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-rw-r--r--tools/profiler/lul/LulDwarfSummariser.cpp549
1 files changed, 549 insertions, 0 deletions
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<PfxInstr>* 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<PfxInstr>* 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<PfxInstr>* 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<PfxInstr>* 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<PfxInstr>* 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<PfxInstr>* 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
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