commit 239425b9fa91ae13d18cf8158b31663876d07acf
author Christopher Ferris <cferris@google.com> Thu May 17 18:37:38 2018 -0700
committer Christopher Ferris <cferris@google.com> Thu May 17 18:58:42 2018 -0700
tree e0fdc1e8cb6d728ad94dd5ca1a4e4161633d3999
parent 3464bc4b439e01244c0a6b5f35e8e949e0f16096

Fix bug when doing signal handler lookup.

The new lld linker uses all non-zero offset executable maps. There was
a bug when trying to find if the stack is in a signal handler that caused
the code to read the wrong place in the elf. Fixed by not adding the elf
offset to the relative pc.

Also fixed the unwind_for_offline tool to dump multiple stacks if necessary.

Added new offline unit test that would have failed with the old code.

Bug: 79936827

Test: Ran unit tests and libbacktrace unit tests.
Test: Dumped backtraces of system pids.
Test: Ran 137-cfi art test.
Change-Id: Iaca8c18c2a314902e64c3f72831234297e8dcb1b

libunwindstack/tests/ElfTest.cpp

diff --git a/libunwindstack/tests/ElfTest.cpp b/libunwindstack/tests/ElfTest.cpp
index f9028c4..aecbf6d 100644
--- a/libunwindstack/tests/ElfTest.cpp
+++ b/libunwindstack/tests/ElfTest.cpp
@@ -133,7 +133,7 @@
   ASSERT_FALSE(elf.GetFunctionName(0, &name, &func_offset));
 
   bool finished;
-  ASSERT_FALSE(elf.Step(0, 0, 0, nullptr, nullptr, &finished));
+  ASSERT_FALSE(elf.Step(0, 0, nullptr, nullptr, &finished));
 }
 
 TEST_F(ElfTest, elf32_invalid_machine) {
@@ -330,7 +330,7 @@
   elf.FakeSetValid(true);
   elf.FakeSetLoadBias(0);
   bool finished;
-  ASSERT_TRUE(elf.Step(0x1000, 0x1000, 0x2000, &regs, &process_memory, &finished));
+  ASSERT_TRUE(elf.Step(0x3000, 0x1000, &regs, &process_memory, &finished));
   EXPECT_FALSE(finished);
   EXPECT_EQ(15U, regs.pc());
   EXPECT_EQ(13U, regs.sp());
@@ -370,7 +370,7 @@
   EXPECT_CALL(*interface, Step(0x1000, 0, &regs, &process_memory, &finished))
       .WillOnce(::testing::Return(true));
 
-  ASSERT_TRUE(elf.Step(0x1004, 0x1000, 0x2000, &regs, &process_memory, &finished));
+  ASSERT_TRUE(elf.Step(0x1004, 0x1000, &regs, &process_memory, &finished));
 }
 
 TEST_F(ElfTest, step_in_interface_non_zero_load_bias) {
@@ -388,7 +388,7 @@
   EXPECT_CALL(*interface, Step(0x7300, 0x4000, &regs, &process_memory, &finished))
       .WillOnce(::testing::Return(true));
 
-  ASSERT_TRUE(elf.Step(0x7304, 0x7300, 0x2000, &regs, &process_memory, &finished));
+  ASSERT_TRUE(elf.Step(0x7304, 0x7300, &regs, &process_memory, &finished));
 }
 
 TEST_F(ElfTest, get_global_invalid_elf) {