Revert "Prevent unsafe narrowing: base/ for Linux part 2 of n"

This reverts commit 1d7afea.

Reason for revert: Test SysInfoTest.AmountOfAvailablePhysicalMemory fails on android-pie-x86-rel

Original change's description:
> Prevent unsafe narrowing: base/ for Linux part 2 of n
>
> Much of the diff here is from changing the physical/virtual memory funcs
> from signed to unsigned.
>
> Bug: 1292951
> Change-Id: I1a396b97fa25c955198237edf995a628da434aa3
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3740962
> Commit-Queue: danakj <danakj@chromium.org>
> Reviewed-by: danakj <danakj@chromium.org>
> Commit-Queue: Peter Kasting <pkasting@chromium.org>
> Owners-Override: danakj <danakj@chromium.org>
> Auto-Submit: Peter Kasting <pkasting@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1021898}

Bug: 1292951, 1343625
Change-Id: I2fc9adeb0f5678447e74b9673ec2ec9ac80f95b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3756793
Auto-Submit: Sky Malice <skym@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Owners-Override: Sky Malice <skym@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1023054}

base/allocator/partition_allocator/partition_alloc_unittest.cc

@@ -97,7 +97,7 @@ bool IsLargeMemoryDevice() {
   //
   // Set to 4GiB, since we have 2GiB Android devices where tests flakily fail
   // (e.g. Nexus 5X, crbug.com/1191195).
-  return base::SysInfo::AmountOfPhysicalMemory() >= 4000ULL * 1024 * 1024;
+  return base::SysInfo::AmountOfPhysicalMemory() >= 4000LL * 1024 * 1024;
 }
 
 bool SetAddressSpaceLimit() {

base/process/process_metrics_unittest.cc

@@ -207,11 +207,11 @@ TEST_F(SystemMetricsTest, ParseMeminfo) {
   EXPECT_EQ(meminfo.shmem, 140204);
   EXPECT_EQ(meminfo.slab, 54212);
 #endif
-  EXPECT_EQ(355725u,
+  EXPECT_EQ(355725,
             base::SysInfo::AmountOfAvailablePhysicalMemory(meminfo) / 1024);
   // Simulate as if there is no MemAvailable.
   meminfo.available = 0;
-  EXPECT_EQ(374448u,
+  EXPECT_EQ(374448,
             base::SysInfo::AmountOfAvailablePhysicalMemory(meminfo) / 1024);
   meminfo = {};
   EXPECT_TRUE(ParseProcMeminfo(valid_input2, &meminfo));
@@ -223,7 +223,7 @@ TEST_F(SystemMetricsTest, ParseMeminfo) {
   EXPECT_EQ(meminfo.swap_total, 524280);
   EXPECT_EQ(meminfo.swap_free, 524200);
   EXPECT_EQ(meminfo.dirty, 4);
-  EXPECT_EQ(69936u,
+  EXPECT_EQ(69936,
             base::SysInfo::AmountOfAvailablePhysicalMemory(meminfo) / 1024);
 }
 

base/profiler/stack_copier_signal.cc

@@ -37,7 +37,7 @@ class AsyncSafeWaitableEvent {
     // futex() can wake up spuriously if this memory address was previously used
     // for a pthread mutex. So, also check the condition.
     while (true) {
-      long res =
+      int res =
           syscall(SYS_futex, futex_int_ptr(), FUTEX_WAIT | FUTEX_PRIVATE_FLAG,
                   0, nullptr, nullptr, 0);
       if (futex_.load(std::memory_order_acquire) != 0)

base/sync_socket_posix.cc

@@ -23,7 +23,6 @@
 #include "base/check_op.h"
 #include "base/containers/span.h"
 #include "base/files/file_util.h"
-#include "base/numerics/safe_conversions.h"
 #include "base/threading/scoped_blocking_call.h"
 #include "build/build_config.h"
 
