jimzah/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2024-11-27 23:52:31 +00:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity
551f153718
zig/lib/std/dwarf/abi.zig
kcbanner c98e03fc7e - rework CFI instruction parsing to not use std.meta 
- move register formatting code to zig-dwardump
2023-07-20 22:58:13 -04:00

243 lines
12 KiB
Zig
Raw Blame History

const builtin = @import("builtin");
const std = @import("../std.zig");
const os = std.os;
const mem = std.mem;
pub const RegisterContext = struct {
eh_frame: bool,
is_macho: bool,
};
pub fn ipRegNum() u8 {
return switch (builtin.cpu.arch) {
.x86 => 8,
.x86_64 => 16,
.arm => 15,
.aarch64 => 32,
else => unreachable,
};
}
pub fn fpRegNum(reg_ctx: RegisterContext) u8 {
return switch (builtin.cpu.arch) {
// GCC on OS X did the opposite of ELF for these registers (only in .eh_frame), and that is now the convention for MachO
.x86 => if (reg_ctx.eh_frame and reg_ctx.is_macho) 4 else 5,
.x86_64 => 6,
.arm => 11,
.aarch64 => 29,
else => unreachable,
};
}
pub fn spRegNum(reg_ctx: RegisterContext) u8 {
return switch (builtin.cpu.arch) {
.x86 => if (reg_ctx.eh_frame and reg_ctx.is_macho) 5 else 4,
.x86_64 => 7,
.arm => 13,
.aarch64 => 31,
else => unreachable,
};
}
fn RegBytesReturnType(comptime ContextPtrType: type) type {
const info = @typeInfo(ContextPtrType);
if (info != .Pointer or info.Pointer.child != os.ucontext_t) {
@compileError("Expected a pointer to ucontext_t, got " ++ @typeName(@TypeOf(ContextPtrType)));
}
return if (info.Pointer.is_const) return []const u8 else []u8;
}
/// Returns a slice containing the backing storage for `reg_number`.
///
/// `reg_ctx` describes in what context the register number is used, as it can have different
/// meanings depending on the DWARF container. It is only required when getting the stack or
/// frame pointer register on some architectures.
pub fn regBytes(ucontext_ptr: anytype, reg_number: u8, reg_ctx: ?RegisterContext) !RegBytesReturnType(@TypeOf(ucontext_ptr)) {
var m = &ucontext_ptr.mcontext;
return switch (builtin.cpu.arch) {
.x86 => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.EAX]),
1 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.ECX]),
2 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.EDX]),
3 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.EBX]),
4...5 => if (reg_ctx) |r| bytes: {
if (reg_number == 4) {
break :bytes if (r.eh_frame and r.is_macho)
mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.EBP])
else
mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.ESP]);
} else {
break :bytes if (r.eh_frame and r.is_macho)
mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.ESP])
else
mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.EBP]);
}
} else error.RegisterContextRequired,
6 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.ESI]),
7 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.EDI]),
8 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.EIP]),
9 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.EFL]),
10 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.CS]),
11 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.SS]),
12 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.DS]),
13 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.ES]),
