Implement working macOS backtrace symbolization

libraries/libstratosphere/source/diag/impl/diag_dump_stack_trace.os.generic.cpp

@@ -30,7 +30,7 @@ namespace ams::diag::impl {
             for (size_t i = 0; i < num_items; ++i) {
                 char symbol_name[0x200];
                 if (const uintptr_t symbol_base = ::ams::diag::GetSymbolName(symbol_name, sizeof(symbol_name), backtrace[i] - 1); symbol_base != 0) {
-                    AMS_SDK_LOG("0x%016" PRIX64 " [ %s+0x%" PRIX64 " ]\n", static_cast<u64>(backtrace[i]), symbol_name, static_cast<u64>(backtrace[i] - (symbol_base + 1)));
+                    AMS_SDK_LOG("0x%016" PRIX64 " [ %s+0x%" PRIX64 " ]\n", static_cast<u64>(backtrace[i]), symbol_name, static_cast<u64>(backtrace[i] - symbol_base));
                 } else {
                     AMS_SDK_LOG("0x%016" PRIX64 " [ unknown ]\n", static_cast<u64>(backtrace[i]));
                 }

libraries/libstratosphere/source/diag/impl/diag_symbol_impl.os.generic.cpp

@@ -263,13 +263,6 @@ namespace ams::diag::impl {
                             return;
                         }
                     }
-                    #elif defined(ATMOSPHERE_OS_MACOS)
-                    {
-                        if (_NSGetExecutablePath(dst, dst_size) != 0) {
-                            dst[0] = 0;
-                            return;
-                        }
-                    }
                     #else
                     #error "Unknown OS for BfdHelper GetExecutablePath"
                     #endif

libraries/libstratosphere/source/diag/impl/diag_symbol_impl.os.macos.cpp

@@ -16,18 +16,304 @@
 #include <stratosphere.hpp>
 #include "diag_symbol_impl.hpp"
 
+#include <unistd.h>
+#include <mach-o/dyld.h>
+#include <mach-o/loader.h>
+#include <mach-o/nlist.h>
+#include <mach-o/stab.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/param.h>
+#include <sys/mman.h>
+#include <cxxabi.h>
+
+
+extern "C" {
+
+    void __module_offset_helper() { /* ... */ }
+
+}
+
 namespace ams::diag::impl {
 
