Merge changes from topics "crashapi2", "crashapi3" into main

* changes:
  header and android_crash_detail prefix for crash_detail API
  Allow to re-use the same crash_detail.

7 files changed, 252 insertions, 116 deletions

diff --git a/libc/Android.bp b/libc/Android.bp
index 071f309fa..7e5e972ee 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -791,6 +791,7 @@ cc_library_static {
         "bionic/abort.cpp",
         "bionic/accept.cpp",
         "bionic/access.cpp",
+        "bionic/android_crash_detail.cpp",
         "bionic/android_set_abort_message.cpp",
         "bionic/android_unsafe_frame_pointer_chase.cpp",
         "bionic/arpa_inet.cpp",
diff --git a/libc/bionic/android_crash_detail.cpp b/libc/bionic/android_crash_detail.cpp
new file mode 100644
index 000000000..30ce50565
--- /dev/null
+++ b/libc/bionic/android_crash_detail.cpp
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <android/crash_detail.h>
+
+#include <async_safe/log.h>
+#include <bionic/crash_detail_internal.h>
+
+#include <bits/stdatomic.h>
+#include <pthread.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+
+#include "private/ScopedPthreadMutexLocker.h"
+#include "private/bionic_defs.h"
+#include "private/bionic_globals.h"
+
+static _Atomic(crash_detail_t*) free_head = nullptr;
+
+__BIONIC_WEAK_FOR_NATIVE_BRIDGE
+crash_detail_t* android_crash_detail_register(const void* name, size_t name_size, const void* data,
+                                              size_t data_size) {
+  auto populate_crash_detail = [&](crash_detail_t* result) {
+    result->name = reinterpret_cast<const char*>(name);
+    result->name_size = name_size;
+    result->data = reinterpret_cast<const char*>(data);
+    result->data_size = data_size;
+  };
+  // This is a atomic fast-path for RAII use-cases where the app keeps creating and deleting
+  // crash details for short periods of time to capture detailed scopes.
+  if (crash_detail_t* head = atomic_load(&free_head)) {
+    while (head != nullptr && !atomic_compare_exchange_strong(&free_head, &head, head->prev_free)) {
+      // intentionally left blank.
+    }
+    if (head) {
+      head->prev_free = nullptr;
+      populate_crash_detail(head);
+      return head;
+    }
+  }
+  ScopedPthreadMutexLocker locker(&__libc_shared_globals()->crash_detail_page_lock);
+  struct crash_detail_page_t* prev = nullptr;
+  struct crash_detail_page_t* page = __libc_shared_globals()->crash_detail_page;
+  if (page != nullptr && page->used == kNumCrashDetails) {
+    prev = page;
+    page = nullptr;
+  }
+  if (page == nullptr) {
+    size_t size = sizeof(crash_detail_page_t);
+    void* map = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
+    if (map == MAP_FAILED) {
+      async_safe_format_log(ANDROID_LOG_ERROR, "libc", "failed to allocate crash_detail_page: %m");
+      return nullptr;
+    }
+    prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, map, size, "crash details");
+    page = reinterpret_cast<struct crash_detail_page_t*>(map);
+    page->prev = prev;
+    __libc_shared_globals()->crash_detail_page = page;
+  }
+  crash_detail_t* result = &page->crash_details[page->used];
+  populate_crash_detail(result);
+  page->used++;
+  return result;
+}
+
+__BIONIC_WEAK_FOR_NATIVE_BRIDGE
+void android_crash_detail_unregister(crash_detail_t* crash_detail) {
+  if (crash_detail) {
+    if (crash_detail->prev_free) {
+      // removing already removed would mess up the free-list by creating a circle.
+      return;
+    }
+    crash_detail->data = nullptr;
+    crash_detail->name = nullptr;
+    crash_detail_t* prev = atomic_load(&free_head);
+    do {
+      crash_detail->prev_free = prev;
+    } while (!atomic_compare_exchange_strong(&free_head, &prev, crash_detail));
+  }
+}
+
+__BIONIC_WEAK_FOR_NATIVE_BRIDGE
+void android_crash_detail_replace_data(crash_detail_t* crash_detail, const void* data,
+                                       size_t data_size) {
+  crash_detail->data = reinterpret_cast<const char*>(data);
+  crash_detail->data_size = data_size;
+}
+
+__BIONIC_WEAK_FOR_NATIVE_BRIDGE
+void android_crash_detail_replace_name(crash_detail_t* crash_detail, const void* name,
+                                       size_t name_size) {
+  crash_detail->name = reinterpret_cast<const char*>(name);
+  crash_detail->name_size = name_size;
+}
diff --git a/libc/bionic/android_set_abort_message.cpp b/libc/bionic/android_set_abort_message.cpp
index 53d75769d..05adf3e4c 100644
--- a/libc/bionic/android_set_abort_message.cpp
+++ b/libc/bionic/android_set_abort_message.cpp
@@ -29,7 +29,6 @@
 #include <android/set_abort_message.h>
 