14 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.FS]),
15 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.GS]),
16...23 => error.InvalidRegister, // TODO: Support loading ST0-ST7 from mcontext.fpregs
// TODO: Map TRAPNO, ERR, UESP
32...39 => error.InvalidRegister, // TODO: Support loading XMM0-XMM7 from mcontext.fpregs
else => error.InvalidRegister,
},
.x86_64 => switch (builtin.os.tag) {
.linux, .netbsd, .solaris => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.RAX]),
1 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.RDX]),
2 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.RCX]),
3 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.RBX]),
4 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.RSI]),
5 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.RDI]),
6 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.RBP]),
7 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.RSP]),
8 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.R8]),
9 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.R9]),
10 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.R10]),
11 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.R11]),
12 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.R12]),
13 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.R13]),
14 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.R14]),
15 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.R15]),
16 => mem.asBytes(&ucontext_ptr.mcontext.gregs[os.REG.RIP]),
17...32 => |i| mem.asBytes(&m.fpregs.xmm[i - 17]),
else => error.InvalidRegister,
},
.freebsd => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.mcontext.rax),
1 => mem.asBytes(&ucontext_ptr.mcontext.rdx),
2 => mem.asBytes(&ucontext_ptr.mcontext.rcx),
3 => mem.asBytes(&ucontext_ptr.mcontext.rbx),
4 => mem.asBytes(&ucontext_ptr.mcontext.rsi),
5 => mem.asBytes(&ucontext_ptr.mcontext.rdi),
6 => mem.asBytes(&ucontext_ptr.mcontext.rbp),
7 => mem.asBytes(&ucontext_ptr.mcontext.rsp),
8 => mem.asBytes(&ucontext_ptr.mcontext.r8),
9 => mem.asBytes(&ucontext_ptr.mcontext.r9),
10 => mem.asBytes(&ucontext_ptr.mcontext.r10),
11 => mem.asBytes(&ucontext_ptr.mcontext.r11),
12 => mem.asBytes(&ucontext_ptr.mcontext.r12),
13 => mem.asBytes(&ucontext_ptr.mcontext.r13),
14 => mem.asBytes(&ucontext_ptr.mcontext.r14),
15 => mem.asBytes(&ucontext_ptr.mcontext.r15),
16 => mem.asBytes(&ucontext_ptr.mcontext.rip),
// TODO: Extract xmm state from mcontext.fpstate?
else => error.InvalidRegister,
},
.openbsd => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.sc_rax),
1 => mem.asBytes(&ucontext_ptr.sc_rdx),
2 => mem.asBytes(&ucontext_ptr.sc_rcx),
3 => mem.asBytes(&ucontext_ptr.sc_rbx),
4 => mem.asBytes(&ucontext_ptr.sc_rsi),
5 => mem.asBytes(&ucontext_ptr.sc_rdi),
6 => mem.asBytes(&ucontext_ptr.sc_rbp),
7 => mem.asBytes(&ucontext_ptr.sc_rsp),
8 => mem.asBytes(&ucontext_ptr.sc_r8),
9 => mem.asBytes(&ucontext_ptr.sc_r9),
10 => mem.asBytes(&ucontext_ptr.sc_r10),
11 => mem.asBytes(&ucontext_ptr.sc_r11),
12 => mem.asBytes(&ucontext_ptr.sc_r12),
13 => mem.asBytes(&ucontext_ptr.sc_r13),
14 => mem.asBytes(&ucontext_ptr.sc_r14),
15 => mem.asBytes(&ucontext_ptr.sc_r15),
16 => mem.asBytes(&ucontext_ptr.sc_rip),
// TODO: Extract xmm state from sc_fpstate?
