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-rw-r--r--libc/bionic/heap_tagging.cpp7
-rw-r--r--libc/bionic/heap_tagging.h2
-rw-r--r--libc/bionic/malloc_common.cpp18
-rw-r--r--libc/bionic/malloc_common_dynamic.cpp9
-rw-r--r--libc/bionic/memory_mitigation_state.cpp6
-rw-r--r--libc/bionic/memory_mitigation_state.h2
-rw-r--r--libc/include/malloc.h54
-rw-r--r--libc/platform/bionic/malloc.h16
-rw-r--r--tests/malloc_test.cpp4
9 files changed, 80 insertions, 38 deletions
diff --git a/libc/bionic/heap_tagging.cpp b/libc/bionic/heap_tagging.cpp
index 4b3d43c21..ffbabb9a0 100644
--- a/libc/bionic/heap_tagging.cpp
+++ b/libc/bionic/heap_tagging.cpp
@@ -99,12 +99,7 @@ HeapTaggingLevel GetHeapTaggingLevel() {
}
// Requires `g_heap_tagging_lock` to be held.
-bool SetHeapTaggingLevel(void* arg, size_t arg_size) {
- if (arg_size != sizeof(HeapTaggingLevel)) {
- return false;
- }
-
- auto tag_level = *reinterpret_cast<HeapTaggingLevel*>(arg);
+bool SetHeapTaggingLevel(HeapTaggingLevel tag_level) {
if (tag_level == heap_tagging_level) {
return true;
}
diff --git a/libc/bionic/heap_tagging.h b/libc/bionic/heap_tagging.h
index db45fc100..110b6ed7a 100644
--- a/libc/bionic/heap_tagging.h
+++ b/libc/bionic/heap_tagging.h
@@ -42,5 +42,5 @@ extern pthread_mutex_t g_heap_tagging_lock;
// These functions can be called in a multithreaded context, and thus should
// only be called when holding the `g_heap_tagging_lock`.
-bool SetHeapTaggingLevel(void* arg, size_t arg_size);
+bool SetHeapTaggingLevel(HeapTaggingLevel level);
HeapTaggingLevel GetHeapTaggingLevel();
diff --git a/libc/bionic/malloc_common.cpp b/libc/bionic/malloc_common.cpp
index 0ee12a7fd..955cf1823 100644
--- a/libc/bionic/malloc_common.cpp
+++ b/libc/bionic/malloc_common.cpp
@@ -102,6 +102,15 @@ extern "C" int malloc_info(int options, FILE* fp) {
}
extern "C" int mallopt(int param, int value) {
+ // Some are handled by libc directly rather than by the allocator.
+ if (param == M_BIONIC_SET_HEAP_TAGGING_LEVEL) {
+ ScopedPthreadMutexLocker locker(&g_heap_tagging_lock);
+ return SetHeapTaggingLevel(static_cast<HeapTaggingLevel>(value));
+ }
+ if (param == M_BIONIC_DISABLE_MEMORY_MITIGATIONS) {
+ return DisableMemoryMitigations(value);
+ }
+ // The rest we pass on...
auto dispatch_table = GetDispatchTable();
if (__predict_false(dispatch_table != nullptr)) {
return dispatch_table->mallopt(param, value);
@@ -316,9 +325,8 @@ extern "C" bool android_mallopt(int opcode, void* arg, size_t arg_size) {
if (opcode == M_SET_ALLOCATION_LIMIT_BYTES) {
return LimitEnable(arg, arg_size);
}
- if (opcode == M_SET_HEAP_TAGGING_LEVEL) {
- ScopedPthreadMutexLocker locker(&g_heap_tagging_lock);
- return SetHeapTaggingLevel(arg, arg_size);
+ if (opcode == M_SET_HEAP_TAGGING_LEVEL && arg_size == sizeof(HeapTaggingLevel)) {
+ return mallopt(M_BIONIC_SET_HEAP_TAGGING_LEVEL, *reinterpret_cast<HeapTaggingLevel*>(arg));
}
if (opcode == M_INITIALIZE_GWP_ASAN) {
if (arg == nullptr || arg_size != sizeof(bool)) {
@@ -329,8 +337,8 @@ extern "C" bool android_mallopt(int opcode, void* arg, size_t arg_size) {
return MaybeInitGwpAsan(globals, *reinterpret_cast<bool*>(arg));
});
}
- if (opcode == M_DISABLE_MEMORY_MITIGATIONS) {
- return DisableMemoryMitigations(arg, arg_size);
+ if (opcode == M_DISABLE_MEMORY_MITIGATIONS && arg_size == sizeof(int)) {
+ return mallopt(M_BIONIC_DISABLE_MEMORY_MITIGATIONS, reinterpret_cast<intptr_t>(arg));
}
errno = ENOTSUP;
return false;
diff --git a/libc/bionic/malloc_common_dynamic.cpp b/libc/bionic/malloc_common_dynamic.cpp
