[Lldb-commits] [lldb] r270658 - Add support for arm64 compact unwind tables, used on darwin arm64
Jason Molenda via lldb-commits
lldb-commits at lists.llvm.org
Tue May 24 21:20:28 PDT 2016
Author: jmolenda
Date: Tue May 24 23:20:28 2016
New Revision: 270658
URL: http://llvm.org/viewvc/llvm-project?rev=270658&view=rev
Log:
Add support for arm64 compact unwind tables, used on darwin arm64
systems (ios, tvos, watchos). It's a simple format to use now that
I have i386/x86_64 supported already.
The unwind instructions are only valid at call sites -- that is,
when lldb is unwinding a frame in the middle of the stack. It
cannot be used for the currently executing frame; it has no information
about prologues/epilogues/etc.
<rdar://problem/12062336>
Modified:
lldb/trunk/include/lldb/Symbol/CompactUnwindInfo.h
lldb/trunk/source/Symbol/CompactUnwindInfo.cpp
lldb/trunk/tools/compact-unwind/compact-unwind-dumper.c
Modified: lldb/trunk/include/lldb/Symbol/CompactUnwindInfo.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/include/lldb/Symbol/CompactUnwindInfo.h?rev=270658&r1=270657&r2=270658&view=diff
==============================================================================
--- lldb/trunk/include/lldb/Symbol/CompactUnwindInfo.h (original)
+++ lldb/trunk/include/lldb/Symbol/CompactUnwindInfo.h Tue May 24 23:20:28 2016
@@ -133,6 +133,9 @@ private:
bool
CreateUnwindPlan_i386 (Target &target, FunctionInfo &function_info, UnwindPlan &unwind_plan, Address pc_or_function_start);
+ bool
+ CreateUnwindPlan_arm64 (Target &target, FunctionInfo &function_info, UnwindPlan &unwind_plan, Address pc_or_function_start);
+
ObjectFile &m_objfile;
lldb::SectionSP m_section_sp;
lldb::DataBufferSP m_section_contents_if_encrypted; // if the binary is encrypted, read the sect contents
Modified: lldb/trunk/source/Symbol/CompactUnwindInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Symbol/CompactUnwindInfo.cpp?rev=270658&r1=270657&r2=270658&view=diff
==============================================================================
--- lldb/trunk/source/Symbol/CompactUnwindInfo.cpp (original)
+++ lldb/trunk/source/Symbol/CompactUnwindInfo.cpp Tue May 24 23:20:28 2016
@@ -101,6 +101,27 @@ namespace lldb_private {
UNWIND_X86_64_REG_R15 = 5,
UNWIND_X86_64_REG_RBP = 6,
};
+
+ FLAGS_ANONYMOUS_ENUM()
+ {
+ UNWIND_ARM64_MODE_MASK = 0x0F000000,
+ UNWIND_ARM64_MODE_FRAMELESS = 0x02000000,
+ UNWIND_ARM64_MODE_DWARF = 0x03000000,
+ UNWIND_ARM64_MODE_FRAME = 0x04000000,
+
+ UNWIND_ARM64_FRAME_X19_X20_PAIR = 0x00000001,
+ UNWIND_ARM64_FRAME_X21_X22_PAIR = 0x00000002,
+ UNWIND_ARM64_FRAME_X23_X24_PAIR = 0x00000004,
+ UNWIND_ARM64_FRAME_X25_X26_PAIR = 0x00000008,
+ UNWIND_ARM64_FRAME_X27_X28_PAIR = 0x00000010,
+ UNWIND_ARM64_FRAME_D8_D9_PAIR = 0x00000100,
+ UNWIND_ARM64_FRAME_D10_D11_PAIR = 0x00000200,
+ UNWIND_ARM64_FRAME_D12_D13_PAIR = 0x00000400,
+ UNWIND_ARM64_FRAME_D14_D15_PAIR = 0x00000800,
+
+ UNWIND_ARM64_FRAMELESS_STACK_SIZE_MASK = 0x00FFF000,
+ UNWIND_ARM64_DWARF_SECTION_OFFSET = 0x00FFFFFF,
+ };
}
@@ -195,6 +216,10 @@ CompactUnwindInfo::GetUnwindPlan (Target
{
return CreateUnwindPlan_x86_64 (target, function_info, unwind_plan, addr);
}
+ if (arch.GetTriple().getArch() == llvm::Triple::aarch64)
