* Re: [PATCH v2 01/13] verification/rvgen: Switch LTL parser to Lark
From: Gabriele Monaco @ 2026-06-03 14:49 UTC (permalink / raw)
To: Nam Cao
Cc: Wander Lairson Costa, Steven Rostedt, linux-trace-kernel,
linux-kernel
In-Reply-To: <e1736ef618e32712eeb65d1714a2fea76298057b.1779956342.git.namcao@linutronix.de>
On Thu, 2026-05-28 at 10:27 +0200, Nam Cao wrote:
> The LTL parser is built using Ply. However, Ply is no longer
> maintained [1].
>
> Switch to use Lark instead. In addition to being actively maintained,
> Lark
> also offers additional features (namely, automatically creating the
> abstract syntax tree) which make the parser simpler.
>
> Link:
> https://github.com/dabeaz/ply/commit/9d7c40099e23ff78f9d86ef69a26c1e8a83e706a
> [1]
> Signed-off-by: Nam Cao <namcao@linutronix.de>
> ---
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
> v2:
> - fix identifier starting with a digit is allowed [Wander]
> - fixup ast node uid [Gabriele]
> - Fix up Literal AST node construction [Wander, Sashiko]
> - FIx up unary op error message [Sashiko]
> - Add nice exception handling [Gabriele]
> ---
> tools/verification/rvgen/__main__.py | 5 +-
> tools/verification/rvgen/rvgen/ltl2ba.py | 202 +++++++++------------
> --
> 2 files changed, 82 insertions(+), 125 deletions(-)
>
> diff --git a/tools/verification/rvgen/__main__.py
> b/tools/verification/rvgen/__main__.py
> index 5c923dc10d0f..0915cf86e43b 100644
> --- a/tools/verification/rvgen/__main__.py
> +++ b/tools/verification/rvgen/__main__.py
> @@ -14,6 +14,7 @@ if __name__ == '__main__':
> from rvgen.container import Container
> from rvgen.ltl2k import ltl2k
> from rvgen.automata import AutomataError
> + from rvgen.ltl2ba import LTLError
> import argparse
> import sys
>
> @@ -57,8 +58,8 @@ if __name__ == '__main__':
> sys.exit(1)
> else:
> monitor = Container(vars(params))
> - except AutomataError as e:
> - print(f"There was an error processing {params.spec}: {e}",
> file=sys.stderr)
> + except (AutomataError, LTLError) as e:
> + print(f"There was an error processing {params.spec}:\n{e}",
> file=sys.stderr)
> sys.exit(1)
>
> print(f"Writing the monitor into the directory {monitor.name}")
> diff --git a/tools/verification/rvgen/rvgen/ltl2ba.py
> b/tools/verification/rvgen/rvgen/ltl2ba.py
> index 016e7cf93bbb..7cebda61bce8 100644
> --- a/tools/verification/rvgen/rvgen/ltl2ba.py
> +++ b/tools/verification/rvgen/rvgen/ltl2ba.py
> @@ -7,9 +7,7 @@
> # https://doi.org/10.1007/978-0-387-34892-6_1
> # With extra optimizations
>
> -from ply.lex import lex
> -from ply.yacc import yacc
> -from .automata import AutomataError
> +import lark
>
> # Grammar:
> # ltl ::= opd | ( ltl ) | ltl binop ltl | unop ltl
> @@ -30,42 +28,41 @@ from .automata import AutomataError
> # imply
> # equivalent
>
> -tokens = (
> - 'AND',
> - 'OR',
> - 'IMPLY',
> - 'UNTIL',
> - 'ALWAYS',
> - 'EVENTUALLY',
> - 'NEXT',
> - 'VARIABLE',
> - 'LITERAL',
> - 'NOT',
> - 'LPAREN',
> - 'RPAREN',
> - 'ASSIGN',
> -)
> -
> -t_AND = r'and'
> -t_OR = r'or'
> -t_IMPLY = r'imply'
> -t_UNTIL = r'until'
> -t_ALWAYS = r'always'
> -t_NEXT = r'next'
> -t_EVENTUALLY = r'eventually'
> -t_VARIABLE = r'[A-Z_0-9]+'
> -t_LITERAL = r'true|false'
> -t_NOT = r'not'
> -t_LPAREN = r'\('
> -t_RPAREN = r'\)'
> -t_ASSIGN = r'='
> -t_ignore_COMMENT = r'\#.*'
> -t_ignore = ' \t\n'
> -
> -def t_error(t):
> - raise AutomataError(f"Illegal character '{t.value[0]}'")
> -
> -lexer = lex()
> +GRAMMAR = r'''
> +start: assign+
> +
> +assign: VARIABLE "=" _ltl
> +
> +_ltl: _opd | binop | unop
> +
> +_opd : VARIABLE
> + | LITERAL
> + | "(" _ltl ")"
> +
> +unop: UNOP _ltl
> +UNOP: "always"
> + | "eventually"
> + | "next"
> + | "not"
> +
> +binop: _opd BINOP _ltl
> +BINOP: "until"
> + | "and"
> + | "or"
> + | "imply"
> +
> +VARIABLE: /[A-Z_][A-Z0-9_]*/
> +LITERAL: "true" | "false"
> +
> +COMMENT: "#" /.*/ "\n"
> +%ignore COMMENT
> +
> +%import common.WS
> +%ignore WS
> +'''
> +
> +class LTLError(Exception):
> + "Exception raised for malformed linear temporal logic"
>
> class GraphNode:
> uid = 0
> @@ -97,7 +94,7 @@ class GraphNode:
> return self.id < other.id
>
> class ASTNode:
> - uid = 1
> + uid = 0
>
> def __init__(self, op):
> self.op = op
> @@ -433,90 +430,49 @@ class Literal:
> node.old |= {n}
> return node.expand(node_set)
>
> -def p_spec(p):
> - '''
> - spec : assign
> - | assign spec
> - '''
> - if len(p) == 3:
> - p[2].append(p[1])
> - p[0] = p[2]
> - else:
> - p[0] = [p[1]]
> -
> -def p_assign(p):
> - '''
> - assign : VARIABLE ASSIGN ltl
> - '''
> - p[0] = (p[1], p[3])
> -
> -def p_ltl(p):
> - '''
> - ltl : opd
> - | binop
> - | unop
> - '''
> - p[0] = p[1]
> -
> -def p_opd(p):
> - '''
> - opd : VARIABLE
> - | LITERAL
> - | LPAREN ltl RPAREN
> - '''
> - if p[1] == "true":
> - p[0] = ASTNode(Literal(True))
> - elif p[1] == "false":