index 2d6a1bbcb..93d4d530f 100644
--- a/libc/bionic/malloc_common_dynamic.cpp
+++ b/libc/bionic/malloc_common_dynamic.cpp
@@ -523,9 +523,8 @@ extern "C" bool android_mallopt(int opcode, void* arg, size_t arg_size) {
}
return FreeMallocLeakInfo(reinterpret_cast<android_mallopt_leak_info_t*>(arg));
}
- if (opcode == M_SET_HEAP_TAGGING_LEVEL) {
- ScopedPthreadMutexLocker locker(&g_heap_tagging_lock);
- return SetHeapTaggingLevel(arg, arg_size);
+ if (opcode == M_SET_HEAP_TAGGING_LEVEL && arg_size == sizeof(HeapTaggingLevel)) {
+ return mallopt(M_BIONIC_SET_HEAP_TAGGING_LEVEL, *reinterpret_cast<HeapTaggingLevel*>(arg));
}
if (opcode == M_INITIALIZE_GWP_ASAN) {
if (arg == nullptr || arg_size != sizeof(bool)) {
@@ -536,8 +535,8 @@ extern "C" bool android_mallopt(int opcode, void* arg, size_t arg_size) {
return MaybeInitGwpAsan(globals, *reinterpret_cast<bool*>(arg));
});
}
- if (opcode == M_DISABLE_MEMORY_MITIGATIONS) {
- return DisableMemoryMitigations(arg, arg_size);
+ if (opcode == M_DISABLE_MEMORY_MITIGATIONS && arg_size == sizeof(int)) {
+ return mallopt(M_BIONIC_DISABLE_MEMORY_MITIGATIONS, reinterpret_cast<intptr_t>(arg));
}
// Try heapprofd's mallopt, as it handles options not covered here.
return HeapprofdMallopt(opcode, arg, arg_size);
diff --git a/libc/bionic/memory_mitigation_state.cpp b/libc/bionic/memory_mitigation_state.cpp
index 4761d8862..b262f8616 100644
--- a/libc/bionic/memory_mitigation_state.cpp
+++ b/libc/bionic/memory_mitigation_state.cpp
@@ -47,8 +47,8 @@
extern "C" void scudo_malloc_set_zero_contents(int zero_contents);
-bool DisableMemoryMitigations(void* arg, size_t arg_size) {
- if (arg || arg_size) {
+bool DisableMemoryMitigations(int arg) {
+ if (arg != 0) {
return false;
}
@@ -61,7 +61,7 @@ bool DisableMemoryMitigations(void* arg, size_t arg_size) {
HeapTaggingLevel current_level = GetHeapTaggingLevel();
if (current_level != M_HEAP_TAGGING_LEVEL_NONE && current_level != M_HEAP_TAGGING_LEVEL_TBI) {
HeapTaggingLevel level = M_HEAP_TAGGING_LEVEL_NONE;
- SetHeapTaggingLevel(reinterpret_cast<void*>(&level), sizeof(level));
+ SetHeapTaggingLevel(level);
}
return true;
diff --git a/libc/bionic/memory_mitigation_state.h b/libc/bionic/memory_mitigation_state.h
index ffa19121d..047b6ad3a 100644
--- a/libc/bionic/memory_mitigation_state.h
+++ b/libc/bionic/memory_mitigation_state.h
@@ -30,4 +30,4 @@
#include <stddef.h>
-bool DisableMemoryMitigations(void* arg, size_t arg_size);
+bool DisableMemoryMitigations(int arg);
diff --git a/libc/include/malloc.h b/libc/include/malloc.h
index a237254b7..598a50bc5 100644
--- a/libc/include/malloc.h
+++ b/libc/include/malloc.h
@@ -204,6 +204,60 @@ int malloc_info(int __must_be_zero, FILE* __fp) __INTRODUCED_IN(23);
#define M_TSDS_COUNT_MAX (-202)
/**
+ * mallopt() option to disable heap initialization across the whole process.
+ * If the hardware supports memory tagging, this also disables memory tagging.
+ * May be called at any time, including when multiple threads are running. The
+ * value is unused but must be set to 0.
+ *
+ * Note that these memory mitigations are only implemented in scudo and
+ * therefore this will have no effect when using another allocator (such as
+ * jemalloc on Android Go devices).
+ *
+ * Available since API level 31.
+ */
+#define M_BIONIC_DISABLE_MEMORY_MITIGATIONS (-203)
+
+/**
+ * mallopt() option to change the heap tagging state. May be called at any
+ * time, including when multiple threads are running.
