From 6e0a1393539aee2a63be864349298ef39cf247cf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micha=C3=ABl=20Zasso?= Date: Sat, 17 Apr 2021 16:28:44 +0200 Subject: [PATCH] deps: V8: cherry-pick 482e5c7750b3 Original commit message: Merged: [wasm-simd] Fix loading fp pair registers We were incorrectly clearing the high reg from the list of regs to load. The intention was to prevent double (and incorrect) loading - loading 128 bits from the low fp and the loading 128 bits from the high fp. But this violates the assumption that the two regs in a pair would be set or unset at the same time. The fix here is to introduce a new enum for register loads, a nop, which does nothing. The high fp of the fp pair will be tied to this nop, so as we iterate down the reglist, we load 128 bits using the low fp, then don't load anything for the high fp. Bug: chromium:1161654 (cherry picked from commit 8c698702ced0de085aa91370d8cb44deab3fcf54) (cherry picked from commit ffd6ff5a61b9343ccc62e6c03b71a33682c6084d) Change-Id: Ib8134574b24f74f24ca9efd34b3444173296d8f1 No-Try: true No-Presubmit: true No-Tree-Checks: true Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2619416 Commit-Queue: Zhi An Ng Reviewed-by: Clemens Backes Cr-Original-Commit-Position: refs/branch-heads/8.8@{#28} Cr-Original-Branched-From: 2dbcdc105b963ee2501c82139eef7e0603977ff0-refs/heads/8.8.278@{#1} Cr-Original-Branched-From: 366d30c99049b3f1c673f8a93deb9f879d0fa9f0-refs/heads/master@{#71094} Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2649176 Reviewed-by: Victor-Gabriel Savu Commit-Queue: Achuith Bhandarkar Cr-Commit-Position: refs/branch-heads/8.6@{#55} Cr-Branched-From: a64aed2333abf49e494d2a5ce24bbd14fff19f60-refs/heads/8.6.395@{#1} Cr-Branched-From: a626bc036236c9bf92ac7b87dc40c9e538b087e3-refs/heads/master@{#69472} Refs: https://github.com/v8/v8/commit/482e5c7750b3ae2f923b507518f6bfe40486ee59 --- common.gypi | 2 +- .../v8/src/wasm/baseline/liftoff-assembler.cc | 15 +++-- .../mjsunit/regress/wasm/regress-1161654.js | 56 +++++++++++++++++++ 3 files changed, 68 insertions(+), 5 deletions(-) create mode 100644 deps/v8/test/mjsunit/regress/wasm/regress-1161654.js diff --git a/common.gypi b/common.gypi index 6d49200da370e3..a1c01c922d0d42 100644 --- a/common.gypi +++ b/common.gypi @@ -36,7 +36,7 @@ # Reset this number to 0 on major V8 upgrades. # Increment by one for each non-official patch applied to deps/v8. - 'v8_embedder_string': '-node.41', + 'v8_embedder_string': '-node.42', ##### V8 defaults for Node.js ##### diff --git a/deps/v8/src/wasm/baseline/liftoff-assembler.cc b/deps/v8/src/wasm/baseline/liftoff-assembler.cc index 923d375064c924..c505cf7e6d17ef 100644 --- a/deps/v8/src/wasm/baseline/liftoff-assembler.cc +++ b/deps/v8/src/wasm/baseline/liftoff-assembler.cc @@ -37,6 +37,7 @@ class StackTransferRecipe { struct RegisterLoad { enum LoadKind : uint8_t { + kNop, // no-op, used for high fp of a fp pair. kConstant, // load a constant value into a register. kStack, // fill a register from a stack slot. kLowHalfStack, // fill a register from the low half of a stack slot. @@ -63,6 +64,10 @@ class StackTransferRecipe { return {half == kLowWord ? kLowHalfStack : kHighHalfStack, kWasmI32, offset}; } + static RegisterLoad Nop() { + // ValueType does not matter. + return {kNop, kWasmI32, 0}; + } private: RegisterLoad(LoadKind kind, ValueType type, int32_t value) @@ -217,11 +222,11 @@ class StackTransferRecipe { RegisterLoad::HalfStack(stack_offset, kHighWord); } else if (dst.is_fp_pair()) { DCHECK_EQ(kWasmS128, type); - // load_dst_regs_.set above will set both low and high fp regs. - // But unlike gp_pair, we load a kWasm128 in one go in ExecuteLoads. - // So unset the top fp register to skip loading it. - load_dst_regs_.clear(dst.high()); + // Only need register_load for low_gp since we load 128 bits at one go. + // Both low and high need to be set in load_dst_regs_ but when iterating + // over it, both low and high will be cleared, so we won't load twice. *register_load(dst.low()) = RegisterLoad::Stack(stack_offset, type); + *register_load(dst.high()) = RegisterLoad::Nop(); } else { *register_load(dst) = RegisterLoad::Stack(stack_offset, type); } @@ -318,6 +323,8 @@ class StackTransferRecipe { for (LiftoffRegister dst : load_dst_regs_) { RegisterLoad* load = register_load(dst); switch (load->kind) { + case RegisterLoad::kNop: + break; case RegisterLoad::kConstant: asm_->LoadConstant(dst, load->type == kWasmI64 ? WasmValue(int64_t{load->value}) diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-1161654.js b/deps/v8/test/mjsunit/regress/wasm/regress-1161654.js new file mode 100644 index 00000000000000..93f2c3b556fc55 --- /dev/null +++ b/deps/v8/test/mjsunit/regress/wasm/regress-1161654.js @@ -0,0 +1,56 @@ +// Copyright 2021 the V8 project authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Flags: --wasm-staging + +// This is a fuzzer-generated test case that exposed a bug in Liftoff that only +// affects ARM, where the fp register aliasing is different from other archs. +// We were inncorrectly clearing the the high fp register in a LiftoffRegList +// indicating registers to load, hitting a DCHECK. +load('test/mjsunit/wasm/wasm-module-builder.js'); + +const builder = new WasmModuleBuilder(); +builder.addMemory(19, 32, false); +builder.addGlobal(kWasmI32, 0); +builder.addType(makeSig([], [])); +builder.addType(makeSig([kWasmI64, kWasmS128, kWasmF32], [kWasmI32])); +// Generate function 1 (out of 5). +builder.addFunction(undefined, 0 /* sig */) + .addBodyWithEnd([ +// signature: v_v +// body: +kExprI32Const, 0x05, // i32.const +kExprReturn, // return +kExprUnreachable, // unreachable +kExprEnd, // end @5 +]); +// Generate function 4 (out of 5). +builder.addFunction(undefined, 1 /* sig */) + .addBodyWithEnd([ +// signature: i_lsf +// body: +kExprLocalGet, 0x01, // local.get +kExprLocalGet, 0x01, // local.get +kExprGlobalGet, 0x00, // global.get +kExprDrop, // drop +kExprLoop, kWasmStmt, // loop @8 + kExprLoop, 0x00, // loop @10 + kExprI32Const, 0x01, // i32.const + kExprMemoryGrow, 0x00, // memory.grow + kExprI64LoadMem8U, 0x00, 0x70, // i64.load8_u + kExprLoop, 0x00, // loop @19 + kExprCallFunction, 0x00, // call function #0: v_v + kExprEnd, // end @23 + kExprI64Const, 0xf1, 0x24, // i64.const + kExprGlobalGet, 0x00, // global.get + kExprDrop, // drop + kExprBr, 0x00, // br depth=0 + kExprEnd, // end @32 + kExprEnd, // end @33 +kExprI32Const, 0x5b, // i32.const +kExprReturn, // return +kExprEnd, // end @37 +]); +// Instantiation is enough to cause a crash. +const instance = builder.instantiate();