Fix handling of load bias values.
It turns out that for the dwarf information, if a FDE indicates it's pc
relative, then pc has to be incremented by the load bias. If not, then
it should not be incremented.
Previously, the code always subtracted load bias values from pcs, and assumed
that all fdes were incremented by load bias values. The new code actually
reads the fdes and adjusted the pcs in the fde and in the eh frame hdr so
that load bias values are already handled properly.
In addition, add dumping of arm exidx values in unwind_reg_info. This allowed
verifying that the debug frame in those elf files was being handled properly.
Added a new unit test that only has a debug frame that has a non-zero load
bias and has fde entries that do not have pc relative encoding.
Fix a couple of other small bugs.
Bug: 109824792
Test: All libbacktrace/libunwindstack unit tests pass.
Test: Ran ART 137-cfi test and 004-ThreadStress.
Test: Verify that displaying the fde start and end pc actually match the
Test: real data for fde that have pc relative set, and that don't.
Test: Verified that the unwind information for arm exidx matches the
Test: debug frame data.
Change-Id: I707555286b5cb05df9f25489e8c5ede753cfe0fb
diff --git a/libunwindstack/tests/UnwindOfflineTest.cpp b/libunwindstack/tests/UnwindOfflineTest.cpp
index 285fc9e..a65c077 100644
--- a/libunwindstack/tests/UnwindOfflineTest.cpp
+++ b/libunwindstack/tests/UnwindOfflineTest.cpp
@@ -1200,4 +1200,43 @@
EXPECT_EQ(0xffcc1558U, unwinder.frames()[18].sp);
}
+// Test using a non-zero load bias library that has the fde entries
+// encoded as 0xb, which is not set as pc relative.
+TEST_F(UnwindOfflineTest, debug_frame_load_bias_arm) {
+ ASSERT_NO_FATAL_FAILURE(Init("debug_frame_load_bias_arm/", ARCH_ARM));
+
+ Unwinder unwinder(128, maps_.get(), regs_.get(), process_memory_);
+ unwinder.Unwind();
+
+ std::string frame_info(DumpFrames(unwinder));
+ ASSERT_EQ(8U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
+ EXPECT_EQ(
+ " #00 pc 0005138c libc.so (__ioctl+8)\n"
+ " #01 pc 0002140f libc.so (ioctl+30)\n"
+ " #02 pc 00039535 libbinder.so (_ZN7android14IPCThreadState14talkWithDriverEb+204)\n"
+ " #03 pc 00039633 libbinder.so (_ZN7android14IPCThreadState20getAndExecuteCommandEv+10)\n"
+ " #04 pc 00039b57 libbinder.so (_ZN7android14IPCThreadState14joinThreadPoolEb+38)\n"
+ " #05 pc 00000c21 mediaserver (main+104)\n"
+ " #06 pc 00084b89 libc.so (__libc_init+48)\n"
+ " #07 pc 00000b77 mediaserver (_start_main+38)\n",
+ frame_info);
+
+ EXPECT_EQ(0xf0be238cU, unwinder.frames()[0].pc);
+ EXPECT_EQ(0xffd4a638U, unwinder.frames()[0].sp);
+ EXPECT_EQ(0xf0bb240fU, unwinder.frames()[1].pc);
+ EXPECT_EQ(0xffd4a638U, unwinder.frames()[1].sp);
+ EXPECT_EQ(0xf1a75535U, unwinder.frames()[2].pc);
+ EXPECT_EQ(0xffd4a650U, unwinder.frames()[2].sp);
+ EXPECT_EQ(0xf1a75633U, unwinder.frames()[3].pc);
+ EXPECT_EQ(0xffd4a6b0U, unwinder.frames()[3].sp);
+ EXPECT_EQ(0xf1a75b57U, unwinder.frames()[4].pc);
+ EXPECT_EQ(0xffd4a6d0U, unwinder.frames()[4].sp);
+ EXPECT_EQ(0x8d1cc21U, unwinder.frames()[5].pc);
+ EXPECT_EQ(0xffd4a6e8U, unwinder.frames()[5].sp);
+ EXPECT_EQ(0xf0c15b89U, unwinder.frames()[6].pc);
+ EXPECT_EQ(0xffd4a700U, unwinder.frames()[6].sp);
+ EXPECT_EQ(0x8d1cb77U, unwinder.frames()[7].pc);
+ EXPECT_EQ(0xffd4a718U, unwinder.frames()[7].sp);
+}
+
} // namespace unwindstack