X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;ds=sidebyside;f=src%2Fshims%2Fposix%2Flinux%2Fforeign_items.rs;h=d16c740ffc547ff8221730e58de13a4eecf25d2d;hb=71f41405500cec42be22f0080bf3f83f97bfa768;hp=364cfde6c0721a96cef188cebe4cd2db07edfb95;hpb=b0e02f02186ff6d5bc8a7654b645ee26135f7709;p=rust.git diff --git a/src/shims/posix/linux/foreign_items.rs b/src/shims/posix/linux/foreign_items.rs index 364cfde6c07..d16c740ffc5 100644 --- a/src/shims/posix/linux/foreign_items.rs +++ b/src/shims/posix/linux/foreign_items.rs @@ -1,7 +1,8 @@ use rustc_middle::mir; +use rustc_target::spec::abi::Abi; +use crate::helpers::{check_abi, check_arg_count}; use crate::*; -use crate::helpers::check_arg_count; use shims::posix::fs::EvalContextExt as _; use shims::posix::linux::sync::futex; use shims::posix::sync::EvalContextExt as _; @@ -12,8 +13,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx fn emulate_foreign_item_by_name( &mut self, link_name: &str, + abi: Abi, args: &[OpTy<'tcx, Tag>], - dest: PlaceTy<'tcx, Tag>, + dest: &PlaceTy<'tcx, Tag>, _ret: mir::BasicBlock, ) -> InterpResult<'tcx, bool> { let this = self.eval_context_mut(); @@ -21,6 +23,7 @@ fn emulate_foreign_item_by_name( match link_name { // errno "__errno_location" => { + check_abi(this, abi, Abi::C { unwind: false })?; let &[] = check_arg_count(args)?; let errno_place = this.last_error_place()?; this.write_scalar(errno_place.to_ref().to_scalar()?, dest)?; @@ -30,28 +33,33 @@ fn emulate_foreign_item_by_name( // These symbols have different names on Linux and macOS, which is the only reason they are not // in the `posix` module. "close" => { - let &[fd] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref fd] = check_arg_count(args)?; let result = this.close(fd)?; this.write_scalar(Scalar::from_i32(result), dest)?; } "opendir" => { - let &[name] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref name] = check_arg_count(args)?; let result = this.opendir(name)?; this.write_scalar(result, dest)?; } "readdir64_r" => { - let &[dirp, entry, result] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref dirp, ref entry, ref result] = check_arg_count(args)?; let result = this.linux_readdir64_r(dirp, entry, result)?; this.write_scalar(Scalar::from_i32(result), dest)?; } "ftruncate64" => { - let &[fd, length] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref fd, ref length] = check_arg_count(args)?; let result = this.ftruncate64(fd, length)?; this.write_scalar(Scalar::from_i32(result), dest)?; } // Linux-only "posix_fadvise" => { - let &[fd, offset, len, advice] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref fd, ref offset, ref len, ref advice] = check_arg_count(args)?; this.read_scalar(fd)?.to_i32()?; this.read_scalar(offset)?.to_machine_isize(this)?; this.read_scalar(len)?.to_machine_isize(this)?; @@ -60,34 +68,37 @@ fn emulate_foreign_item_by_name( this.write_null(dest)?; } "sync_file_range" => { - let &[fd, offset, nbytes, flags] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref fd, ref offset, ref nbytes, ref flags] = check_arg_count(args)?; let result = this.sync_file_range(fd, offset, nbytes, flags)?; this.write_scalar(Scalar::from_i32(result), dest)?; } // Time related shims "clock_gettime" => { + check_abi(this, abi, Abi::C { unwind: false })?; // This is a POSIX function but it has only been tested on linux. - let &[clk_id, tp] = check_arg_count(args)?; + let &[ref clk_id, ref tp] = check_arg_count(args)?; let result = this.clock_gettime(clk_id, tp)?; this.write_scalar(Scalar::from_i32(result), dest)?; } // Querying