| author |  Casey Banner <kcbanner@gmail.com> 2023-07-18 01:21:45-04:00 |
| committer | Casey Banner <kcbanner@gmail.com> 2023-07-20 22:58:16-04:00 |
| log | d99b40d38b48f046b8d7faa7698315d6c93bf685 |
| tree | fe55508c44f064175bbc44541f3bebb826a98100 |
| parent | 1a2bb70956df44e9c1dd2f06e1e98b4b7ff265d6 |
dwarf: fix the unwinder using the incorrect row from the FDE in certain cases
2 files changed, 19 insertions(+), 11 deletions(-)
lib- std
lib/std/dwarf.zig+15-3
| ... | ... | @@ -1740,8 +1740,20 @@ pub const DwarfInfo = struct { |
| 1740 | 1740 | context.reg_context.eh_frame = cie.version != 4; |
| 1741 | 1741 | context.reg_context.is_macho = di.is_macho; |
| 1742 | 1742 | |
| 1743 | _ = try context.vm.runToNative(context.allocator, context.pc, cie, fde); | |
| 1744 | const row = &context.vm.current_row; | |
| 1743 | if (comptime builtin.target.isDarwin()) { | |
| 1744 | std.debug.print(" state before:\n", .{}); | |
| 1745 | std.debug.print(" cfa {?x}:\n", .{context.cfa}); | |
| 1746 | for (context.thread_context.mcontext.ss.regs, 0..) |reg, i| { | |
| 1747 | std.debug.print(" {}:0x{x}\n", .{i, reg}); | |
| 1748 | } | |
| 1749 | std.debug.print(" fp:0x{x}\n", .{context.thread_context.mcontext.ss.fp}); | |
| 1750 | std.debug.print(" lr:0x{x}\n", .{context.thread_context.mcontext.ss.lr}); | |
| 1751 | std.debug.print(" sp:0x{x}\n", .{context.thread_context.mcontext.ss.sp}); | |
| 1752 | std.debug.print(" pc:0x{x}\n", .{context.thread_context.mcontext.ss.pc}); | |
| 1753 | } | |
| 1754 | ||
| 1755 | const row = try context.vm.runToNative(context.allocator, context.pc, cie, fde); | |
| 1756 | std.debug.print(" ran to 0x{x}\n", .{row.offset + fde.pc_begin}); | |
| 1745 | 1757 | |
| 1746 | 1758 | context.cfa = switch (row.cfa.rule) { |
| 1747 | 1759 | .val_offset => |offset| blk: { |
| ... | ... | @@ -1785,7 +1797,7 @@ pub const DwarfInfo = struct { |
| 1785 | 1797 | |
| 1786 | 1798 | var update_tail: ?*RegisterUpdate = null; |
| 1787 | 1799 | var has_next_ip = false; |
| 1788 | for (context.vm.rowColumns(row.*)) |column| { | |
| 1800 | for (context.vm.rowColumns(row)) |column| { | |
| 1789 | 1801 | if (column.register) |register| { |
| 1790 | 1802 | if (register == cie.return_address_register) { |
| 1791 | 1803 | has_next_ip = column.rule != .undefined; |
lib/std/dwarf/call_frame.zig+4-8
| ... | ... | @@ -395,9 +395,7 @@ pub const VirtualMachine = struct { |
| 395 | 395 | } |
| 396 | 396 | |
| 397 | 397 | /// Runs the CIE instructions, then the FDE instructions. Execution halts |
| 398 | /// once the row that corresponds to `pc` is known (and set as `current_row`). | |
| 399 | /// | |
| 400 | /// The state of the row prior to the last execution step is returned. | |
| 398 | /// once the row that corresponds to `pc` is known, and the row is returned. | |
| 401 | 399 | pub fn runTo( |
| 402 | 400 | self: *VirtualMachine, |
| 403 | 401 | allocator: std.mem.Allocator, |
| ... | ... | @@ -419,17 +417,15 @@ pub const VirtualMachine = struct { |
| 419 | 417 | &fde_stream, |
| 420 | 418 | }; |
| 421 | 419 | |
| 422 | outer: for (&streams, 0..) |stream, i| { | |
| 420 | for (&streams, 0..) |stream, i| { | |
| 423 | 421 | while (stream.pos < stream.buffer.len) { |
| 424 | 422 | const instruction = try dwarf.call_frame.Instruction.read(stream, addr_size_bytes, endian); |
| 425 | 423 | prev_row = try self.step(allocator, cie, i == 0, instruction); |
| 426 | if (pc < fde.pc_begin + self.current_row.offset) { | |
| 427 | break :outer; | |
| 428 | } | |
| 424 | if (pc < fde.pc_begin + self.current_row.offset) return prev_row; | |
| 429 | 425 | } |
| 430 | 426 | } |
| 431 | 427 | |
| 432 | return prev_row; | |
| 428 | return self.current_row; | |
| 433 | 429 | } |
| 434 | 430 | |
| 435 | 431 | pub fn runToNative( |