Commit 3ac265d5c0e038e324bae29131dbc4bacb4935ea
2022-05-15T18:43:56
x86-64: Always double jump table slot size for CET (#710) (#711) When CET is enabled, double jump table slot size to add 4 bytes of ENDBR64 for CET. Since CET enabled clang doesn't have the LLVM assembler bug: https://bugs.llvm.org/show_bug.cgi?id=21501 fixed by commit 04d39260d64e08b8bfb3844109ad43d4055b2e8d Author: Rafael Espindola <rafael.espindola@gmail.com> Date: Wed Nov 4 23:50:29 2015 +0000 Simplify .org processing and make it a bit more powerful. we can use .org to allocate jump table slot size to 16 bytes.
diff --git a/src/x86/unix64.S b/src/x86/unix64.S
index 8cf3a23..d9c5bd4 100644
--- a/src/x86/unix64.S
+++ b/src/x86/unix64.S
@@ -39,14 +39,13 @@
actual table. The entry points into the table are all 8 bytes.
The use of ORG asserts that we're at the correct location. */
/* ??? The clang assembler doesn't handle .org with symbolic expressions. */
-#if defined(__clang__) || defined(__APPLE__) || (defined (__sun__) && defined(__svr4__))
+#ifdef __CET__
+/* Double slot size to 16 byte to add 4 bytes of ENDBR64. */
+# define E(BASE, X) .balign 8; .org BASE + X * 16
+#elif defined(__clang__) || defined(__APPLE__) || (defined (__sun__) && defined(__svr4__))
# define E(BASE, X) .balign 8
#else
-# ifdef __CET__
-# define E(BASE, X) .balign 8; .org BASE + X * 16
-# else
-# define E(BASE, X) .balign 8; .org BASE + X * 8
-# endif
+# define E(BASE, X) .balign 8; .org BASE + X * 8
#endif
/* ffi_call_unix64 (void *args, unsigned long bytes, unsigned flags,