@@ -175,7 +174,8 @@ size_t SyncSocket::Peek() {
     // If there is an error in ioctl, signal that the channel would block.
     return 0;
   }
-  return checked_cast<size_t>(number_chars);
+  DCHECK_GE(number_chars, 0);
+  return number_chars;
 }
 
 bool SyncSocket::IsValid() const {

base/system/sys_info.cc

@@ -23,21 +23,21 @@ namespace base {
 namespace {
 #if BUILDFLAG(IS_IOS)
 // For M99, 45% of devices have 2GB of RAM, and 55% have more.
-constexpr uint64_t kLowMemoryDeviceThresholdMB = 1024;
+constexpr int64_t kLowMemoryDeviceThresholdMB = 1024;
 #else
 // Updated Desktop default threshold to match the Android 2021 definition.
-constexpr uint64_t kLowMemoryDeviceThresholdMB = 2048;
+constexpr int64_t kLowMemoryDeviceThresholdMB = 2048;
 #endif
 }  // namespace
 
 // static
-uint64_t SysInfo::AmountOfPhysicalMemory() {
+int64_t SysInfo::AmountOfPhysicalMemory() {
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableLowEndDeviceMode)) {
     // Keep using 512MB as the simulated RAM amount for when users or tests have
     // manually enabled low-end device mode. Note this value is different from
     // the threshold used for low end devices.
-    constexpr uint64_t kSimulatedMemoryForEnableLowEndDeviceMode =
+    constexpr int64_t kSimulatedMemoryForEnableLowEndDeviceMode =
         512 * 1024 * 1024;
     return std::min(kSimulatedMemoryForEnableLowEndDeviceMode,
                     AmountOfPhysicalMemoryImpl());
@@ -47,14 +47,14 @@ uint64_t SysInfo::AmountOfPhysicalMemory() {
 }
 
 // static
-uint64_t SysInfo::AmountOfAvailablePhysicalMemory() {
+int64_t SysInfo::AmountOfAvailablePhysicalMemory() {
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableLowEndDeviceMode)) {
     // Estimate the available memory by subtracting our memory used estimate
     // from the fake |kLowMemoryDeviceThresholdMB| limit.
-    uint64_t memory_used =
+    int64_t memory_used =
         AmountOfPhysicalMemoryImpl() - AmountOfAvailablePhysicalMemoryImpl();
-    uint64_t memory_limit = kLowMemoryDeviceThresholdMB * 1024 * 1024;
+    int64_t memory_limit = kLowMemoryDeviceThresholdMB * 1024 * 1024;
     // std::min ensures no underflow, as |memory_used| can be > |memory_limit|.
     return memory_limit - std::min(memory_used, memory_limit);
   }
@@ -82,8 +82,7 @@ bool DetectLowEndDevice() {
     return false;
 
   int ram_size_mb = SysInfo::AmountOfPhysicalMemoryMB();
-  return ram_size_mb > 0 &&
-         static_cast<uint64_t>(ram_size_mb) <= kLowMemoryDeviceThresholdMB;
+  return (ram_size_mb > 0 && ram_size_mb <= kLowMemoryDeviceThresholdMB);
 }
 
 // static

base/system/sys_info.h

@@ -34,19 +34,19 @@ class BASE_EXPORT SysInfo {
   // Return the number of bytes of physical memory on the current machine.
   // If low-end device mode is manually enabled via command line flag, this
   // will return the lesser of the actual physical memory, or 512MB.
-  static uint64_t AmountOfPhysicalMemory();
+  static int64_t AmountOfPhysicalMemory();
 
   // Return the number of bytes of current available physical memory on the
   // machine.
   // (The amount of memory that can be allocated without any significant
   // impact on the system. It can lead to freeing inactive file-backed
   // and/or speculative file-backed memory).
-  static uint64_t AmountOfAvailablePhysicalMemory();
+  static int64_t AmountOfAvailablePhysicalMemory();
 
   // Return the number of bytes of virtual memory of this process. A return
   // value of zero means that there is no limit on the available virtual
   // memory.
-  static uint64_t AmountOfVirtualMemory();
+  static int64_t AmountOfVirtualMemory();
 
   // Return the number of megabytes of physical memory on the current machine.
   static int AmountOfPhysicalMemoryMB() {
@@ -215,14 +215,14 @@ class BASE_EXPORT SysInfo {
   FRIEND_TEST_ALL_PREFIXES(SysInfoTest, AmountOfAvailablePhysicalMemory);
   FRIEND_TEST_ALL_PREFIXES(debug::SystemMetricsTest, ParseMeminfo);
 
