mirror of
https://github.com/ziglang/zig.git
synced 2025-12-06 06:13:07 +00:00
da018f9726
Whatever was in the frame pointer register prior to clone() will no longer be valid in the child process, so zero it to protect FP-based unwinders. Similarly, mark the link register as undefined to protect DWARF-based unwinders. This is only zeroing the frame pointer(s) on Arm/Thumb because of an LLVM assembler bug: https://github.com/llvm/llvm-project/issues/115891
471 lines
13 KiB
Zig
471 lines
13 KiB
Zig
const std = @import("../../std.zig");
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const maxInt = std.math.maxInt;
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const linux = std.os.linux;
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const SYS = linux.SYS;
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const iovec = std.posix.iovec;
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const iovec_const = std.posix.iovec_const;
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const pid_t = linux.pid_t;
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const uid_t = linux.uid_t;
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const gid_t = linux.gid_t;
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const clock_t = linux.clock_t;
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const stack_t = linux.stack_t;
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const sigset_t = linux.sigset_t;
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const sockaddr = linux.sockaddr;
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const socklen_t = linux.socklen_t;
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const timespec = linux.timespec;
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pub fn syscall0(number: SYS) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [number] "{rax}" (@intFromEnum(number)),
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: "rcx", "r11", "memory"
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);
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}
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pub fn syscall1(number: SYS, arg1: usize) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [number] "{rax}" (@intFromEnum(number)),
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[arg1] "{rdi}" (arg1),
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: "rcx", "r11", "memory"
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);
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}
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pub fn syscall2(number: SYS, arg1: usize, arg2: usize) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [number] "{rax}" (@intFromEnum(number)),
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[arg1] "{rdi}" (arg1),
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[arg2] "{rsi}" (arg2),
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: "rcx", "r11", "memory"
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);
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}
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pub fn syscall3(number: SYS, arg1: usize, arg2: usize, arg3: usize) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [number] "{rax}" (@intFromEnum(number)),
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[arg1] "{rdi}" (arg1),
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[arg2] "{rsi}" (arg2),
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[arg3] "{rdx}" (arg3),
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: "rcx", "r11", "memory"
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);
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}
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pub fn syscall4(number: SYS, arg1: usize, arg2: usize, arg3: usize, arg4: usize) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [number] "{rax}" (@intFromEnum(number)),
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[arg1] "{rdi}" (arg1),
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[arg2] "{rsi}" (arg2),
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[arg3] "{rdx}" (arg3),
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[arg4] "{r10}" (arg4),
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: "rcx", "r11", "memory"
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);
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}
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pub fn syscall5(number: SYS, arg1: usize, arg2: usize, arg3: usize, arg4: usize, arg5: usize) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [number] "{rax}" (@intFromEnum(number)),
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[arg1] "{rdi}" (arg1),
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[arg2] "{rsi}" (arg2),
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[arg3] "{rdx}" (arg3),
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[arg4] "{r10}" (arg4),
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[arg5] "{r8}" (arg5),
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: "rcx", "r11", "memory"
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);
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}
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pub fn syscall6(
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number: SYS,
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arg1: usize,
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arg2: usize,
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arg3: usize,
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arg4: usize,
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arg5: usize,
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arg6: usize,
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) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [number] "{rax}" (@intFromEnum(number)),
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[arg1] "{rdi}" (arg1),
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[arg2] "{rsi}" (arg2),
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[arg3] "{rdx}" (arg3),
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[arg4] "{r10}" (arg4),
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[arg5] "{r8}" (arg5),
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[arg6] "{r9}" (arg6),
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: "rcx", "r11", "memory"
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);
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}
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pub fn clone() callconv(.Naked) usize {
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asm volatile (
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\\ movl $56,%%eax // SYS_clone
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\\ movq %%rdi,%%r11
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\\ movq %%rdx,%%rdi
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\\ movq %%r8,%%rdx
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\\ movq %%r9,%%r8
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\\ movq 8(%%rsp),%%r10
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\\ movq %%r11,%%r9
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\\ andq $-16,%%rsi
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\\ subq $8,%%rsi
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\\ movq %%rcx,(%%rsi)
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\\ syscall
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\\ testq %%rax,%%rax
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\\ jz 1f
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\\ retq
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\\
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\\1: .cfi_undefined %%rip
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\\ xorl %%ebp,%%ebp
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\\
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\\ popq %%rdi
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\\ callq *%%r9
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\\ movl %%eax,%%edi
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\\ movl $60,%%eax // SYS_exit
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\\ syscall
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\\
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);
