From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- tools/profiler/lul/LulDwarfSummariser.cpp | 549 ++++++++++++++++++++++++++++++ 1 file changed, 549 insertions(+) create mode 100644 tools/profiler/lul/LulDwarfSummariser.cpp (limited to 'tools/profiler/lul/LulDwarfSummariser.cpp') diff --git a/tools/profiler/lul/LulDwarfSummariser.cpp b/tools/profiler/lul/LulDwarfSummariser.cpp new file mode 100644 index 0000000000..e9172c3e18 --- /dev/null +++ b/tools/profiler/lul/LulDwarfSummariser.cpp @@ -0,0 +1,549 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "LulDwarfSummariser.h" + +#include "LulDwarfExt.h" + +#include "mozilla/Assertions.h" +#include "mozilla/Sprintf.h" + +// Set this to 1 for verbose logging +#define DEBUG_SUMMARISER 0 + +namespace lul { + +// Do |s64|'s lowest 32 bits sign extend back to |s64| itself? +static inline bool fitsIn32Bits(int64 s64) { + return s64 == ((s64 & 0xffffffff) ^ 0x80000000) - 0x80000000; +} + +// Check a LExpr prefix expression, starting at pfxInstrs[start] up to +// the next PX_End instruction, to ensure that: +// * It only mentions registers that are tracked on this target +// * The start point is sane +// If the expression is ok, return NULL. Else return a pointer +// a const char* holding a bit of text describing the problem. +static const char* checkPfxExpr(const vector* pfxInstrs, + int64_t start) { + size_t nInstrs = pfxInstrs->size(); + if (start < 0 || start >= (ssize_t)nInstrs) { + return "bogus start point"; + } + size_t i; + for (i = start; i < nInstrs; i++) { + PfxInstr pxi = (*pfxInstrs)[i]; + if (pxi.mOpcode == PX_End) break; + if (pxi.mOpcode == PX_DwReg && + !registerIsTracked((DW_REG_NUMBER)pxi.mOperand)) { + return "uses untracked reg"; + } + } + return nullptr; // success +} + +Summariser::Summariser(SecMap* aSecMap, uintptr_t aTextBias, + void (*aLog)(const char*)) + : mSecMap(aSecMap), mTextBias(aTextBias), mLog(aLog) { + mCurrAddr = 0; + mMax1Addr = 0; // Gives an empty range. + + // Initialise the running RuleSet to "haven't got a clue" status. + new (&mCurrRules) RuleSet(); +} + +void Summariser::Entry(uintptr_t aAddress, uintptr_t aLength) { + aAddress += mTextBias; + if (DEBUG_SUMMARISER) { + char buf[100]; + SprintfLiteral(buf, "LUL Entry(%llx, %llu)\n", + (unsigned long long int)aAddress, + (unsigned long long int)aLength); + mLog(buf); + } + // This throws away any previous summary, that is, assumes + // that the previous summary, if any, has been properly finished + // by a call to End(). + mCurrAddr = aAddress; + mMax1Addr = aAddress + aLength; + new (&mCurrRules) RuleSet(); +} + +void Summariser::Rule(uintptr_t aAddress, int aNewReg, LExprHow how, + int16_t oldReg, int64_t offset) { + aAddress += mTextBias; + if (DEBUG_SUMMARISER) { + char buf[100]; + if (how == NODEREF || how == DEREF) { + bool deref = how == DEREF; + SprintfLiteral(buf, "LUL 0x%llx old-r%d = %sr%d + %lld%s\n", + (unsigned long long int)aAddress, aNewReg, + deref ? "*(" : "", (int)oldReg, (long long int)offset, + deref ? ")" : ""); + } else if (how == PFXEXPR) { + SprintfLiteral(buf, "LUL 0x%llx old-r%d = pfx-expr-at %lld\n", + (unsigned long long int)aAddress, aNewReg, + (long long int)offset); + } else { + SprintfLiteral(buf, "LUL 0x%llx old-r%d = (invalid LExpr!)