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, 201 insertions, 0 deletions

diff --git a/scripts/git-resolve.sh b/scripts/git-resolve.sh
new file mode 100755
index 000000000..e9b5940c0
--- /dev/null
+++ b/scripts/git-resolve.sh
@@ -0,0 +1,201 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# (c) 2025, Sasha Levin <sashal@kernel.org>
+
+usage() {
+	echo "Usage: $(basename "$0") [--selftest] [--force] <commit-id> [commit-subject]"
+	echo "Resolves a short git commit ID to its full SHA-1 hash, particularly useful for fixing references in commit messages."
+	echo ""
+	echo "Arguments:"
+	echo "  --selftest      Run self-tests"
+	echo "  --force         Try to find commit by subject if ID lookup fails"
+	echo "  commit-id       Short git commit ID to resolve"
+	echo "  commit-subject  Optional commit subject to help resolve between multiple matches"
+	exit 1
+}
+
+# Convert subject with ellipsis to grep pattern
+convert_to_grep_pattern() {
+	local subject="$1"
+	# First escape ALL regex special characters
+	local escaped_subject
+	escaped_subject=$(printf '%s\n' "$subject" | sed 's/[[\.*^$()+?{}|]/\\&/g')
+	# Also escape colons, parentheses, and hyphens as they are special in our context
+	escaped_subject=$(echo "$escaped_subject" | sed 's/[:-]/\\&/g')
+	# Then convert escaped ... sequence to .*?
+	escaped_subject=$(echo "$escaped_subject" | sed 's/\\\.\\\.\\\./.*?/g')
+	echo "^${escaped_subject}$"
+}
+
+git_resolve_commit() {
+	local force=0
+	if [ "$1" = "--force" ]; then
+		force=1
+		shift
+	fi
+
+	# Split input into commit ID and subject
+	local input="$*"
+	local commit_id="${input%% *}"
+	local subject=""
+
+	# Extract subject if present (everything after the first space)
+	if [[ "$input" == *" "* ]]; then
+		subject="${input#* }"
+		# Strip the ("...") quotes if present
+		subject="${subject#*(\"}"
+		subject="${subject%\")*}"
+	fi
+
+	# Get all possible matching commit IDs
+	local matches
+	readarray -t matches < <(git rev-parse --disambiguate="$commit_id" 2>/dev/null)
+
+	# Return immediately if we have exactly one match
+	if [ ${#matches[@]} -eq 1 ]; then
+		echo "${matches[0]}"
+		return 0
+	fi
+
+	# If no matches and not in force mode, return failure
+	if [ ${#matches[@]} -eq 0 ] && [ $force -eq 0 ]; then
+		return 1
+	fi
+
+	# If we have a subject, try to find a match with that subject
+	if [ -n "$subject" ]; then
+		# Convert subject with possible ellipsis to grep pattern
+		local grep_pattern
+		grep_pattern=$(convert_to_grep_pattern "$subject")
+
+		# In force mode with no ID matches, use git log --grep directly
+		if [ ${#matches[@]} -eq 0 ] && [ $force -eq 1 ]; then
+			# Use git log to search, but filter to ensure subject matches exactly
+			local match
+			match=$(git log --format="%H %s" --grep="$grep_pattern" --perl-regexp -10 | \
+					while read -r hash subject; do
+						if echo "$subject" | grep -qP "$grep_pattern"; then
+							echo "$hash"
+							break
+						fi
+					done)
+			if [ -n "$match" ]; then
+				echo "$match"
+				return 0
+			fi
+		else
+			# Normal subject matching for existing matches
+			for match in "${matches[@]}"; do
+				if git log -1 --format="%s" "$match" | grep -qP "$grep_pattern"; then
