Merge "Clear pointer tags as required for HWASAN for globals."
diff --git a/libc/private/WriteProtected.h b/libc/private/WriteProtected.h
index 69a6822..d240e14 100644
--- a/libc/private/WriteProtected.h
+++ b/libc/private/WriteProtected.h
@@ -46,6 +46,16 @@
WriteProtectedContents<T> contents;
+ int set_protection(int prot) {
+ auto addr = reinterpret_cast<uintptr_t>(&contents);
+#if __has_feature(hwaddress_sanitizer)
+ // The mprotect system call does not currently untag pointers, so do it
+ // ourselves.
+ addr &= (1ULL << 56) - 1;
+#endif
+ return mprotect(reinterpret_cast<void*>(addr), PAGE_SIZE, prot);
+ }
+
public:
WriteProtected() = default;
BIONIC_DISALLOW_COPY_AND_ASSIGN(WriteProtected);
@@ -55,7 +65,7 @@
// multiple times by accident.
memset(&contents, 0, sizeof(contents));
- if (mprotect(&contents, PAGE_SIZE, PROT_READ)) {
+ if (set_protection(PROT_READ)) {
async_safe_fatal("failed to make WriteProtected nonwritable in initialize");
}
}
@@ -70,12 +80,12 @@
template <typename Mutator>
void mutate(Mutator mutator) {
- if (mprotect(&contents, PAGE_SIZE, PROT_READ | PROT_WRITE) != 0) {
+ if (set_protection(PROT_READ | PROT_WRITE) != 0) {
async_safe_fatal("failed to make WriteProtected writable in mutate: %s",
strerror(errno));
}
mutator(&contents.value);
- if (mprotect(&contents, PAGE_SIZE, PROT_READ) != 0) {
+ if (set_protection(PROT_READ) != 0) {
async_safe_fatal("failed to make WriteProtected nonwritable in mutate: %s",
strerror(errno));
}
diff --git a/libdl/libdl_cfi.cpp b/libdl/libdl_cfi.cpp
index 1dd5b21..1446143 100644
--- a/libdl/libdl_cfi.cpp
+++ b/libdl/libdl_cfi.cpp
@@ -45,6 +45,10 @@
static uint16_t shadow_load(void* p) {
uintptr_t addr = reinterpret_cast<uintptr_t>(p);
+#ifdef __aarch64__
+ // Untag the pointer to move it into the address space covered by the shadow.
+ addr &= (1ULL << 56) - 1;
+#endif
uintptr_t ofs = CFIShadow::MemToShadowOffset(addr);
if (ofs > CFIShadow::kShadowSize) return CFIShadow::kInvalidShadow;
return *reinterpret_cast<uint16_t*>(shadow_base_storage.v + ofs);