X-Git-Url: https://git.saurik.com/apple/libplatform.git/blobdiff_plain/89154bfbfa86dc8977dc06e4201daac587013ec8..442fbc9d237f5ec73b89e46275796350834b042e:/src/setjmp/x86_64/_setjmp.s

diff --git a/src/setjmp/x86_64/_setjmp.s b/src/setjmp/x86_64/_setjmp.s
index cd3ad9e..7d42131 100644
--- a/src/setjmp/x86_64/_setjmp.s
+++ b/src/setjmp/x86_64/_setjmp.s
@@ -104,6 +104,7 @@ LEAF(__longjmp, 0)
 	movq	%rsi, %rbp
 	movq	JB_RSP(%rdi), %rsi
 	_OS_PTR_UNMUNGE(%rsi)
+	movsbq	(%rsi), %r12	// probe to detect absolutely corrupt stack pointers
 	movq	%rsi, %rsp
 	movq	JB_R12(%rdi), %r12
 	movq	JB_R13(%rdi), %r13