Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 494 insertions, 0 deletions

diff --git a/rust/quote/runtime.rs b/rust/quote/runtime.rs
new file mode 100644
index 000000000..09a94f5dd
--- /dev/null
+++ b/rust/quote/runtime.rs
@@ -0,0 +1,494 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+use self::get_span::{GetSpan, GetSpanBase, GetSpanInner};
+use crate::{IdentFragment, ToTokens, TokenStreamExt};
+use core::fmt;
+use core::iter;
+use core::ops::BitOr;
+use proc_macro2::{Group, Ident, Punct, Spacing, TokenTree};
+
+#[doc(hidden)]
+pub use alloc::format;
+#[doc(hidden)]
+pub use core::option::Option;
+
+#[doc(hidden)]
+pub type Delimiter = proc_macro2::Delimiter;
+#[doc(hidden)]
+pub type Span = proc_macro2::Span;
+#[doc(hidden)]
+pub type TokenStream = proc_macro2::TokenStream;
+
+#[doc(hidden)]
+pub struct HasIterator; // True
+#[doc(hidden)]
+pub struct ThereIsNoIteratorInRepetition; // False
+
+impl BitOr<ThereIsNoIteratorInRepetition> for ThereIsNoIteratorInRepetition {
+    type Output = ThereIsNoIteratorInRepetition;
+    fn bitor(self, _rhs: ThereIsNoIteratorInRepetition) -> ThereIsNoIteratorInRepetition {
+        ThereIsNoIteratorInRepetition
+    }
+}
+
+impl BitOr<ThereIsNoIteratorInRepetition> for HasIterator {
+    type Output = HasIterator;
+    fn bitor(self, _rhs: ThereIsNoIteratorInRepetition) -> HasIterator {
+        HasIterator
+    }
+}
+
+impl BitOr<HasIterator> for ThereIsNoIteratorInRepetition {
+    type Output = HasIterator;
+    fn bitor(self, _rhs: HasIterator) -> HasIterator {
+        HasIterator
+    }
+}
+
+impl BitOr<HasIterator> for HasIterator {
+    type Output = HasIterator;
+    fn bitor(self, _rhs: HasIterator) -> HasIterator {
+        HasIterator
+    }
+}
+
+/// Extension traits used by the implementation of `quote!`. These are defined
+/// in separate traits, rather than as a single trait due to ambiguity issues.
+///
+/// These traits expose a `quote_into_iter` method which should allow calling
+/// whichever impl happens to be applicable. Calling that method repeatedly on
+/// the returned value should be idempotent.
+#[doc(hidden)]
+pub mod ext {
+    use super::RepInterp;
+    use super::{HasIterator as HasIter, ThereIsNoIteratorInRepetition as DoesNotHaveIter};
+    use crate::ToTokens;
+    use alloc::collections::btree_set::{self, BTreeSet};
+    use core::slice;
+
+    /// Extension trait providing the `quote_into_iter` method on iterators.
+    #[doc(hidden)]
+    pub trait RepIteratorExt: Iterator + Sized {
+        fn quote_into_iter(self) -> (Self, HasIter) {
+            (self, HasIter)
+        }
+    }
+
+    impl<T: Iterator> RepIteratorExt for T {}
+
+    /// Extension trait providing the `quote_into_iter` method for
+    /// non-iterable types. These types interpolate the same value in each
+    /// iteration of the repetition.
+    #[doc(hidden)]
+    pub trait RepToTokensExt {
+        /// Pretend to be an iterator for the purposes of `quote_into_iter`.
+        /// This allows repeated calls to `quote_into_iter` to continue
+        /// correctly returning DoesNotHaveIter.
+        fn next(&self) -> Option<&Self> {
+            Some(self)
+        }
+
+        fn quote_into_iter(&self) -> (&Self, DoesNotHaveIter) {
+            (self, DoesNotHaveIter)
+        }
+    }
+
+    impl<T: ToTokens + ?Sized> RepToTokensExt for T {}
+
+    /// Extension trait providing the `quote_into_iter` method for types that
+    /// can be referenced as an iterator.
