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freebsd add *stat calls interception support
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devnexen committed Nov 26, 2023
1 parent cb35682 commit 6dc0f6c
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Showing 6 changed files with 118 additions and 41 deletions.
15 changes: 15 additions & 0 deletions src/helpers.rs
Original file line number Diff line number Diff line change
Expand Up @@ -225,6 +225,21 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
bug!("No field named {} in type {}", name, base.layout().ty);
}

/// Search if Project (which must be a struct or union type) contains the `name` field.
fn projectable_has_field<P: Projectable<'tcx, Provenance>>(
&self,
base: &P,
name: &str,
) -> bool {
let adt = base.layout().ty.ty_adt_def().unwrap();
for field in adt.non_enum_variant().fields.iter() {
if field.name.as_str() == name {
return true;
}
}
false
}

/// Write an int of the appropriate size to `dest`. The target type may be signed or unsigned,
/// we try to do the right thing anyway. `i128` can fit all integer types except for `u128` so
/// this method is fine for almost all integer types.
Expand Down
11 changes: 11 additions & 0 deletions src/shims/unix/foreign_items.rs
Original file line number Diff line number Diff line change
Expand Up @@ -155,6 +155,17 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
}
"lseek64" => {
let [fd, offset, whence] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
let fd = this.read_scalar(fd)?.to_i32()?;
let offset = this.read_scalar(offset)?.to_i64()?;
let whence = this.read_scalar(whence)?.to_i32()?;
let result = this.lseek64(fd, offset.into(), whence)?;
this.write_scalar(result, dest)?;
}
"lseek" => {
let [fd, offset, whence] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
let fd = this.read_scalar(fd)?.to_i32()?;
let offset = this.read_scalar(offset)?.to_int(this.libc_ty_layout("off_t").size)?;
let whence = this.read_scalar(whence)?.to_i32()?;
let result = this.lseek64(fd, offset, whence)?;
this.write_scalar(result, dest)?;
}
Expand Down
28 changes: 28 additions & 0 deletions src/shims/unix/freebsd/foreign_items.rs
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@ use rustc_target::spec::abi::Abi;

use crate::*;
use shims::foreign_items::EmulateForeignItemResult;
use shims::unix::fs::EvalContextExt as _;
use shims::unix::thread::EvalContextExt as _;

pub fn is_dyn_sym(_name: &str) -> bool {
Expand Down Expand Up @@ -63,6 +64,33 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
this.write_scalar(Scalar::from_target_usize(len, this), dest)?;
}

// File related shims
// For those, we both intercept `func` and `call@FBSD_1.0` symbols cases
// since freebsd 12 the former form can be expected.
"stat" | "stat@FBSD_1.0" => {
let [path, buf] =
this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
let result = this.macos_fbsd_stat(path, buf)?;
this.write_scalar(result, dest)?;
}
"lstat" | "lstat@FBSD_1.0" => {
let [path, buf] =
this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
let result = this.macos_fbsd_lstat(path, buf)?;
this.write_scalar(result, dest)?;
}
"fstat" | "fstat@FBSD_1.0" => {
let [fd, buf] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
let result = this.macos_fbsd_fstat(fd, buf)?;
this.write_scalar(result, dest)?;
}
"readdir_r" | "readdir_r@FBSD_1.0" => {
let [dirp, entry, result] =
this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
let result = this.macos_fbsd_readdir_r(dirp, entry, result)?;
this.write_scalar(result, dest)?;
}

// errno
"__error" => {
let [] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
Expand Down
89 changes: 60 additions & 29 deletions src/shims/unix/fs.rs
Original file line number Diff line number Diff line change
Expand Up @@ -827,24 +827,20 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {

fn lseek64(
&mut self,
fd_op: &OpTy<'tcx, Provenance>,
offset_op: &OpTy<'tcx, Provenance>,
whence_op: &OpTy<'tcx, Provenance>,
fd: i32,
offset: i128,
whence: i32,
) -> InterpResult<'tcx, Scalar<Provenance>> {
let this = self.eval_context_mut();

// Isolation check is done via `FileDescriptor` trait.

