Constify AddrFilters

Author: Marcondiro

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libipt"
-version = "0.3.1"
+version = "0.4.0"
 authors = [
   "sum_catnip <catnip@catnip.fyi>",
   "Marcondiro <cavenatimarco+libiptrs@gmail.com>",

src/enc_dec_builder/filter.rs

@@ -1,20 +1,28 @@
+use crate::error::{PtError, PtErrorCode};
 use libipt_sys::pt_conf_addr_filter;
 use num_enum::TryFromPrimitive;
-use std::convert::TryFrom;
-use std::mem;
+use std::mem::{transmute, zeroed};
 
 /// This corresponds to the IA32_RTIT_ADDRn_CFG MSRs
-#[derive(Clone, Copy, TryFromPrimitive, PartialEq, Debug)]
+#[derive(Clone, Copy, TryFromPrimitive, PartialEq, Debug, Default)]
 #[repr(u32)]
 pub enum AddrFilterType {
+    #[default]
     DISABLED = 0,
     FILTER = 1,
     STOP = 2,
 }
 
+impl AddrFilterType {
+    #[must_use]
+    const fn to_addr_cfg_raw(self, n: u32) -> u64 {
+        (self as u64) << (4 * n)
+    }
+}
+
 /// an address range inside the address filter
 #[derive(Debug, Clone, Copy)]
-pub struct AddrFilterRange {
+pub struct AddrFilter {
     /// This corresponds to the IA32_RTIT_ADDRn_A MSRs
     pub from: u64,
     /// This corresponds to the IA32_RTIT_ADDRn_B MSRs
@@ -23,7 +31,7 @@ pub struct AddrFilterRange {
     pub filter_type: AddrFilterType,
 }
 
-impl AddrFilterRange {
+impl AddrFilter {
     #[inline]
     pub const fn new(from: u64, to: u64, filter_type: AddrFilterType) -> Self {
         Self {
@@ -37,105 +45,160 @@ impl AddrFilterRange {
 /// the address filter configuration
 #[derive(Debug, Clone, Copy)]
 #[repr(transparent)]
-pub struct AddrFilters(pub(super) pt_conf_addr_filter);
+pub struct AddrFilters(pub(crate) pt_conf_addr_filter);
+
 impl AddrFilters {
-    pub const fn builder() -> AddrFiltersBuilder {
-        AddrFiltersBuilder::new()
+    pub const fn new(filters: &[AddrFilter]) -> Result<Self, PtError> {
+        if filters.len() > 4 {
+            return Err(PtError::new(
+                PtErrorCode::BadConfig,
+                "The maximum number of address filters is 4",
+            ));
+        }
+        let mut inner = unsafe { zeroed::<pt_conf_addr_filter>() };
+        // TODO improve this when something better will become const, for example get and the
+        // bindgen methods on config bitfields
+        if !filters.is_empty() {
+            (inner.addr0_a, inner.addr0_b) = (filters[0].from, filters[0].to);
+            unsafe { inner.config.addr_cfg |= filters[0].filter_type.to_addr_cfg_raw(0) };
+        }
+        if filters.len() >= 2 {
+            (inner.addr1_a, inner.addr1_b) = (filters[1].from, filters[1].to);
+            unsafe { inner.config.addr_cfg |= filters[1].filter_type.to_addr_cfg_raw(1) };
+        }
+        if filters.len() >= 3 {
+            (inner.addr2_a, inner.addr2_b) = (filters[2].from, filters[2].to);
+            unsafe { inner.config.addr_cfg |= filters[2].filter_type.to_addr_cfg_raw(2) };
+        }
+        if filters.len() == 4 {
+            (inner.addr3_a, inner.addr3_b) = (filters[3].from, filters[3].to);
+            unsafe { inner.config.addr_cfg |= filters[3].filter_type.to_addr_cfg_raw(3) };
+        }
+
+        Ok(Self(inner))
     }
 
