Merge pull request rust-osdev#1246 from nicholasbishop/bishop-tcg-new…

…-boxed

Add PcrEvent::new_in_box/PcrEventInputs::new_in_box

uefi-test-runner/src/proto/tcg.rs

@@ -1,5 +1,4 @@
 use alloc::vec::Vec;
-use core::mem::MaybeUninit;
 use uefi::proto::tcg::{v1, v2, AlgorithmId, EventType, HashAlgorithm, PcrIndex};
 use uefi::table::boot::BootServices;
 
@@ -63,7 +62,7 @@ fn test_tcg_v1(bt: &BootServices) {
 
     let pcr_index = PcrIndex(8);
 
-    let mut event_buf = [MaybeUninit::uninit(); 256];
+    let mut event_buf = [0; 256];
     let event = v1::PcrEvent::new_in_buffer(
         &mut event_buf,
         pcr_index,
@@ -279,7 +278,7 @@ pub fn test_tcg_v2(bt: &BootServices) {
 
     // Create a PCR event.
     let pcr_index = PcrIndex(8);
-    let mut event_buf = [MaybeUninit::uninit(); 256];
+    let mut event_buf = [0; 256];
     let event_data = [0x12, 0x13, 0x14, 0x15];
     let data_to_hash = b"some-data";
     let event =

uefi/CHANGELOG.md

@@ -4,6 +4,8 @@
 - `uefi::system` is a new module that provides freestanding functions for
   accessing fields of the global system table.
 - Add standard derives for `ConfigTableEntry`.
+- `PcrEvent`/`PcrEventInputs` impl `Align`, `Eq`, and `PartialEq`.
+- Added `PcrEvent::new_in_box` and `PcrEventInputs::new_in_box`.
 
 ## Changed
 - **Breaking:** `uefi::helpers::init` no longer takes an argument.
@@ -14,6 +16,9 @@
   The old `MemoryMap` was renamed to `MemoryMapOwned`.
   - `pub fn memory_map(&self, mt: MemoryType) -> Result<MemoryMap>` now returns
      a `MemoryMapOwned`.
+- **Breaking:** `PcrEvent::new_in_buffer` and `PcrEventInputs::new_in_buffer`
+  now take an initialized buffer (`[u8`] instead of `[MaybeUninit<u8>]`), and if
+  the buffer is too small the required size is returned in the error data.
 
 
 # uefi - 0.29.0 (2024-07-02)

uefi/src/proto/tcg/v1.rs

@@ -9,17 +9,21 @@
 //! [TPM]: https://en.wikipedia.org/wiki/Trusted_Platform_Module
 
 use super::{AlgorithmId, EventType, HashAlgorithm, PcrIndex};
-use crate::data_types::PhysicalAddress;
-use crate::polyfill::maybe_uninit_slice_as_mut_ptr;
+use crate::data_types::{Align, PhysicalAddress};
 use crate::proto::unsafe_protocol;
 use crate::util::{ptr_write_unaligned_and_add, usize_from_u32};
 use crate::{Error, Result, Status, StatusExt};
 use core::fmt::{self, Debug, Formatter};
 use core::marker::PhantomData;
-use core::mem::{self, MaybeUninit};
-use core::ptr;
+use core::{mem, ptr};
 use ptr_meta::Pointee;
 
+#[cfg(feature = "alloc")]
+use {crate::mem::make_boxed, alloc::boxed::Box};
+
+#[cfg(all(feature = "unstable", feature = "alloc"))]
+use {alloc::alloc::Global, core::alloc::Allocator};
+
 /// 20-byte SHA-1 digest.
 pub type Sha1Digest = [u8; 20];
 
@@ -128,19 +132,19 @@ impl PcrEvent {
     /// # Errors
     ///
     /// Returns [`Status::BUFFER_TOO_SMALL`] if the `buffer` is not large
-    /// enough.
+    /// enough. The required size will be returned in the error data.
     ///
     /// Returns [`Status::INVALID_PARAMETER`] if the `event_data` size is too
     /// large.
     pub fn new_in_buffer<'buf>(
-        buffer: &'buf mut [MaybeUninit<u8>],
+        buffer: &'buf mut [u8],
         pcr_index: PcrIndex,
         event_type: EventType,
         digest: Sha1Digest,
         event_data: &[u8],
-    ) -> Result<&'buf mut Self> {
-        let event_data_size =
-            u32::try_from(event_data.len()).map_err(|_| Error::from(Status::INVALID_PARAMETER))?;
+    ) -> Result<&'buf mut Self, Option<usize>> {
+        let event_data_size = u32::try_from(event_data.len())
+            .map_err(|_| Error::new(Status::INVALID_PARAMETER, None))?;
 
         let required_size = mem::size_of::<PcrIndex>()
             + mem::size_of::<EventType>()
@@ -149,10 +153,10 @@ impl PcrEvent {
             + event_data.len();
 
         if buffer.len() < required_size {
-            return Err(Status::BUFFER_TOO_SMALL.into());
+            return Err(Error::new(Status::BUFFER_TOO_SMALL, Some(required_size)));
         }
 
