[llvm-branch-commits] [compiler-rt] release/19.x: Normalize ptrauth handling in sanitizer runtime (#100483) (PR #100634)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: None (llvmbot)

<details>
<summary>Changes</summary>

Backport cc4f98979b079b517edd8a71f56a8975f436e63d

Requested by: @<!-- -->asl

---
Full diff: https://github.com/llvm/llvm-project/pull/100634.diff


1 Files Affected:

- (modified) compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h (+24-22) 


``````````diff
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h b/compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h
index 5200354694851..b5215c0d49c06 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h
@@ -9,31 +9,33 @@
 #ifndef SANITIZER_PTRAUTH_H
 #define SANITIZER_PTRAUTH_H
 
-#if __has_feature(ptrauth_calls)
-#include <ptrauth.h>
+#if __has_feature(ptrauth_intrinsics)
+#  include <ptrauth.h>
 #elif defined(__ARM_FEATURE_PAC_DEFAULT) && !defined(__APPLE__)
-inline unsigned long ptrauth_strip(void* __value, unsigned int __key) {
-  // On the stack the link register is protected with Pointer
-  // Authentication Code when compiled with -mbranch-protection.
-  // Let's stripping the PAC unconditionally because xpaclri is in
-  // the NOP space so will do nothing when it is not enabled or not available.
-  unsigned long ret;
-  asm volatile(
-      "mov x30, %1\n\t"
-      "hint #7\n\t"  // xpaclri
-      "mov %0, x30\n\t"
-      : "=r"(ret)
-      : "r"(__value)
-      : "x30");
-  return ret;
-}
-#define ptrauth_auth_data(__value, __old_key, __old_data) __value
-#define ptrauth_string_discriminator(__string) ((int)0)
+// On the stack the link register is protected with Pointer
+// Authentication Code when compiled with -mbranch-protection.
+// Let's stripping the PAC unconditionally because xpaclri is in
+// the NOP space so will do nothing when it is not enabled or not available.
+#  define ptrauth_strip(__value, __key) \
+    ({                                  \
+      unsigned long ret;                \
+      asm volatile(                     \
+          "mov x30, %1\n\t"             \
+          "hint #7\n\t"                 \
+          "mov %0, x30\n\t"             \
+          "mov x30, xzr\n\t"            \
+          : "=r"(ret)                   \
+          : "r"(__value)                \
+          : "x30");                     \
+      ret;                              \
+    })
+#  define ptrauth_auth_data(__value, __old_key, __old_data) __value
+#  define ptrauth_string_discriminator(__string) ((int)0)
 #else
 // Copied from <ptrauth.h>
-#define ptrauth_strip(__value, __key) __value
-#define ptrauth_auth_data(__value, __old_key, __old_data) __value
-#define ptrauth_string_discriminator(__string) ((int)0)
+#  define ptrauth_strip(__value, __key) __value
+#  define ptrauth_auth_data(__value, __old_key, __old_data) __value
+#  define ptrauth_string_discriminator(__string) ((int)0)
 #endif
 
 #define STRIP_PAC_PC(pc) ((uptr)ptrauth_strip(pc, 0))

``````````

</details>


https://github.com/llvm/llvm-project/pull/100634