system information "pthread_attr_getstack" => { + check_abi(this, abi, Abi::C { unwind: false })?; // We don't support "pthread_attr_setstack", so we just pretend all stacks have the same values here. - let &[attr_place, addr_place, size_place] = check_arg_count(args)?; + let &[ref attr_place, ref addr_place, ref size_place] = check_arg_count(args)?; this.deref_operand(attr_place)?; let addr_place = this.deref_operand(addr_place)?; let size_place = this.deref_operand(size_place)?; this.write_scalar( Scalar::from_uint(STACK_ADDR, this.pointer_size()), - addr_place.into(), + &addr_place.into(), )?; this.write_scalar( Scalar::from_uint(STACK_SIZE, this.pointer_size()), - size_place.into(), + &size_place.into(), )?; // Return success (`0`). @@ -96,80 +107,94 @@ fn emulate_foreign_item_by_name( // Threading "prctl" => { - let &[option, arg2, arg3, arg4, arg5] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref option, ref arg2, ref arg3, ref arg4, ref arg5] = check_arg_count(args)?; let result = this.prctl(option, arg2, arg3, arg4, arg5)?; this.write_scalar(Scalar::from_i32(result), dest)?; } "pthread_condattr_setclock" => { - let &[attr, clock_id] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref attr, ref clock_id] = check_arg_count(args)?; let result = this.pthread_condattr_setclock(attr, clock_id)?; this.write_scalar(Scalar::from_i32(result), dest)?; } "pthread_condattr_getclock" => { - let &[attr, clock_id] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref attr, ref clock_id] = check_arg_count(args)?; let result = this.pthread_condattr_getclock(attr, clock_id)?; this.write_scalar(Scalar::from_i32(result), dest)?; } // Dynamically invoked syscalls "syscall" => { - // FIXME: The libc syscall() function is a variadic function. - // It's valid to call it with more arguments than a syscall - // needs, so none of these syscalls should use check_arg_count. - // It's even valid to call it with the wrong type of arguments, - // as long as they'd end up in the same place with the calling - // convention used. (E.g. using a `usize` instead of a pointer.) - // It's not directly clear which number, size, and type of arguments - // are acceptable in which cases and which aren't. (E.g. some - // types might take up the space of two registers.) - // So this needs to be researched first. - - let sys_getrandom = this - .eval_libc("SYS_getrandom")? - .to_machine_usize(this)?; - - let sys_statx = this - .eval_libc("SYS_statx")? - .to_machine_usize(this)?; - - let sys_futex = this - .eval_libc("SYS_futex")? - .to_machine_usize(this)?; + check_abi(this, abi, Abi::C { unwind: false })?; + // The syscall variadic function is legal to call with more arguments than needed, + // extra arguments are simply ignored. However, all arguments need to be scalars; + // other types might be treated differently by the calling convention. + for arg in args { + if !matches!(arg.layout.abi, rustc_target::abi::Abi::Scalar(_)) { + throw_ub_format!( + "`syscall` arguments must all have scalar layout, but {} does not", + arg.layout.ty + ); + } + } + + let sys_getrandom = this.eval_libc("SYS_getrandom")?.to_machine_usize(this)?; + + let sys_statx = this.eval_libc("SYS_statx")?.to_machine_usize(this)?; + + let sys_futex = this.eval_libc("SYS_futex")?.to_machine_usize(this)?; if args.is_empty() { - throw_ub_format!("incorrect number of arguments for syscall: got 0, expected at least 1"); + throw_ub_format!