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}
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pub const restore = restore_rt;
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pub fn restore_rt() callconv(.Naked) noreturn {
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switch (@import("builtin").zig_backend) {
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.stage2_c => asm volatile (
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\\ movl %[number], %%eax
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\\ syscall
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:
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: [number] "i" (@intFromEnum(SYS.rt_sigreturn)),
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: "rcx", "r11", "memory"
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),
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else => asm volatile (
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\\ syscall
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:
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: [number] "{rax}" (@intFromEnum(SYS.rt_sigreturn)),
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: "rcx", "r11", "memory"
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),
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}
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}
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pub const mode_t = usize;
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pub const time_t = isize;
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pub const nlink_t = usize;
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pub const blksize_t = isize;
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pub const blkcnt_t = isize;
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pub const F = struct {
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pub const DUPFD = 0;
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pub const GETFD = 1;
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pub const SETFD = 2;
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pub const GETFL = 3;
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pub const SETFL = 4;
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pub const GETLK = 5;
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pub const SETLK = 6;
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pub const SETLKW = 7;
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pub const SETOWN = 8;
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pub const GETOWN = 9;
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pub const SETSIG = 10;
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pub const GETSIG = 11;
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pub const SETOWN_EX = 15;
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pub const GETOWN_EX = 16;
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pub const GETOWNER_UIDS = 17;
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pub const RDLCK = 0;
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pub const WRLCK = 1;
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pub const UNLCK = 2;
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};
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pub const VDSO = struct {
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pub const CGT_SYM = "__vdso_clock_gettime";
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pub const CGT_VER = "LINUX_2.6";
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pub const GETCPU_SYM = "__vdso_getcpu";
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pub const GETCPU_VER = "LINUX_2.6";
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};
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pub const ARCH = struct {
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pub const SET_GS = 0x1001;
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pub const SET_FS = 0x1002;
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pub const GET_FS = 0x1003;
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pub const GET_GS = 0x1004;
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};
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pub const REG = struct {
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pub const R8 = 0;
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pub const R9 = 1;
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pub const R10 = 2;
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pub const R11 = 3;
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pub const R12 = 4;
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pub const R13 = 5;
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pub const R14 = 6;
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pub const R15 = 7;
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pub const RDI = 8;
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pub const RSI = 9;
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pub const RBP = 10;
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pub const RBX = 11;
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pub const RDX = 12;
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pub const RAX = 13;
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pub const RCX = 14;
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pub const RSP = 15;
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pub const RIP = 16;
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pub const EFL = 17;
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pub const CSGSFS = 18;
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pub const ERR = 19;
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pub const TRAPNO = 20;
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pub const OLDMASK = 21;
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pub const CR2 = 22;
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};
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pub const Flock = extern struct {
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type: i16,
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whence: i16,
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start: off_t,
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len: off_t,
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pid: pid_t,
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};
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pub const msghdr = extern struct {
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name: ?*sockaddr,
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namelen: socklen_t,
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iov: [*]iovec,
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iovlen: i32,
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__pad1: i32 = 0,
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control: ?*anyopaque,
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controllen: socklen_t,
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__pad2: socklen_t = 0,
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flags: i32,
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};
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pub const msghdr_const = extern struct {
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name: ?*const sockaddr,
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namelen: socklen_t,
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iov: [*]const iovec_const,
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iovlen: i32,
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__pad1: i32 = 0,
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control: ?*const anyopaque,
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controllen: socklen_t,
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__pad2: socklen_t = 0,
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flags: i32,
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};
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pub const off_t = i64;
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pub const ino_t = u64;
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pub const dev_t = u64;
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// The `stat` definition used by the Linux kernel.