+					echo "$match"
+					return 0
+				fi
+			done
+		fi
+	fi
+
+	# No match found
+	return 1
+}
+
+run_selftest() {
+	local test_cases=(
+		'00250b5 ("MAINTAINERS: add new Rockchip SoC list")'
+		'0037727 ("KVM: selftests: Convert xen_shinfo_test away from VCPU_ID")'
+		'ffef737 ("net/tls: Fix skb memory leak when running kTLS traffic")'
+		'd3d7 ("cifs: Improve guard for excluding $LXDEV xattr")'
+		'dbef ("Rename .data.once to .data..once to fix resetting WARN*_ONCE")'
+		'12345678'  # Non-existent commit
+		'12345 ("I'\''m a dummy commit")'  # Valid prefix but wrong subject
+		'--force 99999999 ("net/tls: Fix skb memory leak when running kTLS traffic")'  # Force mode with non-existent ID but valid subject
+		'83be ("firmware: ... auto-update: fix poll_complete() ... errors")'  # Wildcard test
+		'--force 999999999999 ("firmware: ... auto-update: fix poll_complete() ... errors")'  # Force mode wildcard test
+	)
+
+	local expected=(
+		"00250b529313d6262bb0ebbd6bdf0a88c809f6f0"
+		"0037727b3989c3fe1929c89a9a1dfe289ad86f58"
+		"ffef737fd0372ca462b5be3e7a592a8929a82752"
+		"d3d797e326533794c3f707ce1761da7a8895458c"
+		"dbefa1f31a91670c9e7dac9b559625336206466f"
+		""  # Expect empty output for non-existent commit
+		""  # Expect empty output for wrong subject
+		"ffef737fd0372ca462b5be3e7a592a8929a82752"  # Should find commit by subject in force mode
+		"83beece5aff75879bdfc6df8ba84ea88fd93050e"  # Wildcard test
+		"83beece5aff75879bdfc6df8ba84ea88fd93050e"  # Force mode wildcard test
+	)
+
+	local expected_exit_codes=(
+		0
+		0
+		0
+		0
+		0
+		1  # Expect failure for non-existent commit
+		1  # Expect failure for wrong subject
+		0  # Should succeed in force mode
+		0  # Should succeed with wildcard
+		0  # Should succeed with force mode and wildcard
+	)
+
+	local failed=0
+
+	echo "Running self-tests..."
+	for i in "${!test_cases[@]}"; do
+		# Capture both output and exit code
+		local result
+		result=$(git_resolve_commit ${test_cases[$i]})  # Removed quotes to allow --force to be parsed
+		local exit_code=$?
+
+		# Check both output and exit code
+		if [ "$result" != "${expected[$i]}" ] || [ $exit_code != ${expected_exit_codes[$i]} ]; then
+			echo "Test case $((i+1)) FAILED"
+			echo "Input: ${test_cases[$i]}"
+			echo "Expected output: '${expected[$i]}'"
+			echo "Got output: '$result'"
+			echo "Expected exit code: ${expected_exit_codes[$i]}"
+			echo "Got exit code: $exit_code"
+			failed=1
+		else
+			echo "Test case $((i+1)) PASSED"
+		fi
+	done
+
+	if [ $failed -eq 0 ]; then
+		echo "All tests passed!"
+		exit 0
+	else
+		echo "Some tests failed!"
+		exit 1
+	fi
+}
+
+# Check for selftest
+if [ "$1" = "--selftest" ]; then
+	run_selftest
+	exit $?
+fi
+
+# Handle --force flag
+force=""
+if [ "$1" = "--force" ]; then
+	force="--force"
+	shift
+fi
+
+# Verify arguments
+if [ $# -eq 0 ]; then
+	usage
+fi
+
+# Skip validation in force mode
+if [ -z "$force" ]; then
+	# Validate that the first argument matches at least one git commit
+	if [ "$(git rev-parse --disambiguate="$1" 2>/dev/null | wc -l)" -eq 0 ]; then
+		echo "Error: '$1' does not match any git commit"
+		exit 1
+	fi
+fi
+
+git_resolve_commit $force "$@"
+exit $?