-        let mut ptr: *mut u8 = maybe_uninit_slice_as_mut_ptr(buffer);
+        let mut ptr: *mut u8 = buffer.as_mut_ptr().cast();
 
         unsafe {
             ptr_write_unaligned_and_add(&mut ptr, pcr_index);
@@ -167,6 +171,32 @@ impl PcrEvent {
         }
     }
 
+    /// Create a new `PcrEvent` in a [`Box`].
+    ///
+    /// # Errors
+    ///
+    /// Returns [`Status::INVALID_PARAMETER`] if the `event_data` size is too
+    /// large.
+    #[cfg(feature = "alloc")]
+    pub fn new_in_box(
+        pcr_index: PcrIndex,
+        event_type: EventType,
+        digest: Sha1Digest,
+        event_data: &[u8],
+    ) -> Result<Box<Self>> {
+        #[cfg(not(feature = "unstable"))]
+        {
+            make_boxed(|buf| Self::new_in_buffer(buf, pcr_index, event_type, digest, event_data))
+        }
+        #[cfg(feature = "unstable")]
+        {
+            make_boxed(
+                |buf| Self::new_in_buffer(buf, pcr_index, event_type, digest, event_data),
+                Global,
+            )
+        }
+    }
+
     /// PCR index for the event.
     #[must_use]
     pub fn pcr_index(&self) -> PcrIndex {
@@ -200,6 +230,12 @@ impl PcrEvent {
     }
 }
 
+impl Align for PcrEvent {
+    fn alignment() -> usize {
+        1
+    }
+}
+
 // Manual `Debug` implementation since it can't be derived for a packed DST.
 impl Debug for PcrEvent {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
@@ -533,7 +569,7 @@ mod tests {
 
     #[test]
     fn test_new_pcr_event() {
-        let mut event_buf = [MaybeUninit::uninit(); 256];
+        let mut event_buf = [0; 256];
         #[rustfmt::skip]
         let digest = [
             0x00, 0x01, 0x02, 0x03,
@@ -571,6 +607,12 @@ mod tests {
             // Event data
             0x14, 0x15, 0x16, 0x17,
         ]);
+
+        // Check that `new_in_box` gives the same value.
+        assert_eq!(
+            event,
+            &*PcrEvent::new_in_box(PcrIndex(4), EventType::IPL, digest, &data).unwrap()
+        );
     }
 
     #[test]

uefi/src/proto/tcg/v2.rs

@@ -11,17 +11,22 @@
 //! [TPM]: https://en.wikipedia.org/wiki/Trusted_Platform_Module
 
 use super::{v1, AlgorithmId, EventType, HashAlgorithm, PcrIndex};
-use crate::data_types::{PhysicalAddress, UnalignedSlice};
+use crate::data_types::{Align, PhysicalAddress, UnalignedSlice};
 use crate::proto::unsafe_protocol;
 use crate::util::{ptr_write_unaligned_and_add, usize_from_u32};
 use crate::{Error, Result, Status, StatusExt};
 use bitflags::bitflags;
 use core::fmt::{self, Debug, Formatter};
 use core::marker::PhantomData;
-use core::mem::MaybeUninit;
 use core::{mem, ptr, slice};
 use ptr_meta::{Pointee, PtrExt};
 
