diff options
Diffstat (limited to 'tools/jprof/bfd.cpp')
| -rw-r--r-- | tools/jprof/bfd.cpp | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/tools/jprof/bfd.cpp b/tools/jprof/bfd.cpp new file mode 100644 index 0000000000..6be8fde760 --- /dev/null +++ b/tools/jprof/bfd.cpp @@ -0,0 +1,221 @@ +// vim:ts=8:sw=2:et: +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "leaky.h" + +#ifdef USE_BFD +# include <stdio.h> +# include <string.h> +# include <fcntl.h> +# include <unistd.h> +# include <libgen.h> +# include <bfd.h> +# include <cxxabi.h> + +static bfd* try_debug_file(const char* filename, unsigned long crc32) { + int fd = open(filename, O_RDONLY); + if (fd < 0) return nullptr; + + unsigned char buf[4 * 1024]; + unsigned long crc = 0; + + while (1) { + ssize_t count = read(fd, buf, sizeof(buf)); + if (count <= 0) break; + + crc = bfd_calc_gnu_debuglink_crc32(crc, buf, count); + } + + close(fd); + + if (crc != crc32) return nullptr; + + bfd* object = bfd_openr(filename, nullptr); + if (!bfd_check_format(object, bfd_object)) { + bfd_close(object); + return nullptr; + } + + return object; +} + +static bfd* find_debug_file(bfd* lib, const char* aFileName) { + // check for a separate debug file with symbols + asection* sect = bfd_get_section_by_name(lib, ".gnu_debuglink"); + + if (!sect) return nullptr; + + bfd_size_type debuglinkSize = bfd_section_size(objfile->obfd, sect); + + char* debuglink = new char[debuglinkSize]; + bfd_get_section_contents(lib, sect, debuglink, 0, debuglinkSize); + + // crc checksum is aligned to 4 bytes, and after the NUL. + int crc_offset = (int(strlen(debuglink)) & ~3) + 4; + unsigned long crc32 = bfd_get_32(lib, debuglink + crc_offset); + + // directory component + char* dirbuf = strdup(aFileName); + const char* dir = dirname(dirbuf); + + static const char debug_subdir[] = ".debug"; + // This is gdb's default global debugging info directory, but gdb can + // be instructed to use a different directory. + static const char global_debug_dir[] = "/usr/lib/debug"; + + char* filename = + new char[strlen(global_debug_dir) + strlen(dir) + crc_offset + 3]; + + // /path/debuglink + sprintf(filename, "%s/%s", dir, debuglink); + bfd* debugFile = try_debug_file(filename, crc32); + if (!debugFile) { + // /path/.debug/debuglink + sprintf(filename, "%s/%s/%s", dir, debug_subdir, debuglink); + debugFile = try_debug_file(filename, crc32); + if (!debugFile) { + // /usr/lib/debug/path/debuglink + sprintf(filename, "%s/%s/%s", global_debug_dir, dir, debuglink); + debugFile = try_debug_file(filename, crc32); + } + } + + delete[] filename; + free(dirbuf); + delete[] debuglink; + + return debugFile; +} + +// Use an indirect array to avoid copying tons of objects +Symbol** leaky::ExtendSymbols(int num) { + long n = numExternalSymbols + num; + + externalSymbols = (Symbol**)realloc(externalSymbols, + (size_t)(sizeof(externalSymbols[0]) * n)); + Symbol* new_array = new Symbol[n]; + for (int i = 0; i < num; i++) { + externalSymbols[i + numExternalSymbols] = &new_array[i]; + } + lastSymbol = externalSymbols + n; + Symbol** sp = externalSymbols + numExternalSymbols; + numExternalSymbols = n; + return sp; +} + +# define NEXT_SYMBOL \ + do { \ + sp++; \ + if (sp >= lastSymbol) { \ + sp = ExtendSymbols(16384); \ + } \ + } while (0) + +void leaky::ReadSymbols(const char* aFileName, u_long aBaseAddress) { + int initialSymbols = usefulSymbols; + if (nullptr == externalSymbols) { + externalSymbols = (Symbol**)calloc(sizeof(Symbol*), 10000); + Symbol* new_array = new Symbol[10000]; + for (int i = 0; i < 10000; i++) { + externalSymbols[i] = &new_array[i]; + } + numExternalSymbols = 10000; + } + Symbol** sp = externalSymbols + usefulSymbols; + lastSymbol = externalSymbols + numExternalSymbols; + + // Create a dummy symbol for the library so, if it doesn't have any + // symbols, we show it by library. + (*sp)->Init(aFileName, aBaseAddress); + NEXT_SYMBOL; + + bfd_boolean kDynamic = (bfd_boolean) false; + + static int firstTime = 1; + if (firstTime) { + firstTime = 0; + bfd_init(); + } + + bfd* lib = bfd_openr(aFileName, nullptr); + if (nullptr == lib) { + return; + } + if (!bfd_check_format(lib, bfd_object)) { + bfd_close(lib); + return; + } + + bfd* symbolFile = find_debug_file(lib, aFileName); + + // read mini symbols + PTR minisyms; + unsigned int size; + long symcount = 0; + + if (symbolFile) { + symcount = bfd_read_minisymbols(symbolFile, kDynamic, &minisyms, &size); + if (symcount == 0) { + bfd_close(symbolFile); + } else { + bfd_close(lib); + } + } + if (symcount == 0) { + symcount = bfd_read_minisymbols(lib, kDynamic, &minisyms, &size); + if (symcount == 0) { + // symtab is empty; try dynamic symbols + kDynamic = (bfd_boolean) true; + symcount = bfd_read_minisymbols(lib, kDynamic, &minisyms, &size); + } + symbolFile = lib; + } + + asymbol* store; + store = bfd_make_empty_symbol(symbolFile); + + // Scan symbols + size_t demangle_buffer_size = 128; + char* demangle_buffer = (char*)malloc(demangle_buffer_size); + bfd_byte* from = (bfd_byte*)minisyms; + bfd_byte* fromend = from + symcount * size; + for (; from < fromend; from += size) { + asymbol* sym; + sym = + bfd_minisymbol_to_symbol(symbolFile, kDynamic, (const PTR)from, store); + + symbol_info syminfo; + bfd_get_symbol_info(symbolFile, sym, &syminfo); + + // if ((syminfo.type == 'T') || (syminfo.type == 't')) { + const char* nm = bfd_asymbol_name(sym); + if (nm && nm[0]) { + char* dnm = nullptr; + if (strncmp("__thunk", nm, 7)) { + dnm = + abi::__cxa_demangle(nm, demangle_buffer, &demangle_buffer_size, 0); + if (dnm) { + demangle_buffer = dnm; + } + } + (*sp)->Init(dnm ? dnm : nm, syminfo.value + aBaseAddress); + NEXT_SYMBOL; + } + // } + } + + free(demangle_buffer); + demangle_buffer = nullptr; + + bfd_close(symbolFile); + + int interesting = sp - externalSymbols; + if (!quiet) { + printf("%s provided %d symbols\n", aFileName, interesting - initialSymbols); + } + usefulSymbols = interesting; +} + +#endif /* USE_BFD */ |