diff --git a/libunwindstack/DwarfCfa.cpp b/libunwindstack/DwarfCfa.cpp index 4ba8a4b9b..c128b9bb7 100644 --- a/libunwindstack/DwarfCfa.cpp +++ b/libunwindstack/DwarfCfa.cpp @@ -204,7 +204,7 @@ template bool DwarfCfa::LogInstruction(uint32_t indent, uint64_t cfa_offset, uint8_t op, uint64_t* cur_pc) { const auto* cfa = &DwarfCfaInfo::kTable[op]; - if (cfa->name == nullptr) { + if (cfa->name[0] == '\0') { log(indent, "Illegal"); log(indent, "Raw Data: 0x%02x", op); return true; @@ -677,29 +677,29 @@ const DwarfCfaInfo::Info DwarfCfaInfo::kTable[64] = { {DW_EH_PE_uleb128, DW_EH_PE_block}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_EVAL_BLOCK}, }, - {nullptr, 0, 0, {}, {}}, // 0x17 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x18 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x19 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x1a illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x1b illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x1c DW_CFA_lo_user (Treat as illegal) - {nullptr, 0, 0, {}, {}}, // 0x1d illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x1e illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x1f illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x20 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x21 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x22 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x23 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x24 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x25 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x26 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x27 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x28 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x29 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x2a illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x2b illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x2c illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x2d DW_CFA_GNU_window_save (Treat as illegal) + {"", 0, 0, {}, {}}, // 0x17 illegal cfa + {"", 0, 0, {}, {}}, // 0x18 illegal cfa + {"", 0, 0, {}, {}}, // 0x19 illegal cfa + {"", 0, 0, {}, {}}, // 0x1a illegal cfa + {"", 0, 0, {}, {}}, // 0x1b illegal cfa + {"", 0, 0, {}, {}}, // 0x1c DW_CFA_lo_user (Treat as illegal) + {"", 0, 0, {}, {}}, // 0x1d illegal cfa + {"", 0, 0, {}, {}}, // 0x1e illegal cfa + {"", 0, 0, {}, {}}, // 0x1f illegal cfa + {"", 0, 0, {}, {}}, // 0x20 illegal cfa + {"", 0, 0, {}, {}}, // 0x21 illegal cfa + {"", 0, 0, {}, {}}, // 0x22 illegal cfa + {"", 0, 0, {}, {}}, // 0x23 illegal cfa + {"", 0, 0, {}, {}}, // 0x24 illegal cfa + {"", 0, 0, {}, {}}, // 0x25 illegal cfa + {"", 0, 0, {}, {}}, // 0x26 illegal cfa + {"", 0, 0, {}, {}}, // 0x27 illegal cfa + {"", 0, 0, {}, {}}, // 0x28 illegal cfa + {"", 0, 0, {}, {}}, // 0x29 illegal cfa + {"", 0, 0, {}, {}}, // 0x2a illegal cfa + {"", 0, 0, {}, {}}, // 0x2b illegal cfa + {"", 0, 0, {}, {}}, // 0x2c illegal cfa + {"", 0, 0, {}, {}}, // 0x2d DW_CFA_GNU_window_save (Treat as illegal) { "DW_CFA_GNU_args_size", // 0x2e DW_CFA_GNU_args_size 2, @@ -714,21 +714,21 @@ const DwarfCfaInfo::Info DwarfCfaInfo::kTable[64] = { {DW_EH_PE_uleb128, DW_EH_PE_uleb128}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_NUMBER}, }, - {nullptr, 0, 0, {}, {}}, // 0x31 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x32 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x33 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x34 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x35 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x36 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x37 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x38 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x39 illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x3a illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x3b illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x3c illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x3d illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x3e illegal cfa - {nullptr, 0, 0, {}, {}}, // 0x3f DW_CFA_hi_user (Treat as illegal) + {"", 0, 0, {}, {}}, // 0x31 illegal cfa + {"", 0, 0, {}, {}}, // 0x32 illegal cfa + {"", 0, 0, {}, {}}, // 0x33 illegal cfa + {"", 0, 0, {}, {}}, // 0x34 illegal cfa + {"", 0, 0, {}, {}}, // 0x35 illegal cfa + {"", 0, 0, {}, {}}, // 0x36 illegal cfa + {"", 0, 0, {}, {}}, // 0x37 illegal cfa + {"", 0, 0, {}, {}}, // 0x38 illegal cfa + {"", 0, 0, {}, {}}, // 0x39 illegal cfa + {"", 0, 0, {}, {}}, // 0x3a illegal cfa + {"", 0, 0, {}, {}}, // 0x3b illegal cfa + {"", 0, 0, {}, {}}, // 0x3c illegal cfa + {"", 0, 0, {}, {}}, // 0x3d illegal cfa + {"", 0, 0, {}, {}}, // 0x3e illegal cfa + {"", 0, 0, {}, {}}, // 0x3f DW_CFA_hi_user (Treat as illegal) }; // Explicitly instantiate DwarfCfa. diff --git a/libunwindstack/DwarfCfa.h b/libunwindstack/DwarfCfa.h index c5ffb8e89..569c17cef 100644 --- a/libunwindstack/DwarfCfa.h +++ b/libunwindstack/DwarfCfa.h @@ -49,7 +49,14 @@ class DwarfCfaInfo { }; struct Info { - const char* name; + // It may seem cleaner to just change the type of 'name' to 'const char *'. + // However, having a pointer here would require relocation at runtime, + // causing 'kTable' to be placed in data.rel.ro section instead of rodata + // section, adding memory pressure to the system. Note that this is only + // safe because this is only used in C++ code. C++ standard, unlike C + // standard, mandates the array size to be large enough to hold the NULL + // terminator when initialized with a string literal. + const char name[36]; uint8_t supported_version; uint8_t num_operands; uint8_t operands[2];