Merge "Read maps data before using and do safe reads." into main
diff --git a/benchmarks/linker_relocation/include/linker_reloc_bench_asm.h b/benchmarks/linker_relocation/include/linker_reloc_bench_asm.h
index 885e47f..ea63e36 100644
--- a/benchmarks/linker_relocation/include/linker_reloc_bench_asm.h
+++ b/benchmarks/linker_relocation/include/linker_reloc_bench_asm.h
@@ -44,9 +44,7 @@
 
 #elif defined(__riscv)
 
-// No `lga` in clang unless https://reviews.llvm.org/D107278 lands.
-// `la` is equivalent when using PIC (which we do) though.
-#define GOT_RELOC(sym) la a0, sym
+#define GOT_RELOC(sym) lga a0, sym
 #define CALL(sym) call sym@plt
 #define DATA_WORD(val) .quad val
 #define MAIN .globl main; main: li a0, 0; ret
diff --git a/benchmarks/util.h b/benchmarks/util.h
index 99eed5f..347dc35 100644
--- a/benchmarks/util.h
+++ b/benchmarks/util.h
@@ -71,7 +71,7 @@
 
 bool LockToCPU(int cpu_to_lock);
 
-static __inline __attribute__ ((__always_inline__)) void MakeAllocationResident(
+static inline __attribute__((__always_inline__)) void MakeAllocationResident(
     void* ptr, size_t nbytes, int pagesize) {
   uint8_t* data = reinterpret_cast<uint8_t*>(ptr);
   for (size_t i = 0; i < nbytes; i += pagesize) {
diff --git a/libc/bionic/execinfo.cpp b/libc/bionic/execinfo.cpp
index d129f7c..e53a037 100644
--- a/libc/bionic/execinfo.cpp
+++ b/libc/bionic/execinfo.cpp
@@ -73,6 +73,11 @@
 #elif defined(__aarch64__)
     // All instructions are 4 bytes long, skip back one instruction.
     ip -= 4;
+#elif defined(__riscv)
+    // C instructions are the shortest at 2 bytes long. (Unlike thumb, it's
+    // non-trivial to recognize C instructions when going backwards in the
+    // instruction stream.)
+    ip -= 2;
 #elif defined(__i386__) || defined(__x86_64__)
     // It's difficult to decode exactly where the previous instruction is,
     // so subtract 1 to estimate where the instruction lives.
diff --git a/libc/bionic/posix_timers.cpp b/libc/bionic/posix_timers.cpp
index f522516..ccbbfcf 100644
--- a/libc/bionic/posix_timers.cpp
+++ b/libc/bionic/posix_timers.cpp
@@ -34,6 +34,8 @@
 #include <string.h>
 #include <time.h>
 
+#include "private/bionic_lock.h"
+
 // System calls.
 extern "C" int __rt_sigprocmask(int, const sigset64_t*, sigset64_t*, size_t);
 extern "C" int __rt_sigtimedwait(const sigset64_t*, siginfo_t*, const timespec*, size_t);
@@ -60,6 +62,7 @@
   int sigev_notify;
 
   // The fields below are only needed for a SIGEV_THREAD timer.
+  Lock startup_handshake_lock;
   pthread_t callback_thread;
   void (*callback)(sigval_t);
   sigval_t callback_argument;
@@ -73,6 +76,18 @@
 static void* __timer_thread_start(void* arg) {
   PosixTimer* timer = reinterpret_cast<PosixTimer*>(arg);
 
+  // Check that our parent managed to create the kernel timer and bail if not...
+  timer->startup_handshake_lock.lock();
+  if (timer->kernel_timer_id == -1) {
+    free(timer);
+    return nullptr;
+  }
+
+  // Give ourselves a specific meaningful name now we have a kernel timer.
+  char name[16]; // 16 is the kernel-imposed limit.
+  snprintf(name, sizeof(name), "POSIX timer %d", to_kernel_timer_id(timer));
+  pthread_setname_np(timer->callback_thread, name);
+
   sigset64_t sigset = {};
   sigaddset64(&sigset, TIMER_SIGNAL);
 
