[libc-commits] [libc] [libc] fortify jmp buffer for x86-64 (PR #112769)

[Simon Tatham via libc-commits]

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@@ -11,35 +11,97 @@
 #include "src/__support/macros/config.h"
 #include "src/setjmp/setjmp_impl.h"
 
+#if LIBC_COPT_SETJMP_ENABLE_FORTIFICATION
+#include "src/setjmp/checksum.h"
+#endif
+
 #if !defined(LIBC_TARGET_ARCH_IS_X86_64)
 #error "Invalid file include"
 #endif
 
-namespace LIBC_NAMESPACE_DECL {
+#if LIBC_COPT_SETJMP_ENABLE_FORTIFICATION
+#define ACCUMULATE_CHECKSUM()                                                  \
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statham-arm wrote:

There are still two copies of this, one here and the other in `longjmp.cpp`. They have to match, or the checksum computed by `setjmp` won't agree with the one `longjmp` expects. So surely there should be one copy of the implementation, and it should live in a header file that both source files include.

That's also a good place to put the comment explaining the choice of algorithm.

https://github.com/llvm/llvm-project/pull/112769