-  static uint64_t AmountOfPhysicalMemoryImpl();
-  static uint64_t AmountOfAvailablePhysicalMemoryImpl();
+  static int64_t AmountOfPhysicalMemoryImpl();
+  static int64_t AmountOfAvailablePhysicalMemoryImpl();
   static bool IsLowEndDeviceImpl();
   static HardwareInfo GetHardwareInfoSync();
 
 #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID) || \
     BUILDFLAG(IS_AIX)
-  static uint64_t AmountOfAvailablePhysicalMemory(
+  static int64_t AmountOfAvailablePhysicalMemory(
       const SystemMemoryInfoKB& meminfo);
 #endif
 };

base/system/sys_info_fuchsia.cc

@@ -91,12 +91,12 @@ int64_t GetAmountOfTotalDiskSpaceAndVolumePath(const FilePath& path,
 }  // namespace
 
 // static
-uint64_t SysInfo::AmountOfPhysicalMemoryImpl() {
+int64_t SysInfo::AmountOfPhysicalMemoryImpl() {
   return zx_system_get_physmem();
 }
 
 // static
-uint64_t SysInfo::AmountOfAvailablePhysicalMemoryImpl() {
+int64_t SysInfo::AmountOfAvailablePhysicalMemoryImpl() {
   // TODO(https://crbug.com/986608): Implement this.
   NOTIMPLEMENTED_LOG_ONCE();
   return 0;
@@ -108,7 +108,7 @@ int SysInfo::NumberOfProcessors() {
 }
 
 // static
-uint64_t SysInfo::AmountOfVirtualMemory() {
+int64_t SysInfo::AmountOfVirtualMemory() {
   return 0;
 }
 

base/system/sys_info_ios.mm

@@ -14,7 +14,6 @@
 #include "base/check_op.h"
 #include "base/mac/scoped_mach_port.h"
 #include "base/notreached.h"
-#include "base/numerics/safe_conversions.h"
 #include "base/process/process_metrics.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ -116,7 +115,7 @@
 }
 
 // static
-uint64_t SysInfo::AmountOfPhysicalMemoryImpl() {
+int64_t SysInfo::AmountOfPhysicalMemoryImpl() {
   struct host_basic_info hostinfo;
   mach_msg_type_number_t count = HOST_BASIC_INFO_COUNT;
   base::mac::ScopedMachSendRight host(mach_host_self());
@@ -127,17 +126,17 @@
     return 0;
   }
   DCHECK_EQ(HOST_BASIC_INFO_COUNT, count);
-  return hostinfo.max_mem;
+  return static_cast<int64_t>(hostinfo.max_mem);
 }
 
 // static
-uint64_t SysInfo::AmountOfAvailablePhysicalMemoryImpl() {
+int64_t SysInfo::AmountOfAvailablePhysicalMemoryImpl() {
   SystemMemoryInfoKB info;
   if (!GetSystemMemoryInfo(&info))
     return 0;
   // We should add inactive file-backed memory also but there is no such
   // information from iOS unfortunately.
-  return checked_cast<uint64_t>(info.free + info.speculative) * 1024;
+  return static_cast<int64_t>(info.free + info.speculative) * 1024;
 }
 
 // static

base/system/sys_info_linux.cc

@@ -24,50 +24,52 @@
 
 namespace {
 
-uint64_t AmountOfMemory(int pages_name) {
+int64_t AmountOfMemory(int pages_name) {
   long pages = sysconf(pages_name);
   long page_size = sysconf(_SC_PAGESIZE);
-  if (pages < 0 || page_size < 0)
+  if (pages == -1 || page_size == -1) {
+    NOTREACHED();
     return 0;
-  return static_cast<uint64_t>(pages) * static_cast<uint64_t>(page_size);
+  }
+  return static_cast<int64_t>(pages) * page_size;
 }
 
-uint64_t AmountOfPhysicalMemory() {
+int64_t AmountOfPhysicalMemory() {
   return AmountOfMemory(_SC_PHYS_PAGES);
 }
 
 base::LazyInstance<
-    base::internal::LazySysInfoValue<uint64_t, AmountOfPhysicalMemory>>::Leaky
+    base::internal::LazySysInfoValue<int64_t, AmountOfPhysicalMemory>>::Leaky
     g_lazy_physical_memory = LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
 namespace base {
 