     #[inline]
-    pub fn addr0(&self) -> AddrFilterRange {
-        AddrFilterRange {
+    const fn addrn_filter_type(&self, n: u32) -> AddrFilterType {
+        unsafe { transmute((self.0.config.addr_cfg as u32 >> (4 * n)) & 0xf) }
+    }
+
+    pub const fn addr0(&self) -> AddrFilter {
+        AddrFilter {
             from: self.0.addr0_a,
             to: self.0.addr0_b,
-            filter_type: AddrFilterType::try_from(unsafe { self.0.config.ctl.addr0_cfg() })
-                .unwrap(),
+            filter_type: self.addrn_filter_type(0),
         }
     }
 
-    #[inline]
-    pub fn addr1(&self) -> AddrFilterRange {
-        AddrFilterRange {
+    pub const fn addr1(&self) -> AddrFilter {
+        AddrFilter {
             from: self.0.addr1_a,
             to: self.0.addr1_b,
-            filter_type: AddrFilterType::try_from(unsafe { self.0.config.ctl.addr1_cfg() })
-                .unwrap(),
+            filter_type: self.addrn_filter_type(1),
         }
     }
 
-    #[inline]
-    pub fn addr2(&self) -> AddrFilterRange {
-        AddrFilterRange {
+    pub const fn addr2(&self) -> AddrFilter {
+        AddrFilter {
             from: self.0.addr2_a,
             to: self.0.addr2_b,
-            filter_type: AddrFilterType::try_from(unsafe { self.0.config.ctl.addr2_cfg() })
-                .unwrap(),
+            filter_type: self.addrn_filter_type(2),
         }
     }
 
-    #[inline]
-    pub fn addr3(&self) -> AddrFilterRange {
-        AddrFilterRange {
+    pub const fn addr3(&self) -> AddrFilter {
+        AddrFilter {
             from: self.0.addr3_a,
             to: self.0.addr3_b,
-            filter_type: AddrFilterType::try_from(unsafe { self.0.config.ctl.addr3_cfg() })
-                .unwrap(),
+            filter_type: self.addrn_filter_type(3),
         }
     }
-}
 
-#[derive(Debug)]
-#[repr(transparent)]
-pub struct AddrFiltersBuilder(pub(super) pt_conf_addr_filter);
-impl Default for AddrFiltersBuilder {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-impl AddrFiltersBuilder {
-    pub const fn new() -> Self {
-        unsafe { mem::zeroed() }
-    }
-
-    #[inline]
-    pub fn addr0(&mut self, range: AddrFilterRange) -> &mut Self {
+    pub const fn set_addr0(&mut self, range: AddrFilter) {
         self.0.addr0_a = range.from;
         self.0.addr0_b = range.to;
-        unsafe { self.0.config.ctl.set_addr0_cfg(range.filter_type as u32) };
-
-        self
+        unsafe { self.0.config.addr_cfg |= range.filter_type.to_addr_cfg_raw(0) };
     }
 
-    #[inline]
-    pub fn addr1(&mut self, range: AddrFilterRange) -> &mut Self {
+    pub const fn set_addr1(&mut self, range: AddrFilter) {
         self.0.addr1_a = range.from;
         self.0.addr1_b = range.to;
-        unsafe { self.0.config.ctl.set_addr1_cfg(range.filter_type as u32) };
-
-        self
+        unsafe { self.0.config.addr_cfg |= range.filter_type.to_addr_cfg_raw(1) };
     }
 
-    #[inline]
-    pub fn addr2(&mut self, range: AddrFilterRange) -> &mut Self {
+    pub const fn set_addr2(&mut self, range: AddrFilter) {
         self.0.addr2_a = range.from;
         self.0.addr2_b = range.to;
-        unsafe { self.0.config.ctl.set_addr2_cfg(range.filter_type as u32) };
-
-        self
+        unsafe { self.0.config.addr_cfg |= range.filter_type.to_addr_cfg_raw(2) };
     }
 
     #[inline]
-    pub fn addr3(&mut self, range: AddrFilterRange) -> &mut Self {
+    pub const fn set_addr3(&mut self, range: AddrFilter) {
         self.0.addr3_a = range.from;
         self.0.addr3_b = range.to;
-        unsafe { self.0.config.ctl.set_addr3_cfg(range.filter_type as u32) };
+        unsafe { self.0.config.addr_cfg |= range.filter_type.to_addr_cfg_raw(3) };
+    }
 
