Rename library_offset to library_fd_offset
replace lseek() and use pread() instead
add test for library_fd_offset > file_size case
Bug: 17762003
(cherry picked from commit a6c1279098f24a675d0df74ce1946f5d534b425e)
Change-Id: Ie117c745081ee33d07db5341115ff6c8e98b0dec
diff --git a/libc/include/android/dlext.h b/libc/include/android/dlext.h
index f81ec70..f27e4e5 100644
--- a/libc/include/android/dlext.h
+++ b/libc/include/android/dlext.h
@@ -54,11 +54,11 @@
*/
ANDROID_DLEXT_USE_LIBRARY_FD = 0x10,
- /* When opening library using library_fd read it starting with library_offset
+ /* If opening a library using library_fd read it starting at library_fd_offset.
* This flag is only valid when ANDROID_DLEXT_USE_LIBRARY_FD is set.
*/
- ANDROID_DLEXT_USE_LIBRARY_OFFSET = 0x20,
+ ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET = 0x20,
/* Mask of valid bits */
ANDROID_DLEXT_VALID_FLAG_BITS = ANDROID_DLEXT_RESERVED_ADDRESS |
@@ -66,7 +66,7 @@
ANDROID_DLEXT_WRITE_RELRO |
ANDROID_DLEXT_USE_RELRO |
ANDROID_DLEXT_USE_LIBRARY_FD |
- ANDROID_DLEXT_USE_LIBRARY_OFFSET,
+ ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET,
};
typedef struct {
@@ -75,7 +75,7 @@
size_t reserved_size;
int relro_fd;
int library_fd;
- off64_t library_offset;
+ off64_t library_fd_offset;
} android_dlextinfo;
extern void* android_dlopen_ext(const char* filename, int flag, const android_dlextinfo* extinfo);
diff --git a/linker/linker.cpp b/linker/linker.cpp
index d6d5f35..9425c9d 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -817,8 +817,8 @@
if (extinfo != nullptr && (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) != 0) {
fd = extinfo->library_fd;
- if ((extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_OFFSET) != 0) {
- file_offset = extinfo->library_offset;
+ if ((extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET) != 0) {
+ file_offset = extinfo->library_fd_offset;
}
} else {
// Open the file.
@@ -832,13 +832,13 @@
}
if ((file_offset % PAGE_SIZE) != 0) {
- DL_ERR("file offset for the library %s is not page-aligned: %" PRId64, name, file_offset);
+ DL_ERR("file offset for the library \"%s\" is not page-aligned: %" PRId64, name, file_offset);
return nullptr;
}
struct stat file_stat;
if (TEMP_FAILURE_RETRY(fstat(fd, &file_stat)) != 0) {
- DL_ERR("unable to stat file for the library %s: %s", name, strerror(errno));
+ DL_ERR("unable to stat file for the library \"%s\": %s", name, strerror(errno));
return nullptr;
}
@@ -1085,8 +1085,8 @@
return nullptr;
}
if ((extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) == 0 &&
- (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_OFFSET) != 0) {
- DL_ERR("invalid extended flag combination (ANDROID_DLEXT_USE_LIBRARY_OFFSET without ANDROID_DLEXT_USE_LIBRARY_FD): 0x%" PRIx64, extinfo->flags);
+ (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET) != 0) {
+ DL_ERR("invalid extended flag combination (ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET without ANDROID_DLEXT_USE_LIBRARY_FD): 0x%" PRIx64, extinfo->flags);
return nullptr;
}
}
diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp
index e0d6d0e..4b1c0ca 100644
--- a/linker/linker_phdr.cpp
+++ b/linker/linker_phdr.cpp
@@ -142,18 +142,12 @@
}
bool ElfReader::ReadElfHeader() {