+ {
+ return CreateUnwindPlan_arm64 (target, function_info, unwind_plan, addr);
+ }
if (arch.GetTriple().getArch() == llvm::Triple::x86)
{
return CreateUnwindPlan_i386 (target, function_info, unwind_plan, addr);
@@ -1229,3 +1254,166 @@ CompactUnwindInfo::CreateUnwindPlan_i386
}
return false;
}
+
+
+
+// DWARF register numbers from "DWARF for the ARM 64-bit Architecture (AArch64)" doc by ARM
+
+enum arm64_eh_regnum {
+ x19 = 19,
+ x20 = 20,
+ x21 = 21,
+ x22 = 22,
+ x23 = 23,
+ x24 = 24,
+ x25 = 25,
+ x26 = 26,
+ x27 = 27,
+ x28 = 28,
+
+ fp = 29,
+ ra = 30,
+ sp = 31,
+ pc = 32,
+
+ // Compact unwind encodes d8-d15 but we don't have eh_frame / dwarf reg #'s for the 64-bit
+ // fp regs. Normally in DWARF it's context sensitive - so it knows it is fetching a
+ // 32- or 64-bit quantity from reg v8 to indicate s0 or d0 - but the unwinder is operating
+ // at a lower level and we'd try to fetch 128 bits if we were told that v8 were stored on
+ // the stack...
+ v8 = 72,
+ v9 = 73,
+ v10 = 74,
+ v11 = 75,
+ v12 = 76,
+ v13 = 77,
+ v14 = 78,
+ v15 = 79,
+};
+
+bool
+CompactUnwindInfo::CreateUnwindPlan_arm64 (Target &target, FunctionInfo &function_info, UnwindPlan &unwind_plan, Address pc_or_function_start)
+{
+ unwind_plan.SetSourceName ("compact unwind info");
+ unwind_plan.SetSourcedFromCompiler (eLazyBoolYes);
+ unwind_plan.SetUnwindPlanValidAtAllInstructions (eLazyBoolNo);
+ unwind_plan.SetRegisterKind (eRegisterKindEHFrame);
+
+ unwind_plan.SetLSDAAddress (function_info.lsda_address);
+ unwind_plan.SetPersonalityFunctionPtr (function_info.personality_ptr_address);
+
+ UnwindPlan::RowSP row (new UnwindPlan::Row);
+
+ const int wordsize = 8;
+ int mode = function_info.encoding & UNWIND_ARM64_MODE_MASK;
+
+ if (mode == UNWIND_ARM64_MODE_DWARF)
+ return false;
+
+ if (mode == UNWIND_ARM64_MODE_FRAMELESS)
+ {
+ row->SetOffset (0);
+
+ uint32_t stack_size = (EXTRACT_BITS (function_info.encoding, UNWIND_ARM64_FRAMELESS_STACK_SIZE_MASK)) * 16;
+
+ // Our previous Call Frame Address is the stack pointer plus the stack size
+ row->GetCFAValue().SetIsRegisterPlusOffset (arm64_eh_regnum::sp, stack_size);
+
+ // Our previous PC is in the LR
+ row->SetRegisterLocationToRegister(arm64_eh_regnum::pc, arm64_eh_regnum::ra, true);
+
+ unwind_plan.AppendRow (row);
+ return true;
+ }
+
+ // Should not be possible
+ if (mode != UNWIND_ARM64_MODE_FRAME)
+ return false;
+
+
+ // mode == UNWIND_ARM64_MODE_FRAME
+
+ row->GetCFAValue().SetIsRegisterPlusOffset (arm64_eh_regnum::fp , 2 * wordsize);
+ row->SetOffset (0);
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::fp, wordsize * -2, true);
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::pc, wordsize * -1, true);
+ row->SetRegisterLocationToIsCFAPlusOffset (arm64_eh_regnum::sp, 0, true);
+
+ int reg_pairs_saved_count = 1;
+
+ uint32_t saved_register_bits = function_info.encoding & 0xfff;
+
+ if (saved_register_bits & UNWIND_ARM64_FRAME_X19_X20_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::x19, cfa_offset, true);
+ cfa_offset -= wordsize;
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::x20, cfa_offset, true);
+ reg_pairs_saved_count++;
+ }
+