> - p[0] = ASTNode(Literal(False))
> - elif p[1] == '(':
> - p[0] = p[2]
> - else:
> - p[0] = ASTNode(Variable(p[1]))
> -
> -def p_unop(p):
> - '''
> - unop : ALWAYS ltl
> - | EVENTUALLY ltl
> - | NEXT ltl
> - | NOT ltl
> - '''
> - if p[1] == "always":
> - op = AlwaysOp(p[2])
> - elif p[1] == "eventually":
> - op = EventuallyOp(p[2])
> - elif p[1] == "next":
> - op = NextOp(p[2])
> - elif p[1] == "not":
> - op = NotOp(p[2])
> - else:
> - raise AutomataError(f"Invalid unary operator {p[1]}")
> -
> - p[0] = ASTNode(op)
> -
> -def p_binop(p):
> - '''
> - binop : opd UNTIL ltl
> - | opd AND ltl
> - | opd OR ltl
> - | opd IMPLY ltl
> - '''
> - if p[2] == "and":
> - op = AndOp(p[1], p[3])
> - elif p[2] == "until":
> - op = UntilOp(p[1], p[3])
> - elif p[2] == "or":
> - op = OrOp(p[1], p[3])
> - elif p[2] == "imply":
> - op = ImplyOp(p[1], p[3])
> - else:
> - raise AutomataError(f"Invalid binary operator {p[2]}")
> -
> - p[0] = ASTNode(op)
> -
> -parser = yacc()
> +class Transform(lark.visitors.Transformer):
> + def unop(self, node):
> + if node[0] == "always":
> + return ASTNode(AlwaysOp(node[1]))
> + if node[0] == "eventually":
> + return ASTNode(EventuallyOp(node[1]))
> + if node[0] == "next":
> + return ASTNode(NextOp(node[1]))
> + if node[0] == "not":
> + return ASTNode(NotOp(node[1]))
> + raise ValueError("Unknown operator %s" % node[0])
> +
> + def binop(self, node):
> + if node[1] == "until":
> + return ASTNode(UntilOp(node[0], node[2]))
> + if node[1] == "and":
> + return ASTNode(AndOp(node[0], node[2]))
> + if node[1] == "or":
> + return ASTNode(OrOp(node[0], node[2]))
> + if node[1] == "imply":
> + return ASTNode(ImplyOp(node[0], node[2]))
> + raise ValueError("Unknown operator %s" % node[1])
> +
> + def VARIABLE(self, args):
> + return ASTNode(Variable(args))
> +
> + def LITERAL(self, args):
> + return ASTNode(Literal(args == "true"))
> +
> + def start(self, node):
> + return node
> +
> + def assign(self, node):
> + return node[0].op.name, node[1]
> +
> +parser = lark.Lark(GRAMMAR)
>
> def parse_ltl(s: str) -> ASTNode:
> - spec = parser.parse(s)
> + try:
> + spec = parser.parse(s)
> + except lark.exceptions.UnexpectedInput as e:
> + raise LTLError(str(e))
> + spec = Transform().transform(spec)
>
> rule = None
> subexpr = {}
> @@ -528,7 +484,7 @@ def parse_ltl(s: str) -> ASTNode:
> subexpr[assign[0]] = assign[1]
>
> if rule is None:
> - raise AutomataError("Please define your specification in the
> \"RULE = <LTL spec>\" format")
> + raise LTLError("Please define your specification in the
> \"RULE = <LTL spec>\" format")
>
> for node in rule:
> if not isinstance(node.op, Variable):
^ permalink raw reply
* Re: [PATCH v2 02/13] verification/rvgen: Introduce a parse tree for automata using Lark
From: Gabriele Monaco @ 2026-06-03 14:55 UTC (permalink / raw)
To: Nam Cao, Wander Lairson Costa, Steven Rostedt, linux-trace-kernel,
linux-kernel
In-Reply-To: <13a2f241b74e02b13efa7fe188be3fa7e6148b4a.1779956342.git.namcao@linutronix.de>
On Thu, 2026-05-28 at 10:27 +0200, Nam Cao wrote:
> The DOT parsing scripts directly parse the raw text and they are
> quite
> fragile. If the input dot files' formats are slightly changed (for
> instance, by breaking long some lines which is allowed by the DOT
> language
> defined by graphviz), the scripts would fail.
>
> To make the scripts robust, the parser should be implemented based on
> the
> dot language specification, not based on how the existing dot files
> look.
>
> As a first step, use Lark to implement a Parser based on the graphviz
> dot
> language specification. The resulting parse tree is not used yet, but
> the
> existing scripts will be converted one by one to use this new parse
> tree in
> the follow-up commits.
>
> Signed-off-by: Nam Cao <namcao@linutronix.de>
> ---
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
> v2:
> - switch to use Lark's CNAME for identifier [Wander]
> - switch to use Lark's ESCAPED_STRING for string [Sashiko]
> - clean up variable name shadowing [Sashiko]
> - Properly catch Lark exception
> ---
> tools/verification/rvgen/rvgen/automata.py | 186
> +++++++++++++++++++++
> 1 file changed, 186 insertions(+)
>
> diff --git a/tools/verification/rvgen/rvgen/automata.py
> b/tools/verification/rvgen/rvgen/automata.py
> index b9f8149f7118..8649d982383d 100644
> --- a/tools/verification/rvgen/rvgen/automata.py
> +++ b/tools/verification/rvgen/rvgen/automata.py
> @@ -13,6 +13,191 @@ import re
> from typing import Iterator
> from itertools import islice
>
> +import lark
> +
> +class ParseTree:
> + # based on https://graphviz.org/doc/info/lang.html
> + # with the irrelevant stuffs (port and compass) removed
> + grammar = r'''
> + start: "strict"? ("graph" | "digraph") ID? "{" stmt_list "}"
> +
> + stmt_list: (stmt ";"? stmt_list)?