+    #[doc(hidden)]
+    pub trait RepAsIteratorExt<'q> {
+        type Iter: Iterator;
+
+        fn quote_into_iter(&'q self) -> (Self::Iter, HasIter);
+    }
+
+    impl<'q, T: RepAsIteratorExt<'q> + ?Sized> RepAsIteratorExt<'q> for &T {
+        type Iter = T::Iter;
+
+        fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
+            <T as RepAsIteratorExt>::quote_into_iter(*self)
+        }
+    }
+
+    impl<'q, T: RepAsIteratorExt<'q> + ?Sized> RepAsIteratorExt<'q> for &mut T {
+        type Iter = T::Iter;
+
+        fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
+            <T as RepAsIteratorExt>::quote_into_iter(*self)
+        }
+    }
+
+    impl<'q, T: 'q> RepAsIteratorExt<'q> for [T] {
+        type Iter = slice::Iter<'q, T>;
+
+        fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
+            (self.iter(), HasIter)
+        }
+    }
+
+    impl<'q, T: 'q, const N: usize> RepAsIteratorExt<'q> for [T; N] {
+        type Iter = slice::Iter<'q, T>;
+
+        fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
+            (self.iter(), HasIter)
+        }
+    }
+
+    impl<'q, T: 'q> RepAsIteratorExt<'q> for Vec<T> {
+        type Iter = slice::Iter<'q, T>;
+
+        fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
+            (self.iter(), HasIter)
+        }
+    }
+
+    impl<'q, T: 'q> RepAsIteratorExt<'q> for BTreeSet<T> {
+        type Iter = btree_set::Iter<'q, T>;
+
+        fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
+            (self.iter(), HasIter)
+        }
+    }
+
+    impl<'q, T: RepAsIteratorExt<'q>> RepAsIteratorExt<'q> for RepInterp<T> {
+        type Iter = T::Iter;
+
+        fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) {
+            self.0.quote_into_iter()
+        }
+    }
+}
+
+// Helper type used within interpolations to allow for repeated binding names.
+// Implements the relevant traits, and exports a dummy `next()` method.
+#[derive(Copy, Clone)]
+#[doc(hidden)]
+pub struct RepInterp<T>(pub T);
+
+impl<T> RepInterp<T> {
+    // This method is intended to look like `Iterator::next`, and is called when
+    // a name is bound multiple times, as the previous binding will shadow the
+    // original `Iterator` object. This allows us to avoid advancing the
+    // iterator multiple times per iteration.
+    pub fn next(self) -> Option<T> {
+        Some(self.0)
+    }
+}
+
+impl<T: Iterator> Iterator for RepInterp<T> {
+    type Item = T::Item;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.0.next()
+    }
+}
+
+impl<T: ToTokens> ToTokens for RepInterp<T> {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        self.0.to_tokens(tokens);
+    }
+}
+
+#[doc(hidden)]
+#[inline]
+pub fn get_span<T>(span: T) -> GetSpan<T> {
+    GetSpan(GetSpanInner(GetSpanBase(span)))
+}
+
+mod get_span {
+    use core::ops::Deref;
+    use proc_macro2::extra::DelimSpan;
+    use proc_macro2::Span;
+
+    pub struct GetSpan<T>(pub(crate) GetSpanInner<T>);
+
+    pub struct GetSpanInner<T>(pub(crate) GetSpanBase<T>);
+
+    pub struct GetSpanBase<T>(pub(crate) T);
+
+    impl GetSpan<Span> {
+        #[inline]
+        pub fn __into_span(self) -> Span {
+            ((self.0).0).0
+        }
+    }
+
+    impl GetSpanInner<DelimSpan> {
+        #[inline]
+        pub fn __into_span(&self) -> Span {
+            (self.0).0.join()
+        }
+    }
+
+    impl<T> GetSpanBase<T> {
+        #[allow(clippy::unused_self)]
+        pub fn __into_span(&self) -> T {
+            unreachable!()
+        }
+    }
+
+    impl<T> Deref for GetSpan<T> {
+        type Target = GetSpanInner<T>;
+
+        #[inline]
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+
+    impl<T> Deref for GetSpanInner<T> {
+        type Target = GetSpanBase<T>;
+
+        #[inline]
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+}
+
+#[doc(hidden)]
+pub fn push_group(tokens: &mut TokenStream, delimiter: Delimiter, inner: TokenStream) {
+    tokens.append(Group::new(delimiter, inner));
+}
+
+#[doc(hidden)]
+pub fn push_group_spanned(
+    tokens: &mut TokenStream,
+    span: Span,
+    delimiter: Delimiter,
+    inner: TokenStream,
+) {
+    let mut g = Group::new(delimiter, inner);
+    g.set_span(span);
+    tokens.append(g);
+}
+
+#[doc(hidden)]
+pub fn parse(tokens: &mut TokenStream, s: &str) {
+    let s: TokenStream = s.parse().expect("invalid token stream");
+    tokens.extend(iter::once(s));
+}
+
+#[doc(hidden)]
+pub fn parse_spanned(tokens: &mut TokenStream, span: Span, s: &str) {
+    let s: TokenStream = s.parse().expect("invalid token stream");
+    tokens.extend(s.into_iter().map(|t| respan_token_tree(t, span)));
+}
+
+// Token tree with every span replaced by the given one.
