[scudo] Tune FuchsiaConfig for RiscV

[Caslyn]

Summary

Reduce PrimaryRegionSizeLog to 28U to be compatible with a 39 bit
VMA on the fuchsia-riscv platform. PrimaryGroupSizeLog is
reduced to 19 to preserve 512 BatchGroups per region.

This change can be tested on Fuchsia with:

fx set --auto-dir bringup.riscv64 --with //bundles:boot_tests \
fx build bundles:boot_tests \
fx run-boot-test --args={-s,1} boot-libc-unittests \
--cmdline='--gtest_filter=-*DeathTest*:PthreadGetSet*:ScudoSecondaryTest*'

The gtest filter ignores pthread and death tests due to non-scudo
related issues on fuchsia-riscv (ScudoSecondaryTest includes a death
check).

Related Ticket: https://fxbug.dev/125263

[Caslyn]

Fix typo

[fabio-d]

compiler-rt/lib/scudo/standalone/tests/combined_test.cpp

112

I would prefer to keep it for now even if it's deprecated (as @Chia-hungDuan mentioned in https://reviews.llvm.org/D146454#4262007). The reason why I'm asking it is that this configuration actually helped detect an issue in the recent MemMap CLs because, unlike FuchsiaConfig, it enables the secondary allocator cache. We can remove it later when we ensure that other tests that would have caught those issues exist.

[Chia-hungDuan]

compiler-rt/lib/scudo/standalone/tests/combined_test.cpp

112

Same here. If you decide to remove this it'll be better to do it separately. OTOH, you may consider using (or adding) other config that enables secondary cache instead of using AndroidSvelte if you still want to verify the secondary cache.

[Caslyn]

Add back AndroidSvelteConfig to Fuchsia combined tests.

compiler-rt/lib/scudo/standalone/tests/combined_test.cpp

112

Thanks for flagging, I've added this back. It was a mistake for me to remove it for this CL. I misinterpreted the failure of ScudoCombinedDeathTestBasicCombined14_AndroidSvelteConfig on fuchsia-riscv to be due to the config, but it failed because of a separate issue with death-tests on fuchsia-riscv.

compiler-rt/lib/scudo/standalone/allocator_config.h

 };
 
 #if SCUDO_CAN_USE_PRIMARY64
 struct FuchsiaConfig {
   using SizeClassMap = FuchsiaSizeClassMap;
   static const bool MaySupportMemoryTagging = false;
 
   typedef SizeClassAllocator64<FuchsiaConfig> Primary;
+// Support 38-bit VMA for riscv-64
+#if SCUDO_RISCV64
+  static const uptr PrimaryRegionSizeLog = 28U;
+  static const uptr PrimaryGroupSizeLog = 19U;
+#else
   static const uptr PrimaryRegionSizeLog = 30U;
   static const uptr PrimaryGroupSizeLog = 21U;
+#endif
   typedef u32 PrimaryCompactPtrT;
   static const bool PrimaryEnableRandomOffset = true;
   static const uptr PrimaryMapSizeIncrement = 1UL << 18;
   static const uptr PrimaryCompactPtrScale = SCUDO_MIN_ALIGNMENT_LOG;
   static const s32 PrimaryMinReleaseToOsIntervalMs = INT32_MIN;
   static const s32 PrimaryMaxReleaseToOsIntervalMs = INT32_MAX;
 
   typedef MapAllocatorNoCache SecondaryCache;

compiler-rt/lib/scudo/standalone/platform.h

 #endif
 
 #if defined(__TRUSTY__)
 #define SCUDO_TRUSTY 1
 #else
 #define SCUDO_TRUSTY 0
 #endif
 
+#if defined(__riscv) && (__riscv_xlen == 64)
+#define SCUDO_RISCV64 1
+#else
+#define SCUDO_RISCV64 0
+#endif
+
 #if defined(__LP64__)
 #define SCUDO_WORDSIZE 64U
 #else
 #define SCUDO_WORDSIZE 32U
 #endif
 
 #if SCUDO_WORDSIZE == 64U
 #define FIRST_32_SECOND_64(a, b) (b)

compiler-rt/lib/scudo/standalone/tests/combined_test.cpp

template <class TypeParam> struct ScudoCombinedTest : public Test {
   using AllocatorT = TestAllocator<TypeParam>;
   std::unique_ptr<AllocatorT> Allocator;
 };
 
 template <typename T> using ScudoCombinedDeathTest = ScudoCombinedTest<T>;
 
 #if SCUDO_FUCHSIA
 #define SCUDO_TYPED_TEST_ALL_TYPES(FIXTURE, NAME)                              \
-  SCUDO_TYPED_TEST_TYPE(FIXTURE, NAME, AndroidSvelteConfig)                    \
   SCUDO_TYPED_TEST_TYPE(FIXTURE, NAME, FuchsiaConfig)
 #else
 #define SCUDO_TYPED_TEST_ALL_TYPES(FIXTURE, NAME)                              \
   SCUDO_TYPED_TEST_TYPE(FIXTURE, NAME, AndroidSvelteConfig)                    \
   SCUDO_TYPED_TEST_TYPE(FIXTURE, NAME, DefaultConfig)                          \
   SCUDO_TYPED_TEST_TYPE(FIXTURE, NAME, AndroidConfig)
 #endif