> +
> + stmt: node_stmt
> + | edge_stmt
> + | attr_stmt
> + | ID "=" ID
> + | subgraph
> +
> + attr_stmt: attr_type attr_list
> +
> + attr_type: "graph" -> graph
> + | "node" -> node
> + | "edge" -> edge
> +
> + attr_list: "[" a_list? "]" attr_list?
> +
> + a_list: ID "=" ID (";" | ",")? a_list?
> +
> + edge_stmt: (node_id | subgraph) edgerhs attr_list?
> +
> + edgerhs: edgeop (node_id | subgraph) edgerhs?
> +
> + edgeop: "->" | "--"
> +
> + node_stmt: node_id attr_list?
> +
> + node_id: ID
> +
> + subgraph: ("subgraph" ID?)? "{" stmt_list "}"
> +
> + ID: CNAME
> + | /-?(\.[0-9]+|[0-9]+(\.[0-9]*))/
> + | ESCAPED_STRING
> +
> + %import common.CNAME
> + %import common.ESCAPED_STRING
> + %import common.WS
> + %ignore WS
> + '''
> +
> + @staticmethod
> + def parse_edge(tree: lark.Tree) -> tuple[str, str]:
> + # only support a simple node-to-node edge
> + nodes = []
> + for node in tree.iter_subtrees_topdown():
> + if node.data == "node_id":
> + nodes.append(node.children[0].strip('"'))
> +
> + if len(nodes) != 2:
> + raise AutomataError("Only state-to-state transition is
> supported")
> +
> + return tuple(nodes)
> +
> + class ParseNodes(lark.visitors.Visitor):
> + def __init__(self, *args, **kwargs):
> + self.nodes = set()
> + super().__init__(*args, **kwargs)
> +
> + def node_stmt(self, tree):
> + node_id = tree.children[0]
> + node = node_id.children[0].strip('"')
> + self.nodes.add(node)
> +
> + class ParseEdges(lark.visitors.Visitor):
> + def __init__(self, *args, **kwargs):
> + self.edges = set()
> + super().__init__(*args, **kwargs)
> +
> + def edge_stmt(self, tree):
> + edge = ParseTree.parse_edge(tree)
> + self.edges.add(edge)
> +
> + class ParseAttributes(lark.visitors.Interpreter):
> + def __init__(self, *args, **kwargs):
> + '''
> + Stacks of default attributes. [0] is the default
> + attributes for the outermost scope, while [-1] is the
> + default attributes for the current scope.
> + '''
> + self.default_node_attrs = [{}]
> + self.default_edge_attrs = [{}]
> +
> + self.node_attrs = {}
> + self.edge_attrs = {}
> +
> + super().__init__(*args, **kwargs)
> +
> + @staticmethod
> + def __get_attrs(stmt: lark.Tree) -> dict[str, str]:
> + attrs = {}
> +
> + for node in stmt.iter_subtrees():
> + if node.data == "a_list":
> + attrs[node.children[0]] =
> node.children[1].strip('"')
> +
> + return attrs
> +
> +
> + def subgraph(self, tree):
> + # We are entering a new scope, inherit the default
> + # attributes of the outer scope
> + self.default_node_attrs.append(self.default_node_attrs[-
> 1].copy())
> + self.default_edge_attrs.append(self.default_edge_attrs[-
> 1].copy())
> +
> + children = self.visit_children(tree)
> +
> + # Exiting the scope
> + del self.default_node_attrs[-1]
> + del self.default_edge_attrs[-1]
> +
> + return children
> +
> + def node_stmt(self, tree):
> + node_id = tree.children[0]
> + node = node_id.children[0].strip('"')
> +
> + attrs = self.default_node_attrs[-1].copy()
> + attrs |= self.__get_attrs(tree)
> +
> + if attrs:
> + if node in self.node_attrs:
> + self.node_attrs[node] = attrs |
> self.node_attrs[node]
> + else:
> + self.node_attrs[node] = attrs
> +
> + return self.visit_children(tree)
> +
> + def edge_stmt(self, tree):
> + edge = ParseTree.parse_edge(tree)
> +
> + attrs = self.default_edge_attrs[-1].copy()
> + attrs |= self.__get_attrs(tree)
> +
> + if attrs:
> + if edge in self.edge_attrs:
> + self.edge_attrs[edge] = attrs |
> self.edge_attrs[edge]
> + else:
> + self.edge_attrs[edge] = attrs
> +
> + return self.visit_children(tree)
> +
> + def attr_stmt(self, tree):
> + attr_type = tree.children[0].data
> + attrs = self.__get_attrs(tree)
> +
> + if attr_type == "node":
> + self.default_node_attrs[-1] |= attrs
> + elif attr_type == "edge":
> + self.default_edge_attrs[-1] |= attrs
> + else:
> + # graph attributes are irrelevant
> + pass
> +
> + self.visit_children(tree)
> +
> + def __init__(self, dot_file):
> + parser = lark.Lark(self.grammar, parser='lalr')
> + node_parser = self.ParseNodes()
> + edge_parser = self.ParseEdges()
> + attributes_parser = self.ParseAttributes()
> +
> + try:
> + with open(dot_file, "r") as f:
> + tree = parser.parse(f.read())
> + attributes_parser.visit(tree)
> + node_parser.visit(tree)
> + edge_parser.visit(tree)
> + except OSError as exc:
> + raise AutomataError(exc.strerror) from exc
> + except lark.exceptions.UnexpectedInput as exc:
> + raise AutomataError(str(exc))
> +
> + self.nodes = node_parser.nodes
> + self.edges = edge_parser.edges
> + self.node_attrs = attributes_parser.node_attrs
> + self.edge_attrs = attributes_parser.edge_attrs
> +
> class _ConstraintKey:
> """Base class for constraint keys."""