@@ -109,6 +124,7 @@
     return -1;
   }
 
+  timer->kernel_timer_id = -1;
   timer->sigev_notify = (evp == nullptr) ? SIGEV_SIGNAL : evp->sigev_notify;
 
   // If not a SIGEV_THREAD timer, the kernel can handle it without our help.
@@ -149,6 +165,10 @@
   sigaddset64(&sigset, TIMER_SIGNAL);
   sigset64_t old_sigset;
 
+  // Prevent the child thread from running until the timer has been created.
+  timer->startup_handshake_lock.init(false);
+  timer->startup_handshake_lock.lock();
+
   // Use __rt_sigprocmask instead of sigprocmask64 to avoid filtering out TIMER_SIGNAL.
   __rt_sigprocmask(SIG_BLOCK, &sigset, &old_sigset, sizeof(sigset));
 
@@ -162,21 +182,21 @@
     return -1;
   }
 
+  // Try to create the kernel timer.
   sigevent se = *evp;
   se.sigev_signo = TIMER_SIGNAL;
   se.sigev_notify = SIGEV_THREAD_ID;
   se.sigev_notify_thread_id = pthread_gettid_np(timer->callback_thread);
-  if (__timer_create(clock_id, &se, &timer->kernel_timer_id) == -1) {
-    __timer_thread_stop(timer);
+  rc = __timer_create(clock_id, &se, &timer->kernel_timer_id);
+
+  // Let the child run (whether we created the kernel timer or not).
+  timer->startup_handshake_lock.unlock();
+  // If __timer_create(2) failed, the child will kill itself and free the
+  // timer struct, so we just need to exit.
+  if (rc == -1) {
     return -1;
   }
 
-  // Give the thread a specific meaningful name.
-  // It can't do this itself because the kernel timer isn't created until after it's running.
-  char name[16]; // 16 is the kernel-imposed limit.
-  snprintf(name, sizeof(name), "POSIX timer %d", to_kernel_timer_id(timer));
-  pthread_setname_np(timer->callback_thread, name);
-
   *timer_id = timer;
   return 0;
 }
diff --git a/libc/bionic/sys_statvfs.cpp b/libc/bionic/sys_statvfs.cpp
index b3a0aca..3a05c3f 100644
--- a/libc/bionic/sys_statvfs.cpp
+++ b/libc/bionic/sys_statvfs.cpp
@@ -17,7 +17,7 @@
 #include <sys/statfs.h>
 #include <sys/statvfs.h>
 
-static __inline void __bionic_statfs_to_statvfs(const struct statfs* src, struct statvfs* dst) {
+static inline void __bionic_statfs_to_statvfs(const struct statfs* src, struct statvfs* dst) {
   dst->f_bsize = src->f_bsize;
   dst->f_frsize = src->f_frsize;
   dst->f_blocks = src->f_blocks;
diff --git a/libc/bionic/sys_thread_properties.cpp b/libc/bionic/sys_thread_properties.cpp
index d1a73b7..d7188f5 100644
--- a/libc/bionic/sys_thread_properties.cpp
+++ b/libc/bionic/sys_thread_properties.cpp
@@ -77,35 +77,9 @@
 