+ * The value must be one of the M_HEAP_TAGGING_LEVEL_ constants.
+ *
+ * Available since API level 31.
+ */
+#define M_BIONIC_SET_HEAP_TAGGING_LEVEL (-204)
+
+/**
+ * Constants for use with the M_BIONIC_SET_HEAP_TAGGING_LEVEL mallopt() option.
+ */
+enum HeapTaggingLevel {
+ /**
+ * Disable heap tagging and memory tag checks (if supported).
+ * Heap tagging may not be re-enabled after being disabled.
+ */
+ M_HEAP_TAGGING_LEVEL_NONE = 0,
+#define M_HEAP_TAGGING_LEVEL_NONE M_HEAP_TAGGING_LEVEL_NONE
+ /**
+ * Address-only tagging. Heap pointers have a non-zero tag in the
+ * most significant ("top") byte which is checked in free(). Memory
+ * accesses ignore the tag using arm64's Top Byte Ignore (TBI) feature.
+ */
+ M_HEAP_TAGGING_LEVEL_TBI = 1,
+#define M_HEAP_TAGGING_LEVEL_TBI M_HEAP_TAGGING_LEVEL_TBI
+ /**
+ * Enable heap tagging and asynchronous memory tag checks (if supported).
+ * Disable stack trace collection.
+ */
+ M_HEAP_TAGGING_LEVEL_ASYNC = 2,
+#define M_HEAP_TAGGING_LEVEL_ASYNC M_HEAP_TAGGING_LEVEL_ASYNC
+ /**
+ * Enable heap tagging and synchronous memory tag checks (if supported).
+ * Enable stack trace collection.
+ */
+ M_HEAP_TAGGING_LEVEL_SYNC = 3,
+#define M_HEAP_TAGGING_LEVEL_SYNC M_HEAP_TAGGING_LEVEL_SYNC
+};
+
+/**
* [mallopt(3)](http://man7.org/linux/man-pages/man3/mallopt.3.html) modifies
* heap behavior. Values of `__option` are the `M_` constants from this header.
*
diff --git a/libc/platform/bionic/malloc.h b/libc/platform/bionic/malloc.h
index 56badf0fd..313cbdf75 100644
--- a/libc/platform/bionic/malloc.h
+++ b/libc/platform/bionic/malloc.h
@@ -28,6 +28,7 @@
#pragma once
+#include <malloc.h>
#include <stdbool.h>
#include <stdint.h>
@@ -114,21 +115,6 @@ enum {
#define M_DISABLE_MEMORY_MITIGATIONS M_DISABLE_MEMORY_MITIGATIONS
};
-enum HeapTaggingLevel {
- // Disable heap tagging and memory tag checks if supported. Heap tagging may not be re-enabled
- // after being disabled.
- M_HEAP_TAGGING_LEVEL_NONE = 0,
- // Address-only tagging. Heap pointers have a non-zero tag in the most significant byte which is
- // checked in free(). Memory accesses ignore the tag.
- M_HEAP_TAGGING_LEVEL_TBI = 1,
- // Enable heap tagging and asynchronous memory tag checks if supported. Disable stack trace
- // collection.
- M_HEAP_TAGGING_LEVEL_ASYNC = 2,
- // Enable heap tagging and synchronous memory tag checks if supported. Enable stack trace
- // collection.
- M_HEAP_TAGGING_LEVEL_SYNC = 3,
-};
-
// Manipulates bionic-specific handling of memory allocation APIs such as
// malloc. Only for use by the Android platform itself.
//
diff --git a/tests/malloc_test.cpp b/tests/malloc_test.cpp
index bddd9ab63..b35bba983 100644
--- a/tests/malloc_test.cpp
+++ b/tests/malloc_test.cpp
@@ -1256,7 +1256,7 @@ TEST(android_mallopt, set_allocation_limit_multiple_threads) {
#endif
}
-TEST(android_mallopt, disable_memory_mitigations) {
+TEST(malloc, disable_memory_mitigations) {
#if defined(__BIONIC__)
if (!mte_supported()) {
GTEST_SKIP() << "This function can only be tested with MTE";
@@ -1275,7 +1275,7 @@ TEST(android_mallopt, disable_memory_mitigations) {
},
&sem));
- ASSERT_TRUE(android_mallopt(M_DISABLE_MEMORY_MITIGATIONS, nullptr, 0));
+ ASSERT_EQ(1, mallopt(M_BIONIC_DISABLE_MEMORY_MITIGATIONS, 0));
ASSERT_EQ(0, sem_post(&sem));
int my_tagged_addr_ctrl = prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0);
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-03 18:59:28 +0000