>
> @@ -66,6 +251,7 @@ class Automata:
> self.__dot_path = file_path
> self.name = model_name or self.__get_model_name()
> self.__dot_lines = self.__open_dot()
> + self.__parse_tree = ParseTree(file_path)
> self.states, self.initial_state, self.final_states =
> self.__get_state_variables()
> self.env_types = {}
> self.env_stored = set()
^ permalink raw reply
* Re: [PATCH v2 03/13] verification/rvgen: Implement state and transition parser based on Lark
From: Gabriele Monaco @ 2026-06-03 14:55 UTC (permalink / raw)
To: Nam Cao, Wander Lairson Costa, Steven Rostedt, linux-trace-kernel,
linux-kernel
In-Reply-To: <e84c39bab831f1623142e6b83a9513ba99a702f1.1779956342.git.namcao@linutronix.de>
On Thu, 2026-05-28 at 10:27 +0200, Nam Cao wrote:
> The DOT parsing scripts directly parse the raw text and they are
> quite
> fragile. If the input dot files' formats are slightly changed (for
> instance, by breaking long some lines which is allowed by the DOT
> language), the scripts would fail.
>
> Prepare to move away from the raw text processing, implement parsers
> based
> on Lark which parse states, transitions and constraints.
>
> The parse results are not used yet. The existing scripts will be
> converted
> one by one to them, and the raw text processing will eventually be
> removed.
>
> Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
> ---
> v2:
> - fixup guard grammar [Gabriele]
> - fixup inconsistent types in a list [Wander]
> - compiling the parsers only once to avoid overhead [Sashiko]
> - fix up the signature of State.__init__() [Sashiko]
> - gracefully handle node statement without label [Sashiko]
> - lark parse exception handling
> ---
> tools/verification/rvgen/rvgen/automata.py | 216
> +++++++++++++++++++++
> 1 file changed, 216 insertions(+)
>
> diff --git a/tools/verification/rvgen/rvgen/automata.py
> b/tools/verification/rvgen/rvgen/automata.py
> index 8649d982383d..b86275e7bf28 100644
> --- a/tools/verification/rvgen/rvgen/automata.py
> +++ b/tools/verification/rvgen/rvgen/automata.py
> @@ -198,6 +198,164 @@ class ParseTree:
> self.node_attrs = attributes_parser.node_attrs
> self.edge_attrs = attributes_parser.edge_attrs
>
> +class ConstraintCondition:
> + def __init__(self, env: str, op: str, val: str, unit=None):
> + self.env = env
> + self.op = op
> + self.val = val
> + self.unit = unit
> + if unit is None:
> + # try to infer unit from constants or parameters
> + val_for_unit = val.lower().replace("()", "")
> + if val_for_unit.endswith("_ns"):
> + self.unit = "ns"
> + if val_for_unit.endswith("_jiffies"):
> + self.unit = "j"
> +
> +class ConstraintRule:
> + grammar = r'''
> + rule: condition (OP condition)*
> +
> + OP: "&&" | "||"
> +
> + condition: ENV CMP_OP VAL UNIT?
> +
> + ENV: CNAME
> +
> + CMP_OP: "==" | "<=" | "<" | ">=" | ">"
> +
> + VAL: /[0-9]+/
> + | /[A-Z_]+\(\)/
> + | /[A-Z_]+/
> + | /[a-z_]+\(\)/
> + | /[a-z_]+/
> +
> + UNIT: "ns" | "us" | "ms" | "s"
> + '''
> +
> + def __init__(self, c: ConstraintCondition):
> + '''
> + A list of pairs of
> + - the condition (e.g. is_constr_dl == 1)
> + - the logical operator ("||" or "&&") combining this
> + condition with the next one if it exists, otherwise None
> +
> + TODO: Perhaps use an abstract syntax tree instead, because
> + this representation cannot capture precedence
> + '''
> + self.rules = [[c, None]]
> +
> + def chain(self, op: str, c: ConstraintCondition):
> + self.rules[-1][1] = op
> + self.rules.append([c, None])
> +
> +class ConstraintReset:
> + def __init__(self, env):
> + self.env = env
> +
> +class StateLabelParser:
> + grammar = r'''
> + label: CNAME ("\\n" condition)?
> +
> + %import common.CNAME
> + %import common.WS
> + %ignore WS
> + ''' + ConstraintRule.grammar
> +
> + parser = lark.Lark(grammar, parser='lalr', start="label")
> +
> + def __init__(self, label: str):
> + try:
> + tree = self.parser.parse(label)
> + except lark.exceptions.UnexpectedInput as exc:
> + raise(AutomataError(f"Unrecognised state
> \"{label}\"\n{exc}"))
> +
> + self.state = tree.children[0]
> + self.constraint = None
> +
> + if len(tree.children) == 2:
> + self.constraint =
> ConstraintCondition(*tree.children[1].children)
> + if self.constraint.op not in ("<", "<="):
> + raise AutomataError("State constraints must be clock
> expirations like"
> + f" clk<N ({label})")
> +
> +class EventLabelParser:
> + grammar = r'''
> + events: event ("\\n" event)*
> +
> + event: name (";" guard)?
