Handle ARM thumb function symbols.

ARM thumb functions will have the zero bit set to one, which can cause
function name lookups to fail.

Add an ARM special GetFunctionName that handles this condition.

Fix a couple of the function offsets in unit tests.

Bug: 74844137

Test: Ran unit tests.
Test: Ran debuggerd -b on processes on a bullhead device.
Change-Id: Ibd407db34eaaa641f91fdb4f589c44a0dcc0216a
This commit is contained in:
Christopher Ferris 2018-03-15 14:35:01 -07:00
parent 39273df651
commit 704ec9adba
4 changed files with 19 additions and 4 deletions

View File

@ -171,4 +171,17 @@ bool ElfInterfaceArm::StepExidx(uint64_t pc, uint64_t load_bias, Regs* regs, Mem
return return_value;
}
bool ElfInterfaceArm::GetFunctionName(uint64_t addr, uint64_t load_bias, std::string* name,
uint64_t* offset) {
// For ARM, thumb function symbols have bit 0 set, but the address passed
// in here might not have this bit set and result in a failure to find
// the thumb function names. Adjust the address and offset to account
// for this possible case.
if (ElfInterface32::GetFunctionName(addr | 1, load_bias, name, offset)) {
*offset &= ~1;
return true;
}
return false;
}
} // namespace unwindstack

View File

@ -76,6 +76,9 @@ class ElfInterfaceArm : public ElfInterface32 {
bool StepExidx(uint64_t pc, uint64_t load_bias, Regs* regs, Memory* process_memory,
bool* finished);
bool GetFunctionName(uint64_t addr, uint64_t load_bias, std::string* name,
uint64_t* offset) override;
uint64_t start_offset() { return start_offset_; }
size_t total_entries() { return total_entries_; }

View File

@ -188,7 +188,7 @@ TEST_F(UnwindOfflineTest, pc_straddle_arm) {
std::string frame_info(DumpFrames(unwinder));
ASSERT_EQ(4U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
EXPECT_EQ(
" #00 pc 0001a9f8 libc.so (abort+63)\n"
" #00 pc 0001a9f8 libc.so (abort+64)\n"
" #01 pc 00006a1b libbase.so (_ZN7android4base14DefaultAborterEPKc+6)\n"
" #02 pc 00007441 libbase.so (_ZN7android4base10LogMessageD2Ev+748)\n"
" #03 pc 00015147 /does/not/exist/libhidlbase.so\n",
@ -575,7 +575,7 @@ TEST_F(UnwindOfflineTest, jit_debug_arm) {
std::string frame_info(DumpFrames(unwinder));
ASSERT_EQ(76U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
EXPECT_EQ(
" #00 pc 00018a5e libarttestd.so (Java_Main_unwindInProcess+865)\n"
" #00 pc 00018a5e libarttestd.so (Java_Main_unwindInProcess+866)\n"
" #01 pc 0000212d (offset 0x2000) 137-cfi.odex (boolean Main.unwindInProcess(boolean, int, "
"boolean)+92)\n"
" #02 pc 00011cb1 anonymous:e2796000 (boolean Main.bar(boolean)+72)\n"

View File

@ -53,8 +53,7 @@ void DumpArm(ElfInterfaceArm* interface) {
printf(" PC 0x%" PRIx64, addr + load_bias);
uint64_t func_offset;
uint64_t pc = addr + load_bias;
// This might be a thumb function, so set the low bit.
if (interface->GetFunctionName(pc | 1, load_bias, &name, &func_offset) && !name.empty()) {
if (interface->GetFunctionName(pc, load_bias, &name, &func_offset) && !name.empty()) {
printf(" <%s>", name.c_str());
}
printf("\n");