diff options
Diffstat (limited to 'app/perfsymboltable.cpp')
| -rw-r--r-- | app/perfsymboltable.cpp | 230 |
1 files changed, 158 insertions, 72 deletions
diff --git a/app/perfsymboltable.cpp b/app/perfsymboltable.cpp index 445528c..3bc68bc 100644 --- a/app/perfsymboltable.cpp +++ b/app/perfsymboltable.cpp @@ -32,6 +32,7 @@ #include <QDir> #include <QStack> +#include <tuple> #include <cstring> #include <fcntl.h> @@ -598,6 +599,150 @@ PerfElfMap::ElfInfo PerfSymbolTable::findElf(quint64 ip) const return m_elfs.findElf(ip); } +struct AddrRange +{ + Dwarf_Addr low = 0; + Dwarf_Addr high = 0; + + void setMinMax(const AddrRange range) + { + if (range.low && (low == 0 || low > range.low)) + low = range.low; + if (range.high && (high == 0 || high < range.high)) + high = range.high; + } + + bool contains(Dwarf_Addr addr) const + { + return low <= addr && addr < high; + } + + bool operator<(const AddrRange &rhs) const + { + return std::tie(low, high) < std::tie(rhs.low, high); + } +}; +Q_DECLARE_TYPEINFO(AddrRange, Q_MOVABLE_TYPE); + +struct DieRangeMap +{ + DieRangeMap(Dwarf_Die *die = nullptr, Dwarf_Addr bias = 0) + : die(die) + , bias(bias) + { + if (die) + gatherRanges(die, bias); + } + + bool contains(Dwarf_Addr addr) const + { + if (!range.contains(addr)) + return false; + return std::any_of(ranges.begin(), ranges.end(), + [addr](AddrRange range) { + return range.contains(addr); + }); + } + + bool operator<(const DieRangeMap &rhs) const + { + return range < rhs.range; + } + + Dwarf_Die *die = nullptr; + AddrRange range; // may be non-continuous, but allows quick checks and sorting + QVector<AddrRange> ranges; + Dwarf_Addr bias; + +private: + void gatherRanges(Dwarf_Die *parent_die, Dwarf_Addr bias) + { + Dwarf_Die die; + if (dwarf_child(parent_die, &die) != 0) + return; + + do { + switch (dwarf_tag(&die)) { + case DW_TAG_subprogram: + case DW_TAG_inlined_subroutine: + addRanges(&die, bias); + break; + }; + bool declaration = false; + Dwarf_Attribute attr_mem; + dwarf_formflag(dwarf_attr(&die, DW_AT_declaration, &attr_mem), &declaration); + if (!declaration) { + // let's be curious and look deeper in the tree, + // function are not necessarily at the first level, but + // might be nested inside a namespace, structure etc. + gatherRanges(&die, bias); + } + } while (dwarf_siblingof(&die, &die) == 0); + } + + void addRanges(Dwarf_Die *die, Dwarf_Addr bias) + { + Dwarf_Addr low = 0, high = 0; + Dwarf_Addr base = 0; + ptrdiff_t offset = 0; + while ((offset = dwarf_ranges(die, offset, &base, &low, &high)) > 0) { + addRange(low, high, bias); + } + } + + void addRange(Dwarf_Addr low, Dwarf_Addr high, Dwarf_Addr bias) + { + AddrRange ret; + ret.low = low + bias; + ret.high = high + bias; + range.setMinMax(ret); + ranges.push_back(ret); + } +}; +Q_DECLARE_TYPEINFO(DieRangeMap, Q_MOVABLE_TYPE); + +class DieRangeMaps +{ +public: + DieRangeMaps(Dwfl_Module *mod = nullptr) + { + if (!mod) + return; + + Dwarf_Die *die = nullptr; + Dwarf_Addr bias = 0; + while ((die = dwfl_module_nextcu(mod, die, &bias))) { + DieRangeMap map(die, bias); + if (map.range.low == 0 && map.range.high == 0) { + // no range entries, skip + continue; + } + range.setMinMax(map.range); + maps.push_back(std::move(map)); + } + } + + Dwarf_Die *findDie(Dwarf_Addr addr, Dwarf_Addr *bias) const + { + if (!range.contains(addr)) + return nullptr; + + auto it = std::find_if(maps.begin(), maps.end(), + [addr](const