> +
> + guard: reset
> + | rule
> + | rule ";" reset
> + | reset ";" rule
> +
> + name: CNAME
> +
> + reset: "reset" "(" ENV ")"
> +
> + %import common.CNAME
> + %import common.WS
> + %ignore WS
> + ''' + ConstraintRule.grammar
> +
> + parser = lark.Lark(grammar, parser='lalr', start="events")
> +
> + class GetEvents(lark.visitors.Transformer):
> + def guard(self, args):
> + reset = None
> + rule = None
> + for arg in args:
> + if arg.data == "reset":
> + reset = ConstraintReset(arg.children[0])
> + elif arg.data == "rule":
> + conditions = arg.children
> + rule = ConstraintRule(conditions[0])
> + for i in range(1, len(conditions), 2):
> + rule.chain(conditions[i], conditions[i + 1])
> + return reset, rule
> +
> + def OP(self, args):
> + return args
> +
> + def condition(self, args):
> + return ConstraintCondition(*args)
> +
> + def event(self, args):
> + assert(len(args) <= 2)
> + name = args[0]
> + rule, reset = None, None
> + if len(args) == 2:
> + reset, rule = args[1]
> + return name, reset, rule
> +
> + def events(self, args):
> + return args
> +
> + def name(self, args):
> + return args[0]
> +
> + def __init__(self, label: str):
> + try:
> + tree = self.parser.parse(label)
> + self.events = self.GetEvents().transform(tree)
> + except lark.exceptions.UnexpectedInput as exc:
> + raise(AutomataError(f"Unrecognised event
> \"{label}\"\n{exc}"))
> +
> +class Transition:
> + def __init__(self, src: str, dst: str, event: str,
> + reset: ConstraintReset, rule: ConstraintRule):
> + self.src = src
> + self.dst = dst
> + self.event = event
> + self.rule = rule
> + self.reset = reset
> +
> +class State:
> + def __init__(self, name: str, inv: ConstraintCondition):
> + self.name = name
> + self.inv = inv
> +
> class _ConstraintKey:
> """Base class for constraint keys."""
>
> @@ -252,6 +410,8 @@ class Automata:
> self.name = model_name or self.__get_model_name()
> self.__dot_lines = self.__open_dot()
> self.__parse_tree = ParseTree(file_path)
> + self.transitions = self.__parse_transitions()
> + self._states, self._initial_state, self._final_states =
> self.__parse_states()
> self.states, self.initial_state, self.final_states =
> self.__get_state_variables()
> self.env_types = {}
> self.env_stored = set()
> @@ -327,6 +487,62 @@ class Automata:
>
> return cursor
>
> + def __parse_transitions(self):
> + transitions = []
> +
> + for edge in self.__parse_tree.edges:
> + attr = self.__parse_tree.edge_attrs.get(edge)
> + if not attr:
> + continue
> +
> + label = attr.get("label")
> +
> + src, dst = edge
> +
> + parser = EventLabelParser(label)
> + for event, reset, rule in parser.events:
> + transitions.append(Transition(src, dst, event,
> reset, rule))
> +
> + transitions.sort(key=lambda t : (t.src, t.event))
> + return transitions
> +
> + def __parse_states(self):
> + initial_state = ""
> + states = []
> + final_states = []
> +
> + for node in self.__parse_tree.nodes:
> + attr = self.__parse_tree.node_attrs[node]
> + label = attr.get("label")
> +
> + if node.startswith(Automata.init_marker):
> + initial_state = node[len(Automata.init_marker):]
> +
> + if not label:
> + continue
> +
> + parser = StateLabelParser(label)
> + state = State(parser.state, parser.constraint)
> +
> + states.append(state)
> +
> + shape = attr.get("shape")
> + if shape in ("doublecircle", "ellipse"):
> + final_states.append(state)
> +
> +
> + initial_state = next((s for s in states if s.name ==
> initial_state), None)
> + if not initial_state:
> + raise AutomataError("The automaton doesn't have an
> initial state")
> +
> + if not final_states:
> + final_states.append(initial_state)
> +
> + states.remove(initial_state)
> + states.sort(key=lambda s : s.name)
> + states.insert(0, initial_state)
> + return states, initial_state, final_states
> +
> def __get_state_variables(self) -> tuple[list[str], str,
> list[str]]:
> # wait for node declaration
> states = []
^ permalink raw reply
* Re: [PATCH v2 04/13] verification/rvgen: Convert __fill_verify_invariants_func() to Lark
From: Gabriele Monaco @ 2026-06-03 14:56 UTC (permalink / raw)
To: Nam Cao, Wander Lairson Costa, Steven Rostedt, linux-trace-kernel,
linux-kernel
In-Reply-To: <d1fbbafd8af64a9663b3982845ecb2c3c5a4eded.1779956342.git.namcao@linutronix.de>
On Thu, 2026-05-28 at 10:27 +0200, Nam Cao wrote:
> Convert __fill_verify_invariants_func() to use the parsed states
> information from Lark, prepare to remove the old raw text parsing
> code.
>
> Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
> ---
> v2: fix up __start_to_invariant_check()'s signature [Sashiko]
> ---
> tools/verification/rvgen/rvgen/dot2k.py | 32 ++++++++++++++++-------
> --
> 1 file changed, 21 insertions(+), 11 deletions(-)
>
> diff --git a/tools/verification/rvgen/rvgen/dot2k.py
> b/tools/verification/rvgen/rvgen/dot2k.py
> index e6f476b903b0..a344cbbcb346 100644
> --- a/tools/verification/rvgen/rvgen/dot2k.py
> +++ b/tools/verification/rvgen/rvgen/dot2k.py
> @@ -12,6 +12,7 @@ from collections import deque
> from .dot2c import Dot2c
> from .generator import Monitor
> from .automata import _EventConstraintKey, _StateConstraintKey,
> AutomataError
> +from .automata import ConstraintRule, ConstraintCondition
>
>
> class dot2k(Monitor, Dot2c):
> @@ -177,6 +178,14 @@ class ha2k(dot2k):
> raise AutomataError("Detected deterministic automaton,
> use the 'da' class")
> self.trace_h = self._read_template_file("trace_hybrid.h")
> self.__parse_constraints()
> + self.has_invariant = False
> + self.has_guard = False
> + for state in self._states:
> + if state.inv:
> + self.has_invariant = True
> + for transition in self.transitions:
