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

[Schrodinger ZHU Yifan via libc-commits]

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@@ -8,35 +8,83 @@
 
 #include "src/setjmp/longjmp.h"
 #include "include/llvm-libc-macros/offsetof-macro.h"
+#include "src/__support/OSUtil/io.h"
 #include "src/__support/common.h"
 #include "src/__support/macros/config.h"
+#include "src/setjmp/checksum.h"
+#include "src/stdlib/abort.h"
 
 #if !defined(LIBC_TARGET_ARCH_IS_X86_64)
 #error "Invalid file include"
 #endif
 
 namespace LIBC_NAMESPACE_DECL {
 
+#if LIBC_COPT_SETJMP_ENABLE_FORTIFICATION
+extern "C" [[gnu::cold, noreturn]] void __libc_jmpbuf_corruption() {
+  write_to_stderr("invalid checksum detected in longjmp\n");
+  abort();
+}
+#define LOAD_CHKSUM_STATE_REGISTERS()                                          \
+  asm("mov %0, %%rcx\n\t" ::"m"(jmpbuf::value_mask) : "rcx");                  \
+  asm("mov %0, %%rdx\n\t" ::"m"(jmpbuf::checksum_cookie) : "rdx");
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SchrodingerZhu wrote:

fixed.

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