Author: Jason Molenda Date: 2025-05-09T20:41:15-07:00 New Revision: a230bb029813b2988019dce342e2e622af14bd1d
URL: https://github.com/llvm/llvm-project/commit/a230bb029813b2988019dce342e2e622af14bd1d DIFF: https://github.com/llvm/llvm-project/commit/a230bb029813b2988019dce342e2e622af14bd1d.diff LOG: Revert "[lldb] Provide lr value in faulting frame on arm64 (#138805)" This test is failing on the LLDB Incremental bot (arm64), which is running an older set of tools (Xcode 15.2) and OS (macOS 14.1) and the CFI directives must not be emitted correctly by either the tools or the OS. I will need to reproduce how this is compiling on that older setup and see what the issue is. Reverting for now so the bots are not blocked. This reverts commit e897cb139ee6ef5c145fed5394c4d96baa658e6b. Added: Modified: lldb/source/Target/RegisterContextUnwind.cpp Removed: lldb/test/API/functionalities/unwind/frameless-faulted/Makefile lldb/test/API/functionalities/unwind/frameless-faulted/TestUnwindFramelessFaulted.py lldb/test/API/functionalities/unwind/frameless-faulted/interrupt-and-trap-funcs.c lldb/test/API/functionalities/unwind/frameless-faulted/main.c ################################################################################ diff --git a/lldb/source/Target/RegisterContextUnwind.cpp b/lldb/source/Target/RegisterContextUnwind.cpp index cf4b96c6eda9f..4c760b84e45a5 100644 --- a/lldb/source/Target/RegisterContextUnwind.cpp +++ b/lldb/source/Target/RegisterContextUnwind.cpp @@ -248,7 +248,6 @@ void RegisterContextUnwind::InitializeZerothFrame() { active_row = m_full_unwind_plan_sp->GetRowForFunctionOffset(m_current_offset); row_register_kind = m_full_unwind_plan_sp->GetRegisterKind(); - PropagateTrapHandlerFlagFromUnwindPlan(m_full_unwind_plan_sp); if (active_row && log) { StreamString active_row_strm; active_row->Dump(active_row_strm, m_full_unwind_plan_sp.get(), &m_thread, @@ -1376,7 +1375,6 @@ RegisterContextUnwind::SavedLocationForRegister( } } - // Check if the active_row has a register location listed. if (regnum.IsValid() && active_row && active_row->GetRegisterInfo(regnum.GetAsKind(unwindplan_registerkind), unwindplan_regloc)) { @@ -1390,10 +1388,11 @@ RegisterContextUnwind::SavedLocationForRegister( // This is frame 0 and we're retrieving the PC and it's saved in a Return // Address register and it hasn't been saved anywhere yet -- that is, // it's still live in the actual register. Handle this specially. + if (!have_unwindplan_regloc && return_address_reg.IsValid() && - return_address_reg.GetAsKind(eRegisterKindLLDB) != - LLDB_INVALID_REGNUM) { - if (IsFrameZero()) { + IsFrameZero()) { + if (return_address_reg.GetAsKind(eRegisterKindLLDB) != + LLDB_INVALID_REGNUM) { lldb_private::UnwindLLDB::ConcreteRegisterLocation new_regloc; new_regloc.type = UnwindLLDB::ConcreteRegisterLocation:: eRegisterInLiveRegisterContext; @@ -1407,17 +1406,6 @@ RegisterContextUnwind::SavedLocationForRegister( return_address_reg.GetAsKind(eRegisterKindLLDB), return_address_reg.GetAsKind(eRegisterKindLLDB)); return UnwindLLDB::RegisterSearchResult::eRegisterFound; - } else if (BehavesLikeZerothFrame()) { - // This function was interrupted asynchronously -- it faulted, - // an async interrupt, a timer fired, a debugger expression etc. - // The caller's pc is in the Return Address register, but the - // UnwindPlan for this function may have no location