+#[cfg(feature = "alloc")]
+use {crate::mem::make_boxed, alloc::boxed::Box};
+
+#[cfg(all(feature = "unstable", feature = "alloc"))]
+use {alloc::alloc::Global, core::alloc::Allocator};
+
 /// Version information.
 ///
 /// Layout compatible with the C type `EFI_TG2_VERSION`.
@@ -158,7 +163,7 @@ struct EventHeader {
 /// `TCG_PCR_EVENT2` for reading events. To help clarify the usage, our
 /// API renames these types to `PcrEventInputs` and `PcrEvent`,
 /// respectively.
-#[derive(Pointee)]
+#[derive(Eq, Pointee)]
 #[repr(C, packed)]
 pub struct PcrEventInputs {
     size: u32,
@@ -172,24 +177,24 @@ impl PcrEventInputs {
     /// # Errors
     ///
     /// Returns [`Status::BUFFER_TOO_SMALL`] if the `buffer` is not large
-    /// enough.
+    /// enough. The required size will be returned in the error data.
     ///
     /// Returns [`Status::INVALID_PARAMETER`] if the `event_data` size is too
     /// large.
     pub fn new_in_buffer<'buf>(
-        buffer: &'buf mut [MaybeUninit<u8>],
+        buffer: &'buf mut [u8],
         pcr_index: PcrIndex,
         event_type: EventType,
         event_data: &[u8],
-    ) -> Result<&'buf Self> {
+    ) -> Result<&'buf mut Self, Option<usize>> {
         let required_size =
             mem::size_of::<u32>() + mem::size_of::<EventHeader>() + event_data.len();
 
         if buffer.len() < required_size {
-            return Err(Status::BUFFER_TOO_SMALL.into());
+            return Err(Error::new(Status::BUFFER_TOO_SMALL, Some(required_size)));
         }
-        let size_field =
-            u32::try_from(required_size).map_err(|_| Error::from(Status::INVALID_PARAMETER))?;
+        let size_field = u32::try_from(required_size)
+            .map_err(|_| Error::new(Status::INVALID_PARAMETER, None))?;
 
         let mut ptr: *mut u8 = buffer.as_mut_ptr().cast();
 
@@ -206,13 +211,44 @@ impl PcrEventInputs {
             );
             ptr::copy(event_data.as_ptr(), ptr, event_data.len());
 
-            let ptr: *const PcrEventInputs =
-                ptr_meta::from_raw_parts(buffer.as_ptr().cast(), event_data.len());
-            Ok(&*ptr)
+            let ptr: *mut PcrEventInputs =
+                ptr_meta::from_raw_parts_mut(buffer.as_mut_ptr().cast(), event_data.len());
+            Ok(&mut *ptr)
+        }
+    }
+
+    /// Create a new `PcrEventInputs` in a [`Box`].
+    ///
+    /// # Errors
+    ///
+    /// Returns [`Status::INVALID_PARAMETER`] if the `event_data` size is too
+    /// large.
+    #[cfg(feature = "alloc")]
+    pub fn new_in_box(
+        pcr_index: PcrIndex,
+        event_type: EventType,
+        event_data: &[u8],
+    ) -> Result<Box<Self>> {
+        #[cfg(not(feature = "unstable"))]
+        {
+            make_boxed(|buf| Self::new_in_buffer(buf, pcr_index, event_type, event_data))
+        }
+        #[cfg(feature = "unstable")]
+        {
+            make_boxed(
+                |buf| Self::new_in_buffer(buf, pcr_index, event_type, event_data),
+                Global,
+            )
         }
     }
 }
 
+impl Align for PcrEventInputs {
+    fn alignment() -> usize {
+        1
+    }
+}
+
 impl Debug for PcrEventInputs {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         f.debug_struct("PcrEventInputs")
@@ -223,6 +259,15 @@ impl Debug for PcrEventInputs {
     }
 }
 
+// Manual `PartialEq` implementation since it can't be derived for a packed DST.
+impl PartialEq for PcrEventInputs {
+    fn eq(&self, other: &PcrEventInputs) -> bool {
+        self.size == other.size
+            && self.event_header == other.event_header
+            && self.event == other.event
+    }
+}
+
 #[repr(C, packed)]
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 struct AlgorithmDigestSize {
@@ -785,7 +830,7 @@ mod tests {
 
     #[test]
     fn test_new_event() {
-        let mut buf = [MaybeUninit::uninit(); 22];
+        let mut buf = [0; 22];
         let event_data = [0x12, 0x13, 0x14, 0x15];
         let event =
             PcrEventInputs::new_in_buffer(&mut buf, PcrIndex(4), EventType::IPL, &event_data)
@@ -824,6 +869,12 @@ mod tests {
             // Event data
             0x12, 0x13, 0x14, 0x15,
         ]);
+
+        // Check that `new_in_box` gives the same value.
+        assert_eq!(
+            event,
+            &*PcrEventInputs::new_in_box(PcrIndex(4), EventType::IPL, &event_data).unwrap()
+        );
     }
 
     #[test]