Merge "Do not unmap reserved region on dlclose"
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 70c2ca5..1c1650e 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -356,7 +356,13 @@
}
if (si->base != 0 && si->size != 0) {
- munmap(reinterpret_cast<void*>(si->base), si->size);
+ if (!si->is_mapped_by_caller()) {
+ munmap(reinterpret_cast<void*>(si->base), si->size);
+ } else {
+ // remap the region as PROT_NONE, MAP_ANONYMOUS | MAP_NORESERVE
+ mmap(reinterpret_cast<void*>(si->base), si->size, PROT_NONE,
+ MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
+ }
}
soinfo *prev = nullptr, *trav;
@@ -1160,6 +1166,7 @@
si_->base = elf_reader.load_start();
si_->size = elf_reader.load_size();
+ si_->set_mapped_by_caller(elf_reader.is_mapped_by_caller());
si_->load_bias = elf_reader.load_bias();
si_->phnum = elf_reader.phdr_count();
si_->phdr = elf_reader.loaded_phdr();
@@ -3248,6 +3255,19 @@
return local_group_root_;
}
+
+void soinfo::set_mapped_by_caller(bool mapped_by_caller) {
+ if (mapped_by_caller) {
+ flags_ |= FLAG_MAPPED_BY_CALLER;
+ } else {
+ flags_ &= ~FLAG_MAPPED_BY_CALLER;
+ }
+}
+
+bool soinfo::is_mapped_by_caller() const {
+ return (flags_ & FLAG_MAPPED_BY_CALLER) != 0;
+}
+
// This function returns api-level at the time of
// dlopen/load. Note that libraries opened by system
// will always have 'current' api level.
diff --git a/linker/linker.h b/linker/linker.h
index 5a06853..389c5b3 100644
--- a/linker/linker.h
+++ b/linker/linker.h
@@ -79,11 +79,13 @@
#define ELF64_R_TYPE(info) (((info) >> 56) & 0xff)
#endif
-#define FLAG_LINKED 0x00000001
-#define FLAG_EXE 0x00000004 // The main executable
-#define FLAG_LINKER 0x00000010 // The linker itself
-#define FLAG_GNU_HASH 0x00000040 // uses gnu hash
-#define FLAG_NEW_SOINFO 0x40000000 // new soinfo format
+#define FLAG_LINKED 0x00000001
+#define FLAG_EXE 0x00000004 // The main executable
+#define FLAG_LINKER 0x00000010 // The linker itself
+#define FLAG_GNU_HASH 0x00000040 // uses gnu hash
+#define FLAG_MAPPED_BY_CALLER 0x00000080 // the map is reserved by the caller
+ // and should not be unmapped
+#define FLAG_NEW_SOINFO 0x40000000 // new soinfo format
#define SUPPORTED_DT_FLAGS_1 (DF_1_NOW | DF_1_GLOBAL | DF_1_NODELETE)
@@ -337,6 +339,9 @@
const std::vector<std::string>& get_dt_runpath() const;
android_namespace_t* get_namespace();
+ void set_mapped_by_caller(bool reserved_map);
+ bool is_mapped_by_caller() const;
+
private:
bool elf_lookup(SymbolName& symbol_name, const version_info* vi, uint32_t* symbol_index) const;
ElfW(Sym)* elf_addr_lookup(const void* addr);
diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp
index 4c4ce17..e81e325 100644
--- a/linker/linker_phdr.cpp
+++ b/linker/linker_phdr.cpp
@@ -137,7 +137,8 @@
ElfReader::ElfReader()
: did_read_(false), did_load_(false), fd_(-1), file_offset_(0), file_size_(0), phdr_num_(0),
phdr_table_(nullptr), shdr_table_(nullptr), shdr_num_(0), dynamic_(nullptr), strtab_(nullptr),
- strtab_size_(0), load_start_(nullptr), load_size_(0), load_bias_(0), loaded_phdr_(nullptr) {
+ strtab_size_(0), load_start_(nullptr), load_size_(0), load_bias_(0), loaded_phdr_(nullptr),
+ mapped_by_caller_(false) {
}
bool ElfReader::Read(const char* name, int fd, off64_t file_offset, off64_t file_size) {
@@ -467,6 +468,7 @@
}
} else {
start = extinfo->reserved_addr;
+ mapped_by_caller_ = true;
}
load_start_ = start;
diff --git a/linker/linker_phdr.h b/linker/linker_phdr.h
index c359cca..89ec094 100644
--- a/linker/linker_phdr.h
+++ b/linker/linker_phdr.h
@@ -53,6 +53,7 @@
const ElfW(Phdr)* loaded_phdr() const { return loaded_phdr_; }
const ElfW(Dyn)* dynamic() const { return dynamic_; }
const char* get_string(ElfW(Word) index) const;
+ bool is_mapped_by_caller() const { return mapped_by_caller_; }
private:
bool ReadElfHeader();
@@ -99,6 +100,9 @@
// Loaded phdr.