\n", + (unsigned long long int)aAddress, aNewReg); + } + mLog(buf); + } + + if (mCurrAddr < aAddress) { + // Flush the existing summary first. + mSecMap->AddRuleSet(&mCurrRules, mCurrAddr, aAddress - mCurrAddr); + if (DEBUG_SUMMARISER) { + mLog("LUL "); + mCurrRules.Print(mCurrAddr, aAddress - mCurrAddr, mLog); + mLog("\n"); + } + mCurrAddr = aAddress; + } + + // If for some reason summarisation fails, either or both of these + // become non-null and point at constant text describing the + // problem. Using two rather than just one avoids complications of + // having to concatenate two strings to produce a complete error message. + const char* reason1 = nullptr; + const char* reason2 = nullptr; + + // |offset| needs to be a 32 bit value that sign extends to 64 bits + // on a 64 bit target. We will need to incorporate |offset| into + // any LExpr made here. So we may as well check it right now. + if (!fitsIn32Bits(offset)) { + reason1 = "offset not in signed 32-bit range"; + goto cant_summarise; + } + + // FIXME: factor out common parts of the arch-dependent summarisers. + +#if defined(GP_ARCH_arm) + + // ----------------- arm ----------------- // + + // Now, can we add the rule to our summary? This depends on whether + // the registers and the overall expression are representable. This + // is the heart of the summarisation process. + switch (aNewReg) { + case DW_REG_CFA: + // This is a rule that defines the CFA. The only forms we + // choose to represent are: r7/11/12/13 + offset. The offset + // must fit into 32 bits since 'uintptr_t' is 32 bit on ARM, + // hence there is no need to check it for overflow. + if (how != NODEREF) { + reason1 = "rule for DW_REG_CFA: invalid |how|"; + goto cant_summarise; + } + switch (oldReg) { + case DW_REG_ARM_R7: + case DW_REG_ARM_R11: + case DW_REG_ARM_R12: + case DW_REG_ARM_R13: + break; + default: + reason1 = "rule for DW_REG_CFA: invalid |oldReg|"; + goto cant_summarise; + } + mCurrRules.mCfaExpr = LExpr(how, oldReg, offset); + break; + + case DW_REG_ARM_R7: + case DW_REG_ARM_R11: + case DW_REG_ARM_R12: + case DW_REG_ARM_R13: + case DW_REG_ARM_R14: + case DW_REG_ARM_R15: { + // This is a new rule for R7, R11, R12, R13 (SP), R14 (LR) or + // R15 (the return address). + switch (how) { + case NODEREF: + case DEREF: + // Check the old register is one we're tracking. + if (!registerIsTracked((DW_REG_NUMBER)oldReg) && + oldReg != DW_REG_CFA) { + reason1 = "rule for R7/11/12/13/14/15: uses untracked reg"; + goto cant_summarise; + } + break; + case PFXEXPR: { + // Check that the prefix expression only mentions tracked registers. + const vector* pfxInstrs = mSecMap->GetPfxInstrs(); + reason2 = checkPfxExpr(pfxInstrs, offset); + if (reason2) { + reason1 = "rule for R7/11/12/13/14/15: "; + goto cant_summarise; + } + break; + } + default: + goto cant_summarise; + } + LExpr expr = LExpr(how, oldReg, offset); + switch (aNewReg) { + case DW_REG_ARM_R7: + mCurrRules.mR7expr = expr; + break; + case DW_REG_ARM_R11: + mCurrRules.mR11expr = expr; + break; + case DW_REG_ARM_R12: + mCurrRules.mR12expr = expr; + break; + case DW_REG_ARM_R13: + mCurrRules.mR13expr = expr; + break; + case DW_REG_ARM_R14: + mCurrRules.mR14expr = expr; + break; + case DW_REG_ARM_R15: + mCurrRules.mR15expr = expr; + break; + default: + MOZ_ASSERT(0); + } + break; + } + + default: + // Leave |reason1| and |reason2| unset here. This program point + // is reached so often that it causes a flood of "Can't + // summarise" messages. In any case, we don't really care about + // the fact that this summary would produce a new value for a + // register that we're not tracking. We do on the other hand + // care if the summary's expression *uses* a register that we're + // not tracking. But in that case one of the above failures + // should tell us which. + goto cant_summarise; + } + + // Mark callee-saved registers (r4 .. r11) as unchanged, if there is + // no other information about them. FIXME: do this just once, at + // the point where the ruleset is committed. + if (mCurrRules.mR7expr.mHow == UNKNOWN) { + mCurrRules.mR7expr = LExpr(NODEREF, DW_REG_ARM_R7, 0); + } + if (mCurrRules.mR11expr.mHow == UNKNOWN) { + mCurrRules.mR11expr = LExpr(NODEREF, DW_REG_ARM_R11, 0); + } + if (mCurrRules.mR12expr.mHow == UNKNOWN) { + mCurrRules.mR12expr = LExpr(NODEREF, DW_REG_ARM_R12, 0); + } + + // The old r13 (SP) value before the call is always the same as the + // CFA. + mCurrRules.mR13expr = LExpr(NODEREF, DW_REG_CFA, 0); + + // If there's no information about R15 (the return address), say + // it's a copy of R14 (the link register). + if (mCurrRules.mR15expr.mHow == UNKNOWN) { + mCurrRules.mR15expr = LExpr(NODEREF, DW_REG_ARM_R14, 0); + } + +#elif defined(GP_ARCH_arm64) + + // ----------------- arm64 ----------------- // + + switch (aNewReg) { + case DW_REG_CFA: + if (how != NODEREF) { + reason1 = "rule for DW_REG_CFA: invalid |how|"; + goto cant_summarise; + } + switch (oldReg) { + case DW_REG_AARCH64_X29: + case DW_REG_AARCH64_SP: + break; + default: + reason1 = "rule for DW_REG_CFA: invalid |oldReg|"; + goto cant_summarise; + } + mCurrRules.mCfaExpr = LExpr(how, oldReg, offset); + break; + + case DW_REG_AARCH64_X29: + case DW_REG_AARCH64_X30: + case DW_REG_AARCH64_SP: { + switch (how) { + case NODEREF: + case DEREF: + // Check the old register is one we're tracking. + if (!registerIsTracked((DW_REG_NUMBER)oldReg) && + oldReg != DW_REG_CFA) { + reason1 = "rule for X29/X30/SP: uses untracked reg"; + goto cant_summarise; + } + break; + case PFXEXPR: { + // Check that the prefix expression only mentions tracked registers. + const vector* pfxInstrs = mSecMap->GetPfxInstrs(); + reason2 = checkPfxExpr(pfxInstrs, offset); + if (reason2) { + reason1 = "rule for X29/X30/SP: "; + goto cant_summarise; + } + break; + } + default: + goto cant_summarise; + } + LExpr expr = LExpr(how, oldReg, offset); + switch (aNewReg) { + case DW_REG_AARCH64_X29: + mCurrRules.mX29expr = expr; + break; + case DW_REG_AARCH64_X30: + mCurrRules.mX30expr = expr; + break; + case DW_REG_AARCH64_SP: + mCurrRules.mSPexpr = expr; + break; + default: + MOZ_ASSERT(0); + } + break; + } + default: + // Leave |reason1| and |reason2| unset here, for the reasons explained + // in the analogous point + goto cant_summarise; + } + + if (mCurrRules.mX29expr.mHow == UNKNOWN) { + mCurrRules.mX29expr = LExpr(NODEREF, DW_REG_AARCH64_X29, 0); + } + if (mCurrRules.mX30expr.mHow == UNKNOWN) { + mCurrRules.mX30expr = LExpr(NODEREF, DW_REG_AARCH64_X30, 0); + } + // On aarch64, it seems the old SP value before the call is always the + // same as the CFA. Therefore, in the absence of any other way to + // recover the SP, specify that the CFA should be copied. + if (mCurrRules.mSPexpr.mHow == UNKNOWN) { + mCurrRules.mSPexpr = LExpr(NODEREF, DW_REG_CFA, 0); + } +#elif defined(GP_ARCH_amd64) || defined(GP_ARCH_x86) + + // ---------------- x64/x86 ---------------- // + + // Now, can we add the rule to our summary? This depends on whether + // the registers and the overall expression are representable. This + // is the heart of the summarisation process. + switch (aNewReg) { + case DW_REG_CFA: { + // This is a rule that defines the CFA. The only forms we choose to + // represent are: = SP+offset, = FP+offset, or =prefix-expr. + switch (how) { + case NODEREF: + if (oldReg != DW_REG_INTEL_XSP && oldReg != DW_REG_INTEL_XBP) { + reason1 = "rule for DW_REG_CFA: invalid |oldReg|"; + goto cant_summarise; + } + break; + case DEREF: + reason1 = "rule for DW_REG_CFA: invalid |how|"; + goto cant_summarise; + case PFXEXPR: { + // Check that the prefix expression only mentions tracked registers. + const vector* pfxInstrs = mSecMap->GetPfxInstrs(); + reason2 = checkPfxExpr(pfxInstrs, offset); + if (reason2) { + reason1 = "rule for CFA: "; + goto cant_summarise; + } + break; + } + default: + goto cant_summarise; + } + mCurrRules.mCfaExpr = LExpr(how, oldReg, offset); + break; + } + + case DW_REG_INTEL_XSP: + case DW_REG_INTEL_XBP: + case DW_REG_INTEL_XIP: { + // This is a new rule for XSP, XBP or XIP (the return address). + switch (how) { + case NODEREF: + case DEREF: + // Check the old register is one we're tracking. + if (!registerIsTracked((DW_REG_NUMBER)oldReg) && + oldReg != DW_REG_CFA) { + reason1 = "rule for XSP/XBP/XIP: uses untracked reg"; + goto cant_summarise; + } + break; + case PFXEXPR: { + // Check that the prefix expression only mentions tracked registers. + const vector* pfxInstrs = mSecMap->GetPfxInstrs(); + reason2 = checkPfxExpr(pfxInstrs, offset); + if (reason2) { + reason1 = "rule for XSP/XBP/XIP: "; + goto cant_summarise; + } + break; + } + default: + goto cant_summarise; + } + LExpr expr = LExpr(how, oldReg, offset); + switch (aNewReg) { + case DW_REG_INTEL_XBP: + mCurrRules.mXbpExpr = expr; + break; + case DW_REG_INTEL_XSP: + mCurrRules.mXspExpr = expr; + break; + case DW_REG_INTEL_XIP: + mCurrRules.mXipExpr = expr; + break; + default: + MOZ_CRASH("impossible value for aNewReg"); + } + break; + } + + default: + // Leave |reason1| and |reason2| unset here, for the reasons + // explained in the analogous point in the ARM case just above. + goto cant_summarise; + } + + // On Intel, it seems the old SP value before the call is always the + // same as the CFA. Therefore, in the absence of any other way to + // recover the SP, specify that the CFA should be copied. + if (mCurrRules.mXspExpr.mHow == UNKNOWN) { + mCurrRules.mXspExpr = LExpr(NODEREF, DW_REG_CFA, 0); + } + + // Also, gcc says "Undef" for BP when it is unchanged. + if (mCurrRules.mXbpExpr.mHow == UNKNOWN) { + mCurrRules.mXbpExpr = LExpr(NODEREF, DW_REG_INTEL_XBP, 0); + } + +#elif