rule for - // the RA reg. - // This means that the caller's return address is in the RA reg - // when the function was interrupted--descend down one stack frame - // to retrieve it from the trap handler's saved context. - unwindplan_regloc.SetSame(); - have_unwindplan_regloc = true; } } @@ -1934,7 +1922,6 @@ void RegisterContextUnwind::PropagateTrapHandlerFlagFromUnwindPlan( } m_frame_type = eTrapHandlerFrame; - UnwindLogMsg("This frame is marked as a trap handler via its UnwindPlan"); if (m_current_offset_backed_up_one != m_current_offset) { // We backed up the pc by 1 to compute the symbol context, but diff --git a/lldb/test/API/functionalities/unwind/frameless-faulted/Makefile b/lldb/test/API/functionalities/unwind/frameless-faulted/Makefile deleted file mode 100644 index fca47ae47491c..0000000000000 --- a/lldb/test/API/functionalities/unwind/frameless-faulted/Makefile +++ /dev/null @@ -1,13 +0,0 @@ -C_SOURCES := main.c - -interrupt-and-trap-funcs.o: interrupt-and-trap-funcs.c - $(CC) $(CFLAGS) -E -o interrupt-and-trap-funcs.s $(SRCDIR)/interrupt-and-trap-funcs.c - $(CC) $(CFLAGS) -c -o interrupt-and-trap-funcs.o interrupt-and-trap-funcs.s - -include Makefile.rules - -a.out: interrupt-and-trap-funcs.o - -# Needs to come after include -OBJECTS += interrupt-and-trap-funcs.o - diff --git a/lldb/test/API/functionalities/unwind/frameless-faulted/TestUnwindFramelessFaulted.py b/lldb/test/API/functionalities/unwind/frameless-faulted/TestUnwindFramelessFaulted.py deleted file mode 100644 index a03d994045773..0000000000000 --- a/lldb/test/API/functionalities/unwind/frameless-faulted/TestUnwindFramelessFaulted.py +++ /dev/null @@ -1,122 +0,0 @@ -"""Test that lldb backtraces a frameless function that faults correctly.""" - -import lldbsuite.test.lldbutil as lldbutil -from lldbsuite.test.lldbtest import * -from lldbsuite.test.decorators import * -import shutil -import os - - -class TestUnwindFramelessFaulted(TestBase): - NO_DEBUG_INFO_TESTCASE = True - - @skipIf( - oslist=no_match([lldbplatformutil.getDarwinOSTriples(), "linux"]), - archs=no_match(["aarch64", "arm64", "arm64e"]), - ) - def test_frameless_faulted_unwind(self): - self.build() - - (target, process, thread, bp) = lldbutil.run_to_name_breakpoint( - self, "main", only_one_thread=False - ) - - # The test program will have a backtrace like this at its deepest: - # - # * frame #0: 0x0000000102adc468 a.out`break_to_debugger + 4 - # frame #1: 0x0000000102adc458 a.out`trap + 16 - # frame #2: 0x0000000102adc440 a.out`to_be_interrupted + 20 - # frame #3: 0x0000000102adc418 a.out`main at main.c:4:7 - # frame #4: 0x0000000193b7eb4c dyld`start + 6000 - - correct_frames = ["break_to_debugger", "trap", "to_be_interrupted", "main"] - - # Keep track of when main has branch & linked, instruction step until we're - # back in main() - main_has_bl_ed = False - - # Instruction step through the binary until we are in a function not - # listed in correct_frames. - frame = thread.GetFrameAtIndex(0) - step_count = 0 - max_step_count = 200 - while ( - process.GetState() == lldb.eStateStopped - and frame.name in correct_frames - and step_count < max_step_count - ): - starting_index = 0 - if self.TraceOn(): - self.runCmd("bt") - - # Find which index into correct_frames the current stack frame is - for idx, name in enumerate(correct_frames): - if frame.name == name: - starting_index = idx - - # Test that all frames after the current frame listed in - # correct_frames appears in the backtrace. - frame_idx = 0 - for expected_frame in correct_frames[starting_index:]: - self.assertEqual(thread.GetFrameAtIndex(frame_idx).name, expected_frame) - frame_idx = frame_idx + 1 - - # When we're at our deepest level, test that register passing of - # x0 and x20 follow the by-hand UnwindPlan rules. - # In this test program, we can get x0 in the middle of the stack - # and we CAN'T get x20. The opposites of the normal AArch64 SysV - # ABI. - if frame.name == "break_to_debugger": - tbi_frame = thread.GetFrameAtIndex(2) - self.assertEqual(tbi_frame.name, "to_be_interrupted") - # The original argument to to_be_interrupted(), 10 - # Normally can't get x0 mid-stack, but UnwindPlans have - # special rules to make this possible. - x0_reg = tbi_frame.register["x0"] - self.assertTrue(x0_reg.IsValid()) - self.assertEqual(x0_reg.GetValueAsUnsigned(), 10) - # The incremented return value from to_be_interrupted(), 11 - x24_reg = tbi_frame.register["x24"] - self.assertTrue(x24_reg.IsValid()) - self.assertEqual(x24_reg.GetValueAsUnsigned(), 11) - # x20 can normally be fetched mid-stack, but the UnwindPlan - # has a rule saying it can't be fetched. - x20_reg = tbi_frame.register["x20"] - self.assertTrue(x20_reg.error.fail) - - trap_frame = thread.GetFrameAtIndex(1) - self.assertEqual(trap_frame.name, "trap") - # Confirm that we can fetch x0 from trap() which - # is normally not possible w/ SysV AbI, but special - # UnwindPlans in use. - x0_reg = trap_frame.register["x0"] - self.assertTrue(x0_reg.IsValid()) - self.assertEqual(x0_reg.GetValueAsUnsigned(), 10) - x1_reg = trap_frame.register["x1"] - self.assertTrue(x1_reg.error.fail) - - main_frame = thread.GetFrameAtIndex(3) - self.assertEqual(main_frame.name, "main") - # x20 can normally be fetched mid-stack, but the UnwindPlan - # has a rule saying it can't be fetched. - x20_reg = main_frame.register["x20"] - self.assertTrue(x20_reg.error.fail) - # x21 can be fetched mid-stack. - x21_reg = main_frame.register["x21"] - self.assertTrue(x21_reg.error.success) - - # manually move past the BRK instruction in - # break_to_debugger(). lldb-server doesn't - # advance past the builtin_debugtrap() BRK - # instruction. - if ( - thread.GetStopReason() == lldb.eStopReasonException - and frame.name == "break_to_debugger" - ): - frame.SetPC(frame.GetPC() + 4) - - if self.TraceOn(): - print("StepInstruction") - thread.StepInstruction(False) - frame = thread.GetFrameAtIndex(0) - step_count = step_count + 1 diff --git a/lldb/test/API/functionalities/unwind/frameless-faulted/interrupt-and-trap-funcs.c b/lldb/test/API/functionalities/unwind/frameless-faulted/interrupt-and-trap-funcs.c deleted file mode 100644 index ba6537226f920..0000000000000 --- a/lldb/test/API/functionalities/unwind/frameless-faulted/interrupt-and-trap-funcs.c +++ /dev/null @@ -1,126 +0,0 @@ -// This is assembly code that needs to be run -// through the preprocessor, for simplicity of -// preprocessing it's named .c to start with. -// -// clang-format off - - -#define DW_CFA_register 0x9 -#define ehframe_x0 0 -#define ehframe_x20 20 -#define ehframe_x22 22 -#define ehframe_x23 23 -#define ehframe_pc 32 - -#if defined(__APPLE__) -#define TO_BE_INTERRUPTED _to_be_interrupted -#define TRAP _trap -#define BREAK_TO_DEBUGGER _break_to_debugger -#else -#define TO_BE_INTERRUPTED to_be_interrupted -#define TRAP trap -#define BREAK_TO_DEBUGGER break_to_debugger -#endif - - .text -//-------------------------------------- -// to_be_interrupted() a frameless function that does a non-ABI -// function call to trap(), simulating an async signal/interrup/exception/fault. -// Before it branches to trap(), put the return address in x23. -// trap() knows to branch back to $x23 when it has finished. -//-------------------------------------- - .globl TO_BE_INTERRUPTED -TO_BE_INTERRUPTED: - .cfi_startproc - - // This is a garbage entry to ensure that eh_frame is emitted. - // If there's no eh_frame, lldb can use the assembly emulation scan, - // which always includes a rule for $lr, and we won't replicate the - // bug we're testing for. - .cfi_escape DW_CFA_register, ehframe_x22, ehframe_x23 - mov x24, x0 - add x24, x24, #1 - -#if defined(__APPLE__) - adrp x23, L_.return@PAGE // put return address in x23 - add x23, x23, L_.return@PAGEOFF -#else - adrp x23, .L.return - add x23, x23, :lo12:.L.return -#endif - - b TRAP // branch to trap handler, fake async interrupt - -#if defined(__APPLE__) -L_.return: -#else -.L.return: -#endif - mov x0, x24 - ret - .cfi_endproc - - - -//-------------------------------------- -// trap() trap handler function, sets up stack frame -// with special unwind rule for the pc value of the -// "interrupted" stack frame (it's in x23), then calls -// break_to_debugger(). -//-------------------------------------- - .globl TRAP -TRAP: - .cfi_startproc - .cfi_signal_frame - - // The pc value when we were interrupted is in x23 - .cfi_escape DW_CFA_register, ehframe_pc, ehframe_x23 - - // For fun, mark x0 as unmodified so the caller can - // retrieve the value if it wants. - .cfi_same_value ehframe_x0 - - // Mark x20 as undefined. This is a callee-preserved - // (non-volatile) register by the SysV AArch64 ABI, but - // it'll be fun to see lldb not passing a value past this - // point on the stack. - .cfi_undefined ehframe_x20 - - // standard prologue save of fp & lr so we can call - // break_to_debugger() - sub sp, sp, #32 - stp x29, x30, [sp, #16] - add x29, sp, #16 - .cfi_def_cfa w29, 16 - .cfi_offset w30, -8 - .cfi_offset w29, -16 - - bl BREAK_TO_DEBUGGER - - ldp x29, x30, [sp, #16] - .cfi_same_value x29 - .cfi_same_value x30 - .cfi_def_cfa sp, 32 - add sp, sp, #32 - .cfi_same_value sp - .cfi_def_cfa sp, 0 - - // jump back to $x23 to resume execution of to_be_interrupted - br x23 - .cfi_endproc - -//-------------------------------------- -// break_to_debugger() executes a BRK instruction -//-------------------------------------- - .globl BREAK_TO_DEBUGGER -BREAK_TO_DEBUGGER: - .cfi_startproc - - // For fun, mark x0 as unmodified so the caller can - // retrieve the value if it wants. - .cfi_same_value ehframe_x0 - - brk #0xf000 // __builtin_debugtrap aarch64 instruction - - ret - .cfi_endproc diff --git a/lldb/test/API/functionalities/unwind/frameless-faulted/main.c b/lldb/test/API/functionalities/unwind/frameless-faulted/main.c deleted file mode 100644 index e5f690a21a45e..0000000000000 --- a/lldb/test/API/functionalities/unwind/frameless-faulted/main.c +++ /dev/null @@ -1,7 +0,0 @@ -int to_be_interrupted(int); - -int main() { - int c = 10; - c = to_be_interrupted(c); - return c; -} _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
