zig/lib/std/os/linux/loongarch64.zig
Alex Rønne Petersen da018f9726
std.os.linux: Add unwinding protection in clone() implementations.
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
2024-12-11 00:10:17 +01:00

211 lines
5.9 KiB
Zig

const std = @import("../../std.zig");
const linux = std.os.linux;
const SYS = linux.SYS;
const iovec = std.os.iovec;
const uid_t = linux.uid_t;
const gid_t = linux.gid_t;
const stack_t = linux.stack_t;
const sigset_t = linux.sigset_t;
pub fn syscall0(number: SYS) usize {
return asm volatile (
\\ syscall 0
: [ret] "={$r4}" (-> usize),
: [number] "{$r11}" (@intFromEnum(number)),
: "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8", "memory"
);
}
pub fn syscall1(number: SYS, arg1: usize) usize {
return asm volatile (
\\ syscall 0
: [ret] "={$r4}" (-> usize),
: [number] "{$r11}" (@intFromEnum(number)),
[arg1] "{$r4}" (arg1),
: "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8", "memory"
);
}
pub fn syscall2(number: SYS, arg1: usize, arg2: usize) usize {
return asm volatile (
\\ syscall 0
: [ret] "={$r4}" (-> usize),
: [number] "{$r11}" (@intFromEnum(number)),
[arg1] "{$r4}" (arg1),
[arg2] "{$r5}" (arg2),
: "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8", "memory"
);
}
pub fn syscall3(number: SYS, arg1: usize, arg2: usize, arg3: usize) usize {
return asm volatile (
\\ syscall 0
: [ret] "={$r4}" (-> usize),
: [number] "{$r11}" (@intFromEnum(number)),
[arg1] "{$r4}" (arg1),
[arg2] "{$r5}" (arg2),
[arg3] "{$r6}" (arg3),
: "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8", "memory"
);
}
pub fn syscall4(number: SYS, arg1: usize, arg2: usize, arg3: usize, arg4: usize) usize {
return asm volatile (
\\ syscall 0
: [ret] "={$r4}" (-> usize),
: [number] "{$r11}" (@intFromEnum(number)),
[arg1] "{$r4}" (arg1),
[arg2] "{$r5}" (arg2),
[arg3] "{$r6}" (arg3),
[arg4] "{$r7}" (arg4),
: "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8", "memory"
);
}
pub fn syscall5(number: SYS, arg1: usize, arg2: usize, arg3: usize, arg4: usize, arg5: usize) usize {
return asm volatile (
\\ syscall 0
: [ret] "={$r4}" (-> usize),
: [number] "{$r11}" (@intFromEnum(number)),
[arg1] "{$r4}" (arg1),
[arg2] "{$r5}" (arg2),
[arg3] "{$r6}" (arg3),
[arg4] "{$r7}" (arg4),
[arg5] "{$r8}" (arg5),
: "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8", "memory"
);
}
pub fn syscall6(
number: SYS,
arg1: usize,
arg2: usize,
arg3: usize,
arg4: usize,
arg5: usize,
arg6: usize,
) usize {
return asm volatile (
\\ syscall 0
: [ret] "={$r4}" (-> usize),
: [number] "{$r11}" (@intFromEnum(number)),
[arg1] "{$r4}" (arg1),
[arg2] "{$r5}" (arg2),
[arg3] "{$r6}" (arg3),
[arg4] "{$r7}" (arg4),
[arg5] "{$r8}" (arg5),
[arg6] "{$r9}" (arg6),
: "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8", "memory"
);
}
pub fn clone() callconv(.Naked) usize {
// __clone(func, stack, flags, arg, ptid, tls, ctid)
// a0, a1, a2, a3, a4, a5, a6
// sys_clone(flags, stack, ptid, ctid, tls)
// a0, a1, a2, a3, a4
asm volatile (
\\ bstrins.d $a1, $zero, 3, 0 # stack to 16 align
\\
\\ # Save function pointer and argument pointer on new thread stack
\\ addi.d $a1, $a1, -16
\\ st.d $a0, $a1, 0 # save function pointer
\\ st.d $a3, $a1, 8 # save argument pointer
\\ or $a0, $a2, $zero
\\ or $a2, $a4, $zero
\\ or $a3, $a6, $zero
\\ or $a4, $a5, $zero
\\ ori $a7, $zero, 220 # SYS_clone
\\ syscall 0 # call clone
\\
\\ beqz $a0, 1f # whether child process
\\ jirl $zero, $ra, 0 # parent process return
\\1:
\\ .cfi_undefined 1
\\ move $fp, $zero
\\ move $ra, $zero
\\
\\ ld.d $t8, $sp, 0 # function pointer
\\ ld.d $a0, $sp, 8 # argument pointer
\\ jirl $ra, $t8, 0 # call the user's function
\\ ori $a7, $zero, 93 # SYS_exit
\\ syscall 0 # child process exit
);
}
pub const restore = restore_rt;
pub fn restore_rt() callconv(.Naked) noreturn {
asm volatile (
\\ or $a7, $zero, %[number]
\\ syscall 0
:
: [number] "r" (@intFromEnum(SYS.rt_sigreturn)),
: "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8", "memory"
);
}
pub const blksize_t = i32;
pub const nlink_t = u32;
pub const time_t = i64;
pub const mode_t = u32;
pub const off_t = i64;
pub const ino_t = u64;
pub const dev_t = u32;
pub const blkcnt_t = i64;
pub const timeval = extern struct {
tv_sec: time_t,
tv_usec: i64,
};
pub const F = struct {
pub const DUPFD = 0;
pub const GETFD = 1;
pub const SETFD = 2;
pub const GETFL = 3;
pub const SETFL = 4;
pub const GETLK = 5;
pub const SETLK = 6;
pub const SETLKW = 7;
pub const SETOWN = 8;
pub const GETOWN = 9;
pub const SETSIG = 10;
pub const GETSIG = 11;
pub const RDLCK = 0;
pub const WRLCK = 1;
pub const UNLCK = 2;
pub const SETOWN_EX = 15;
pub const GETOWN_EX = 16;
pub const GETOWNER_UIDS = 17;
};
pub const VDSO = struct {
pub const CGT_SYM = "__vdso_clock_gettime";
pub const CGT_VER = "LINUX_5.10";
};
pub const mcontext_t = extern struct {
pc: u64,
regs: [32]u64,
flags: u32,
extcontext: [0]u64 align(16),
};
pub const ucontext_t = extern struct {
flags: c_ulong,
link: ?*ucontext_t,
stack: stack_t,
sigmask: sigset_t,
_pad: [1024 / 8 - @sizeOf(sigset_t)]u8,
mcontext: mcontext_t,
};
pub const Elf_Symndx = u32;
/// TODO
pub const getcontext = {};