 #include <async_safe/log.h>
-#include <bionic/set_abort_message_internal.h>
 
 #include <bits/stdatomic.h>
 #include <pthread.h>
@@ -60,8 +59,6 @@ static_assert(offsetof(magic_abort_msg_t, msg) == 2 * sizeof(uint64_t),
               "The in-memory layout of magic_abort_msg_t is not consistent with what automated "
               "tools expect.");
 
-static _Atomic(crash_detail_t*) free_head = nullptr;
-
 [[clang::optnone]]
 static void fill_abort_message_magic(magic_abort_msg_t* new_magic_abort_message) {
   // 128-bit magic for the abort message. Chosen by fair dice roll.
@@ -103,65 +100,3 @@ void android_set_abort_message(const char* msg) {
   strcpy(new_magic_abort_message->msg.msg, msg);
   __libc_shared_globals()->abort_msg = &new_magic_abort_message->msg;
 }
-
-__BIONIC_WEAK_FOR_NATIVE_BRIDGE
-crash_detail_t* android_register_crash_detail(const void* name, size_t name_size, const void* data,
-                                              size_t data_size) {
-  auto populate_crash_detail = [&](crash_detail_t* result) {
-    result->name = reinterpret_cast<const char*>(name);
-    result->name_size = name_size;
-    result->data = reinterpret_cast<const char*>(data);
-    result->data_size = data_size;
-  };
-  // This is a atomic fast-path for RAII use-cases where the app keeps creating and deleting
-  // crash details for short periods of time to capture detailed scopes.
-  if (crash_detail_t* head = atomic_load(&free_head)) {
-    while (head != nullptr && !atomic_compare_exchange_strong(&free_head, &head, head->prev_free)) {
-      // intentionally left blank.
-    }
-    if (head) {
-      head->prev_free = nullptr;
-      populate_crash_detail(head);
-      return head;
-    }
-  }
-  ScopedPthreadMutexLocker locker(&__libc_shared_globals()->crash_detail_page_lock);
-  struct crash_detail_page_t* prev = nullptr;
-  struct crash_detail_page_t* page = __libc_shared_globals()->crash_detail_page;
-  if (page != nullptr && page->used == kNumCrashDetails) {
-    prev = page;
-    page = nullptr;
-  }
-  if (page == nullptr) {
-    size_t size = sizeof(crash_detail_page_t);
-    void* map = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
-    if (map == MAP_FAILED) {
-      async_safe_format_log(ANDROID_LOG_ERROR, "libc", "failed to allocate crash_detail_page: %m");
-      return nullptr;
-    }
-    prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, map, size, "crash details");
-    page = reinterpret_cast<struct crash_detail_page_t*>(map);
-    page->prev = prev;
-    __libc_shared_globals()->crash_detail_page = page;
-  }
-  crash_detail_t* result = &page->crash_details[page->used];
-  populate_crash_detail(result);
-  page->used++;
-  return result;
-}
-
-__BIONIC_WEAK_FOR_NATIVE_BRIDGE
-void android_unregister_crash_detail(crash_detail_t* crash_detail) {
-  if (crash_detail) {
-    if (crash_detail->prev_free) {
-      // removing already removed would mess up the free-list by creating a circle.
-      return;
-    }
-    crash_detail->data = nullptr;
-    crash_detail->name = nullptr;
-    crash_detail_t* prev = atomic_load(&free_head);
-    do {
-      crash_detail->prev_free = prev;
-    } while (!atomic_compare_exchange_strong(&free_head, &prev, crash_detail));
-  }
-}
diff --git a/libc/include/android/crash_detail.h b/libc/include/android/crash_detail.h
new file mode 100644
index 000000000..1fd082f54
--- /dev/null
+++ b/libc/include/android/crash_detail.h
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#pragma once
+
+/**
+ * @file android/crash_detail.h
+ * @brief Attach extra information to android crashes.
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+typedef struct crash_detail_t crash_detail_t;
