[MTE] fix missing thread id from stack_mte_ring mapping
We would use thread->tid to name the mapping before it was set, so it
would always be zero.
Bug: 378140560
Change-Id: Id30c22b7e9d0155c79579b097c81e27f662b5d6d
diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index ba20c51..54bfa20 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -351,15 +351,20 @@
extern "C" int __rt_sigprocmask(int, const sigset64_t*, sigset64_t*, size_t);
-__attribute__((no_sanitize("hwaddress")))
+__attribute__((no_sanitize("hwaddress", "memtag")))
#if defined(__aarch64__)
// This function doesn't return, but it does appear in stack traces. Avoid using return PAC in this
// function because we may end up resetting IA, which may confuse unwinders due to mismatching keys.
__attribute__((target("branch-protection=bti")))
#endif
-static int __pthread_start(void* arg) {
+static int
+__pthread_start(void* arg) {
pthread_internal_t* thread = reinterpret_cast<pthread_internal_t*>(arg);
-
+#if defined(__aarch64__)
+ if (thread->should_allocate_stack_mte_ringbuffer) {
+ thread->bionic_tcb->tls_slot(TLS_SLOT_STACK_MTE) = __allocate_stack_mte_ringbuffer(0, thread);
+ }
+#endif
__hwasan_thread_enter();
// Wait for our creating thread to release us. This lets it have time to
@@ -450,9 +455,9 @@
// This has to be done under g_thread_creation_lock or g_thread_list_lock to avoid racing with
// __pthread_internal_remap_stack_with_mte.
#ifdef __aarch64__
- if (__libc_memtag_stack_abi) {
- tcb->tls_slot(TLS_SLOT_STACK_MTE) = __allocate_stack_mte_ringbuffer(0, thread);
- }
+ thread->should_allocate_stack_mte_ringbuffer = __libc_memtag_stack_abi;
+#else
+ thread->should_allocate_stack_mte_ringbuffer = false;
#endif
sigset64_t block_all_mask;
diff --git a/libc/bionic/pthread_internal.cpp b/libc/bionic/pthread_internal.cpp
index bec9703..c6426ed 100644
--- a/libc/bionic/pthread_internal.cpp
+++ b/libc/bionic/pthread_internal.cpp
@@ -208,7 +208,10 @@
__libc_memtag_stack_abi = true;
for (pthread_internal_t* t = g_thread_list; t != nullptr; t = t->next) {
- if (t->terminating) continue;
+ // should_allocate_stack_mte_ringbuffer indicates the thread is already
+ // aware that this process requires stack MTE, and will allocate the
+ // ring buffer in __pthread_start.
+ if (t->terminating || t->should_allocate_stack_mte_ringbuffer) continue;
t->bionic_tcb->tls_slot(TLS_SLOT_STACK_MTE) =
__allocate_stack_mte_ringbuffer(0, t->is_main() ? nullptr : t);
}
diff --git a/libc/bionic/pthread_internal.h b/libc/bionic/pthread_internal.h
index 5db42ab..cbaa9a6 100644
--- a/libc/bionic/pthread_internal.h
+++ b/libc/bionic/pthread_internal.h
@@ -181,6 +181,7 @@
bionic_tcb* bionic_tcb;
char stack_mte_ringbuffer_vma_name_buffer[32];
+ bool should_allocate_stack_mte_ringbuffer;
bool is_main() { return start_routine == nullptr; }
};
diff --git a/tests/struct_layout_test.cpp b/tests/struct_layout_test.cpp
index 1f04344..b9fd315 100644
--- a/tests/struct_layout_test.cpp
+++ b/tests/struct_layout_test.cpp
@@ -30,7 +30,7 @@
#define CHECK_OFFSET(name, field, offset) \
check_offset(#name, #field, offsetof(name, field), offset);
#ifdef __LP64__
- CHECK_SIZE(pthread_internal_t, 816);
+ CHECK_SIZE(pthread_internal_t, 824);
CHECK_OFFSET(pthread_internal_t, next, 0);
CHECK_OFFSET(pthread_internal_t, prev, 8);
CHECK_OFFSET(pthread_internal_t, tid, 16);
@@ -57,6 +57,7 @@
CHECK_OFFSET(pthread_internal_t, errno_value, 768);
CHECK_OFFSET(pthread_internal_t, bionic_tcb, 776);
CHECK_OFFSET(pthread_internal_t, stack_mte_ringbuffer_vma_name_buffer, 784);
+ CHECK_OFFSET(pthread_internal_t, should_allocate_stack_mte_ringbuffer, 816);
CHECK_SIZE(bionic_tls, 12200);
CHECK_OFFSET(bionic_tls, key_data, 0);
CHECK_OFFSET(bionic_tls, locale, 2080);
@@ -74,7 +75,7 @@
CHECK_OFFSET(bionic_tls, bionic_systrace_disabled, 12193);
CHECK_OFFSET(bionic_tls, padding, 12194);
#else
- CHECK_SIZE(pthread_internal_t, 704);
+ CHECK_SIZE(pthread_internal_t, 708);
CHECK_OFFSET(pthread_internal_t, next, 0);
CHECK_OFFSET(pthread_internal_t, prev, 4);
CHECK_OFFSET(pthread_internal_t, tid, 8);
@@ -101,6 +102,7 @@
CHECK_OFFSET(pthread_internal_t, errno_value, 664);
CHECK_OFFSET(pthread_internal_t, bionic_tcb, 668);
CHECK_OFFSET(pthread_internal_t, stack_mte_ringbuffer_vma_name_buffer, 672);
+ CHECK_OFFSET(pthread_internal_t, should_allocate_stack_mte_ringbuffer, 704);
CHECK_SIZE(bionic_tls, 11080);
CHECK_OFFSET(bionic_tls, key_data, 0);
CHECK_OFFSET(bionic_tls, locale, 1040);