> + if transition.rule or transition.reset:
> + self.has_guard = True
>
> def fill_monitor_class_type(self) -> str:
> if self._is_id_monitor():
> @@ -218,14 +227,13 @@ class ha2k(dot2k):
> assert env.rstrip(f"_{self.name}") in self.envs
> return env
>
> - def __start_to_invariant_check(self, constr: str) -> str:
> + def __start_to_invariant_check(self, inv: ConstraintCondition) -
> > str:
> # by default assume the timer has ns expiration
> - env = self.__get_constraint_env(constr)
> clock_type = "ns"
> - if self.env_types.get(env.rstrip(f"_{self.name}")) == "j":
> + if inv.unit == "j":
> clock_type = "jiffy"
>
> - return f"return ha_check_invariant_{clock_type}(ha_mon,
> {env}, time_ns)"
> + return f"return ha_check_invariant_{clock_type}(ha_mon,
> {inv.env}_{self.name}, time_ns)"
>
> def __start_to_conv(self, constr: str) -> str:
> """
> @@ -320,20 +328,22 @@ class ha2k(dot2k):
> self.invariants[key] = rules[0]
>
> def __fill_verify_invariants_func(self) -> list[str]:
> - buff = []
> - if not self.invariants:
> + if not self.has_invariant:
> return []
>
> - buff.append(
> + buff = [
> f"""static inline bool ha_verify_invariants(struct ha_monitor
> *ha_mon,
> \t\t\t\t\tenum {self.enum_states_def} curr_state, enum
> {self.enum_events_def} event,
> \t\t\t\t\tenum {self.enum_states_def} next_state, u64 time_ns)
> -{{""")
> +{{"""]
>
> _else = ""
> - for state, constr in sorted(self.invariants.items()):
> - check_str = self.__start_to_invariant_check(constr)
> - buff.append(f"\t{_else}if (curr_state ==
> {self.states[state]}{self.enum_suffix})")
> + for state in self._states:
> + if not state.inv:
> + continue
> +
> + check_str = self.__start_to_invariant_check(state.inv)
> + buff.append(f"\t{_else}if (curr_state ==
> {state.name}{self.enum_suffix})")
> buff.append(f"\t\t{check_str};")
> _else = "else "
>
^ permalink raw reply
* Re: [PATCH v2 05/13] verification/rvgen: Convert __fill_setup_invariants_func() to Lark
From: Gabriele Monaco @ 2026-06-03 15:24 UTC (permalink / raw)
To: Nam Cao, Wander Lairson Costa, Steven Rostedt, linux-trace-kernel,
linux-kernel
In-Reply-To: <0b2cf5e1bb03d0e3a667b0fc2c7093123ef0a78c.1779956342.git.namcao@linutronix.de>
On Thu, 2026-05-28 at 10:27 +0200, Nam Cao wrote:
> Prepare for self.invariants and __parse_constraints() to be removed.
> convert __fill_setup_invariants_func() to use the new parsed states
> from Lark.
>
> Signed-off-by: Nam Cao <namcao@linutronix.de>
> ---
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
> v2: add missing time conversion [Sashiko]
> ---
> tools/verification/rvgen/rvgen/dot2k.py | 44 ++++++++++++++++++++---
> --
> 1 file changed, 35 insertions(+), 9 deletions(-)
>
> diff --git a/tools/verification/rvgen/rvgen/dot2k.py
> b/tools/verification/rvgen/rvgen/dot2k.py
> index a344cbbcb346..d9f8e1c7737a 100644
> --- a/tools/verification/rvgen/rvgen/dot2k.py
> +++ b/tools/verification/rvgen/rvgen/dot2k.py
> @@ -250,6 +250,26 @@ class ha2k(dot2k):
> return (f"ha_start_timer_{clock_type}(ha_mon,
> {rule["env"]}{self.enum_suffix},"
> f" {value}, time_ns)")
>
> + def __parse_invariant(self, inv):
> + # by default assume the timer has ns expiration
> + clock_type = "ns"
> + if inv.unit == "j":
> + clock_type = "jiffy"
> +
> + env = inv.env + self.enum_suffix
> + val = inv.val.replace("()", "(ha_mon)")
> +
> + match inv.unit:
> + case "us":
> + val *= 10**3
> + case "ms":
> + val *= 10**6
> + case "s":
> + val *= 10**9
> +
> + return (f"ha_start_timer_{clock_type}(ha_mon, {env},"
> + f" {val}, time_ns)")
> +
> def __format_guard_rules(self, rules: list[str]) -> list[str]:
> """
> Merge guard constraints as a single C return statement.
> @@ -463,15 +483,14 @@ f"""static inline bool ha_verify_guards(struct
> ha_monitor *ha_mon,
> return conflict_guards, conflict_invs
>
> def __fill_setup_invariants_func(self) -> list[str]:
> - buff = []
> - if not self.invariants:
> + if not self.has_invariant:
> return []
>
> - buff.append(
> + buff = [
> f"""static inline void ha_setup_invariants(struct ha_monitor
> *ha_mon,
> \t\t\t\t enum {self.enum_states_def} curr_state, enum
> {self.enum_events_def} event,
> \t\t\t\t enum {self.enum_states_def} next_state, u64 time_ns)
> -{{""")
> +{{"""]
>
> conditions = ["next_state == curr_state"]
> conditions += [f"event != {e}{self.enum_suffix}"
> @@ -480,13 +499,20 @@ f"""static inline void
> ha_setup_invariants(struct ha_monitor *ha_mon,
> buff.append(f"\tif ({condition_str})\n\t\treturn;")
>
> _else = ""
> - for state, constr in sorted(self.invariants.items()):
> - buff.append(f"\t{_else}if (next_state ==
> {self.states[state]}{self.enum_suffix})")
> - buff.append(f"\t\t{constr};")
> + for state in self._states:
> + inv = state.inv
> + if not inv:
> + continue
> + inv = self.__parse_invariant(inv)
> + buff.append(f"\t{_else}if (next_state ==
> {state.name}{self.enum_suffix})")
> + buff.append(f"\t\t{inv};")
> _else = "else "
>
> - for state in self.invariants:
> - buff.append(f"\telse if (curr_state ==
> {self.states[state]}{self.enum_suffix})")
> + for state in self._states:
> + inv = state.inv
> + if not inv:
> + continue
> + buff.append(f"\telse if (curr_state ==
> {state.name}{self.enum_suffix})")
> buff.append("\t\tha_cancel_timer(ha_mon);")
>
> buff.append("}\n")
^ permalink raw reply
* [PATCH v3] tracing: fix CFI violation in probestub test
From: Eva Kurchatova @ 2026-06-03 15:31 UTC (permalink / raw)
To: mhiramat, rostedt
Cc: linux-trace-kernel, linux-kernel, mathieu.desnoyers, peterz,
jpoimboe, samitolvanen, eva.kurchatova
When multiple callbacks are registered on the same tracepoint,
callbacks will be indirectly called via traceiter helper.