   // Find the thread-pointer register for the given thread.
   void** tp_reg = nullptr;
-#if defined(__x86_64__)
-  {
-    ErrnoRestorer errno_restorer;
-    errno = 0;
-    uintptr_t fs_base = ptrace(PTRACE_PEEKUSER, tid, offsetof(user_regs_struct, fs_base), nullptr);
-    if (errno == 0) {
-      tp_reg = reinterpret_cast<void**>(fs_base);
-    }
-  }
-#elif defined(__i386__)
-  struct user_regs_struct regs;
-  struct iovec pt_iov = {
-      .iov_base = &regs,
-      .iov_len = sizeof(regs),
-  };
-
-  if (ptrace(PTRACE_GETREGSET, tid, NT_PRSTATUS, &pt_iov) == 0) {
-    struct user_desc u_info;
-    u_info.entry_number = regs.xgs >> 3;
-    if (ptrace(PTRACE_GET_THREAD_AREA, tid, u_info.entry_number, &u_info) == 0) {
-      tp_reg = reinterpret_cast<void**>(u_info.base_addr);
-    }
-  }
-#elif defined(__aarch64__)
+#if defined(__aarch64__)
   uint64_t reg;
-  struct iovec pt_iov {
-    .iov_base = &reg, .iov_len = sizeof(reg),
-  };
-
+  struct iovec pt_iov { .iov_base = &reg, .iov_len = sizeof(reg) };
   if (ptrace(PTRACE_GETREGSET, tid, NT_ARM_TLS, &pt_iov) == 0) {
     tp_reg = reinterpret_cast<void**>(reg);
   }
@@ -114,6 +88,31 @@
     // Reset the tp_reg if ptrace was unsuccessful.
     tp_reg = nullptr;
   }
+#elif defined(__i386__)
+  struct user_regs_struct regs;
+  struct iovec pt_iov = { .iov_base = &regs, .iov_len = sizeof(regs) };
+  if (ptrace(PTRACE_GETREGSET, tid, NT_PRSTATUS, &pt_iov) == 0) {
+    struct user_desc u_info;
+    u_info.entry_number = regs.xgs >> 3;
+    if (ptrace(PTRACE_GET_THREAD_AREA, tid, u_info.entry_number, &u_info) == 0) {
+      tp_reg = reinterpret_cast<void**>(u_info.base_addr);
+    }
+  }
+#elif defined(__riscv)
+  struct user_regs_struct regs;
+  struct iovec pt_iov = { .iov_base = &regs, .iov_len = sizeof(regs) };
+  if (ptrace(PTRACE_GETREGSET, tid, NT_PRSTATUS, &pt_iov) == 0) {
+    tp_reg = reinterpret_cast<void**>(regs.tp);
+  }
+#elif defined(__x86_64__)
+  {
+    ErrnoRestorer errno_restorer;
+    errno = 0;
+    uintptr_t fs_base = ptrace(PTRACE_PEEKUSER, tid, offsetof(user_regs_struct, fs_base), nullptr);
+    if (errno == 0) {
+      tp_reg = reinterpret_cast<void**>(fs_base);
+    }
+  }
 #endif
 
   if (tp_reg == nullptr) {
diff --git a/libc/include/bits/threads_inlines.h b/libc/include/bits/threads_inlines.h
index 5878e0a..459866e 100644
--- a/libc/include/bits/threads_inlines.h
+++ b/libc/include/bits/threads_inlines.h
@@ -124,7 +124,7 @@
 };
 #pragma clang diagnostic pop
 
-static inline void* _Nonnull __bionic_thrd_trampoline(void* _Nonnull __arg) {
+static __inline void* _Nonnull __bionic_thrd_trampoline(void* _Nonnull __arg) {
   struct __bionic_thrd_data __data =
       *__BIONIC_CAST(static_cast, struct __bionic_thrd_data*, __arg);
   free(__arg);
diff --git a/libc/include/strings.h b/libc/include/strings.h
index 2f4f764..4b8cc08 100644
--- a/libc/include/strings.h
+++ b/libc/include/strings.h
@@ -61,13 +61,13 @@
 
 /** Deprecated. Use memmove() instead. */
 #define bcopy(b1, b2, len) __bionic_bcopy((b1), (b2), (len))
-static __inline__ __always_inline void __bionic_bcopy(const void* _Nonnull b1, void* _Nonnull b2, size_t len) {
+static __inline __always_inline void __bionic_bcopy(const void* _Nonnull b1, void* _Nonnull b2, size_t len) {
   __builtin_memmove(b2, b1, len);
 }
 
 /** Deprecated. Use memset() instead. */
 #define bzero(b, len) __bionic_bzero((b), (len))
-static __inline__ __always_inline void __bionic_bzero(void* _Nonnull b, size_t len) {
+static __inline __always_inline void __bionic_bzero(void* _Nonnull b, size_t len) {
   __builtin_memset(b, 0, len);
 }
 
diff --git a/libc/include/sys/cdefs.h b/libc/include/sys/cdefs.h
index 7625d38..5d1718e 100644
--- a/libc/include/sys/cdefs.h
+++ b/libc/include/sys/cdefs.h
@@ -87,9 +87,12 @@
 #define	__STRING(x)	#x
 #define	___STRING(x)	__STRING(x)
 