let fd = this.read_scalar(fd_op)?.to_i32()?;
let offset = this.read_scalar(offset_op)?.to_i64()?;
let whence = this.read_scalar(whence_op)?.to_i32()?;

let seek_from = if whence == this.eval_libc_i32("SEEK_SET") {
SeekFrom::Start(u64::try_from(offset).unwrap())
} else if whence == this.eval_libc_i32("SEEK_CUR") {
SeekFrom::Current(offset)
SeekFrom::Current(i64::try_from(offset).unwrap())
} else if whence == this.eval_libc_i32("SEEK_END") {
SeekFrom::End(offset)
SeekFrom::End(i64::try_from(offset).unwrap())
} else {
let einval = this.eval_libc("EINVAL");
this.set_last_error(einval)?;
Expand Down Expand Up @@ -911,13 +907,16 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
this.try_unwrap_io_result(result)
}

fn macos_stat(
fn macos_fbsd_stat(
&mut self,
path_op: &OpTy<'tcx, Provenance>,
buf_op: &OpTy<'tcx, Provenance>,
) -> InterpResult<'tcx, Scalar<Provenance>> {
let this = self.eval_context_mut();
this.assert_target_os("macos", "stat");

if !matches!(&*this.tcx.sess.target.os, "macos" | "freebsd") {
panic!("`macos_fbsd_stat` should not be called on {}", this.tcx.sess.target.os);
}

let path_scalar = this.read_pointer(path_op)?;
let path = this.read_path_from_c_str(path_scalar)?.into_owned();
Expand All @@ -940,13 +939,16 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
}

// `lstat` is used to get symlink metadata.
fn macos_lstat(
fn macos_fbsd_lstat(
&mut self,
path_op: &OpTy<'tcx, Provenance>,
buf_op: &OpTy<'tcx, Provenance>,
) -> InterpResult<'tcx, Scalar<Provenance>> {
let this = self.eval_context_mut();
this.assert_target_os("macos", "lstat");

if !matches!(&*this.tcx.sess.target.os, "macos" | "freebsd") {
panic!("`macos_fbsd_lstat` should not be called on {}", this.tcx.sess.target.os);
}

let path_scalar = this.read_pointer(path_op)?;
let path = this.read_path_from_c_str(path_scalar)?.into_owned();
Expand All @@ -967,14 +969,16 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
Ok(Scalar::from_i32(this.macos_stat_write_buf(metadata, buf_op)?))
}

fn macos_fstat(
fn macos_fbsd_fstat(
&mut self,
fd_op: &OpTy<'tcx, Provenance>,
buf_op: &OpTy<'tcx, Provenance>,
) -> InterpResult<'tcx, Scalar<Provenance>> {
let this = self.eval_context_mut();

this.assert_target_os("macos", "fstat");
if !matches!(&*this.tcx.sess.target.os, "macos" | "freebsd") {
panic!("`macos_fbsd_fstat` should not be called on {}", this.tcx.sess.target.os);
}

let fd = this.read_scalar(fd_op)?.to_i32()?;

Expand Down Expand Up @@ -1213,7 +1217,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
let this = self.eval_context_mut();

#[cfg_attr(not(unix), allow(unused_variables))]
let mode = if this.tcx.sess.target.os == "macos" {
let mode = if matches!(&*this.tcx.sess.target.os, "macos" | "freebsd") {
u32::from(this.read_scalar(mode_op)?.to_u16()?)
} else {
this.read_scalar(mode_op)?.to_u32()?
Expand Down Expand Up @@ -1385,15 +1389,17 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
Ok(Scalar::from_maybe_pointer(entry, this))
}

fn macos_readdir_r(
fn macos_fbsd_readdir_r(
&mut self,
dirp_op: &OpTy<'tcx, Provenance>,
entry_op: &OpTy<'tcx, Provenance>,
result_op: &OpTy<'tcx, Provenance>,
) -> InterpResult<'tcx, Scalar<Provenance>> {
let this = self.eval_context_mut();

this.assert_target_os("macos", "readdir_r");
if !matches!(&*this.tcx.sess.target.os, "macos" | "freebsd") {
panic!("`macos_fbsd_readdir_r` should not be called on {}", this.tcx.sess.target.os);
}

let dirp = this.read_target_usize(dirp_op)?;