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pub const Stat = extern struct {
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dev: dev_t,
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ino: ino_t,
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nlink: usize,
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mode: u32,
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uid: uid_t,
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gid: gid_t,
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__pad0: u32,
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rdev: dev_t,
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size: off_t,
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blksize: isize,
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blocks: i64,
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atim: timespec,
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mtim: timespec,
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ctim: timespec,
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__unused: [3]isize,
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pub fn atime(self: @This()) timespec {
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return self.atim;
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}
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pub fn mtime(self: @This()) timespec {
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return self.mtim;
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}
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pub fn ctime(self: @This()) timespec {
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return self.ctim;
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}
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};
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pub const timeval = extern struct {
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sec: isize,
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usec: isize,
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};
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pub const timezone = extern struct {
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minuteswest: i32,
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dsttime: i32,
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};
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pub const Elf_Symndx = u32;
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pub const greg_t = usize;
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pub const gregset_t = [23]greg_t;
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pub const fpstate = extern struct {
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cwd: u16,
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swd: u16,
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ftw: u16,
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fop: u16,
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rip: usize,
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rdp: usize,
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mxcsr: u32,
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mxcr_mask: u32,
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st: [8]extern struct {
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significand: [4]u16,
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exponent: u16,
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padding: [3]u16 = undefined,
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},
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xmm: [16]extern struct {
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element: [4]u32,
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},
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padding: [24]u32 = undefined,
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};
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pub const fpregset_t = *fpstate;
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pub const sigcontext = extern struct {
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r8: usize,
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r9: usize,
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r10: usize,
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r11: usize,
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r12: usize,
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r13: usize,
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r14: usize,
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r15: usize,
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rdi: usize,
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rsi: usize,
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rbp: usize,
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rbx: usize,
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rdx: usize,
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rax: usize,
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rcx: usize,
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rsp: usize,
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rip: usize,
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eflags: usize,
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cs: u16,
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gs: u16,
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fs: u16,
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pad0: u16 = undefined,
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err: usize,
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trapno: usize,
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oldmask: usize,
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cr2: usize,
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fpstate: *fpstate,
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reserved1: [8]usize = undefined,
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};
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pub const mcontext_t = extern struct {
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gregs: gregset_t,
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fpregs: fpregset_t,
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reserved1: [8]usize = undefined,
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};
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pub const ucontext_t = extern struct {
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flags: usize,
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link: ?*ucontext_t,
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stack: stack_t,
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mcontext: mcontext_t,
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sigmask: sigset_t,
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fpregs_mem: [64]usize,
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};
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fn gpRegisterOffset(comptime reg_index: comptime_int) usize {
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return @offsetOf(ucontext_t, "mcontext") + @offsetOf(mcontext_t, "gregs") + @sizeOf(usize) * reg_index;
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}
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fn getContextInternal() callconv(.Naked) usize {
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// TODO: Read GS/FS registers?
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asm volatile (
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\\ movq $0, %[flags_offset:c](%%rdi)
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\\ movq $0, %[link_offset:c](%%rdi)
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\\ movq %%r8, %[r8_offset:c](%%rdi)
