Properly handle empty map after read-only map.
Recently, the maps for an elf in memory might show up looking like:
f0000-f1000 0 r-- /system/lib/libc.so
f1000-f2000 0 ---
f2000-f3000 1000 r-x /system/lib/libc.so
f3000-f4000 2000 rw- /system/lib/libc.so
The problem is that there is logic in the code that assumed that the
map before the execute map must be the read-only map. In the case
above, this is not true. Add a new prev_real_map that will point
to the previous map that is not one of these empty maps.
This will fix the backtraces that look like this:
#00 pc 0000000000050d58 /apex/com.android.runtime/lib64/bionic/libc.so!libc.so (offset 0x50000) (syscall+24) (BuildId: 5252408bf30e395d49ee270b54c77ca4)
To get rid of the !libc.so and the offset value, which is not correct.
Added new unit tests to verify this.
Added new offline test which an empty map between read-only and execute
map. Before this change, the backtraces had lines like
libc.so!libc.so (offset XXX) would be present.
Bug: 148075852
Test: Ran unit tests.
Change-Id: Ie04bfc96b8f91ed885cb1e655cf1e346efe48a45
diff --git a/libunwindstack/tests/UnwindOfflineTest.cpp b/libunwindstack/tests/UnwindOfflineTest.cpp
index 364101a..c2bd836 100644
--- a/libunwindstack/tests/UnwindOfflineTest.cpp
+++ b/libunwindstack/tests/UnwindOfflineTest.cpp
@@ -169,15 +169,18 @@
};
std::unordered_map<std::string, uint32_t> UnwindOfflineTest::arm64_regs_ = {
- {"x0", ARM64_REG_R0}, {"x1", ARM64_REG_R1}, {"x2", ARM64_REG_R2}, {"x3", ARM64_REG_R3},
- {"x4", ARM64_REG_R4}, {"x5", ARM64_REG_R5}, {"x6", ARM64_REG_R6}, {"x7", ARM64_REG_R7},
- {"x8", ARM64_REG_R8}, {"x9", ARM64_REG_R9}, {"x10", ARM64_REG_R10}, {"x11", ARM64_REG_R11},
- {"x12", ARM64_REG_R12}, {"x13", ARM64_REG_R13}, {"x14", ARM64_REG_R14}, {"x15", ARM64_REG_R15},
- {"x16", ARM64_REG_R16}, {"x17", ARM64_REG_R17}, {"x18", ARM64_REG_R18}, {"x19", ARM64_REG_R19},
- {"x20", ARM64_REG_R20}, {"x21", ARM64_REG_R21}, {"x22", ARM64_REG_R22}, {"x23", ARM64_REG_R23},
- {"x24", ARM64_REG_R24}, {"x25", ARM64_REG_R25}, {"x26", ARM64_REG_R26}, {"x27", ARM64_REG_R27},
- {"x28", ARM64_REG_R28}, {"x29", ARM64_REG_R29}, {"sp", ARM64_REG_SP}, {"lr", ARM64_REG_LR},
- {"pc", ARM64_REG_PC},
+ {"x0", ARM64_REG_R0}, {"x1", ARM64_REG_R1}, {"x2", ARM64_REG_R2},
+ {"x3", ARM64_REG_R3}, {"x4", ARM64_REG_R4}, {"x5", ARM64_REG_R5},
+ {"x6", ARM64_REG_R6}, {"x7", ARM64_REG_R7}, {"x8", ARM64_REG_R8},
+ {"x9", ARM64_REG_R9}, {"x10", ARM64_REG_R10}, {"x11", ARM64_REG_R11},
+ {"x12", ARM64_REG_R12}, {"x13", ARM64_REG_R13}, {"x14", ARM64_REG_R14},
+ {"x15", ARM64_REG_R15}, {"x16", ARM64_REG_R16}, {"x17", ARM64_REG_R17},
+ {"x18", ARM64_REG_R18}, {"x19", ARM64_REG_R19}, {"x20", ARM64_REG_R20},
+ {"x21", ARM64_REG_R21}, {"x22", ARM64_REG_R22}, {"x23", ARM64_REG_R23},
+ {"x24", ARM64_REG_R24}, {"x25", ARM64_REG_R25}, {"x26", ARM64_REG_R26},
+ {"x27", ARM64_REG_R27}, {"x28", ARM64_REG_R28}, {"x29", ARM64_REG_R29},
+ {"sp", ARM64_REG_SP}, {"lr", ARM64_REG_LR}, {"pc", ARM64_REG_PC},
+ {"pst", ARM64_REG_PSTATE},
};
std::unordered_map<std::string, uint32_t> UnwindOfflineTest::x86_regs_ = {
@@ -1697,4 +1700,40 @@
EXPECT_EQ(0xffe67d10ULL, unwinder.frames()[16].sp);
}
+TEST_F(UnwindOfflineTest, empty_arm64) {
+ ASSERT_NO_FATAL_FAILURE(Init("empty_arm64/", ARCH_ARM64));
+
+ Unwinder unwinder(128, maps_.get(), regs_.get(), process_memory_);
+ unwinder.Unwind();
+
+ std::string frame_info(DumpFrames(unwinder));
+ ASSERT_EQ(7U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
+ EXPECT_EQ(
+ " #00 pc 00000000000963a4 libc.so (__ioctl+4)\n"
+ " #01 pc 000000000005344c libc.so (ioctl+140)\n"
+ " #02 pc 0000000000050ce4 libbinder.so "
+ "(android::IPCThreadState::talkWithDriver(bool)+308)\n"
+ " #03 pc 0000000000050e98 libbinder.so "
+ "(android::IPCThreadState::getAndExecuteCommand()+24)\n"
+ " #04 pc 00000000000516ac libbinder.so (android::IPCThreadState::joinThreadPool(bool)+60)\n"
+ " #05 pc 00000000000443b0 netd (main+1056)\n"
+ " #06 pc 0000000000045594 libc.so (__libc_init+108)\n",
+ frame_info);
+
+ EXPECT_EQ(0x72a02203a4U, unwinder.frames()[0].pc);
+ EXPECT_EQ(0x7ffb6c0b50U, unwinder.frames()[0].sp);
+ EXPECT_EQ(0x72a01dd44cU, unwinder.frames()[1].pc);
+ EXPECT_EQ(0x7ffb6c0b50U, unwinder.frames()[1].sp);
+ EXPECT_EQ(0x729f759ce4U, unwinder.frames()[2].pc);
+ EXPECT_EQ(0x7ffb6c0c50U, unwinder.frames()[2].sp);
+ EXPECT_EQ(0x729f759e98U, unwinder.frames()[3].pc);
+ EXPECT_EQ(0x7ffb6c0ce0U, unwinder.frames()[3].sp);
+ EXPECT_EQ(0x729f75a6acU, unwinder.frames()[4].pc);
+ EXPECT_EQ(0x7ffb6c0d10U, unwinder.frames()[4].sp);
+ EXPECT_EQ(0x5d478af3b0U, unwinder.frames()[5].pc);
+ EXPECT_EQ(0x7ffb6c0d40U, unwinder.frames()[5].sp);
+ EXPECT_EQ(0x72a01cf594U, unwinder.frames()[6].pc);
+ EXPECT_EQ(0x7ffb6c0f30U, unwinder.frames()[6].sp);
+}
+
} // namespace unwindstack