Expand Down Expand Up @@ -1424,7 +1430,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
// }

let entry_place = this.deref_pointer_as(entry_op, this.libc_ty_layout("dirent"))?;
let name_place = this.project_field(&entry_place, 5)?;
let name_place = this.project_field_named(&entry_place, "d_name")?;

let file_name = dir_entry.file_name(); // not a Path as there are no separators!
let (name_fits, file_name_buf_len) = this.write_os_str_to_c_str(
Expand All @@ -1448,16 +1454,41 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {

let file_type = this.file_type_to_d_type(dir_entry.file_type())?;

this.write_int_fields_named(
&[
("d_ino", ino.into()),
("d_seekoff", 0),
("d_reclen", 0),
("d_namlen", file_name_len.into()),
("d_type", file_type.into()),
],
&entry_place,
)?;
// macOS offset field is d_seekoff
if this.projectable_has_field(&entry_place, "d_seekoff") {
this.write_int_fields_named(
&[
("d_ino", ino.into()),
("d_seekoff", 0),
("d_reclen", 0),
("d_namlen", file_name_len.into()),
("d_type", file_type.into()),
],
&entry_place,
)?;
// freebsd 12 and onwards had added the d_off field
} else if this.projectable_has_field(&entry_place, "d_off") {
this.write_int_fields_named(
&[
("d_fileno", ino.into()),
("d_off", 0),
("d_reclen", 0),
("d_type", file_type.into()),
("d_namlen", file_name_len.into()),
],
&entry_place,
)?;
} else {
this.write_int_fields_named(
&[
("d_fileno", ino.into()),
("d_reclen", 0),
("d_type", file_type.into()),
("d_namlen", file_name_len.into()),
],
&entry_place,
)?;
}

let result_place = this.deref_pointer(result_op)?;
this.write_scalar(this.read_scalar(entry_op)?, &result_place)?;
Expand Down
15 changes: 4 additions & 11 deletions src/shims/unix/macos/foreign_items.rs
Original file line number Diff line number Diff line change
Expand Up @@ -40,18 +40,18 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
"stat" | "stat64" | "stat$INODE64" => {
let [path, buf] =
this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
let result = this.macos_stat(path, buf)?;
let result = this.macos_fbsd_stat(path, buf)?;
this.write_scalar(result, dest)?;
}
"lstat" | "lstat64" | "lstat$INODE64" => {
let [path, buf] =
this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
let result = this.macos_lstat(path, buf)?;
let result = this.macos_fbsd_lstat(path, buf)?;
this.write_scalar(result, dest)?;
}
"fstat" | "fstat64" | "fstat$INODE64" => {
let [fd, buf] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
let result = this.macos_fstat(fd, buf)?;
let result = this.macos_fbsd_fstat(fd, buf)?;
this.write_scalar(result, dest)?;
}
"opendir$INODE64" => {
Expand All @@ -62,14 +62,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
"readdir_r" | "readdir_r$INODE64" => {
let [dirp, entry, result] =
this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
let result = this.macos_readdir_r(dirp, entry, result)?;
this.write_scalar(result, dest)?;
}
"lseek" => {
let [fd, offset, whence] =
this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
// macOS is 64bit-only, so this is lseek64
let result = this.lseek64(fd, offset, whence)?;
let result = this.macos_fbsd_readdir_r(dirp, entry, result)?;
this.write_scalar(result, dest)?;
}
"realpath$DARWIN_EXTSN" => {
Expand Down
1 change: 0 additions & 1 deletion tests/pass-dep/shims/libc-fs-with-isolation.rs
Original file line number Diff line number Diff line change
@@ -1,5 +1,4 @@
//@ignore-target-windows: no libc on Windows
//@ignore-target-freebsd: FIXME needs foreign function `stat@FBSD_1.0`
//@compile-flags: -Zmiri-isolation-error=warn-nobacktrace
//@normalize-stderr-test: "(stat(x)?)" -> "$$STAT"

Expand Down

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