defined(GP_ARCH_mips64) + // ---------------- mips ---------------- // + // + // Now, can we add the rule to our summary? This depends on whether + // the registers and the overall expression are representable. This + // is the heart of the summarisation process. + switch (aNewReg) { + case DW_REG_CFA: + // This is a rule that defines the CFA. The only forms we can + // represent are: = SP+offset or = FP+offset. + if (how != NODEREF) { + reason1 = "rule for DW_REG_CFA: invalid |how|"; + goto cant_summarise; + } + if (oldReg != DW_REG_MIPS_SP && oldReg != DW_REG_MIPS_FP) { + reason1 = "rule for DW_REG_CFA: invalid |oldReg|"; + goto cant_summarise; + } + mCurrRules.mCfaExpr = LExpr(how, oldReg, offset); + break; + + case DW_REG_MIPS_SP: + case DW_REG_MIPS_FP: + case DW_REG_MIPS_PC: { + // This is a new rule for SP, FP or PC (the return address). + switch (how) { + case NODEREF: + case DEREF: + // Check the old register is one we're tracking. + if (!registerIsTracked((DW_REG_NUMBER)oldReg) && + oldReg != DW_REG_CFA) { + reason1 = "rule for SP/FP/PC: uses untracked reg"; + goto cant_summarise; + } + break; + case PFXEXPR: { + // Check that the prefix expression only mentions tracked registers. + const vector* pfxInstrs = mSecMap->GetPfxInstrs(); + reason2 = checkPfxExpr(pfxInstrs, offset); + if (reason2) { + reason1 = "rule for SP/FP/PC: "; + goto cant_summarise; + } + break; + } + default: + goto cant_summarise; + } + LExpr expr = LExpr(how, oldReg, offset); + switch (aNewReg) { + case DW_REG_MIPS_FP: + mCurrRules.mFPexpr = expr; + break; + case DW_REG_MIPS_SP: + mCurrRules.mSPexpr = expr; + break; + case DW_REG_MIPS_PC: + mCurrRules.mPCexpr = expr; + break; + default: + MOZ_CRASH("impossible value for aNewReg"); + } + break; + } + default: + // Leave |reason1| and |reason2| unset here, for the reasons + // explained in the analogous point in the ARM case just above. + goto cant_summarise; + } + + // On MIPS, it seems the old SP value before the call is always the + // same as the CFA. Therefore, in the absence of any other way to + // recover the SP, specify that the CFA should be copied. + if (mCurrRules.mSPexpr.mHow == UNKNOWN) { + mCurrRules.mSPexpr = LExpr(NODEREF, DW_REG_CFA, 0); + } + + // Also, gcc says "Undef" for FP when it is unchanged. + if (mCurrRules.mFPexpr.mHow == UNKNOWN) { + mCurrRules.mFPexpr = LExpr(NODEREF, DW_REG_MIPS_FP, 0); + } + +#else + +# error "Unsupported arch" +#endif + + return; + +cant_summarise: + if (reason1 || reason2) { + char buf[200]; + SprintfLiteral(buf, + "LUL can't summarise: " + "SVMA=0x%llx: %s%s, expr=LExpr(%s,%u,%lld)\n", + (unsigned long long int)(aAddress - mTextBias), + reason1 ? reason1 : "", reason2 ? reason2 : "", + NameOf_LExprHow(how), (unsigned int)oldReg, + (long long int)offset); + mLog(buf); + } +} + +uint32_t Summariser::AddPfxInstr(PfxInstr pfxi) { + return mSecMap->AddPfxInstr(pfxi); +} + +void Summariser::End() { + if (DEBUG_SUMMARISER) { + mLog("LUL End\n"); + } + if (mCurrAddr < mMax1Addr) { + mSecMap->AddRuleSet(&mCurrRules, mCurrAddr, mMax1Addr - mCurrAddr); + if (DEBUG_SUMMARISER) { + mLog("LUL "); + mCurrRules.Print(mCurrAddr, mMax1Addr - mCurrAddr, mLog); + mLog("\n"); + } + } +} + +} // namespace lul -- cgit v1.2.3