 // static
-uint64_t SysInfo::AmountOfPhysicalMemoryImpl() {
+int64_t SysInfo::AmountOfPhysicalMemoryImpl() {
   return g_lazy_physical_memory.Get().value();
 }
 
 // static
-uint64_t SysInfo::AmountOfAvailablePhysicalMemoryImpl() {
+int64_t SysInfo::AmountOfAvailablePhysicalMemoryImpl() {
   SystemMemoryInfoKB info;
   if (!GetSystemMemoryInfo(&info))
     return 0;
   return AmountOfAvailablePhysicalMemory(info);
 }
 
 // static
-uint64_t SysInfo::AmountOfAvailablePhysicalMemory(
+int64_t SysInfo::AmountOfAvailablePhysicalMemory(
     const SystemMemoryInfoKB& info) {
   // See details here:
   // https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=34e431b0ae398fc54ea69ff85ec700722c9da773
   // The fallback logic (when there is no MemAvailable) would be more precise
   // if we had info about zones watermarks (/proc/zoneinfo).
-  int res_kb = info.available != 0
-                   ? info.available - info.active_file
-                   : info.free + info.reclaimable + info.inactive_file;
-  return checked_cast<uint64_t>(res_kb) * 1024;
+  int64_t res_kb = info.available != 0
+                       ? info.available - info.active_file
+                       : info.free + info.reclaimable + info.inactive_file;
+  return res_kb * 1024;
 }
 
 // static

base/system/sys_info_mac.mm

@@ -16,7 +16,6 @@
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_mach_port.h"
 #include "base/notreached.h"
-#include "base/numerics/safe_conversions.h"
 #include "base/process/process_metrics.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ -75,7 +74,7 @@
 }
 
 // static
-uint64_t SysInfo::AmountOfPhysicalMemoryImpl() {
+int64_t SysInfo::AmountOfPhysicalMemoryImpl() {
   struct host_basic_info hostinfo;
   mach_msg_type_number_t count = HOST_BASIC_INFO_COUNT;
   base::mac::ScopedMachSendRight host(mach_host_self());
@@ -86,17 +85,17 @@
     return 0;
   }
   DCHECK_EQ(HOST_BASIC_INFO_COUNT, count);
-  return hostinfo.max_mem;
+  return static_cast<int64_t>(hostinfo.max_mem);
 }
 
 // static
-uint64_t SysInfo::AmountOfAvailablePhysicalMemoryImpl() {
+int64_t SysInfo::AmountOfAvailablePhysicalMemoryImpl() {
   SystemMemoryInfoKB info;
   if (!GetSystemMemoryInfo(&info))
     return 0;
   // We should add inactive file-backed memory also but there is no such
   // information from Mac OS unfortunately.
-  return checked_cast<uint64_t>(info.free + info.speculative) * 1024;
+  return static_cast<int64_t>(info.free + info.speculative) * 1024;
 }
 
 // static

base/system/sys_info_openbsd.cc

@@ -14,12 +14,14 @@
 
 namespace {
 
-uint64_t AmountOfMemory(int pages_name) {
+int64_t AmountOfMemory(int pages_name) {
   long pages = sysconf(pages_name);
   long page_size = sysconf(_SC_PAGESIZE);
-  if (pages < 0 || page_size < 0)
+  if (pages == -1 || page_size == -1) {
+    NOTREACHED();
     return 0;
-  return static_cast<uint64_t>(pages) * static_cast<uint64_t>(page_size);
+  }
+  return static_cast<int64_t>(pages) * page_size;
 }
 
 }  // namespace
@@ -39,12 +41,12 @@ int SysInfo::NumberOfProcessors() {
 }
 
 // static
-uint64_t SysInfo::AmountOfPhysicalMemoryImpl() {
+int64_t SysInfo::AmountOfPhysicalMemoryImpl() {
   return AmountOfMemory(_SC_PHYS_PAGES);
 }
 
 // static
-uint64_t SysInfo::AmountOfAvailablePhysicalMemoryImpl() {
+int64_t SysInfo::AmountOfAvailablePhysicalMemoryImpl() {
   // We should add inactive file-backed memory also but there is no such
   // information from OpenBSD unfortunately.
   return AmountOfMemory(_SC_AVPHYS_PAGES);