Index: compiler-rt/trunk/include/xray/xray_interface.h =================================================================== --- compiler-rt/trunk/include/xray/xray_interface.h +++ compiler-rt/trunk/include/xray/xray_interface.h @@ -18,7 +18,13 @@ extern "C" { -enum XRayEntryType { ENTRY = 0, EXIT = 1, TAIL = 2 }; +// Synchronize this with AsmPrinter::SledKind in LLVM. +enum XRayEntryType { + ENTRY = 0, + EXIT = 1, + TAIL = 2, + LOG_ARGS_ENTRY = 3, +}; // Provide a function to invoke for when instrumentation points are hit. This is // a user-visible control surface that overrides the default implementation. The @@ -60,6 +66,17 @@ // Reverses the effect of __xray_patch(). See XRayPatchingStatus for possible // result values. extern XRayPatchingStatus __xray_unpatch(); + +// Use XRay to log the first argument of each (instrumented) function call. +// When this function exits, all threads will have observed the effect and +// start logging their subsequent affected function calls (if patched). +// +// Returns 1 on success, 0 on error. +extern int __xray_set_handler_arg1(void (*)(int32_t, XRayEntryType, uint64_t)); + +// Disables the XRay handler used to log first arguments of function calls. +// Returns 1 on success, 0 on error. +extern int __xray_remove_handler_arg1(); } #endif Index: compiler-rt/trunk/lib/xray/xray_AArch64.cc =================================================================== --- compiler-rt/trunk/lib/xray/xray_AArch64.cc +++ compiler-rt/trunk/lib/xray/xray_AArch64.cc @@ -92,8 +92,9 @@ } bool patchFunctionEntry(const bool Enable, const uint32_t FuncId, - const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { - return patchSled(Enable, FuncId, Sled, __xray_FunctionEntry); + const XRaySledEntry &Sled, + void (*Trampoline)()) XRAY_NEVER_INSTRUMENT { + return patchSled(Enable, FuncId, Sled, Trampoline); } bool patchFunctionExit(const bool Enable, const uint32_t FuncId, @@ -110,3 +111,7 @@ bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; } } // namespace __xray + +extern "C" void __xray_ArgLoggerEntry() XRAY_NEVER_INSTRUMENT { + // FIXME: this will have to be implemented in the trampoline assembly file +} Index: compiler-rt/trunk/lib/xray/xray_arm.cc =================================================================== --- compiler-rt/trunk/lib/xray/xray_arm.cc +++ compiler-rt/trunk/lib/xray/xray_arm.cc @@ -128,8 +128,9 @@ } bool patchFunctionEntry(const bool Enable, const uint32_t FuncId, - const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { - return patchSled(Enable, FuncId, Sled, __xray_FunctionEntry); + const XRaySledEntry &Sled, + void (*Trampoline)()) XRAY_NEVER_INSTRUMENT { + return patchSled(Enable, FuncId, Sled, Trampoline); } bool patchFunctionExit(const bool Enable, const uint32_t FuncId, @@ -146,3 +147,7 @@ bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; } } // namespace __xray + +extern "C" void __xray_ArgLoggerEntry() XRAY_NEVER_INSTRUMENT { + // FIXME: this will have to be implemented in the trampoline assembly file +} Index: compiler-rt/trunk/lib/xray/xray_fdr_logging.cc =================================================================== --- compiler-rt/trunk/lib/xray/xray_fdr_logging.cc +++ compiler-rt/trunk/lib/xray/xray_fdr_logging.cc @@ -494,6 +494,7 @@ switch (Entry) { case XRayEntryType::ENTRY: + case XRayEntryType::LOG_ARGS_ENTRY: FuncRecord.RecordKind = uint8_t(FunctionRecord::RecordKinds::FunctionEnter); break; case XRayEntryType::EXIT: Index: compiler-rt/trunk/lib/xray/xray_interface.cc =================================================================== --- compiler-rt/trunk/lib/xray/xray_interface.cc +++ compiler-rt/trunk/lib/xray/xray_interface.cc @@ -48,6 +48,9 @@ // This is the function to call when we encounter the entry or exit sleds. std::atomic XRayPatchedFunction{nullptr}; +// This is the function to call from the arg1-enabled sleds/trampolines. +std::atomic XRayArgLogger{nullptr}; + // MProtectHelper is an RAII wrapper for calls to mprotect(...) that will undo // any successful mprotect(...) changes. This is used to make a page writeable // and executable, and upon destruction if it was successful in doing so returns @@ -185,7 +188,7 @@ bool Success = false; switch (Sled.Kind) { case XRayEntryType::ENTRY: - Success = patchFunctionEntry(Enable, FuncId, Sled); + Success = patchFunctionEntry(Enable, FuncId, Sled, __xray_FunctionEntry); break; case XRayEntryType::EXIT: Success = patchFunctionExit(Enable, FuncId, Sled); @@ -193,6 +196,9 @@ case XRayEntryType::TAIL: Success = patchFunctionTailExit(Enable, FuncId, Sled); break; + case XRayEntryType::LOG_ARGS_ENTRY: + Success = patchFunctionEntry(Enable, FuncId, Sled, __xray_ArgLoggerEntry); + break; default: Report("Unsupported sled kind: %d\n", int(Sled.Kind)); continue; @@ -211,3 +217,16 @@ XRayPatchingStatus __xray_unpatch() XRAY_NEVER_INSTRUMENT { return controlPatching(false); } + +int __xray_set_handler_arg1(void (*Handler)(int32_t, XRayEntryType, uint64_t)) +{ + if (!XRayInitialized.load(std::memory_order_acquire)) { + return 0; + } + // A relaxed write might not be visible even if the current thread gets + // scheduled on a different CPU/NUMA node. We need to wait for everyone to + // have this handler installed for consistency of collected data across CPUs. + XRayArgLogger.store(Handler, std::memory_order_release); + return 1; +} +int __xray_remove_handler_arg1() { return __xray_set_handler_arg1(nullptr); } Index: compiler-rt/trunk/lib/xray/xray_interface_internal.h =================================================================== --- compiler-rt/trunk/lib/xray/xray_interface_internal.h +++ compiler-rt/trunk/lib/xray/xray_interface_internal.h @@ -49,7 +49,7 @@ }; bool patchFunctionEntry(bool Enable, uint32_t FuncId, - const XRaySledEntry &Sled); + const XRaySledEntry &Sled, void (*Trampoline)()); bool patchFunctionExit(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled); bool patchFunctionTailExit(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled); @@ -62,6 +62,7 @@ extern void __xray_FunctionEntry(); extern void __xray_FunctionExit(); extern void __xray_FunctionTailExit(); +extern void __xray_ArgLoggerEntry(); } #endif Index: compiler-rt/trunk/lib/xray/xray_trampoline_x86_64.S =================================================================== --- compiler-rt/trunk/lib/xray/xray_trampoline_x86_64.S +++ compiler-rt/trunk/lib/xray/xray_trampoline_x86_64.S @@ -53,6 +53,9 @@ .text .file "xray_trampoline_x86.S" + +//===----------------------------------------------------------------------===// + .globl __xray_FunctionEntry .align 16, 0x90 .type __xray_FunctionEntry,@function @@ -81,6 +84,8 @@ .size __xray_FunctionEntry, .Ltmp1-__xray_FunctionEntry .cfi_endproc +//===----------------------------------------------------------------------===// + .globl __xray_FunctionExit .align 16, 0x90 .type __xray_FunctionExit,@function @@ -117,6 +122,8 @@ .size __xray_FunctionExit, .Ltmp3-__xray_FunctionExit .cfi_endproc +//===----------------------------------------------------------------------===// + .global __xray_FunctionTailExit .align 16, 0x90 .type __xray_FunctionTailExit,@function @@ -145,3 +152,39 @@ .Ltmp5: .size __xray_FunctionTailExit, .Ltmp5-__xray_FunctionTailExit .cfi_endproc + +//===----------------------------------------------------------------------===// + + .globl __xray_ArgLoggerEntry + .align 16, 0x90 + .type __xray_ArgLoggerEntry,@function +__xray_ArgLoggerEntry: + .cfi_startproc + pushq %rbp + .cfi_def_cfa_offset 16 + SAVE_REGISTERS + + // Again, these function pointer loads must be atomic; MOV is fine. + movq _ZN6__xray13XRayArgLoggerE(%rip), %rax + testq %rax, %rax + jne .Larg1entryLog + + // If [arg1 logging handler] not set, defer to no-arg logging. + movq _ZN6__xray19XRayPatchedFunctionE(%rip), %rax + testq %rax, %rax + je .Larg1entryFail + +.Larg1entryLog: + movq %rdi, %rdx // first argument will become the third + xorq %rsi, %rsi // XRayEntryType::ENTRY into the second + movl %r10d, %edi // 32-bit function ID becomes the first + callq *%rax + +.Larg1entryFail: + RESTORE_REGISTERS + popq %rbp + retq + +.Larg1entryEnd: + .size __xray_ArgLoggerEntry, .Larg1entryEnd-__xray_ArgLoggerEntry + .cfi_endproc Index: compiler-rt/trunk/lib/xray/xray_x86_64.cc =================================================================== --- compiler-rt/trunk/lib/xray/xray_x86_64.cc +++ compiler-rt/trunk/lib/xray/xray_x86_64.cc @@ -82,7 +82,8 @@ static constexpr int64_t MaxOffset{std::numeric_limits::max()}; bool patchFunctionEntry(const bool Enable, const uint32_t FuncId, - const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { + const XRaySledEntry &Sled, + void (*Trampoline)()) XRAY_NEVER_INSTRUMENT { // Here we do the dance of replacing the following sled: // // xray_sled_n: @@ -103,13 +104,12 @@ // 4. Do an atomic write over the jmp instruction for the "mov r10d" // opcode and first operand. // - // Prerequisite is to compute the relative offset to the - // __xray_FunctionEntry function's address. - int64_t TrampolineOffset = reinterpret_cast(__xray_FunctionEntry) - + // Prerequisite is to compute the relative offset to the trampoline's address. + int64_t TrampolineOffset = reinterpret_cast(Trampoline) - (static_cast(Sled.Address) + 11); if (TrampolineOffset < MinOffset || TrampolineOffset > MaxOffset) { Report("XRay Entry trampoline (%p) too far from sled (%p)\n", - __xray_FunctionEntry, reinterpret_cast(Sled.Address)); + Trampoline, reinterpret_cast(Sled.Address)); return false; } if (Enable) { Index: compiler-rt/trunk/test/xray/TestCases/Linux/arg1-logger.cc =================================================================== --- compiler-rt/trunk/test/xray/TestCases/Linux/arg1-logger.cc +++ compiler-rt/trunk/test/xray/TestCases/Linux/arg1-logger.cc @@ -0,0 +1,41 @@ +// Check that we can get the first function argument logged +// using a custom logging function. +// +// RUN: %clangxx_xray -std=c++11 %s -o %t +// RUN: XRAY_OPTIONS="patch_premain=true verbosity=1 xray_logfile_base=arg1-logger-" %run %t 2>&1 | FileCheck %s +// +// After all that, clean up the XRay log file. +// +// RUN: rm arg1-logger-* +// +// At the time of writing, the ARM trampolines weren't written yet. +// XFAIL: arm || aarch64 + +#include "xray/xray_interface.h" + +#include +#include + +void arg1logger(int32_t fn, XRayEntryType t, uint64_t a1) { + printf("Arg1: %" PRIx64 ", XRayEntryType %u\n", a1, t); +} + +[[clang::xray_always_instrument, clang::xray_log_args(1)]] void foo(void *) {} + +int main() { + // CHECK: XRay: Log file in 'arg1-logger-{{.*}}' + + __xray_set_handler_arg1(arg1logger); + foo(nullptr); + // CHECK: Arg1: 0, XRayEntryType 0 + + __xray_remove_handler_arg1(); + foo((void *) 0xBADC0DE); + // nothing expected to see here + + __xray_set_handler_arg1(arg1logger); + foo((void *) 0xDEADBEEFCAFE); + // CHECK-NEXT: Arg1: deadbeefcafe, XRayEntryType 0 + foo((void *) -1); + // CHECK-NEXT: Arg1: ffffffffffffffff, XRayEntryType 0 +}