Struct mmap_rs::UnsafeMmapFlags

pub struct UnsafeMmapFlags { /* fields omitted */ }

The available flags to configure the allocated mapping, but that are considered unsafe to use.

Implementations

impl UnsafeMmapFlags

pub const MAP_FIXED: Self

Maps the memory mapping at the address specified, replacing any pages that have been mapped at that address range.

This is not supported on Microsoft Windows.

pub const JIT: Self

Allows mapping the page as RWX. While this may seem useful for self-modifying code and JIT engines, it is instead recommended to convert between mutable and executable mappings using Mmap::make_mut() and MmapMut::make_exec() instead.

As it may be tempting to use this flag, this flag has been (indirectly) marked as unsafe. Make sure to read the text below to understand the complications of this flag before using it.

RWX pages are an interesting targets to attackers, e.g. for buffer overflow attacks, as RWX mappings can potentially simplify such attacks. Without RWX mappings, attackers instead have to resort to return-oriented programming (ROP) gadgets. To prevent buffer overflow attacks, contemporary CPUs allow pages to be marked as non-executable which is then used by the operating system to ensure that pages are either marked as writeable or as executable, but not both. This is also known as W^X.

While the x86 and x86-64 architectures guarantee cache coherency between the L1 instruction and the L1 data cache, other architectures such as Arm and AArch64 do not. If the user modified the pages, then executing the code may result in undefined behavior. To ensure correct behavior a user has to flush the instruction cache after modifying and before executing the page.

pub const fn empty() -> Self

Returns an empty set of flags.

pub const fn all() -> Self

Returns the set containing all flags.

pub const fn bits(&self) -> u32

Returns the raw value of the flags currently stored.

pub const fn from_bits(bits: u32) -> Option<Self>

Convert from underlying bit representation, unless that representation contains bits that do not correspond to a flag.

pub const fn from_bits_truncate(bits: u32) -> Self

Convert from underlying bit representation, dropping any bits that do not correspond to flags.

pub const unsafe fn from_bits_unchecked(bits: u32) -> Self

Convert from underlying bit representation, preserving all bits (even those not corresponding to a defined flag).

Safety

The caller of the bitflags! macro can chose to allow or disallow extra bits for their bitflags type.

The caller of from_bits_unchecked() has to ensure that all bits correspond to a defined flag or that extra bits are valid for this bitflags type.

pub const fn is_empty(&self) -> bool

Returns true if no flags are currently stored.

pub const fn is_all(&self) -> bool

Returns true if all flags are currently set.

pub const fn intersects(&self, other: Self) -> bool

Returns true if there are flags common to both self and other.

pub const fn contains(&self, other: Self) -> bool

Returns true if all of the flags in other are contained within self.

pub fn insert(&mut self, other: Self)

Inserts the specified flags in-place.

pub fn remove(&mut self, other: Self)

Removes the specified flags in-place.

pub fn toggle(&mut self, other: Self)

Toggles the specified flags in-place.

pub fn set(&mut self, other: Self, value: bool)

Inserts or removes the specified flags depending on the passed value.

pub const fn intersection(self, other: Self) -> Self

Returns the intersection between the flags in self and other.

Specifically, the returned set contains only the flags which are present in both self and other.

This is equivalent to using the & operator (e.g. ops::BitAnd), as in flags & other.

pub const fn union(self, other: Self) -> Self

Returns the union of between the flags in self and other.

Specifically, the returned set contains all flags which are present in either self or other, including any which are present in both (see Self::symmetric_difference if that is undesirable).

This is equivalent to using the | operator (e.g. ops::BitOr), as in flags | other.

pub const fn difference(self, other: Self) -> Self

Returns the difference between the flags in self and other.

Specifically, the returned set contains all flags present in self, except for the ones present in other.

It is also conceptually equivalent to the “bit-clear” operation: flags & !other (and this syntax is also supported).