+
+/**
+ * Register a new buffer to get logged into tombstones for crashes.
+ *
+ * It will be added to both the tombstone proto in the crash_detail field, and
+ * in the tombstone text format.
+ *
+ * Tombstone proto definition:
+ *   https://cs.android.com/android/platform/superproject/main/+/main:system/core/debuggerd/proto/tombstone.proto
+ *
+ * The lifetime of name and data has to be valid until the program crashes, or until
+ * android_crash_detail_unregister is called.
+ *
+ * Example usage:
+ *   const char* stageName = "garbage_collection";
+ *   crash_detail_t* cd = android_crash_detail_register("stage", stageName, strlen(stageName));
+ *   do_garbage_collection();
+ *   android_crash_detail_unregister(cd);
+ *
+ * If this example crashes in do_garbage_collection, a line will show up in the textual representation of the tombstone:
+ *   Extra crash detail: stage: 'garbage_collection'
+ *
+ * Introduced in API 35.
+ *
+ * \param name identifying name for this extra data.
+ *             this should generally be a human-readable debug string, but we are treating
+ *             it as arbitrary bytes because it could be corrupted by the crash.
+ * \param name_size number of bytes of the buffer pointed to by name
+ * \param data a buffer containing the extra detail bytes, if null the crash detail
+ *             is disabled until android_crash_detail_replace_data replaces it with
+ *             a non-null pointer.
+ * \param data_size number of bytes of the buffer pointed to by data
+ *
+ * \return a handle to the extra crash detail.
+ */
+crash_detail_t* _Nullable android_crash_detail_register(
+    const void* _Nonnull name, size_t name_size, const void* _Nullable data, size_t data_size) __INTRODUCED_IN(35);
+
+/**
+ * Unregister crash detail from being logged into tombstones.
+ *
+ * After this function returns, the lifetime of the objects crash_detail was
+ * constructed from no longer needs to be valid.
+ *
+ * Introduced in API 35.
+ *
+ * \param crash_detail the crash_detail that should be removed.
+ */
+void android_crash_detail_unregister(crash_detail_t* _Nonnull crash_detail) __INTRODUCED_IN(35);
+
+/**
+ * Replace data of crash detail.
+ *
+ * This is more efficient than using android_crash_detail_unregister followed by
+ * android_crash_detail_register. If you very frequently need to swap out the data,
+ * you can hold onto the crash_detail.
+ *
+ * Introduced in API 35.
+ *
+ * \param data the new buffer containing the extra detail bytes, or null to disable until
+ *             android_crash_detail_replace_data is called again with non-null data.
+ * \param data_size the number of bytes of the buffer pointed to by data.
+ */
+void android_crash_detail_replace_data(crash_detail_t* _Nonnull crash_detail, const void* _Nullable data, size_t data_size) __INTRODUCED_IN(35);
+
+/**
+ * Replace name of crash detail.
+ *
+ * This is more efficient than using android_crash_detail_unregister followed by
+ * android_crash_detail_register. If you very frequently need to swap out the name,
+ * you can hold onto the crash_detail.
+ *
+ * Introduced in API 35.
+ *
+ * \param name identifying name for this extra data.
+ * \param name_size number of bytes of the buffer pointed to by name
+ */
+void android_crash_detail_replace_name(crash_detail_t* _Nonnull crash_detail, const void* _Nonnull name, size_t name_size) __INTRODUCED_IN(35);
+
+__END_DECLS
diff --git a/libc/include/android/set_abort_message.h b/libc/include/android/set_abort_message.h
index e92c6ec87..2525242ab 100644
--- a/libc/include/android/set_abort_message.h
+++ b/libc/include/android/set_abort_message.h
@@ -30,7 +30,7 @@
 
