Move SigSafeArena() out to absl/base/internal/low_level_alloc.h
This allows dynamic memory allocation for computing stack traces to avoid a stack overflow.
PiperOrigin-RevId: 786512779
Change-Id: Ib5ef8fef436672b99d9678137e3b2bb65ca47eba
diff --git a/absl/base/internal/low_level_alloc.cc b/absl/base/internal/low_level_alloc.cc
index 2dd3604..0afd2f9 100644
--- a/absl/base/internal/low_level_alloc.cc
+++ b/absl/base/internal/low_level_alloc.cc
@@ -19,6 +19,8 @@
#include "absl/base/internal/low_level_alloc.h"
+#include <stdint.h>
+
#include <optional>
#include <type_traits>
@@ -220,6 +222,32 @@
uint32_t random ABSL_GUARDED_BY(mu);
};
+// ---------------------------------------------------------------
+// An async-signal-safe arena for LowLevelAlloc
+static std::atomic<base_internal::LowLevelAlloc::Arena *> g_sig_safe_arena;
+
+base_internal::LowLevelAlloc::Arena *SigSafeArena() {
+ return g_sig_safe_arena.load(std::memory_order_acquire);
+}
+
+void InitSigSafeArena() {
+ if (SigSafeArena() == nullptr) {
+ uint32_t flags = 0;
+#ifndef ABSL_LOW_LEVEL_ALLOC_ASYNC_SIGNAL_SAFE_MISSING
+ flags |= base_internal::LowLevelAlloc::kAsyncSignalSafe;
+#endif
+ base_internal::LowLevelAlloc::Arena *new_arena =
+ base_internal::LowLevelAlloc::NewArena(flags);
+ base_internal::LowLevelAlloc::Arena *old_value = nullptr;
+ if (!g_sig_safe_arena.compare_exchange_strong(old_value, new_arena,
+ std::memory_order_release,
+ std::memory_order_relaxed)) {
+ // We lost a race to allocate an arena; deallocate.
+ base_internal::LowLevelAlloc::DeleteArena(new_arena);
+ }
+ }
+}
+
namespace {
// Static storage space for the lazily-constructed, default global arena
// instances. We require this space because the whole point of LowLevelAlloc
diff --git a/absl/base/internal/low_level_alloc.h b/absl/base/internal/low_level_alloc.h
index c2f1f25..23218dd 100644
--- a/absl/base/internal/low_level_alloc.h
+++ b/absl/base/internal/low_level_alloc.h
@@ -120,6 +120,12 @@
LowLevelAlloc(); // no instances
};
+// Returns a global async-signal-safe arena for LowLevelAlloc.
+LowLevelAlloc::Arena *SigSafeArena();
+
+// Ensures the global async-signal-safe arena for LowLevelAlloc is initialized.
+void InitSigSafeArena();
+
} // namespace base_internal
ABSL_NAMESPACE_END
} // namespace absl
diff --git a/absl/debugging/symbolize_elf.inc b/absl/debugging/symbolize_elf.inc
index 17baff4..f635061 100644
--- a/absl/debugging/symbolize_elf.inc
+++ b/absl/debugging/symbolize_elf.inc
@@ -233,29 +233,6 @@
};
// ---------------------------------------------------------------
-// An async-signal-safe arena for LowLevelAlloc
-static std::atomic<base_internal::LowLevelAlloc::Arena *> g_sig_safe_arena;
-
-static base_internal::LowLevelAlloc::Arena *SigSafeArena() {
- return g_sig_safe_arena.load(std::memory_order_acquire);
-}
-
-static void InitSigSafeArena() {
- if (SigSafeArena() == nullptr) {
- base_internal::LowLevelAlloc::Arena *new_arena =
- base_internal::LowLevelAlloc::NewArena(
- base_internal::LowLevelAlloc::kAsyncSignalSafe);
- base_internal::LowLevelAlloc::Arena *old_value = nullptr;
- if (!g_sig_safe_arena.compare_exchange_strong(old_value, new_arena,
- std::memory_order_release,
- std::memory_order_relaxed)) {
- // We lost a race to allocate an arena; deallocate.
- base_internal::LowLevelAlloc::DeleteArena(new_arena);
- }
- }
-}
-
-// ---------------------------------------------------------------
// An AddrMap is a vector of ObjFile, using SigSafeArena() for allocation.
class AddrMap {
@@ -287,7 +264,7 @@
size_t new_allocated = allocated_ * 2 + 50;
ObjFile *new_obj_ =
static_cast<ObjFile *>(base_internal::LowLevelAlloc::AllocWithArena(
- new_allocated * sizeof(*new_obj_), SigSafeArena()));
+ new_allocated * sizeof(*new_obj_), base_internal::SigSafeArena()));
if (obj_) {
memcpy(new_obj_, obj_, allocated_ * sizeof(*new_obj_));
base_internal::LowLevelAlloc::Free(obj_);
@@ -335,8 +312,9 @@
private:
char *CopyString(const char *s) {
size_t len = strlen(s);
- char *dst = static_cast<char *>(
- base_internal::LowLevelAlloc::AllocWithArena(len + 1, SigSafeArena()));
+ char *dst =
+ static_cast<char *>(base_internal::LowLevelAlloc::AllocWithArena(
+ len + 1, base_internal::SigSafeArena()));
ABSL_RAW_CHECK(dst != nullptr, "out of memory");
memcpy(dst, s, len + 1);
return dst;
@@ -441,14 +419,14 @@
// Return (and set null) g_cached_symbolized_state if it is not null.
// Otherwise return a new symbolizer.
static Symbolizer *AllocateSymbolizer() {
- InitSigSafeArena();
+ base_internal::InitSigSafeArena();
Symbolizer *symbolizer =
g_cached_symbolizer.exchange(nullptr, std::memory_order_acquire);
if (symbolizer != nullptr) {
return symbolizer;
}
return new (base_internal::LowLevelAlloc::AllocWithArena(
- SymbolizerSize(), SigSafeArena())) Symbolizer();
+ SymbolizerSize(), base_internal::SigSafeArena())) Symbolizer();
}
// Set g_cached_symbolize_state to s if it is null, otherwise
@@ -1678,7 +1656,7 @@
SAFE_ASSERT(start <= end);
SAFE_ASSERT(filename != nullptr);
- InitSigSafeArena();
+ base_internal::InitSigSafeArena();
if (!g_file_mapping_mu.TryLock()) {
return false;
@@ -1690,8 +1668,9 @@
} else {
// TODO(ckennelly): Move this into a string copy routine.
size_t len = strlen(filename);
- char *dst = static_cast<char *>(
- base_internal::LowLevelAlloc::AllocWithArena(len + 1, SigSafeArena()));
+ char *dst =
+ static_cast<char *>(base_internal::LowLevelAlloc::AllocWithArena(
+ len + 1, base_internal::SigSafeArena()));
ABSL_RAW_CHECK(dst != nullptr, "out of memory");
memcpy(dst, filename, len + 1);