DieRangeMap &map) { + return map.contains(addr); + }); + if (it == maps.end()) + return nullptr; + + *bias = it->bias; + return it->die; + } +public: + AddrRange range; // may be non-continuous, but allows quick checks + QVector<DieRangeMap> maps; +}; +Q_DECLARE_TYPEINFO(DieRangeMaps, Q_MOVABLE_TYPE); + int symbolIndex(const Elf64_Rel &rel) { return ELF64_R_SYM(rel.r_info); @@ -771,77 +916,6 @@ static QByteArray fakeSymbolFromSection(Dwfl_Module *mod, Dwarf_Addr addr) return sym; } -// based on MIT licensed https://github.com/bombela/backward-cpp -static bool die_has_pc(Dwarf_Die* die, Dwarf_Addr pc) -{ - Dwarf_Addr low, high; - - // continuous range - if (dwarf_hasattr(die, DW_AT_low_pc) && dwarf_hasattr(die, DW_AT_high_pc)) { - if (dwarf_lowpc(die, &low) != 0) - return false; - if (dwarf_highpc(die, &high) != 0) { - Dwarf_Attribute attr_mem; - Dwarf_Attribute* attr = dwarf_attr(die, DW_AT_high_pc, &attr_mem); - Dwarf_Word value; - if (dwarf_formudata(attr, &value) != 0) - return false; - high = low + value; - } - return pc >= low && pc < high; - } - - // non-continuous range. - Dwarf_Addr base; - ptrdiff_t offset = 0; - while ((offset = dwarf_ranges(die, offset, &base, &low, &high)) > 0) { - if (pc >= low && pc < high) - return true; - } - return false; -} - -static bool find_fundie_by_pc(Dwarf_Die* parent_die, Dwarf_Addr pc) -{ - Dwarf_Die die; - if (dwarf_child(parent_die, &die) != 0) - return false; - - do { - switch (dwarf_tag(&die)) { - case DW_TAG_subprogram: - case DW_TAG_inlined_subroutine: - if (die_has_pc(&die, pc)) - return true; - }; - bool declaration = false; - Dwarf_Attribute attr_mem; - dwarf_formflag(dwarf_attr(&die, DW_AT_declaration, &attr_mem), &declaration); - if (!declaration) { - // let's be curious and look deeper in the tree, - // function are not necessarily at the first level, but - // might be nested inside a namespace, structure etc. - if (find_fundie_by_pc(&die, pc)) - return true; - } - } while (dwarf_siblingof(&die, &die) == 0); - return false; -} - -Dwarf_Die *find_die(Dwfl_Module *mod, Dwarf_Addr addr, Dwarf_Addr *bias) -{ - auto die = dwfl_module_addrdie(mod, addr, bias); - if (die) - return die; - - while ((die = dwfl_module_nextcu(mod, die, bias))) { - if (find_fundie_by_pc(die, addr - *bias)) - return die; - } - - return nullptr; -} - int PerfSymbolTable::lookupFrame(Dwarf_Addr ip, bool isKernel, bool *isInterworking) { @@ -883,7 +957,18 @@ int PerfSymbolTable::lookupFrame(Dwarf_Addr ip, bool isKernel, } else { Dwarf_Addr bias = 0; functionLocation.address -= off; // in case we don't find anything better - Dwarf_Die *die = find_die(mod, addressLocation.address, &bias); + + auto die = dwfl_module_addrdie(mod, addressLocation.address, &bias); + if (!die) { + // broken DWARF emitter by clang, e.g. no aranges + // cf.: https://sourceware.org/ml/elfutils-devel/2017-q2/msg00180.html + // build a custom lookup table and query that one + if (!m_dieRangeMaps.contains(mod)) { + m_dieRangeMaps[mod] = DieRangeMaps(mod); + } + const auto& maps = m_dieRangeMaps[mod]; + die = maps.findDie(addressLocation.address, &bias); + } if (die) { auto srcloc = dwarf_getsrc_die(die, addressLocation.address - bias); @@ -1036,6 +1121,7 @@ Dwfl *PerfSymbolTable::attachDwfl(void *arg) void PerfSymbolTable::clearCache() { m_addressCache.clearInvalid(); + m_dieRangeMaps.clear(); m_perfMap.clear(); if (m_perfMapFile.isOpen()) m_perfMapFile.reset(); |