-        self
+    pub const fn iter(&self) -> Iter<'_> {
+        Iter::new(self)
     }
+}
+
+impl Default for AddrFilters {
+    fn default() -> Self {
+        Self(unsafe { zeroed() })
+    }
+}
+
+impl PartialEq for AddrFilters {
+    fn eq(&self, other: &Self) -> bool {
+        (
+            self.0.addr0_a,
+            self.0.addr0_b,
+            self.0.addr1_a,
+            self.0.addr1_b,
+            self.0.addr2_a,
+            self.0.addr2_b,
+            self.0.addr3_a,
+            self.0.addr3_b,
+        ) == (
+            other.0.addr0_a,
+            other.0.addr0_b,
+            other.0.addr1_a,
+            other.0.addr1_b,
+            other.0.addr2_a,
+            other.0.addr2_b,
+            other.0.addr3_a,
+            other.0.addr3_b,
+        ) && unsafe { self.0.config.addr_cfg == other.0.config.addr_cfg }
+    }
+}
+
+pub struct Iter<'a> {
+    filters: &'a AddrFilters,
+    i: usize,
+}
+
+impl<'a> Iter<'a> {
+    const fn new(filters: &'a AddrFilters) -> Self {
+        Self { filters, i: 0 }
+    }
+}
 
-    pub fn build(&self) -> AddrFilters {
-        AddrFilters(self.0)
+impl<'a> Iterator for Iter<'a> {
+    type Item = AddrFilter;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let filter = match self.i {
+            0 => self.filters.addr0(),
+            1 => self.filters.addr1(),
+            2 => self.filters.addr2(),
+            3 => self.filters.addr3(),
+            _ => return None,
+        };
+        self.i += 1;
+        Some(filter)
     }
 }
 
@@ -145,12 +208,13 @@ mod test {
 
     #[test]
     fn test_addrfilter() {
-        let filter = AddrFilters::builder()
-            .addr0(AddrFilterRange::new(1, 2, AddrFilterType::DISABLED))
-            .addr1(AddrFilterRange::new(3, 4, AddrFilterType::FILTER))
-            .addr2(AddrFilterRange::new(5, 6, AddrFilterType::STOP))
-            .addr3(AddrFilterRange::new(7, 8, AddrFilterType::DISABLED))
-            .build();
+        let filter = AddrFilters::new(&[
+            AddrFilter::new(1, 2, AddrFilterType::DISABLED),
+            AddrFilter::new(3, 4, AddrFilterType::FILTER),
+            AddrFilter::new(5, 6, AddrFilterType::STOP),
+            AddrFilter::new(7, 8, AddrFilterType::DISABLED),
+        ])
+        .unwrap();
 
         assert_eq!(filter.addr0().from, 1);
         assert_eq!(filter.addr0().to, 2);

src/enc_dec_builder/mod.rs

@@ -313,12 +313,13 @@ mod test {
         let mut data = [18u8; 3];
         let mut c = EncoderDecoderBuilder::<BlockDecoder>::new()
             .filter(
-                AddrFiltersBuilder::new()
-                    .addr0(AddrFilterRange::new(1, 2, AddrFilterType::STOP))
-                    .addr1(AddrFilterRange::new(3, 4, AddrFilterType::FILTER))
-                    .addr2(AddrFilterRange::new(5, 6, AddrFilterType::DISABLED))
-                    .addr3(AddrFilterRange::new(7, 8, AddrFilterType::STOP))
-                    .build(),
+                AddrFilters::new(&[
+                    AddrFilter::new(1, 2, AddrFilterType::STOP),
+                    AddrFilter::new(3, 4, AddrFilterType::FILTER),
+                    AddrFilter::new(5, 6, AddrFilterType::DISABLED),
+                    AddrFilter::new(7, 8, AddrFilterType::STOP),
+                ])
+                .unwrap(),
             )
             .cpu(Cpu::intel(1, 2, 3))
             .freq(Frequency::new(1, 2, 3, 4))