Merge "linker: Handle libraries with disjoint mappings correctly."
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 61cd818..56e85e4 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -415,11 +415,9 @@
//
// Intended to be called by libc's __gnu_Unwind_Find_exidx().
_Unwind_Ptr do_dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) {
- for (soinfo* si = solist_get_head(); si != 0; si = si->next) {
- if ((pc >= si->base) && (pc < (si->base + si->size))) {
- *pcount = si->ARM_exidx_count;
- return reinterpret_cast<_Unwind_Ptr>(si->ARM_exidx);
- }
+ if (soinfo* si = find_containing_library(reinterpret_cast<void*>(pc))) {
+ *pcount = si->ARM_exidx_count;
+ return reinterpret_cast<_Unwind_Ptr>(si->ARM_exidx);
}
*pcount = 0;
return 0;
@@ -938,8 +936,18 @@
soinfo* find_containing_library(const void* p) {
ElfW(Addr) address = reinterpret_cast<ElfW(Addr)>(p);
for (soinfo* si = solist_get_head(); si != nullptr; si = si->next) {
- if (address >= si->base && address - si->base < si->size) {
- return si;
+ if (address < si->base || address - si->base >= si->size) {
+ continue;
+ }
+ ElfW(Addr) vaddr = address - si->load_bias;
+ for (size_t i = 0; i != si->phnum; ++i) {
+ const ElfW(Phdr)* phdr = &si->phdr[i];
+ if (phdr->p_type != PT_LOAD) {
+ continue;
+ }
+ if (vaddr >= phdr->p_vaddr && vaddr < phdr->p_vaddr + phdr->p_memsz) {
+ return si;
+ }
}
}
return nullptr;
diff --git a/tests/Android.bp b/tests/Android.bp
index c1eaeec..ab11d47 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -642,6 +642,8 @@
"libnstest_ns_a_public1_internal",
"libnstest_ns_b_public2",
"libnstest_ns_b_public3",
+ "libsegment_gap_inner",
+ "libsegment_gap_outer",
"ld_preload_test_helper",
"ld_preload_test_helper_lib1",
"ld_preload_test_helper_lib2",
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 8a3b6f3..ff5b1a9 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -49,6 +49,12 @@
#pragma clang diagnostic pop
#endif // defined(__ANDROID__) && (defined(__arm__) || defined(__i386__))
+// Declared manually because the macro definitions in <elf.h> conflict with LLVM headers.
+#ifdef __arm__
+typedef uintptr_t _Unwind_Ptr;
+extern "C" _Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr, int*);
+#endif
+
#define ASSERT_SUBSTR(needle, haystack) \
ASSERT_PRED_FORMAT2(::testing::IsSubstring, needle, haystack)
@@ -1732,4 +1738,28 @@
ASSERT_TRUE(handle != nullptr) << dlerror();
}
+TEST(dlfcn, segment_gap) {
+ void* handle = dlopen("libsegment_gap_outer.so", RTLD_NOW);
+ ASSERT_TRUE(handle != nullptr) << dlerror();
+
+ auto get_inner = reinterpret_cast<void* (*)()>(dlsym(handle, "get_inner"));
+ void* inner = get_inner();
+ (void)inner;
+
+#if __arm__
+ int count;
+ _Unwind_Ptr outer_exidx = dl_unwind_find_exidx(reinterpret_cast<_Unwind_Ptr>(get_inner), &count);
+ _Unwind_Ptr inner_exidx = dl_unwind_find_exidx(reinterpret_cast<_Unwind_Ptr>(inner), &count);
+ EXPECT_NE(0u, outer_exidx);
+ EXPECT_NE(0u, inner_exidx);
+ EXPECT_NE(inner_exidx, outer_exidx);
+#endif
+
+ Dl_info info;
+ int rc = dladdr(inner, &info);
+ ASSERT_NE(rc, 0);
+
+ EXPECT_NE(nullptr, strstr(info.dli_fname, "libsegment_gap_inner.so"));
+}
+
#endif
diff --git a/tests/libs/Android.bp b/tests/libs/Android.bp
index d58b6b8..422cd75 100644
--- a/tests/libs/Android.bp
+++ b/tests/libs/Android.bp
@@ -918,3 +918,18 @@
defaults: ["bionic_testlib_defaults"],
srcs: ["exec_linker_helper_lib.cpp"],
}
+
+cc_test_library {
+ name: "libsegment_gap_outer",
+ host_supported: false,
+ defaults: ["bionic_testlib_defaults"],
+ srcs: ["segment_gap_outer.cpp"],
+ ldflags: ["-Wl,-T,bionic/tests/libs/segment_gap_outer.lds"],
+}
+
+cc_test_library {
+ name: "libsegment_gap_inner",
+ host_supported: false,
+ defaults: ["bionic_testlib_defaults"],
+ srcs: ["segment_gap_inner.cpp"],
+}
diff --git a/tests/libs/segment_gap_inner.cpp b/tests/libs/segment_gap_inner.cpp
new file mode 100644
index 0000000..f23b065
--- /dev/null
+++ b/tests/libs/segment_gap_inner.cpp
@@ -0,0 +1 @@
+extern "C" void inner() {}
diff --git a/tests/libs/segment_gap_outer.cpp b/tests/libs/segment_gap_outer.cpp
new file mode 100644
index 0000000..fb448e7
--- /dev/null
+++ b/tests/libs/segment_gap_outer.cpp
@@ -0,0 +1,25 @@
+#include <android/dlext.h>
+#include <dlfcn.h>
+#include <jni.h>
+#include <stdlib.h>
+
+extern "C" void text_before_start_of_gap() {}
+char end_of_gap[0x1000];
+
+extern "C" void* get_inner() {
+ android_dlextinfo info = {};
+ info.flags = ANDROID_DLEXT_RESERVED_ADDRESS;
+
+ char* start_of_gap =
+ reinterpret_cast<char*>(reinterpret_cast<uintptr_t>(text_before_start_of_gap) & ~0xfffull) +
+ 0x1000;
+ info.reserved_addr = start_of_gap;
+ info.reserved_size = end_of_gap - start_of_gap;
+
+ void *handle = android_dlopen_ext("libsegment_gap_inner.so", RTLD_NOW, &info);
+ if (!handle) {
+ __builtin_trap();
+ }
+
+ return dlsym(handle, "inner");
+}
diff --git a/tests/libs/segment_gap_outer.lds b/tests/libs/segment_gap_outer.lds
new file mode 100644
index 0000000..f326aab
--- /dev/null
+++ b/tests/libs/segment_gap_outer.lds
@@ -0,0 +1,27 @@
+SECTIONS {
+ # This starts off fairly normal: rodata, text, data, relro, bss with
+ # appropriate alignment between them.
+ . = SIZEOF_HEADERS;
+ .rodata : {}
+ . = ALIGN(0x1000);
+ .text : {}
+ . = ALIGN(0x1000);
+ .data : {}
+ . = ALIGN(0x1000);
+ .data.rel.ro : {}
+ . = ALIGN(0x1000);
+ .bss : {}
+
+ # Now create the gap. We need a text segment first to prevent the linker from
+ # merging .bss with .bss.end_of_gap.
+ . = ALIGN(0x1000);
+ .text.text_before_start_of_gap : {
+ *(.text.text_before_start_of_gap);
+ }
+
+ # Place end_of_gap at the end of the gap.
+ . = 0x1000000;
+ .bss.end_of_gap : {
+ *(.bss.end_of_gap);
+ }
+}