198 lines · cpp
1// SPDX-License-Identifier: GPL-2.02 3/*4 * Must come before the linux/compiler.h include, which defines several5 * macros (e.g. noinline) that conflict with compiler builtins used6 * by LLVM.7 */8#pragma GCC diagnostic push9#pragma GCC diagnostic ignored "-Wunused-parameter" /* Needed for LLVM <= 15 */10#include <llvm/DebugInfo/Symbolize/Symbolize.h>11#include <llvm/Support/TargetSelect.h>12#pragma GCC diagnostic pop13 14#include <inttypes.h>15#include <stdio.h>16#include <sys/types.h>17#include <linux/compiler.h>18extern "C" {19#include <linux/zalloc.h>20}21#include "symbol_conf.h"22#include "llvm-c-helpers.h"23 24extern "C"25char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name);26 27using namespace llvm;28using llvm::symbolize::LLVMSymbolizer;29 30/*31 * Allocate a static LLVMSymbolizer, which will live to the end of the program.32 * Unlike the bfd paths, LLVMSymbolizer has its own cache, so we do not need33 * to store anything in the dso struct.34 */35static LLVMSymbolizer *get_symbolizer()36{37 static LLVMSymbolizer *instance = nullptr;38 if (instance == nullptr) {39 LLVMSymbolizer::Options opts;40 /*41 * LLVM sometimes demangles slightly different from the rest42 * of the code, and this mismatch can cause new_inline_sym()43 * to get confused and mark non-inline symbol as inlined44 * (since the name does not properly match up with base_sym).45 * Thus, disable the demangling and let the rest of the code46 * handle it.47 */48 opts.Demangle = false;49 instance = new LLVMSymbolizer(opts);50 }51 return instance;52}53 54/* Returns 0 on error, 1 on success. */55static int extract_file_and_line(const DILineInfo &line_info, char **file,56 unsigned int *line)57{58 if (file) {59 if (line_info.FileName == "<invalid>") {60 /* Match the convention of libbfd. */61 *file = nullptr;62 } else {63 /* The caller expects to get something it can free(). */64 *file = strdup(line_info.FileName.c_str());65 if (*file == nullptr)66 return 0;67 }68 }69 if (line)70 *line = line_info.Line;71 return 1;72}73 74extern "C"75int llvm_addr2line(const char *dso_name, u64 addr,76 char **file, unsigned int *line,77 bool unwind_inlines,78 llvm_a2l_frame **inline_frames)79{80 LLVMSymbolizer *symbolizer = get_symbolizer();81 object::SectionedAddress sectioned_addr = {82 addr,83 object::SectionedAddress::UndefSection84 };85 86 if (unwind_inlines) {87 Expected<DIInliningInfo> res_or_err =88 symbolizer->symbolizeInlinedCode(dso_name,89 sectioned_addr);90 if (!res_or_err)91 return 0;92 unsigned num_frames = res_or_err->getNumberOfFrames();93 if (num_frames == 0)94 return 0;95 96 if (extract_file_and_line(res_or_err->getFrame(0),97 file, line) == 0)98 return 0;99 100 *inline_frames = (llvm_a2l_frame *)calloc(101 num_frames, sizeof(**inline_frames));102 if (*inline_frames == nullptr)103 return 0;104 105 for (unsigned i = 0; i < num_frames; ++i) {106 const DILineInfo &src = res_or_err->getFrame(i);107 108 llvm_a2l_frame &dst = (*inline_frames)[i];109 if (src.FileName == "<invalid>")110 /* Match the convention of libbfd. */111 dst.filename = nullptr;112 else113 dst.filename = strdup(src.FileName.c_str());114 dst.funcname = strdup(src.FunctionName.c_str());115 dst.line = src.Line;116 117 if (dst.filename == nullptr ||118 dst.funcname == nullptr) {119 for (unsigned j = 0; j <= i; ++j) {120 zfree(&(*inline_frames)[j].filename);121 zfree(&(*inline_frames)[j].funcname);122 }123 zfree(inline_frames);124 return 0;125 }126 }127 128 return num_frames;129 } else {130 if (inline_frames)131 *inline_frames = nullptr;132 133 Expected<DILineInfo> res_or_err =134 symbolizer->symbolizeCode(dso_name, sectioned_addr);135 if (!res_or_err)136 return 0;137 return extract_file_and_line(*res_or_err, file, line);138 }139}140 141static char *142make_symbol_relative_string(struct dso *dso, const char *sym_name,143 u64 addr, u64 base_addr)144{145 if (!strcmp(sym_name, "<invalid>"))146 return NULL;147 148 char *demangled = dso__demangle_sym(dso, 0, sym_name);149 if (base_addr && base_addr != addr) {150 char buf[256];151 snprintf(buf, sizeof(buf), "%s+0x%" PRIx64,152 demangled ? demangled : sym_name, addr - base_addr);153 free(demangled);154 return strdup(buf);155 } else {156 if (demangled)157 return demangled;158 else159 return strdup(sym_name);160 }161}162 163extern "C"164char *llvm_name_for_code(struct dso *dso, const char *dso_name, u64 addr)165{166 LLVMSymbolizer *symbolizer = get_symbolizer();167 object::SectionedAddress sectioned_addr = {168 addr,169 object::SectionedAddress::UndefSection170 };171 Expected<DILineInfo> res_or_err =172 symbolizer->symbolizeCode(dso_name, sectioned_addr);173 if (!res_or_err) {174 return NULL;175 }176 return make_symbol_relative_string(177 dso, res_or_err->FunctionName.c_str(),178 addr, res_or_err->StartAddress ? *res_or_err->StartAddress : 0);179}180 181extern "C"182char *llvm_name_for_data(struct dso *dso, const char *dso_name, u64 addr)183{184 LLVMSymbolizer *symbolizer = get_symbolizer();185 object::SectionedAddress sectioned_addr = {186 addr,187 object::SectionedAddress::UndefSection188 };189 Expected<DIGlobal> res_or_err =190 symbolizer->symbolizeData(dso_name, sectioned_addr);191 if (!res_or_err) {192 return NULL;193 }194 return make_symbol_relative_string(195 dso, res_or_err->Name.c_str(),196 addr, res_or_err->Start);197}198