( + "incorrect number of arguments for syscall: got 0, expected at least 1" + ); } - match this.read_scalar(args[0])?.to_machine_usize(this)? { + match this.read_scalar(&args[0])?.to_machine_usize(this)? { // `libc::syscall(NR_GETRANDOM, buf.as_mut_ptr(), buf.len(), GRND_NONBLOCK)` // is called if a `HashMap` is created the regular way (e.g. HashMap). id if id == sys_getrandom => { // The first argument is the syscall id, so skip over it. - let &[_, ptr, len, flags] = check_arg_count(args)?; - getrandom(this, ptr, len, flags, dest)?; + if args.len() < 4 { + throw_ub_format!( + "incorrect number of arguments for `getrandom` syscall: got {}, expected at least 4", + args.len() + ); + } + getrandom(this, &args[1], &args[2], &args[3], dest)?; } // `statx` is used by `libstd` to retrieve metadata information on `linux` // instead of using `stat`,`lstat` or `fstat` as on `macos`. id if id == sys_statx => { // The first argument is the syscall id, so skip over it. - let &[_, dirfd, pathname, flags, mask, statxbuf] = check_arg_count(args)?; - let result = this.linux_statx(dirfd, pathname, flags, mask, statxbuf)?; + if args.len() < 6 { + throw_ub_format!( + "incorrect number of arguments for `statx` syscall: got {}, expected at least 6", + args.len() + ); + } + let result = + this.linux_statx(&args[1], &args[2], &args[3], &args[4], &args[5])?; this.write_scalar(Scalar::from_machine_isize(result.into(), this), dest)?; } // `futex` is used by some synchonization primitives. id if id == sys_futex => { futex(this, args, dest)?; } - id => throw_unsup_format!("miri does not support syscall ID {}", id), + id => throw_unsup_format!("Miri does not support syscall ID {}", id), } } // Miscelanneous "getrandom" => { - let &[ptr, len, flags] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref ptr, ref len, ref flags] = check_arg_count(args)?; getrandom(this, ptr, len, flags, dest)?; } "sched_getaffinity" => { - let &[pid, cpusetsize, mask] = check_arg_count(args)?; + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref pid, ref cpusetsize, ref mask] = check_arg_count(args)?; this.read_scalar(pid)?.to_i32()?; this.read_scalar(cpusetsize)?.to_machine_usize(this)?; this.deref_operand(mask)?; @@ -181,8 +206,11 @@ fn emulate_foreign_item_by_name( // Incomplete shims that we "stub out" just to get pre-main initialization code to work. // These shims are enabled only when the caller is in the standard library. - "pthread_getattr_np" if this.frame().instance.to_string().starts_with("std::sys::unix::") => { - let &[_thread, _attr] = check_arg_count(args)?; + "pthread_getattr_np" + if this.frame().instance.to_string().starts_with("std::sys::unix::") => + { + check_abi(this, abi, Abi::C { unwind: false })?; + let &[ref _thread, ref _attr] = check_arg_count(args)?; this.write_null(dest)?; } @@ -196,17 +224,18 @@ fn emulate_foreign_item_by_name( // Shims the linux `getrandom` syscall. fn getrandom<'tcx>( this: &mut MiriEvalContext<'_, 'tcx>, - ptr: OpTy<'tcx, Tag>, - len: OpTy<'tcx, Tag>, - flags: OpTy<'tcx, Tag>, - dest: PlaceTy<'tcx, Tag>, + ptr: &OpTy<'tcx, Tag>, + len: &OpTy<'tcx, Tag>, + flags: &OpTy<'tcx, Tag>, + dest: &PlaceTy<'tcx, Tag>, ) -> InterpResult<'tcx> { let ptr = this.read_scalar(ptr)?.check_init()?; let len = this.read_scalar(len)?.to_machine_usize(this)?; // The only supported flags are GRND_RANDOM and GRND_NONBLOCK, // neither of which have any effect on our current PRNG. - this.read_scalar(flags)?.to_i32()?; + // See for a discussion of argument sizes. + let _flags = this.read_scalar(flags)?.to_i32(); this.gen_random(ptr, len)?; this.write_scalar(Scalar::from_machine_usize(len, this), dest)?;