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\\ movq %%r9, %[r9_offset:c](%%rdi)
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\\ movq %%r10, %[r10_offset:c](%%rdi)
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\\ movq %%r11, %[r11_offset:c](%%rdi)
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\\ movq %%r12, %[r12_offset:c](%%rdi)
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\\ movq %%r13, %[r13_offset:c](%%rdi)
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\\ movq %%r14, %[r14_offset:c](%%rdi)
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\\ movq %%r15, %[r15_offset:c](%%rdi)
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\\ movq %%rdi, %[rdi_offset:c](%%rdi)
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\\ movq %%rsi, %[rsi_offset:c](%%rdi)
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\\ movq %%rbp, %[rbp_offset:c](%%rdi)
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\\ movq %%rbx, %[rbx_offset:c](%%rdi)
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\\ movq %%rdx, %[rdx_offset:c](%%rdi)
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\\ movq %%rax, %[rax_offset:c](%%rdi)
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\\ movq %%rcx, %[rcx_offset:c](%%rdi)
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\\ movq (%%rsp), %%rcx
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\\ movq %%rcx, %[rip_offset:c](%%rdi)
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\\ leaq 8(%%rsp), %%rcx
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\\ movq %%rcx, %[rsp_offset:c](%%rdi)
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\\ pushfq
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\\ popq %[efl_offset:c](%%rdi)
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\\ leaq %[fpmem_offset:c](%%rdi), %%rcx
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\\ movq %%rcx, %[fpstate_offset:c](%%rdi)
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\\ fnstenv (%%rcx)
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\\ fldenv (%%rcx)
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\\ stmxcsr %[mxcsr_offset:c](%%rdi)
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\\ leaq %[stack_offset:c](%%rdi), %%rsi
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\\ movq %%rdi, %%r8
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\\ xorl %%edi, %%edi
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\\ movl %[sigaltstack], %%eax
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\\ syscall
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\\ testq %%rax, %%rax
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\\ jnz 0f
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\\ movl %[sigprocmask], %%eax
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\\ xorl %%esi, %%esi
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\\ leaq %[sigmask_offset:c](%%r8), %%rdx
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\\ movl %[sigset_size], %%r10d
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\\ syscall
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\\0:
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\\ retq
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:
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: [flags_offset] "i" (@offsetOf(ucontext_t, "flags")),
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[link_offset] "i" (@offsetOf(ucontext_t, "link")),
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[r8_offset] "i" (comptime gpRegisterOffset(REG.R8)),
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[r9_offset] "i" (comptime gpRegisterOffset(REG.R9)),
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[r10_offset] "i" (comptime gpRegisterOffset(REG.R10)),
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[r11_offset] "i" (comptime gpRegisterOffset(REG.R11)),
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[r12_offset] "i" (comptime gpRegisterOffset(REG.R12)),
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[r13_offset] "i" (comptime gpRegisterOffset(REG.R13)),
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[r14_offset] "i" (comptime gpRegisterOffset(REG.R14)),
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[r15_offset] "i" (comptime gpRegisterOffset(REG.R15)),
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[rdi_offset] "i" (comptime gpRegisterOffset(REG.RDI)),
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[rsi_offset] "i" (comptime gpRegisterOffset(REG.RSI)),
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[rbp_offset] "i" (comptime gpRegisterOffset(REG.RBP)),
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[rbx_offset] "i" (comptime gpRegisterOffset(REG.RBX)),
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[rdx_offset] "i" (comptime gpRegisterOffset(REG.RDX)),
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[rax_offset] "i" (comptime gpRegisterOffset(REG.RAX)),
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[rcx_offset] "i" (comptime gpRegisterOffset(REG.RCX)),
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[rsp_offset] "i" (comptime gpRegisterOffset(REG.RSP)),
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[rip_offset] "i" (comptime gpRegisterOffset(REG.RIP)),
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[efl_offset] "i" (comptime gpRegisterOffset(REG.EFL)),
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[fpstate_offset] "i" (@offsetOf(ucontext_t, "mcontext") + @offsetOf(mcontext_t, "fpregs")),
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[fpmem_offset] "i" (@offsetOf(ucontext_t, "fpregs_mem")),
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[mxcsr_offset] "i" (@offsetOf(ucontext_t, "fpregs_mem") + @offsetOf(fpstate, "mxcsr")),
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[sigaltstack] "i" (@intFromEnum(linux.SYS.sigaltstack)),
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[stack_offset] "i" (@offsetOf(ucontext_t, "stack")),
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[sigprocmask] "i" (@intFromEnum(linux.SYS.rt_sigprocmask)),
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[sigmask_offset] "i" (@offsetOf(ucontext_t, "sigmask")),
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[sigset_size] "i" (linux.NSIG / 8),
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: "cc", "memory", "rax", "rcx", "rdx", "rdi", "rsi", "r8", "r10", "r11"
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);
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}
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pub inline fn getcontext(context: *ucontext_t) usize {
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// This method is used so that getContextInternal can control
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// its prologue in order to read RSP from a constant offset
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// An aligned stack is not needed for getContextInternal.
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var clobber_rdi: usize = undefined;
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return asm volatile (
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\\ callq %[getContextInternal:P]
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: [_] "={rax}" (-> usize),
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[_] "={rdi}" (clobber_rdi),
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: [_] "{rdi}" (context),
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[getContextInternal] "X" (&getContextInternal),
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: "cc", "memory", "rcx", "rdx", "rsi", "r8", "r10", "r11"
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);
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}
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