-#if defined(__cplusplus)
-#define	__inline	inline		/* convert to C++ keyword */
-#endif /* !__cplusplus */
+// C++ has `inline` as a keyword, as does C99, but ANSI C (aka C89 aka C90)
+// does not. Everything accepts the `__inline__` extension though. We could
+// just use that directly in our own code, but there's historical precedent
+// for `__inline` meaning it's still used in upstream BSD code (and potentially
+// downstream in vendor or app code).
+#define	__inline __inline__
 
 #define __always_inline __attribute__((__always_inline__))
 #define __attribute_const__ __attribute__((__const__))
@@ -260,7 +263,7 @@
  * them available externally. FORTIFY'ed functions try to be as close to possible as 'invisible';
  * having stack protectors detracts from that (b/182948263).
  */
-#  define __BIONIC_FORTIFY_INLINE static __inline__ __attribute__((__no_stack_protector__)) \
+#  define __BIONIC_FORTIFY_INLINE static __inline __attribute__((__no_stack_protector__)) \
       __always_inline __VERSIONER_FORTIFY_INLINE
 /*
  * We should use __BIONIC_FORTIFY_VARIADIC instead of __BIONIC_FORTIFY_INLINE
@@ -268,9 +271,9 @@
  * The __always_inline attribute is useless, misleading, and could trigger
  * clang compiler bug to incorrectly inline variadic functions.
  */
-#  define __BIONIC_FORTIFY_VARIADIC static __inline__
+#  define __BIONIC_FORTIFY_VARIADIC static __inline
 /* Error functions don't have bodies, so they can just be static. */
-#  define __BIONIC_ERROR_FUNCTION_VISIBILITY static __attribute__((__unused__))
+#  define __BIONIC_ERROR_FUNCTION_VISIBILITY static __unused
 #else
 /* Further increase sharing for some inline functions */
 #  define __pass_object_size_n(n)
diff --git a/linker/linker_main.cpp b/linker/linker_main.cpp
index 089eceb..e27fd91 100644
--- a/linker/linker_main.cpp
+++ b/linker/linker_main.cpp
@@ -422,20 +422,11 @@
 
   ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(si->base);
 
-  // We haven't supported non-PIE since Lollipop for security reasons.
+  // For security reasons we dropped non-PIE support in API level 21,
+  // and the NDK no longer supports earlier API levels.
   if (elf_hdr->e_type != ET_DYN) {
-    // We don't use async_safe_fatal here because we don't want a tombstone:
-    // even after several years we still find ourselves on app compatibility
-    // investigations because some app's trying to launch an executable that
-    // hasn't worked in at least three years, and we've "helpfully" dropped a
-    // tombstone for them. The tombstone never provided any detail relevant to
-    // fixing the problem anyway, and the utility of drawing extra attention
-    // to the problem is non-existent at this late date.
-    async_safe_format_fd(STDERR_FILENO,
-                         "\"%s\": error: Android 5.0 and later only support "
-                         "position-independent executables (-fPIE).\n",
-                         g_argv[0]);
-    _exit(EXIT_FAILURE);
+    __linker_error("error: %s: Android only supports position-independent "
+                   "executables (-fPIE)\n", exe_info.path.c_str());
   }
 