+ if (saved_register_bits & UNWIND_ARM64_FRAME_X21_X22_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::x21, cfa_offset, true);
+ cfa_offset -= wordsize;
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::x22, cfa_offset, true);
+ reg_pairs_saved_count++;
+ }
+
+ if (saved_register_bits & UNWIND_ARM64_FRAME_X23_X24_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::x23, cfa_offset, true);
+ cfa_offset -= wordsize;
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::x24, cfa_offset, true);
+ reg_pairs_saved_count++;
+ }
+
+ if (saved_register_bits & UNWIND_ARM64_FRAME_X25_X26_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::x25, cfa_offset, true);
+ cfa_offset -= wordsize;
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::x26, cfa_offset, true);
+ reg_pairs_saved_count++;
+ }
+
+ if (saved_register_bits & UNWIND_ARM64_FRAME_X27_X28_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::x27, cfa_offset, true);
+ cfa_offset -= wordsize;
+ row->SetRegisterLocationToAtCFAPlusOffset (arm64_eh_regnum::x28, cfa_offset, true);
+ reg_pairs_saved_count++;
+ }
+
+ // If we use the v8-v15 regnums here, the unwinder will try to grab 128 bits off the stack;
+ // not sure if we have a good way to represent the 64-bitness of these saves.
+
+ if (saved_register_bits & UNWIND_ARM64_FRAME_D8_D9_PAIR)
+ {
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_D10_D11_PAIR)
+ {
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_D12_D13_PAIR)
+ {
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_D14_D15_PAIR)
+ {
+ reg_pairs_saved_count++;
+ }
+
+ unwind_plan.AppendRow (row);
+ return true;
+}
+
Modified: lldb/trunk/tools/compact-unwind/compact-unwind-dumper.c
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/compact-unwind/compact-unwind-dumper.c?rev=270658&r1=270657&r2=270658&view=diff
==============================================================================
--- lldb/trunk/tools/compact-unwind/compact-unwind-dumper.c (original)
+++ lldb/trunk/tools/compact-unwind/compact-unwind-dumper.c Tue May 24 23:20:28 2016
@@ -14,6 +14,28 @@
#include <stdio.h>
#include <mach-o/nlist.h>
+
+enum {
+ UNWIND_ARM64_MODE_MASK = 0x0F000000,
+ UNWIND_ARM64_MODE_FRAMELESS = 0x02000000,
+ UNWIND_ARM64_MODE_DWARF = 0x03000000,
+ UNWIND_ARM64_MODE_FRAME = 0x04000000,
+
+ UNWIND_ARM64_FRAME_X19_X20_PAIR = 0x00000001,
+ UNWIND_ARM64_FRAME_X21_X22_PAIR = 0x00000002,
+ UNWIND_ARM64_FRAME_X23_X24_PAIR = 0x00000004,
+ UNWIND_ARM64_FRAME_X25_X26_PAIR = 0x00000008,
+ UNWIND_ARM64_FRAME_X27_X28_PAIR = 0x00000010,
+ UNWIND_ARM64_FRAME_D8_D9_PAIR = 0x00000100,
+ UNWIND_ARM64_FRAME_D10_D11_PAIR = 0x00000200,
+ UNWIND_ARM64_FRAME_D12_D13_PAIR = 0x00000400,
+ UNWIND_ARM64_FRAME_D14_D15_PAIR = 0x00000800,
+
+ UNWIND_ARM64_FRAMELESS_STACK_SIZE_MASK = 0x00FFF000,
+ UNWIND_ARM64_DWARF_SECTION_OFFSET = 0x00FFFFFF,
+};
+
+
#define EXTRACT_BITS(value, mask) \
( (value >> __builtin_ctz(mask)) & (((1 << __builtin_popcount(mask)))-1) )
@@ -901,6 +923,129 @@ print_encoding_i386 (struct baton baton,
}
}
+void
+print_encoding_arm64 (struct baton baton, uint8_t *function_start, uint32_t encoding)
+{
+ const int wordsize = 8;
+ int mode = encoding & UNWIND_ARM64_MODE_MASK;
+ switch (mode)
+ {
+ case UNWIND_ARM64_MODE_FRAME:
+ {
+ printf ("frame func: CFA is fp+%d ", 16);
+ printf (" pc=[CFA-8] fp=[CFA-16]");
+ int reg_pairs_saved_count = 1;
+ uint32_t saved_register_bits = encoding & 0xfff;
+ if (saved_register_bits & UNWIND_ARM64_FRAME_X19_X20_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ printf (" x19=[CFA%d]", cfa_offset);
+ cfa_offset -= wordsize;
+ printf (" x20=[CFA%d]", cfa_offset);
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_X21_X22_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ printf (" x21=[CFA%d]", cfa_offset);
+ cfa_offset -= wordsize;
+ printf (" x22=[CFA%d]", cfa_offset);
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_X23_X24_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ printf (" x23=[CFA%d]", cfa_offset);
+ cfa_offset -= wordsize;
+ printf (" x24=[CFA%d]", cfa_offset);
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_X25_X26_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ printf (" x25=[CFA%d]", cfa_offset);
+ cfa_offset -= wordsize;
+ printf (" x26=[CFA%d]", cfa_offset);
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_X27_X28_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ printf (" x27=[CFA%d]", cfa_offset);
+ cfa_offset -= wordsize;
+ printf (" x28=[CFA%d]", cfa_offset);
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_D8_D9_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ printf (" d8=[CFA%d]", cfa_offset);
+ cfa_offset -= wordsize;
+ printf (" d9=[CFA%d]", cfa_offset);
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_D10_D11_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ printf (" d10=[CFA%d]", cfa_offset);
+ cfa_offset -= wordsize;
+ printf (" d11=[CFA%d]", cfa_offset);
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_D12_D13_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ printf (" d12=[CFA%d]", cfa_offset);
+ cfa_offset -= wordsize;
+ printf (" d13=[CFA%d]", cfa_offset);
+ reg_pairs_saved_count++;
+ }
+ if (saved_register_bits & UNWIND_ARM64_FRAME_D14_D15_PAIR)
+ {
+ int cfa_offset = reg_pairs_saved_count * -2 * wordsize;
+ cfa_offset -= wordsize;
+ printf (" d14=[CFA%d]", cfa_offset);
+ cfa_offset -= wordsize;
+ printf (" d15=[CFA%d]", cfa_offset);
+ reg_pairs_saved_count++;
+ }
+
+ }
+ break;
+
+ case UNWIND_ARM64_MODE_FRAMELESS:
+ {
+ uint32_t stack_size = encoding & UNWIND_ARM64_FRAMELESS_STACK_SIZE_MASK;
+ printf ("frameless function: stack size %d ", stack_size * 16);
+
+ }
+ break;
+
+ case UNWIND_ARM64_MODE_DWARF:
+ {
+ uint32_t dwarf_offset = encoding & UNWIND_ARM64_DWARF_SECTION_OFFSET;
+ printf ("DWARF unwind instructions: FDE at offset %d (file address 0x%" PRIx64 ")",
+ dwarf_offset, dwarf_offset + baton.eh_section_file_address);
+ }
+ break;
+
+ case 0:
+ {
+ printf (" no unwind information");
+ }
+ break;
+ }
+}
+
+
void print_encoding (struct baton baton, uint8_t *function_start, uint32_t encoding)
{
@@ -913,6 +1058,10 @@ void print_encoding (struct baton baton,
{
print_encoding_i386 (baton, function_start, encoding);
}
+ else if (baton.cputype == CPU_TYPE_ARM64)
+ {
+ print_encoding_arm64 (baton, function_start, encoding);
+ }
else
{
printf (" -- unsupported encoding arch -- ");
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