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

[Schrodinger ZHU Yifan via libc-commits]

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@@ -54,6 +54,7 @@ to learn about the defaults for your platform and target.
     - ``LIBC_CONF_SCANF_DISABLE_INDEX_MODE``: Disable index mode in the scanf format string.
 * **"setjmp" options**
     - ``LIBC_CONF_SETJMP_AARCH64_RESTORE_PLATFORM_REGISTER``: Make setjmp save the value of x18, and longjmp restore it. The AArch64 ABI delegates this register to platform ABIs, which can choose whether to make it caller-saved.
+    - ``LIBC_CONF_SETJMP_ENABLE_FORTIFICATION``: Protect jmp_buf by masking its contents and storing a simple checksum, to make it harder for an attacker to read meaningful information from a jmp_buf or to modify it. This is only supported on x86-64 Linux.
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SchrodingerZhu wrote:

fixed

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