   // Use LD_LIBRARY_PATH and LD_PRELOAD (but only if we aren't setuid/setgid).
diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp
index fa712a1..b9229ca 100644
--- a/linker/linker_phdr.cpp
+++ b/linker/linker_phdr.cpp
@@ -298,7 +298,6 @@
   }
 
   if (header_.e_shentsize != sizeof(ElfW(Shdr))) {
-    // Fail if app is targeting Android O or above
     if (get_application_target_sdk_version() >= 26) {
       DL_ERR_AND_LOG("\"%s\" has unsupported e_shentsize: 0x%x (expected 0x%zx)",
                      name_.c_str(), header_.e_shentsize, sizeof(ElfW(Shdr)));
@@ -312,12 +311,10 @@
   }
 
   if (header_.e_shstrndx == 0) {
-    // Fail if app is targeting Android O or above
     if (get_application_target_sdk_version() >= 26) {
       DL_ERR_AND_LOG("\"%s\" has invalid e_shstrndx", name_.c_str());
       return false;
     }
-
     DL_WARN_documented_change(26,
                               "invalid-elf-header_section-headers-enforced-for-api-level-26",
                               "\"%s\" has invalid e_shstrndx", name_.c_str());
diff --git a/tests/time_test.cpp b/tests/time_test.cpp
index ca8e260..baafbf6 100644
--- a/tests/time_test.cpp
+++ b/tests/time_test.cpp
@@ -31,6 +31,8 @@
 #include <thread>
 
 #include "SignalUtils.h"
+#include "android-base/file.h"
+#include "android-base/strings.h"
 #include "utils.h"
 
 using namespace std::chrono_literals;
@@ -797,21 +799,41 @@
   ASSERT_EQ(1, timer_create_NULL_signal_handler_invocation_count);
 }
 
-TEST(time, timer_create_EINVAL) {
-  clockid_t invalid_clock = 16;
+static int GetThreadCount() {
+  std::string status;
+  if (android::base::ReadFileToString("/proc/self/status", &status)) {
+    for (const auto& line : android::base::Split(status, "\n")) {
+      int thread_count;
+      if (sscanf(line.c_str(), "Threads: %d", &thread_count) == 1) {
+        return thread_count;
+      }
+    }
+  }
+  return -1;
+}
 
-  // A SIGEV_SIGNAL timer is easy; the kernel does all that.
+TEST(time, timer_create_EINVAL) {
+  const clockid_t kInvalidClock = 16;
+
+  // A SIGEV_SIGNAL timer failure is easy; that's the kernel's problem.
   timer_t timer_id;
-  ASSERT_EQ(-1, timer_create(invalid_clock, nullptr, &timer_id));
+  ASSERT_EQ(-1, timer_create(kInvalidClock, nullptr, &timer_id));
   ASSERT_ERRNO(EINVAL);
 
-  // A SIGEV_THREAD timer is more interesting because we have stuff to clean up.
-  sigevent se;
-  memset(&se, 0, sizeof(se));
+  // A SIGEV_THREAD timer failure is more interesting because we have a thread
+  // to clean up (https://issuetracker.google.com/340125671).
+  sigevent se = {};
   se.sigev_notify = SIGEV_THREAD;
   se.sigev_notify_function = NoOpNotifyFunction;
-  ASSERT_EQ(-1, timer_create(invalid_clock, &se, &timer_id));
+  ASSERT_EQ(-1, timer_create(kInvalidClock, &se, &timer_id));
   ASSERT_ERRNO(EINVAL);
+
+  // timer_create() doesn't guarantee that the thread will be dead _before_
+  // it returns because that would require extra synchronization that's
+  // unnecessary in the normal (successful) case. A timeout here means we
+  // leaked a thread.
+  while (GetThreadCount() > 1) {
+  }
 }
 
 TEST(time, timer_create_multiple) {
diff --git a/tests/utils.h b/tests/utils.h
index dcb08f5..3c83b73 100644
--- a/tests/utils.h
+++ b/tests/utils.h
@@ -38,6 +38,7 @@
 #endif
 
 #include <atomic>
+#include <iomanip>
 #include <string>
 #include <regex>
 
@@ -253,7 +254,7 @@
     AssertChildExited(pid, expected_exit_status, &error_msg);
     if (expected_output_regex != nullptr) {
       if (!std::regex_search(output_, std::regex(expected_output_regex))) {
-        FAIL() << "regex " << expected_output_regex << " didn't match " << output_;
+        FAIL() << "regex " << std::quoted(expected_output_regex) << " didn't match " << std::quoted(output_);
       }
     }
   }