zig/lib/std/os/linux/aarch64.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

294 lines
6.8 KiB
Zig

const std = @import("../../std.zig");
const maxInt = std.math.maxInt;
const linux = std.os.linux;
const SYS = linux.SYS;
const socklen_t = linux.socklen_t;
const sockaddr = linux.sockaddr;
const iovec = std.posix.iovec;
const iovec_const = std.posix.iovec_const;
const uid_t = linux.uid_t;
const gid_t = linux.gid_t;
const pid_t = linux.pid_t;
const stack_t = linux.stack_t;
const sigset_t = linux.sigset_t;
const timespec = std.os.linux.timespec;
pub fn syscall0(number: SYS) usize {
return asm volatile ("svc #0"
: [ret] "={x0}" (-> usize),
: [number] "{x8}" (@intFromEnum(number)),
: "memory", "cc"
);
}
pub fn syscall1(number: SYS, arg1: usize) usize {
return asm volatile ("svc #0"
: [ret] "={x0}" (-> usize),
: [number] "{x8}" (@intFromEnum(number)),
[arg1] "{x0}" (arg1),
: "memory", "cc"
);
}
pub fn syscall2(number: SYS, arg1: usize, arg2: usize) usize {
return asm volatile ("svc #0"
: [ret] "={x0}" (-> usize),
: [number] "{x8}" (@intFromEnum(number)),
[arg1] "{x0}" (arg1),
[arg2] "{x1}" (arg2),
: "memory", "cc"
);
}
pub fn syscall3(number: SYS, arg1: usize, arg2: usize, arg3: usize) usize {
return asm volatile ("svc #0"
: [ret] "={x0}" (-> usize),
: [number] "{x8}" (@intFromEnum(number)),
[arg1] "{x0}" (arg1),
[arg2] "{x1}" (arg2),
[arg3] "{x2}" (arg3),
: "memory", "cc"
);
}
pub fn syscall4(number: SYS, arg1: usize, arg2: usize, arg3: usize, arg4: usize) usize {
return asm volatile ("svc #0"
: [ret] "={x0}" (-> usize),
: [number] "{x8}" (@intFromEnum(number)),
[arg1] "{x0}" (arg1),
[arg2] "{x1}" (arg2),
[arg3] "{x2}" (arg3),
[arg4] "{x3}" (arg4),
: "memory", "cc"
);
}
pub fn syscall5(number: SYS, arg1: usize, arg2: usize, arg3: usize, arg4: usize, arg5: usize) usize {
return asm volatile ("svc #0"
: [ret] "={x0}" (-> usize),
: [number] "{x8}" (@intFromEnum(number)),
[arg1] "{x0}" (arg1),
[arg2] "{x1}" (arg2),
[arg3] "{x2}" (arg3),
[arg4] "{x3}" (arg4),
[arg5] "{x4}" (arg5),
: "memory", "cc"
);
}
pub fn syscall6(
number: SYS,
arg1: usize,
arg2: usize,
arg3: usize,
arg4: usize,
arg5: usize,
arg6: usize,
) usize {
return asm volatile ("svc #0"
: [ret] "={x0}" (-> usize),
: [number] "{x8}" (@intFromEnum(number)),
[arg1] "{x0}" (arg1),
[arg2] "{x1}" (arg2),
[arg3] "{x2}" (arg3),
[arg4] "{x3}" (arg4),
[arg5] "{x4}" (arg5),
[arg6] "{x5}" (arg6),
: "memory", "cc"
);
}
pub fn clone() callconv(.Naked) usize {
// __clone(func, stack, flags, arg, ptid, tls, ctid)
// x0, x1, w2, x3, x4, x5, x6
//
// syscall(SYS_clone, flags, stack, ptid, tls, ctid)
// x8, x0, x1, x2, x3, x4
asm volatile (
\\ // align stack and save func,arg
\\ and x1,x1,#-16
\\ stp x0,x3,[x1,#-16]!
\\
\\ // syscall
\\ uxtw x0,w2
\\ mov x2,x4
\\ mov x3,x5
\\ mov x4,x6
\\ mov x8,#220 // SYS_clone
\\ svc #0
\\
\\ cbz x0,1f
\\ // parent
\\ ret
\\
\\ // child
\\1: .cfi_undefined lr
\\ mov fp, 0
\\ mov lr, 0
\\
\\ ldp x1,x0,[sp],#16
\\ blr x1
\\ mov x8,#93 // SYS_exit
\\ svc #0
);
}
pub const restore = restore_rt;
pub fn restore_rt() callconv(.Naked) noreturn {
switch (@import("builtin").zig_backend) {
.stage2_c => asm volatile (
\\ mov x8, %[number]
\\ svc #0
:
: [number] "i" (@intFromEnum(SYS.rt_sigreturn)),
: "memory", "cc"
),
else => asm volatile (
\\ svc #0
:
: [number] "{x8}" (@intFromEnum(SYS.rt_sigreturn)),
: "memory", "cc"
),
}
}
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 SETOWN = 8;
pub const GETOWN = 9;
pub const SETSIG = 10;
pub const GETSIG = 11;
pub const GETLK = 5;
pub const SETLK = 6;
pub const SETLKW = 7;
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 = "__kernel_clock_gettime";
pub const CGT_VER = "LINUX_2.6.39";
};
pub const Flock = extern struct {
type: i16,
whence: i16,
start: off_t,
len: off_t,
pid: pid_t,
__unused: [4]u8,
};
pub const msghdr = extern struct {
name: ?*sockaddr,
namelen: socklen_t,
iov: [*]iovec,
iovlen: i32,
__pad1: i32 = 0,
control: ?*anyopaque,
controllen: socklen_t,
__pad2: socklen_t = 0,
flags: i32,
};
pub const msghdr_const = extern struct {
name: ?*const sockaddr,
namelen: socklen_t,
iov: [*]const iovec_const,
iovlen: i32,
__pad1: i32 = 0,
control: ?*const anyopaque,
controllen: socklen_t,
__pad2: socklen_t = 0,
flags: i32,
};
pub const blksize_t = i32;
pub const nlink_t = u32;
pub const time_t = isize;
pub const mode_t = u32;
pub const off_t = isize;
pub const ino_t = usize;
pub const dev_t = usize;
pub const blkcnt_t = isize;
// The `stat` definition used by the Linux kernel.
pub const Stat = extern struct {
dev: dev_t,
ino: ino_t,
mode: mode_t,
nlink: nlink_t,
uid: uid_t,
gid: gid_t,
rdev: dev_t,
__pad: usize,
size: off_t,
blksize: blksize_t,
__pad2: i32,
blocks: blkcnt_t,
atim: timespec,
mtim: timespec,
ctim: timespec,
__unused: [2]u32,
pub fn atime(self: @This()) timespec {
return self.atim;
}
pub fn mtime(self: @This()) timespec {
return self.mtim;
}
pub fn ctime(self: @This()) timespec {
return self.ctim;
}
};
pub const timeval = extern struct {
sec: isize,
usec: isize,
};
pub const timezone = extern struct {
minuteswest: i32,
dsttime: i32,
};
pub const mcontext_t = extern struct {
fault_address: usize,
regs: [31]usize,
sp: usize,
pc: usize,
pstate: usize,
// Make sure the field is correctly aligned since this area
// holds various FP/vector registers
reserved1: [256 * 16]u8 align(16),
};
pub const ucontext_t = extern struct {
flags: usize,
link: ?*ucontext_t,
stack: stack_t,
sigmask: sigset_t,
mcontext: mcontext_t,
};
/// TODO
pub const getcontext = {};
pub const Elf_Symndx = u32;