+fn respan_token_tree(mut token: TokenTree, span: Span) -> TokenTree {
+    match &mut token {
+        TokenTree::Group(g) => {
+            let stream = g
+                .stream()
+                .into_iter()
+                .map(|token| respan_token_tree(token, span))
+                .collect();
+            *g = Group::new(g.delimiter(), stream);
+            g.set_span(span);
+        }
+        other => other.set_span(span),
+    }
+    token
+}
+
+#[doc(hidden)]
+pub fn push_ident(tokens: &mut TokenStream, s: &str) {
+    let span = Span::call_site();
+    push_ident_spanned(tokens, span, s);
+}
+
+#[doc(hidden)]
+pub fn push_ident_spanned(tokens: &mut TokenStream, span: Span, s: &str) {
+    tokens.append(ident_maybe_raw(s, span));
+}
+
+#[doc(hidden)]
+pub fn push_lifetime(tokens: &mut TokenStream, lifetime: &str) {
+    tokens.extend([
+        TokenTree::Punct(Punct::new('\'', Spacing::Joint)),
+        TokenTree::Ident(Ident::new(&lifetime[1..], Span::call_site())),
+    ]);
+}
+
+#[doc(hidden)]
+pub fn push_lifetime_spanned(tokens: &mut TokenStream, span: Span, lifetime: &str) {
+    tokens.extend([
+        TokenTree::Punct({
+            let mut apostrophe = Punct::new('\'', Spacing::Joint);
+            apostrophe.set_span(span);
+            apostrophe
+        }),
+        TokenTree::Ident(Ident::new(&lifetime[1..], span)),
+    ]);
+}
+
+macro_rules! push_punct {
+    ($name:ident $spanned:ident $char1:tt) => {
+        #[doc(hidden)]
+        pub fn $name(tokens: &mut TokenStream) {
+            tokens.append(Punct::new($char1, Spacing::Alone));
+        }
+        #[doc(hidden)]
+        pub fn $spanned(tokens: &mut TokenStream, span: Span) {
+            let mut punct = Punct::new($char1, Spacing::Alone);
+            punct.set_span(span);
+            tokens.append(punct);
+        }
+    };
+    ($name:ident $spanned:ident $char1:tt $char2:tt) => {
+        #[doc(hidden)]
+        pub fn $name(tokens: &mut TokenStream) {
+            tokens.append(Punct::new($char1, Spacing::Joint));
+            tokens.append(Punct::new($char2, Spacing::Alone));
+        }
+        #[doc(hidden)]
+        pub fn $spanned(tokens: &mut TokenStream, span: Span) {
+            let mut punct = Punct::new($char1, Spacing::Joint);
+            punct.set_span(span);
+            tokens.append(punct);
+            let mut punct = Punct::new($char2, Spacing::Alone);
+            punct.set_span(span);
+            tokens.append(punct);
+        }
+    };
+    ($name:ident $spanned:ident $char1:tt $char2:tt $char3:tt) => {
+        #[doc(hidden)]
+        pub fn $name(tokens: &mut TokenStream) {
+            tokens.append(Punct::new($char1, Spacing::Joint));
+            tokens.append(Punct::new($char2, Spacing::Joint));
+            tokens.append(Punct::new($char3, Spacing::Alone));
+        }
+        #[doc(hidden)]
+        pub fn $spanned(tokens: &mut TokenStream, span: Span) {
+            let mut punct = Punct::new($char1, Spacing::Joint);
+            punct.set_span(span);
+            tokens.append(punct);
+            let mut punct = Punct::new($char2, Spacing::Joint);
+            punct.set_span(span);
+            tokens.append(punct);
+            let mut punct = Punct::new($char3, Spacing::Alone);
+            punct.set_span(span);
+            tokens.append(punct);
+        }
+    };
+}
+
+push_punct!(push_add push_add_spanned '+');
+push_punct!(push_add_eq push_add_eq_spanned '+' '=');
+push_punct!(push_and push_and_spanned '&');
+push_punct!(push_and_and push_and_and_spanned '&' '&');
+push_punct!(push_and_eq push_and_eq_spanned '&' '=');
+push_punct!(push_at push_at_spanned '@');
+push_punct!(push_bang push_bang_spanned '!');
+push_punct!(push_caret push_caret_spanned '^');
+push_punct!(push_caret_eq push_caret_eq_spanned '^' '=');
+push_punct!(push_colon push_colon_spanned ':');