This is equivalent to using the - operator (e.g. ops::Sub), as in flags - other.

pub const fn symmetric_difference(self, other: Self) -> Self

Returns the symmetric difference between the flags in self and other.

Specifically, the returned set contains the flags present which are present in self or other, but that are not present in both. Equivalently, it contains the flags present in exactly one of the sets self and other.

This is equivalent to using the ^ operator (e.g. ops::BitXor), as in flags ^ other.

pub const fn complement(self) -> Self

Returns the complement of this set of flags.

Specifically, the returned set contains all the flags which are not set in self, but which are allowed for this type.

Alternatively, it can be thought of as the set difference between Self::all() and self (e.g. Self::all() - self)

This is equivalent to using the ! operator (e.g. ops::Not), as in !flags.

Trait Implementations

impl Binary for UnsafeMmapFlags

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl BitAnd<UnsafeMmapFlags> for UnsafeMmapFlags

fn bitand(self, other: Self) -> Self

Returns the intersection between the two sets of flags.

type Output = Self

The resulting type after applying the & operator.

impl BitAndAssign<UnsafeMmapFlags> for UnsafeMmapFlags

fn bitand_assign(&mut self, other: Self)

Disables all flags disabled in the set.

impl BitOr<UnsafeMmapFlags> for UnsafeMmapFlags

fn bitor(self, other: UnsafeMmapFlags) -> Self

Returns the union of the two sets of flags.

type Output = Self

The resulting type after applying the | operator.

impl BitOrAssign<UnsafeMmapFlags> for UnsafeMmapFlags

fn bitor_assign(&mut self, other: Self)

Adds the set of flags.

impl BitXor<UnsafeMmapFlags> for UnsafeMmapFlags

fn bitxor(self, other: Self) -> Self

Returns the left flags, but with all the right flags toggled.

type Output = Self

The resulting type after applying the ^ operator.

impl BitXorAssign<UnsafeMmapFlags> for UnsafeMmapFlags

fn bitxor_assign(&mut self, other: Self)

Toggles the set of flags.

impl Clone for UnsafeMmapFlags

fn clone(&self) -> UnsafeMmapFlags

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for UnsafeMmapFlags

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Extend<UnsafeMmapFlags> for UnsafeMmapFlags

fn extend<T: IntoIterator<Item = Self>>(&mut self, iterator: T)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬 This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬 This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl FromIterator<UnsafeMmapFlags> for UnsafeMmapFlags

fn from_iter<T: IntoIterator<Item = Self>>(iterator: T) -> Self

Creates a value from an iterator.

impl Hash for UnsafeMmapFlags

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl LowerHex for UnsafeMmapFlags

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Not for UnsafeMmapFlags

fn not(self) -> Self

Returns the complement of this set of flags.

type Output = Self

The resulting type after applying the ! operator.

impl Octal for UnsafeMmapFlags

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Ord for UnsafeMmapFlags

fn cmp(&self, other: &UnsafeMmapFlags) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<UnsafeMmapFlags> for UnsafeMmapFlags

fn eq(&self, other: &UnsafeMmapFlags) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &UnsafeMmapFlags) -> bool

This method tests for !=.

impl PartialOrd<UnsafeMmapFlags> for UnsafeMmapFlags

fn partial_cmp(&self, other: &UnsafeMmapFlags) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Sub<UnsafeMmapFlags> for UnsafeMmapFlags

fn sub(self, other: Self) -> Self

Returns the set difference of the two sets of flags.

type Output = Self

The resulting type after applying the - operator.

impl SubAssign<UnsafeMmapFlags> for UnsafeMmapFlags

fn sub_assign(&mut self, other: Self)

Disables all flags enabled in the set.

impl UpperHex for UnsafeMmapFlags

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for UnsafeMmapFlags

impl Eq for UnsafeMmapFlags

impl StructuralEq for UnsafeMmapFlags

impl StructuralPartialEq for UnsafeMmapFlags