[Sanitizers] Introduce GET_LINK_MAP_BY_DLOPEN_HANDLE() macro

[samsonov]

lib/sanitizer_common/sanitizer_linux.cc

809

Looks like you need a named constant for 544 (maybe, in sanitizer_platform_limits_posix.h). Is it possible to calculate it in sanitizer_platform_limits_posix.cc by using offsetof() ?

[kutuzov.viktor.84]

Reworked. Thanks.

[kutuzov.viktor.84]

Is it possible to calculate it in sanitizer_platform_limits_posix.cc by using offsetof() ?

The Obj_Entry structure is defined in rtld's internals and have a lot of members so it doesn't seem reasonable to replicate its definition in sanitizers sources.

lib/sanitizer_common/sanitizer_common_interceptors.inc

88

Should these macros expand into do {} while(0)?

[eugenis]

Looks ok.

lib/sanitizer_common/sanitizer_common_interceptors.inc

88

They could.

lib/asan/asan_interceptors.cc

 // But asan does not remember UserId's for threads (pthread_t);
 // and remembers all ever existed threads, so the linear search by UserId
 // can be slow.
 #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
   do {                                                         \
   } while (false)
 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)
 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
-#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, res) CoverageUpdateMapping()
+#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle) \
+  CoverageUpdateMapping()
 #define COMMON_INTERCEPTOR_LIBRARY_UNLOADED() CoverageUpdateMapping()
 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (!asan_inited)
 #include "sanitizer_common/sanitizer_common_interceptors.inc"
 
 // Syscall interceptors don't have contexts, we don't support suppressions
 // for them.
 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) ASAN_READ_RANGE(nullptr, p, s)
 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) ASAN_WRITE_RANGE(nullptr, p, s)

lib/dfsan/dfsan_custom.cc

 }
 
 // dlopen() ultimately calls mmap() down inside the loader, which generally
 // doesn't participate in dynamic symbol resolution.  Therefore we won't
 // intercept its calls to mmap, and we have to hook it here.
 SANITIZER_INTERFACE_ATTRIBUTE void *
 __dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label,
               dfsan_label flag_label, dfsan_label *ret_label) {
-  link_map *map = (link_map *)dlopen(filename, flag);
+  void *handle = dlopen(filename, flag);
+  link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE(handle);
   if (map)
     ForEachMappedRegion(map, unpoison);
   *ret_label = 0;
-  return (void *)map;
+  return handle;
 }
 
 struct pthread_create_info {
   void *(*start_routine_trampoline)(void *, void *, dfsan_label, dfsan_label *);
   void *start_routine;
   void *arg;
 };
 

lib/msan/msan_interceptors.cc

 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \
   do {                                                \
   } while (false)  // FIXME
 #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
   do {                                                         \
   } while (false)  // FIXME
 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)
 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
-#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, map) \
-  if (map) ForEachMappedRegion((link_map *)map, __msan_unpoison);
+#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle)  \
+  do {                                                       \
+    link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE((handle)); \
+    if (map) ForEachMappedRegion(map, __msan_unpoison);      \
+  } while (false)
 
 #include "sanitizer_common/sanitizer_common_interceptors.inc"
 
 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) CHECK_UNPOISONED(p, s)
 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) \
   do {                                       \
   } while (false)
 #define COMMON_SYSCALL_POST_READ_RANGE(p, s) \

lib/sanitizer_common/sanitizer_common_interceptors.inc

 #define COMMON_INTERCEPTOR_FILE_OPEN(ctx, file, path) {}
 #endif
 
 #ifndef COMMON_INTERCEPTOR_FILE_CLOSE
 #define COMMON_INTERCEPTOR_FILE_CLOSE(ctx, file) {}
 #endif
 
 #ifndef COMMON_INTERCEPTOR_LIBRARY_LOADED
-#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, map) {}
+#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle) {}
 #endif
 
 #ifndef COMMON_INTERCEPTOR_LIBRARY_UNLOADED
 #define COMMON_INTERCEPTOR_LIBRARY_UNLOADED() {}
 #endif
 
 #ifndef COMMON_INTERCEPTOR_ENTER_NOIGNORE
 #define COMMON_INTERCEPTOR_ENTER_NOIGNORE(ctx, ...) \

lib/sanitizer_common/sanitizer_linux.cc

bool LibraryNameIs(const char *full_name, const char *base_name) {
   uptr base_name_length = internal_strlen(base_name);
   if (internal_strncmp(name, base_name, base_name_length)) return false;
   return (name[base_name_length] == '-' || name[base_name_length] == '.');
 }
 
 #if !SANITIZER_ANDROID
 // Call cb for each region mapped by map.
 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
+  CHECK_NE(map, nullptr);
 #if !SANITIZER_FREEBSD
   typedef ElfW(Phdr) Elf_Phdr;
   typedef ElfW(Ehdr) Elf_Ehdr;
 #endif  // !SANITIZER_FREEBSD
   char *base = (char *)map->l_addr;
   Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
   char *phdrs = base + ehdr->e_phoff;
   char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
 
   // Find the segment with the minimum base so we can "relocate" the p_vaddr
   // fields.  Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
   // objects have a non-zero base.
   uptr preferred_base = (uptr)-1;

lib/sanitizer_common/sanitizer_platform_limits_posix.h

 //===----------------------------------------------------------------------===//
 
 #ifndef SANITIZER_PLATFORM_LIMITS_POSIX_H
 #define SANITIZER_PLATFORM_LIMITS_POSIX_H
 
 #include "sanitizer_internal_defs.h"
 #include "sanitizer_platform.h"
 
+#if SANITIZER_FREEBSD
+// FreeBSD's dlopen() returns a pointer to an Obj_Entry structure that
+// incroporates the map structure.
+# define GET_LINK_MAP_BY_DLOPEN_HANDLE(handle) \
+    ((link_map*)((handle) == nullptr ? nullptr : ((char*)(handle) + 544)))
+#else
+# define GET_LINK_MAP_BY_DLOPEN_HANDLE(handle) ((link_map*)(handle))
+#endif  // !SANITIZER_FREEBSD
+
 namespace __sanitizer {
   extern unsigned struct_utsname_sz;
   extern unsigned struct_stat_sz;
 #if !SANITIZER_FREEBSD && !SANITIZER_IOS
   extern unsigned struct_stat64_sz;
 #endif
   extern unsigned struct_rusage_sz;
   extern unsigned siginfo_t_sz;

lib/tsan/rtl/tsan_interceptors.cc

#define COMMON_INTERCEPTOR_FILE_OPEN(ctx, file, path) \
   }
 
 #define COMMON_INTERCEPTOR_FILE_CLOSE(ctx, file) \
   if (file) {                                    \
     int fd = fileno_unlocked(file);              \
     if (fd >= 0) FdClose(thr, pc, fd);           \
   }
 
-#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, res)  \
+#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle) \
   libignore()->OnLibraryLoaded(filename)
 
 #define COMMON_INTERCEPTOR_LIBRARY_UNLOADED() \
   libignore()->OnLibraryUnloaded()
 
 #define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path) \
   Acquire(((TsanInterceptorContext *) ctx)->thr, pc, Dir2addr(path))