else => error.InvalidRegister,
},
.macos => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.mcontext.ss.rax),
1 => mem.asBytes(&ucontext_ptr.mcontext.ss.rdx),
2 => mem.asBytes(&ucontext_ptr.mcontext.ss.rcx),
3 => mem.asBytes(&ucontext_ptr.mcontext.ss.rbx),
4 => mem.asBytes(&ucontext_ptr.mcontext.ss.rsi),
5 => mem.asBytes(&ucontext_ptr.mcontext.ss.rdi),
6 => mem.asBytes(&ucontext_ptr.mcontext.ss.rbp),
7 => mem.asBytes(&ucontext_ptr.mcontext.ss.rsp),
8 => mem.asBytes(&ucontext_ptr.mcontext.ss.r8),
9 => mem.asBytes(&ucontext_ptr.mcontext.ss.r9),
10 => mem.asBytes(&ucontext_ptr.mcontext.ss.r10),
11 => mem.asBytes(&ucontext_ptr.mcontext.ss.r11),
12 => mem.asBytes(&ucontext_ptr.mcontext.ss.r12),
13 => mem.asBytes(&ucontext_ptr.mcontext.ss.r13),
14 => mem.asBytes(&ucontext_ptr.mcontext.ss.r14),
15 => mem.asBytes(&ucontext_ptr.mcontext.ss.r15),
16 => mem.asBytes(&ucontext_ptr.mcontext.ss.rip),
else => error.InvalidRegister,
},
else => error.UnimplementedOs,
},
.arm => switch (builtin.os.tag) {
.linux => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.mcontext.arm_r0),
1 => mem.asBytes(&ucontext_ptr.mcontext.arm_r1),
2 => mem.asBytes(&ucontext_ptr.mcontext.arm_r2),
3 => mem.asBytes(&ucontext_ptr.mcontext.arm_r3),
4 => mem.asBytes(&ucontext_ptr.mcontext.arm_r4),
5 => mem.asBytes(&ucontext_ptr.mcontext.arm_r5),
6 => mem.asBytes(&ucontext_ptr.mcontext.arm_r6),
7 => mem.asBytes(&ucontext_ptr.mcontext.arm_r7),
8 => mem.asBytes(&ucontext_ptr.mcontext.arm_r8),
9 => mem.asBytes(&ucontext_ptr.mcontext.arm_r9),
10 => mem.asBytes(&ucontext_ptr.mcontext.arm_r10),
11 => mem.asBytes(&ucontext_ptr.mcontext.arm_fp),
12 => mem.asBytes(&ucontext_ptr.mcontext.arm_ip),
13 => mem.asBytes(&ucontext_ptr.mcontext.arm_sp),
14 => mem.asBytes(&ucontext_ptr.mcontext.arm_lr),
15 => mem.asBytes(&ucontext_ptr.mcontext.arm_pc),
// CPSR is not allocated a register number (See: https://github.com/ARM-software/abi-aa/blob/main/aadwarf32/aadwarf32.rst, Section 4.1)
else => error.InvalidRegister,
},
else => error.UnimplementedOs,
},
.aarch64 => switch (builtin.os.tag) {
.macos => switch (reg_number) {
0...28 => mem.asBytes(&ucontext_ptr.mcontext.ss.regs[reg_number]),
29 => mem.asBytes(&ucontext_ptr.mcontext.ss.fp),
30 => mem.asBytes(&ucontext_ptr.mcontext.ss.lr),
31 => mem.asBytes(&ucontext_ptr.mcontext.ss.sp),
32 => mem.asBytes(&ucontext_ptr.mcontext.ss.pc),
else => error.InvalidRegister,
},
.netbsd => switch (reg_number) {
0...34 => mem.asBytes(&ucontext_ptr.mcontext.gregs[reg_number]),
else => error.InvalidRegister,
},
.freebsd => switch (reg_number) {
0...29 => mem.asBytes(&ucontext_ptr.mcontext.gpregs.x[reg_number]),
30 => mem.asBytes(&ucontext_ptr.mcontext.gpregs.lr),
31 => mem.asBytes(&ucontext_ptr.mcontext.gpregs.sp),
// TODO: This seems wrong, but it was in the previous debug.zig code for mapping PC, check this
32 => mem.asBytes(&ucontext_ptr.mcontext.gpregs.elr),
else => error.InvalidRegister,
},
else => switch (reg_number) {
0...30 => mem.asBytes(&ucontext_ptr.mcontext.regs[reg_number]),
31 => mem.asBytes(&ucontext_ptr.mcontext.sp),
32 => mem.asBytes(&ucontext_ptr.mcontext.pc),
else => error.InvalidRegister,
},
},
else => error.UnimplementedArch,
};
}
/// Returns the ABI-defined default value this register has in the unwinding table
/// before running any of the CIE instructions.
pub fn getRegDefaultValue(reg_number: u8, out: []u8) void {
// TODO: Implement any ABI-specific rules for the default value for registers
_ = reg_number;
@memset(out, undefined);
}
Reference in New Issue View Git Blame Copy Permalink