Merge new upstream LTS 20230802.0

1 files changed, 32 insertions, 16 deletions

diff --git a/absl/debugging/failure_signal_handler.cc b/absl/debugging/failure_signal_handler.cc
index ef8ab9e5..992c89c3 100644
--- a/absl/debugging/failure_signal_handler.cc
+++ b/absl/debugging/failure_signal_handler.cc
@@ -31,6 +31,13 @@
 
 #ifdef ABSL_HAVE_MMAP
 #include <sys/mman.h>
+#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+#endif
+
+#ifdef __linux__
+#include <sys/prctl.h>
 #endif
 
 #include <algorithm>
@@ -77,10 +84,10 @@ struct FailureSignalData {
   struct sigaction previous_action;
   // StructSigaction is used to silence -Wmissing-field-initializers.
   using StructSigaction = struct sigaction;
-  #define FSD_PREVIOUS_INIT FailureSignalData::StructSigaction()
+#define FSD_PREVIOUS_INIT FailureSignalData::StructSigaction()
 #else
   void (*previous_handler)(int);
-  #define FSD_PREVIOUS_INIT SIG_DFL
+#define FSD_PREVIOUS_INIT SIG_DFL
 #endif
 };
 
@@ -132,7 +139,7 @@ const char* FailureSignalToString(int signo) {
 #ifdef ABSL_HAVE_SIGALTSTACK
 
 static bool SetupAlternateStackOnce() {
-#if defined(__wasm__) || defined (__asjms__)
+#if defined(__wasm__) || defined(__asjms__)
   const size_t page_mask = getpagesize() - 1;
 #else
   const size_t page_mask = static_cast<size_t>(sysconf(_SC_PAGESIZE)) - 1;
@@ -154,9 +161,6 @@ static bool SetupAlternateStackOnce() {
 #ifndef MAP_STACK
 #define MAP_STACK 0
 #endif
-#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
-#define MAP_ANONYMOUS MAP_ANON
-#endif
   sigstk.ss_sp = mmap(nullptr, sigstk.ss_size, PROT_READ | PROT_WRITE,
                       MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0);
   if (sigstk.ss_sp == MAP_FAILED) {
@@ -172,6 +176,20 @@ static bool SetupAlternateStackOnce() {
   if (sigaltstack(&sigstk, nullptr) != 0) {
     ABSL_RAW_LOG(FATAL, "sigaltstack() failed with errno=%d", errno);
   }
+
+#ifdef __linux__
+#if defined(PR_SET_VMA) && defined(PR_SET_VMA_ANON_NAME)
+  // Make a best-effort attempt to name the allocated region in
+  // /proc/$PID/smaps.
+  //
+  // The call to prctl() may fail if the kernel was not configured with the
+  // CONFIG_ANON_VMA_NAME kernel option.  This is OK since the call is
+  // primarily a debugging aid.
+  prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, sigstk.ss_sp, sigstk.ss_size,
+        "absl-signalstack");
+#endif
+#endif  // __linux__
+
   return true;
 }
 
@@ -218,10 +236,6 @@ static void InstallOneFailureHandler(FailureSignalData* data,
 
 #endif
 
-static void WriteToStderr(const char* data) {
-  absl::raw_log_internal::AsyncSignalSafeWriteToStderr(data, strlen(data));
-}
-
 static void WriteSignalMessage(int signo, int cpu,
                                void (*writerfn)(const char*)) {
   char buf[96];
@@ -234,7 +248,7 @@ static void WriteSignalMessage(int signo, int cpu,
   if (signal_string != nullptr && signal_string[0] != '\0') {
     snprintf(buf, sizeof(buf), "*** %s received at time=%ld%s ***\n",
              signal_string,
-             static_cast<long>(time(nullptr)),   // NOLINT(runtime/int)
+             static_cast<long>(time(nullptr)),  // NOLINT(runtime/int)
              on_cpu);
   } else {
     snprintf(buf, sizeof(buf), "*** Signal %d received at time=%ld%s ***\n",
@@ -297,7 +311,8 @@ static void PortableSleepForSeconds(int seconds) {
   struct timespec sleep_time;
   sleep_time.tv_sec = seconds;
   sleep_time.tv_nsec = 0;
-  while (nanosleep(&sleep_time, &sleep_time) != 0 && errno == EINTR) {}
+  while (nanosleep(&sleep_time, &sleep_time) != 0 && errno == EINTR) {
+  }
 #endif
 }
 
@@ -307,9 +322,7 @@ static void PortableSleepForSeconds(int seconds) {
 // set amount of time. If AbslFailureSignalHandler() hangs for more than
 // the alarm timeout, ImmediateAbortSignalHandler() will abort the
 // program.
-static void ImmediateAbortSignalHandler(int) {
-  RaiseToDefaultHandler(SIGABRT);
-}
+static void ImmediateAbortSignalHandler(int) { RaiseToDefaultHandler(SIGABRT); }
 #endif
 
 // absl::base_internal::GetTID() returns pid_t on most platforms, but
@@ -362,7 +375,10 @@ static void AbslFailureSignalHandler(int signo, siginfo_t*, void* ucontext) {
 #endif
 
   // First write to stderr.
-  WriteFailureInfo(signo, ucontext, my_cpu, WriteToStderr);
+  WriteFailureInfo(
+      signo, ucontext, my_cpu, +[](const char* data) {
+        absl::raw_log_internal::AsyncSignalSafeWriteError(data, strlen(data));
+      });
 
   // Riskier code (because it is less likely to be async-signal-safe)
   // goes after this point.