Pointers to __probestub_* callbacks reside in __tracepoints section,
which is excluded from ENDBR checks in objtool, causing objtool to
assume those functions are never indirectly called.
Registering multiple callbacks using sched_wakeup test will result
in #CP exception due to missing ENDBR in __probestub_sched_wakeup
on a CFI-enabled machine.
Fix this by adding CFI_NOSEAL annotation to probestub declaration.
Fixes: d5173f753750 ("objtool: Exclude __tracepoints data from ENDBR checks")
Signed-off-by: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
---
include/linux/tracepoint.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 763eea4d80d8..2d2b9f8cdda4 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -20,6 +20,7 @@
#include <linux/rcupdate_trace.h>
#include <linux/tracepoint-defs.h>
#include <linux/static_call.h>
+#include <linux/cfi.h>
struct module;
struct tracepoint;
@@ -389,6 +390,13 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
void __probestub_##_name(void *__data, proto) \
{ \
} \
+ /* \
+ * Annotate the probestub 'CFI_NOSEAL' to stop objtool from \
+ * requesting the kernel remove the ENDBR, because the only \
+ * references to the function are in the __tracepoint section, \
+ * that objtool doesn't scan. \
+ */ \
+ CFI_NOSEAL(__probestub_##_name); \
DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); \
DEFINE_RUST_DO_TRACE(_name, TP_PROTO(proto), TP_ARGS(args))
--
2.54.0
^ permalink raw reply related
* Re: [PATCH v2 13/13] verification/rvgen: Remove dead code
From: Gabriele Monaco @ 2026-06-03 15:36 UTC (permalink / raw)
To: Nam Cao, Wander Lairson Costa, Steven Rostedt, linux-trace-kernel,
linux-kernel
In-Reply-To: <9120d2a5987b79b646dde4001381581b703c0dd7.1779956342.git.namcao@linutronix.de>
On Thu, 2026-05-28 at 10:28 +0200, Nam Cao wrote:
> The conversion to use Lark left some dead code behind. Remove them.
>
> Signed-off-by: Nam Cao <namcao@linutronix.de>
> ---
You might want to remove unused imports (linters should help you with
that too):
* re, typing.Iterator, and itertools.islice from automata.py
* deque and ConstraintRule from dot2k
Other than that
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
> tools/verification/rvgen/rvgen/automata.py | 154 -------------------
> --
> tools/verification/rvgen/rvgen/dot2k.py | 28 +---
> 2 files changed, 1 insertion(+), 181 deletions(-)
>
> diff --git a/tools/verification/rvgen/rvgen/automata.py
> b/tools/verification/rvgen/rvgen/automata.py
> index a3be327c2a73..b6ff5fceb820 100644
> --- a/tools/verification/rvgen/rvgen/automata.py
> +++ b/tools/verification/rvgen/rvgen/automata.py
> @@ -356,19 +356,6 @@ class State:
> self.name = name
> self.inv = inv
>
> -class _ConstraintKey:
> - """Base class for constraint keys."""
> -
> -class _StateConstraintKey(_ConstraintKey, int):
> - """Key for a state constraint. Under the hood just state_id."""
> - def __new__(cls, state_id: int):
> - return super().__new__(cls, state_id)
> -
> -class _EventConstraintKey(_ConstraintKey, tuple):
> - """Key for an event constraint. Under the hood just
> tuple(state_id,event_id)."""
> - def __new__(cls, state_id: int, event_id: int):
> - return super().__new__(cls, (state_id, event_id))
> -
> class AutomataError(Exception):
> """Exception raised for errors in automata parsing and
> validation.
>
> @@ -387,28 +374,10 @@ class Automata:
>
> invalid_state_str = "INVALID_STATE"
> init_marker = "__init_"
> - node_marker = "{node"
> - # val can be numerical, uppercase (constant or macro), lowercase
> (parameter or function)
> - # only numerical values should have units
> - constraint_rule = re.compile(r"""
> - ^
> - (?P<env>[a-zA-Z_][a-zA-Z0-9_]+) # C-like identifier for the
> env var
> - (?P<op>[!<=>]{1,2}) # operator
> - (?P<val>
> - [0-9]+ | # numerical value
> - [A-Z_]+\(\) | # macro
> - [A-Z_]+ | # constant
> - [a-z_]+\(\) | # function
> - [a-z_]+ # parameter
> - )
> - (?P<unit>[a-z]{1,2})? # optional unit for
> numerical values
> - """, re.VERBOSE)
> - constraint_reset = re.compile(r"^reset\((?P<env>[a-zA-Z_][a-zA-
> Z0-9_]+)\)")
>
> def __init__(self, file_path, model_name=None):
> self.__dot_path = file_path
> self.name = model_name or self.__get_model_name()
> - self.__dot_lines = self.__open_dot()
> self.__parse_tree = ParseTree(file_path)
> self.transitions = self.__parse_transitions()
> self.states, self.initial_state, self.final_states =
> self.__parse_states()
> @@ -435,57 +404,6 @@ class Automata:
>
> return model_name
>
> - def __open_dot(self) -> list[str]:
> - dot_lines = []
> - try:
> - with open(self.__dot_path) as dot_file:
> - dot_lines = dot_file.readlines()
> - except OSError as exc:
> - raise AutomataError(exc.strerror) from exc
> -
> - if not dot_lines:
> - raise AutomataError(f"{self.__dot_path} is empty")
> -
> - # checking the first line:
> - line = dot_lines[0].split()
> -
> - if len(line) < 2 or line[0] != "digraph" or line[1] !=
> "state_automaton":
> - raise AutomataError(f"Not a valid .dot format:
> {self.__dot_path}")
> -
> - return dot_lines
> -
> - def __get_cursor_begin_states(self) -> int:
> - for cursor, line in enumerate(self.__dot_lines):