+    namespace {
+
+        class CurrentExecutableHelper {
+            private:
+                struct SymbolInfo {
+                    uintptr_t address;
+                    const char *name;
+                };
+            private:
+                os::NativeHandle m_fd;
+                void *m_file_map;
+                size_t m_file_size;
+                SymbolInfo *m_symbols;
+                size_t m_num_symbol;
+                const char *m_module_name;
+                uintptr_t m_module_address;
+                size_t m_module_size;
+                uintptr_t m_module_displacement;
+            private:
+                CurrentExecutableHelper() : m_fd(-1), m_file_map(nullptr), m_file_size(0), m_symbols(nullptr), m_num_symbol(0), m_module_name(nullptr), m_module_address(0), m_module_size(0), m_module_displacement(0) {
+                    /* Get the current executable name. */
+                    char exe_path[4_KB] = {};
+                    GetExecutablePath(exe_path, sizeof(exe_path));
+
+                    /* Open the current executable. */
+                    os::NativeHandle fd;
+                    do {
+                        fd = ::open(exe_path, O_RDONLY);
+                    } while (fd < 0 && errno == EINTR);
+                    if (fd < 0) {
+                        return;
+                    }
+                    ON_SCOPE_EXIT { if (fd >= 0) { s32 ret; do { ret = ::close(fd); } while (ret < 0 && errno == EINTR); } };
+
+                    /* Get the file size. */
+                    struct stat st;
+                    if (fstat(fd, std::addressof(st)) < 0) {
+                        return;
+                    }
+
+                    /* Check that the file can be mapped. */
+                    const size_t exe_size = st.st_size;
+                    if (exe_size == 0) {
+                        return;
+                    }
+
+                    /* Map the executable. */
+                    void *exe_map = mmap(nullptr, exe_size, PROT_READ, MAP_PRIVATE, fd, 0);
+                    if (exe_map == MAP_FAILED) {
+                        return;
+                    }
+                    ON_SCOPE_EXIT { if (exe_map != nullptr) { munmap(exe_map, exe_size); } };
+
+                    /* Get the file's u32 magic. */
+                    const uintptr_t exe_start = reinterpret_cast<uintptr_t>(exe_map);
+                    const u32 magic = *reinterpret_cast<const u32 *>(exe_start);
+
+                    /* Get/parse the mach header. */
+                    u32 ncmds;
+                    bool is_64;
+                    if (magic == MH_MAGIC) {
+                        const auto *header = reinterpret_cast<const struct mach_header *>(exe_start);
+                        ncmds       = header->ncmds;
+                        is_64       = false;
+                    } else if (magic == MH_MAGIC_64) {
+                        const auto *header = reinterpret_cast<const struct mach_header_64 *>(exe_start);
+                        ncmds       = header->ncmds;
+                        is_64       = true;
+                    } else {
+                        return;
+                    }
+
+                    /* Find the symbol load command. */
+                    const auto *lc = reinterpret_cast<const struct load_command *>(exe_start + (is_64 ? sizeof(struct mach_header_64) : sizeof(struct mach_header)));
+                    for (u32 i = 0; i < ncmds; ++i) {
+                        /* If we encounter the symbol table, parse it. */
+                        if (lc->cmd == LC_SYMTAB) {
+                            if (is_64) {
+                                this->ParseSymbolTable<struct nlist_64>(exe_start, reinterpret_cast<const struct symtab_command *>(lc));
+                            } else {
+
+                                this->ParseSymbolTable<struct nlist>(exe_start, reinterpret_cast<const struct symtab_command *>(lc));
+                            }
+                            break;
+                        } else if (lc->cmd == LC_SEGMENT) {
+                            const auto *sc = reinterpret_cast<const struct segment_command *>(lc);
+                            if (std::strcmp(sc->segname, "__TEXT") == 0) {
+                                AMS_ASSERT(m_module_address == 0);
+                                m_module_address = sc->vmaddr;
+                                m_module_size    = sc->vmsize;
+                                AMS_ASSERT(m_module_address != 0);
+                            }
+                        } else if (lc->cmd == LC_SEGMENT_64) {
+                            const auto *sc = reinterpret_cast<const struct segment_command_64 *>(lc);
+                            if (std::strcmp(sc->segname, "__TEXT") == 0) {
+                                AMS_ASSERT(m_module_address == 0);
+                                m_module_address = sc->vmaddr;
+                                m_module_size    = sc->vmsize;
+                                AMS_ASSERT(m_module_address != 0);
+                            }
+                        }
+
+                        /* Advance to the next load command. */
+                        lc = reinterpret_cast<const struct load_command *>(reinterpret_cast<uintptr_t>(lc) + lc->cmdsize);
+                    }
+
+                    for (size_t i = 0; i < m_num_symbol; ++i) {
+                        if (std::strcmp(m_symbols[i].name, "___module_offset_helper") == 0) {
+                            m_module_displacement = reinterpret_cast<uintptr_t>(&__module_offset_helper) - m_symbols[i].address;
+                            break;
+                        }
+                    }
+
+                    if (m_module_address > 0 && m_module_size > 0 && m_num_symbol > 0) {
+                        std::swap(m_fd, fd);
+                        std::swap(m_file_map, exe_map);
+                        m_file_size = exe_size;
+                    }
+                }
+
+                ~CurrentExecutableHelper() {
+                    if (m_file_map != nullptr) {
+                        munmap(m_file_map, m_file_size);
+                    }
+
+                    if (m_fd >= 0) {
+                        s32 ret;
+                        do { ret = ::close(m_fd); } while (ret < 0 && errno == EINTR);
+                    }
+                }
+            public:
