insertions(+) diff --git a/content/notes/clang-supports-wiping-call-used-registers.md b/content/notes/clang-supports-wiping-call-used-registers.md index 488e846..37ccfc7 100644 --- a/content/notes/clang-supports-wiping-call-used-registers.md +++ b/content/notes/clang-supports-wiping-call-used-registers.md @@ -1,6 +1,9 @@ --- title: "Clang supports wiping call-used registers" date: 2023-04-17T00:01:52-07:00 +syndicatedCopies: + - title: 'The Fediverse' + url: 'https://pleroma.envs.net/notice/AUjf1wCr0xk0yCVpKK' --- Here's a compiler flag that slipped my notice: [Clear Linux has `-fzero-call-used-regs=used` in its `CFLAGS`](https://github.com/clearlinux/autospec/blob/46c9d3a49c51235efef62280deb9136f2ee9b203/autospec/specfiles.py#L542) for security-sensitive x86_64 packages, wiping call-used registers on return to protect against ROP exploits. In my benchmarks, there was almost no perf difference between `skip`, `used-gpr` and `used` which is surprising; I thought that this would really hurt instruction cache optimization.