+push_punct!(push_colon2 push_colon2_spanned ':' ':');
+push_punct!(push_comma push_comma_spanned ',');
+push_punct!(push_div push_div_spanned '/');
+push_punct!(push_div_eq push_div_eq_spanned '/' '=');
+push_punct!(push_dot push_dot_spanned '.');
+push_punct!(push_dot2 push_dot2_spanned '.' '.');
+push_punct!(push_dot3 push_dot3_spanned '.' '.' '.');
+push_punct!(push_dot_dot_eq push_dot_dot_eq_spanned '.' '.' '=');
+push_punct!(push_eq push_eq_spanned '=');
+push_punct!(push_eq_eq push_eq_eq_spanned '=' '=');
+push_punct!(push_ge push_ge_spanned '>' '=');
+push_punct!(push_gt push_gt_spanned '>');
+push_punct!(push_le push_le_spanned '<' '=');
+push_punct!(push_lt push_lt_spanned '<');
+push_punct!(push_mul_eq push_mul_eq_spanned '*' '=');
+push_punct!(push_ne push_ne_spanned '!' '=');
+push_punct!(push_or push_or_spanned '|');
+push_punct!(push_or_eq push_or_eq_spanned '|' '=');
+push_punct!(push_or_or push_or_or_spanned '|' '|');
+push_punct!(push_pound push_pound_spanned '#');
+push_punct!(push_question push_question_spanned '?');
+push_punct!(push_rarrow push_rarrow_spanned '-' '>');
+push_punct!(push_larrow push_larrow_spanned '<' '-');
+push_punct!(push_rem push_rem_spanned '%');
+push_punct!(push_rem_eq push_rem_eq_spanned '%' '=');
+push_punct!(push_fat_arrow push_fat_arrow_spanned '=' '>');
+push_punct!(push_semi push_semi_spanned ';');
+push_punct!(push_shl push_shl_spanned '<' '<');
+push_punct!(push_shl_eq push_shl_eq_spanned '<' '<' '=');
+push_punct!(push_shr push_shr_spanned '>' '>');
+push_punct!(push_shr_eq push_shr_eq_spanned '>' '>' '=');
+push_punct!(push_star push_star_spanned '*');
+push_punct!(push_sub push_sub_spanned '-');
+push_punct!(push_sub_eq push_sub_eq_spanned '-' '=');
+
+#[doc(hidden)]
+pub fn push_underscore(tokens: &mut TokenStream) {
+    push_underscore_spanned(tokens, Span::call_site());
+}
+
+#[doc(hidden)]
+pub fn push_underscore_spanned(tokens: &mut TokenStream, span: Span) {
+    tokens.append(Ident::new("_", span));
+}
+
+// Helper method for constructing identifiers from the `format_ident!` macro,
+// handling `r#` prefixes.
+#[doc(hidden)]
+pub fn mk_ident(id: &str, span: Option<Span>) -> Ident {
+    let span = span.unwrap_or_else(Span::call_site);
+    ident_maybe_raw(id, span)
+}
+
+fn ident_maybe_raw(id: &str, span: Span) -> Ident {
+    if let Some(id) = id.strip_prefix("r#") {
+        Ident::new_raw(id, span)
+    } else {
+        Ident::new(id, span)
+    }
+}
+
+// Adapts from `IdentFragment` to `fmt::Display` for use by the `format_ident!`
+// macro, and exposes span information from these fragments.
+//
+// This struct also has forwarding implementations of the formatting traits
+// `Octal`, `LowerHex`, `UpperHex`, and `Binary` to allow for their use within
+// `format_ident!`.
+#[derive(Copy, Clone)]
+#[doc(hidden)]
+pub struct IdentFragmentAdapter<T: IdentFragment>(pub T);
+
+impl<T: IdentFragment> IdentFragmentAdapter<T> {
+    pub fn span(&self) -> Option<Span> {
+        self.0.span()
+    }
+}
+
+impl<T: IdentFragment> fmt::Display for IdentFragmentAdapter<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        IdentFragment::fmt(&self.0, f)
+    }
+}
+
+impl<T: IdentFragment + fmt::Octal> fmt::Octal for IdentFragmentAdapter<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Octal::fmt(&self.0, f)
+    }
+}
+
+impl<T: IdentFragment + fmt::LowerHex> fmt::LowerHex for IdentFragmentAdapter<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::LowerHex::fmt(&self.0, f)
+    }
+}
+
+impl<T: IdentFragment + fmt::UpperHex> fmt::UpperHex for IdentFragmentAdapter<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::UpperHex::fmt(&self.0, f)
+    }
+}
+
+impl<T: IdentFragment + fmt::Binary> fmt::Binary for IdentFragmentAdapter<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Binary::fmt(&self.0, f)
+    }
+}