+                static CurrentExecutableHelper &GetInstance() {
+                    AMS_FUNCTION_LOCAL_STATIC(CurrentExecutableHelper, s_current_executable_helper_instance);
+                    return s_current_executable_helper_instance;
+                }
+            private:
+                template<typename NlistType>
+                void ParseSymbolTable(uintptr_t exe_start, const struct symtab_command *c) {
+                    /* Check pre-conditions. */
+                    AMS_ASSERT(m_fd == -1);
+                    AMS_ASSERT(m_file_map == nullptr);
+                    AMS_ASSERT(m_symbols == nullptr);
+
+                    /* Get the strtab/symtab. */
+                    const auto *symtab = reinterpret_cast<const NlistType *>(exe_start + c->symoff);
+                    const char *strtab = reinterpret_cast<const char *>(exe_start + c->stroff);
+
+                    /* Determine the number of functions. */
+                    size_t funcs = 0;
+
+                    for (size_t i = 0; i < c->nsyms; ++i) {
+                        if (symtab[i].n_type != N_FUN || symtab[i].n_sect == NO_SECT) {
+                            continue;
+                        }
+
+                        ++funcs;
+                    }
+
+                    /* Allocate functions. */
+                    m_symbols = reinterpret_cast<SymbolInfo *>(std::malloc(sizeof(SymbolInfo) * funcs));
+                    if (m_symbols == nullptr) {
+                        return;
+                    }
+
+                    /* Set all symbols. */
+                    m_num_symbol = 0;
+                    for (size_t i = 0; i < c->nsyms; ++i) {
+                        if (symtab[i].n_type != N_FUN || symtab[i].n_sect == NO_SECT) {
+                            continue;
+                        }
+
+                        m_symbols[m_num_symbol].address = symtab[i].n_value;
+                        m_symbols[m_num_symbol].name    = strtab + symtab[i].n_un.n_strx;
+
+                        ++m_num_symbol;
+                    }
+                    AMS_ASSERT(m_num_symbol == funcs);
+
+                    /* Sort the symbols. */
+                    std::sort(m_symbols + 0, m_symbols + m_num_symbol, [] (const SymbolInfo &lhs, const SymbolInfo &rhs) {
+                        return lhs.address < rhs.address;
+                    });
+                }
+
+                size_t GetSymbolSizeImpl(const SymbolInfo *symbol) const {
+                    /* Do our best to guess. */
+                    if (symbol != m_symbols + m_num_symbol - 1) {
+                        return (symbol + 1)->address - symbol->address;
+                    } else if (m_module_address + m_module_size >= symbol->address) {
+                        return m_module_address + m_module_size - symbol->address;
+                    } else {
+                        return 0;
+                    }
+                }
+
+                const SymbolInfo *GetBestSymbol(uintptr_t address) const {
+                    address -= m_module_displacement;
+
+                    const SymbolInfo *best_symbol = std::lower_bound(m_symbols + 0, m_symbols + m_num_symbol, address, [](const SymbolInfo &lhs, uintptr_t rhs) {
+                        return lhs.address < rhs;
+                    });
+
+                    if (best_symbol == m_symbols + m_num_symbol) {
+                        return nullptr;
+                    }
+
+                    if (best_symbol->address != address && best_symbol > m_symbols) {
+                        --best_symbol;
+                    }
+
+                    const auto vma = best_symbol->address;
+                    const auto end = vma + this->GetSymbolSizeImpl(best_symbol);
+
+                    if (vma <= address && address < end) {
+                        return best_symbol;
+                    } else {
+                        return nullptr;
+                    }
+                }
+            public:
+                uintptr_t GetSymbolName(char *dst, size_t dst_size, uintptr_t address) const {
+                    if (m_fd < 0) {
+                        return 0;
+                    }
+
+                    /* Get the symbol. */
+                    const auto *symbol = this->GetBestSymbol(address);
+                    if (symbol == nullptr) {
+                        return 0;
+                    }
+
+                    /* Print the symbol. */
+                    const char *name = symbol->name;
+
+                    int cpp_name_status = 0;
+                    if (char *demangled = abi::__cxa_demangle(name, nullptr, 0, std::addressof(cpp_name_status)); cpp_name_status == 0) {
+                        AMS_ASSERT(demangled != nullptr);
+                        util::TSNPrintf(dst, dst_size, "%s", demangled);
+                        std::free(demangled);
+                    } else {
+                        util::TSNPrintf(dst, dst_size, "%s", name);
+                    }
+
+                    return symbol->address + m_module_displacement;
+                }
+
+                size_t GetSymbolSize(uintptr_t address) const {
+                    if (m_fd < 0) {
+                        return 0;
+                    }
+
+                    /* Get the symbol. */
+                    const auto *symbol = this->GetBestSymbol(address);
+                    if (symbol == nullptr) {
+                        return 0;
+                    }
+
+                    return this->GetSymbolSizeImpl(symbol);
+                }
+            private:
+                static void GetExecutablePath(char *dst, size_t dst_size) {
+                    u32 len = dst_size;
+                    if (_NSGetExecutablePath(dst, std::addressof(len)) != 0) {
+                        dst[0] = 0;
+                        return;
+                    }
+                }
+        };
+
+    }
+
     uintptr_t GetSymbolNameImpl(char *dst, size_t dst_size, uintptr_t address) {
-        /* TODO: How should we do this on macOS? */
+        return CurrentExecutableHelper::GetInstance().GetSymbolName(dst, dst_size, address);
-        AMS_UNUSED(dst, dst_size, address);
-        return 0;
     }
 
     size_t GetSymbolSizeImpl(uintptr_t address) {
-        /* TODO: How should we do this on macOS? */
+        return CurrentExecutableHelper::GetInstance().GetSymbolSize(address);
-        AMS_UNUSED(address);
-        return 0;
     }
 
 }