const ElfW(Phdr)* loaded_phdr_;
+
+ // Is map owned by the caller
+ bool mapped_by_caller_;
};
size_t phdr_table_get_load_size(const ElfW(Phdr)* phdr_table, size_t phdr_count,
diff --git a/tests/dlext_test.cpp b/tests/dlext_test.cpp
index 261aa55..d28e9cc 100644
--- a/tests/dlext_test.cpp
+++ b/tests/dlext_test.cpp
@@ -275,7 +275,8 @@
ASSERT_TRUE(fn != nullptr);
EXPECT_EQ(4, fn());
- uint32_t* taxicab_number = reinterpret_cast<uint32_t*>(dlsym(handle, "dlopen_testlib_taxicab_number"));
+ uint32_t* taxicab_number =
+ reinterpret_cast<uint32_t*>(dlsym(handle, "dlopen_testlib_taxicab_number"));
ASSERT_DL_NOTNULL(taxicab_number);
EXPECT_EQ(1729U, *taxicab_number);
@@ -284,8 +285,7 @@
TEST_F(DlExtTest, Reserved) {
- void* start = mmap(nullptr, LIBSIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS,
- -1, 0);
+ void* start = mmap(nullptr, LIBSIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
ASSERT_TRUE(start != MAP_FAILED);
android_dlextinfo extinfo;
extinfo.flags = ANDROID_DLEXT_RESERVED_ADDRESS;
@@ -299,11 +299,17 @@
EXPECT_LT(reinterpret_cast<void*>(f),
reinterpret_cast<char*>(start) + LIBSIZE);
EXPECT_EQ(4, f());
+
+ // Check that after dlclose reserved address space is unmapped (and can be reused)
+ dlclose(handle_);
+ handle_ = nullptr;
+
+ void* new_start = mmap(start, PAGE_SIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ ASSERT_NE(start, new_start) << "dlclose unmapped reserved space";
}
TEST_F(DlExtTest, ReservedTooSmall) {
- void* start = mmap(nullptr, PAGE_SIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS,
- -1, 0);
+ void* start = mmap(nullptr, PAGE_SIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
ASSERT_TRUE(start != MAP_FAILED);
android_dlextinfo extinfo;
extinfo.flags = ANDROID_DLEXT_RESERVED_ADDRESS;
@@ -314,8 +320,7 @@
}
TEST_F(DlExtTest, ReservedHint) {
- void* start = mmap(nullptr, LIBSIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS,
- -1, 0);
+ void* start = mmap(nullptr, LIBSIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
ASSERT_TRUE(start != MAP_FAILED);
android_dlextinfo extinfo;
extinfo.flags = ANDROID_DLEXT_RESERVED_ADDRESS_HINT;
@@ -332,8 +337,7 @@
}
TEST_F(DlExtTest, ReservedHintTooSmall) {
- void* start = mmap(nullptr, PAGE_SIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS,
- -1, 0);
+ void* start = mmap(nullptr, PAGE_SIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
ASSERT_TRUE(start != MAP_FAILED);
android_dlextinfo extinfo;
extinfo.flags = ANDROID_DLEXT_RESERVED_ADDRESS_HINT;
@@ -350,8 +354,7 @@
}
TEST_F(DlExtTest, LoadAtFixedAddress) {
- void* start = mmap(nullptr, LIBSIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS,
- -1, 0);
+ void* start = mmap(nullptr, LIBSIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
ASSERT_TRUE(start != MAP_FAILED);
munmap(start, LIBSIZE);
@@ -367,6 +370,12 @@
EXPECT_LT(reinterpret_cast<void*>(f), reinterpret_cast<char*>(start) + LIBSIZE);
EXPECT_EQ(4, f());
+ dlclose(handle_);
+ handle_ = nullptr;
+
+ // Check that dlclose unmapped the file
+ void* addr = mmap(start, LIBSIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ ASSERT_EQ(start, addr) << "dlclose did not unmap the memory";
}
TEST_F(DlExtTest, LoadAtFixedAddressTooSmall) {
@@ -390,8 +399,7 @@
protected:
virtual void SetUp() {
DlExtTest::SetUp();
- void* start = mmap(nullptr, LIBSIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS,
- -1, 0);
+ void* start = mmap(nullptr, LIBSIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
ASSERT_TRUE(start != MAP_FAILED);
extinfo_.flags = ANDROID_DLEXT_RESERVED_ADDRESS;
extinfo_.reserved_addr = start;
@@ -442,7 +450,8 @@
ASSERT_DL_NOTNULL(f);
EXPECT_EQ(4, f());
- uint32_t* taxicab_number = reinterpret_cast<uint32_t*>(dlsym(handle_, "dlopen_testlib_taxicab_number"));
+ uint32_t* taxicab_number =
+ reinterpret_cast<uint32_t*>(dlsym(handle_, "dlopen_testlib_taxicab_number"));
ASSERT_DL_NOTNULL(taxicab_number);
EXPECT_EQ(1729U, *taxicab_number);
}