- off64_t actual_offset = lseek64(fd_, file_offset_, SEEK_SET);
-
- if (actual_offset != file_offset_) {
- DL_ERR("seek to %" PRId64 " failed: %s", file_offset_, strerror(errno));
- return false;
- }
-
- ssize_t rc = TEMP_FAILURE_RETRY(read(fd_, &header_, sizeof(header_)));
+ ssize_t rc = TEMP_FAILURE_RETRY(pread64(fd_, &header_, sizeof(header_), file_offset_));
if (rc < 0) {
DL_ERR("can't read file \"%s\": %s", name_, strerror(errno));
return false;
}
+
if (rc != sizeof(header_)) {
DL_ERR("\"%s\" is too small to be an ELF executable: only found %zd bytes", name_,
static_cast<size_t>(rc));
diff --git a/tests/dlext_test.cpp b/tests/dlext_test.cpp
index 55b0642..7f706c1 100644
--- a/tests/dlext_test.cpp
+++ b/tests/dlext_test.cpp
@@ -121,9 +121,9 @@
snprintf(lib_path, sizeof(lib_path), LIBZIPPATH, android_data);
android_dlextinfo extinfo;
- extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD | ANDROID_DLEXT_USE_LIBRARY_OFFSET;
+ extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD | ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET;
extinfo.library_fd = TEMP_FAILURE_RETRY(open(lib_path, O_RDONLY | O_CLOEXEC));
- extinfo.library_offset = LIBZIP_OFFSET;
+ extinfo.library_fd_offset = LIBZIP_OFFSET;
handle_ = android_dlopen_ext(lib_path, RTLD_NOW, &extinfo);
ASSERT_DL_NOTNULL(handle_);
@@ -141,23 +141,32 @@
snprintf(lib_path, sizeof(lib_path), LIBZIPPATH, android_data);
android_dlextinfo extinfo;
- extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD | ANDROID_DLEXT_USE_LIBRARY_OFFSET;
+ extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD | ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET;
extinfo.library_fd = TEMP_FAILURE_RETRY(open(lib_path, O_RDONLY | O_CLOEXEC));
- extinfo.library_offset = 17;
+ extinfo.library_fd_offset = 17;
handle_ = android_dlopen_ext("libname_placeholder", RTLD_NOW, &extinfo);
ASSERT_TRUE(handle_ == nullptr);
- ASSERT_STREQ("dlopen failed: file offset for the library libname_placeholder is not page-aligned: 17", dlerror());
+ ASSERT_STREQ("dlopen failed: file offset for the library \"libname_placeholder\" is not page-aligned: 17", dlerror());
+
+ extinfo.library_fd_offset = (5LL<<58) + PAGE_SIZE;
+ handle_ = android_dlopen_ext("libname_placeholder", RTLD_NOW, &extinfo);
+
+ ASSERT_TRUE(handle_ == nullptr);
+ // TODO: Better error message when reading with offset > file_size
+ ASSERT_STREQ("dlopen failed: \"libname_placeholder\" has bad ELF magic", dlerror());
+
+ close(extinfo.library_fd);
}
TEST_F(DlExtTest, ExtInfoUseOffsetWihtoutFd) {
android_dlextinfo extinfo;
- extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_OFFSET;
- extinfo.library_offset = LIBZIP_OFFSET;
+ extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET;
+ extinfo.library_fd_offset = LIBZIP_OFFSET;
handle_ = android_dlopen_ext("/some/lib/that/does_not_exist", RTLD_NOW, &extinfo);
ASSERT_TRUE(handle_ == nullptr);
- ASSERT_STREQ("dlopen failed: invalid extended flag combination (ANDROID_DLEXT_USE_LIBRARY_OFFSET without ANDROID_DLEXT_USE_LIBRARY_FD): 0x20", dlerror());
+ ASSERT_STREQ("dlopen failed: invalid extended flag combination (ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET without ANDROID_DLEXT_USE_LIBRARY_FD): 0x20", dlerror());
}
TEST_F(DlExtTest, Reserved) {