 /**
  * @file android/set_abort_message.h
- * @brief Attach extra information to android crashes.
+ * @brief The android_set_abort_message() function.
  */
 
 #include <stddef.h>
@@ -51,51 +51,4 @@ typedef struct crash_detail_t crash_detail_t;
  */
 void android_set_abort_message(const char* _Nullable __msg);
 
-/**
- * Register a new buffer to get logged into tombstones for crashes.
- *
- * It will be added to both the tombstone proto in the crash_detail field, and
- * in the tombstone text format.
- *
- * Tombstone proto definition:
- *   https://cs.android.com/android/platform/superproject/main/+/main:system/core/debuggerd/proto/tombstone.proto
- *
- * The lifetime of name and data has to be valid until the program crashes, or until
- * android_unregister_crash_detail is called.
- *
- * Example usage:
- *   const char* stageName = "garbage_collection";
- *   crash_detail_t* cd = android_register_crash_detail("stage", stageName, strlen(stageName));
- *   do_garbage_collection();
- *   android_unregister_crash_detail(cd);
- *
- * If this example crashes in do_garbage_collection, a line will show up in the textual representation of the tombstone:
- *   Extra crash detail: stage: 'garbage_collection'
- *
- * Introduced in API 35.
- *
- * \param name identifying name for this extra data.
- *             this should generally be a human-readable debug string, but we are treating
- *             it as arbitrary bytes because it could be corrupted by the crash.
- * \param name_size number of bytes of the buffer pointed to by name
- * \param data a buffer containing the extra detail bytes
- * \param data_size number of bytes of the buffer pointed to by data
- *
- * \return a handle to the extra crash detail for use with android_unregister_crash_detail.
- */
-crash_detail_t* _Nullable android_register_crash_detail(
-    const void* _Nonnull name, size_t name_size, const void* _Nonnull data, size_t data_size) __INTRODUCED_IN(35);
-
-/**
- * Unregister crash detail from being logged into tombstones.
- *
- * After this function returns, the lifetime of the objects crash_detail was
- * constructed from no longer needs to be valid.
- *
- * Introduced in API 35.
- *
- * \param crash_detail the crash_detail that should be removed.
- */
-void android_unregister_crash_detail(crash_detail_t* _Nonnull crash_detail) __INTRODUCED_IN(35);
-
 __END_DECLS
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index ecdb25c46..5e9763bef 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1586,8 +1586,10 @@ LIBC_U { # introduced=UpsideDownCake
 
 LIBC_V { # introduced=VanillaIceCream
   global:
-    android_register_crash_detail;
-    android_unregister_crash_detail;
+    android_crash_detail_register;
+    android_crash_detail_unregister;
+    android_crash_detail_replace_name;
+    android_crash_detail_replace_data;
     epoll_pwait2;
     epoll_pwait2_64;
     localtime_rz;
diff --git a/libc/platform/bionic/set_abort_message_internal.h b/libc/platform/bionic/crash_detail_internal.h
index 4dff3acba..d8508a509 100644
--- a/libc/platform/bionic/set_abort_message_internal.h
+++ b/libc/platform/bionic/crash_detail_internal.h
@@ -28,7 +28,7 @@
 
 #pragma once
 
-#include <android/set_abort_message.h>
+#include <android/crash_detail.h>
 #include <stddef.h>
 #include <sys/cdefs.h>