diff options
Diffstat (limited to 'lib/sanitizer_common/sanitizer_symbolizer_linux_libcdep.cc')
| -rw-r--r-- | lib/sanitizer_common/sanitizer_symbolizer_linux_libcdep.cc | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/lib/sanitizer_common/sanitizer_symbolizer_linux_libcdep.cc b/lib/sanitizer_common/sanitizer_symbolizer_linux_libcdep.cc new file mode 100644 index 000000000000..82ce50e0aacb --- /dev/null +++ b/lib/sanitizer_common/sanitizer_symbolizer_linux_libcdep.cc @@ -0,0 +1,227 @@ +//===-- sanitizer_symbolizer_linux_libcdep.cc -----------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file is shared between AddressSanitizer and ThreadSanitizer +// run-time libraries. +// Linux-specific implementation of symbolizer parts. +//===----------------------------------------------------------------------===// + +#include "sanitizer_platform.h" +#if SANITIZER_LINUX +#include "sanitizer_common.h" +#include "sanitizer_internal_defs.h" +#include "sanitizer_libc.h" +#include "sanitizer_placement_new.h" +#include "sanitizer_symbolizer.h" + +// Android NDK r8e elf.h depends on stdint.h without including the latter. +#include <stdint.h> + +#include <elf.h> +#include <errno.h> +#include <poll.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> + +#if !SANITIZER_ANDROID +#include <link.h> +#endif + +namespace __sanitizer { + +static const int kSymbolizerStartupTimeMillis = 10; + +bool StartSymbolizerSubprocess(const char *path_to_symbolizer, + int *input_fd, int *output_fd) { + if (!FileExists(path_to_symbolizer)) { + Report("WARNING: invalid path to external symbolizer!\n"); + return false; + } + + int *infd = NULL; + int *outfd = NULL; + // The client program may close its stdin and/or stdout and/or stderr + // thus allowing socketpair to reuse file descriptors 0, 1 or 2. + // In this case the communication between the forked processes may be + // broken if either the parent or the child tries to close or duplicate + // these descriptors. The loop below produces two pairs of file + // descriptors, each greater than 2 (stderr). + int sock_pair[5][2]; + for (int i = 0; i < 5; i++) { + if (pipe(sock_pair[i]) == -1) { + for (int j = 0; j < i; j++) { + internal_close(sock_pair[j][0]); + internal_close(sock_pair[j][1]); + } + Report("WARNING: Can't create a socket pair to start " + "external symbolizer (errno: %d)\n", errno); + return false; + } else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) { + if (infd == NULL) { + infd = sock_pair[i]; + } else { + outfd = sock_pair[i]; + for (int j = 0; j < i; j++) { + if (sock_pair[j] == infd) continue; + internal_close(sock_pair[j][0]); + internal_close(sock_pair[j][1]); + } + break; + } + } + } + CHECK(infd); + CHECK(outfd); + + int pid = fork(); + if (pid == -1) { + // Fork() failed. + internal_close(infd[0]); + internal_close(infd[1]); + internal_close(outfd[0]); + internal_close(outfd[1]); + Report("WARNING: failed to fork external symbolizer " + " (errno: %d)\n", errno); + return false; + } else if (pid == 0) { + // Child subprocess. + internal_close(STDOUT_FILENO); + internal_close(STDIN_FILENO); + internal_dup2(outfd[0], STDIN_FILENO); + internal_dup2(infd[1], STDOUT_FILENO); + internal_close(outfd[0]); + internal_close(outfd[1]); + internal_close(infd[0]); + internal_close(infd[1]); + for (int fd = getdtablesize(); fd > 2; fd--) + internal_close(fd); + execl(path_to_symbolizer, path_to_symbolizer, (char*)0); + internal__exit(1); + } + + // Continue execution in parent process. + internal_close(outfd[0]); + internal_close(infd[1]); + *input_fd = infd[0]; + *output_fd = outfd[1]; + + // Check that symbolizer subprocess started successfully. + int pid_status; + SleepForMillis(kSymbolizerStartupTimeMillis); + int exited_pid = waitpid(pid, &pid_status, WNOHANG); + if (exited_pid != 0) { + // Either waitpid failed, or child has already exited. + Report("WARNING: external symbolizer didn't start up correctly!\n"); + return false; + } + + return true; +} + +#if SANITIZER_ANDROID +uptr GetListOfModules(LoadedModule *modules, uptr max_modules, + string_predicate_t filter) { + return 0; +} + +void SymbolizerPrepareForSandboxing() { + // Do nothing on Android. +} +#else // SANITIZER_ANDROID +typedef ElfW(Phdr) Elf_Phdr; + +struct DlIteratePhdrData { + LoadedModule *modules; + uptr current_n; + bool first; + uptr max_n; + string_predicate_t filter; +}; + +static const uptr kMaxPathLength = 512; + +static char proc_self_exe_cache_str[kMaxPathLength]; +static uptr proc_self_exe_cache_len = 0; + +static uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) { + uptr module_name_len = internal_readlink( + "/proc/self/exe", buf, buf_len); + int readlink_error; + if (internal_iserror(buf_len, &readlink_error)) { + if (proc_self_exe_cache_len) { + // If available, use the cached module name. + CHECK_LE(proc_self_exe_cache_len, buf_len); + internal_strncpy(buf, proc_self_exe_cache_str, buf_len); + module_name_len = internal_strlen(proc_self_exe_cache_str); + } else { + // We can't read /proc/self/exe for some reason, assume the name of the + // binary is unknown. + Report("WARNING: readlink(\"/proc/self/exe\") failed with errno %d, " + "some stack frames may not be symbolized\n", readlink_error); + module_name_len = internal_snprintf(buf, buf_len, "/proc/self/exe"); + } + CHECK_LT(module_name_len, buf_len); + buf[module_name_len] = '\0'; + } + return module_name_len; +} + +static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { + DlIteratePhdrData *data = (DlIteratePhdrData*)arg; + if (data->current_n == data->max_n) + return 0; + InternalScopedBuffer<char> module_name(kMaxPathLength); + module_name.data()[0] = '\0'; + if (data->first) { + data->first = false; + // First module is the binary itself. + ReadBinaryName(module_name.data(), module_name.size()); + } else if (info->dlpi_name) { + internal_strncpy(module_name.data(), info->dlpi_name, module_name.size()); + } + if (module_name.data()[0] == '\0') + return 0; + if (data->filter && !data->filter(module_name.data())) + return 0; + void *mem = &data->modules[data->current_n]; + LoadedModule *cur_module = new(mem) LoadedModule(module_name.data(), + info->dlpi_addr); + data->current_n++; + for (int i = 0; i < info->dlpi_phnum; i++) { + const Elf_Phdr *phdr = &info->dlpi_phdr[i]; + if (phdr->p_type == PT_LOAD) { + uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; + uptr cur_end = cur_beg + phdr->p_memsz; + cur_module->addAddressRange(cur_beg, cur_end); + } + } + return 0; +} + +uptr GetListOfModules(LoadedModule *modules, uptr max_modules, + string_predicate_t filter) { + CHECK(modules); + DlIteratePhdrData data = {modules, 0, true, max_modules, filter}; + dl_iterate_phdr(dl_iterate_phdr_cb, &data); + return data.current_n; +} + +void SymbolizerPrepareForSandboxing() { + if (!proc_self_exe_cache_len) { + proc_self_exe_cache_len = + ReadBinaryName(proc_self_exe_cache_str, kMaxPathLength); + } +} +#endif // SANITIZER_ANDROID + +} // namespace __sanitizer + +#endif // SANITIZER_LINUX |