> - split_line = line.split()
> -
> - if len(split_line) and split_line[0] ==
> self.node_marker:
> - return cursor
> -
> - raise AutomataError("Could not find a beginning state")
> -
> - def __get_cursor_begin_events(self) -> int:
> - state = 0
> - cursor = 0 # make pyright happy
> -
> - for cursor, line in enumerate(self.__dot_lines):
> - line = line.split()
> - if not line:
> - continue
> -
> - if state == 0:
> - if line[0] == self.node_marker:
> - state = 1
> - elif line[0] != self.node_marker:
> - break
> - else:
> - raise AutomataError("Could not find beginning event")
> -
> - cursor += 1 # skip initial state transition
> - if cursor == len(self.__dot_lines):
> - raise AutomataError("Dot file ended after event
> beginning")
> -
> - return cursor
> -
> def __parse_transitions(self):
> transitions = []
>
> @@ -542,51 +460,6 @@ class Automata:
> states.insert(0, initial_state)
> return states, initial_state, final_states
>
> - def __get_state_variables(self) -> tuple[list[str], str,
> list[str]]:
> - # wait for node declaration
> - states = []
> - final_states = []
> - initial_state = ""
> -
> - has_final_states = False
> - cursor = self.__get_cursor_begin_states()
> -
> - # process nodes
> - for line in islice(self.__dot_lines, cursor, None):
> - split_line = line.split()
> - if not split_line or split_line[0] != self.node_marker:
> - break
> -
> - raw_state = split_line[-1]
> -
> - # "enabled_fired"}; -> enabled_fired
> - state = raw_state.replace('"', '').replace('};',
> '').replace(',', '_')
> - if state.startswith(self.init_marker):
> - initial_state = state[len(self.init_marker):]
> - else:
> - states.append(state)
> - if "doublecircle" in line:
> - final_states.append(state)
> - has_final_states = True
> -
> - if "ellipse" in line:
> - final_states.append(state)
> - has_final_states = True
> -
> - if not initial_state:
> - raise AutomataError("The automaton doesn't have an
> initial state")
> -
> - states = sorted(set(states))
> - states.remove(initial_state)
> -
> - # Insert the initial state at the beginning of the states
> - states.insert(0, initial_state)
> -
> - if not has_final_states:
> - final_states.append(initial_state)
> -
> - return states, initial_state, final_states
> -
> def __get_event_variables(self) -> tuple[list[str], list[str]]:
> events: list[str] = []
> envs: list[str] = []
> @@ -609,26 +482,6 @@ class Automata:
>
> return sorted(set(events)), sorted(set(envs))
>
> - def _split_constraint_expr(self, constr: list[str]) ->
> Iterator[tuple[str,
> -
>
> str | None]]:
> - """
> - Get a list of strings of the type constr1 && constr2 and
> returns a list of
> - constraints and separators: [[constr1,"&&"],[constr2,None]]
> - """
> - exprs = []
> - seps = []
> - for c in constr:
> - while "&&" in c or "||" in c:
> - a = c.find("&&")
> - o = c.find("||")
> - pos = a if o < 0 or 0 < a < o else o
> - exprs.append(c[:pos].replace(" ", ""))
> - seps.append(c[pos:pos + 2].replace(" ", ""))
> - c = c[pos + 2:].replace(" ", "")
> - exprs.append(c)
> - seps.append(None)
> - return zip(exprs, seps)
> -
> def __extract_env_var(self, constraint: ConstraintCondition):
> if constraint.unit:
> self.env_types[constraint.env] = constraint.unit
> @@ -697,10 +550,3 @@ class Automata:
>
> def is_hybrid_automata(self) -> bool:
> return bool(self.envs)
> -
> - def is_event_constraint(self, key: _ConstraintKey) -> bool:
> - """
> - Given the key in self.constraints return true if it is an
> event
> - constraint, false if it is a state constraint
> - """
> - return isinstance(key, _EventConstraintKey)
> diff --git a/tools/verification/rvgen/rvgen/dot2k.py
> b/tools/verification/rvgen/rvgen/dot2k.py
> index 49cb3e724a93..d6779ac6b7dd 100644
> --- a/tools/verification/rvgen/rvgen/dot2k.py
> +++ b/tools/verification/rvgen/rvgen/dot2k.py
> @@ -11,9 +11,7 @@
> from collections import deque
> from .dot2c import Dot2c
> from .generator import Monitor
> -from .automata import _EventConstraintKey, _StateConstraintKey,
> AutomataError
> -from .automata import ConstraintRule, ConstraintCondition
> -
> +from .automata import ConstraintRule, ConstraintCondition,
> AutomataError
>
> class dot2k(Monitor, Dot2c):
> template_dir = "dot2k"
> @@ -217,9 +215,6 @@ class ha2k(dot2k):
> value *= 10**9
> return str(value) + "ull"
>
> - def __parse_single_constraint(self, rule: dict, value: str) ->
> str:
> - return f"ha_get_env(ha_mon, {rule["env"]}{self.enum_suffix},
> time_ns) {rule["op"]} {value}"
> -
> def __parse_guard_rule(self, rule) -> list[str]:
> buff = []
> for c, sep in rule.rules:
> @@ -233,12 +228,6 @@ class ha2k(dot2k):
> buff.append(cond)
> return buff
>
> - def __get_constraint_env(self, constr: str) -> str:
> - """Extract the second argument from an ha_ function"""
> - env =
> constr.split("(")[1].split()[1].rstrip(")").rstrip(",")
> - assert env.rstrip(f"_{self.name}") in self.envs
> - return env
> -
> def __start_to_invariant_check(self, inv: ConstraintCondition) -
> > str:
> # by default assume the timer has ns expiration
> clock_type = "ns"
> @@ -249,21 +238,6 @@ class ha2k(dot2k):
>
> return f"return ha_check_invariant_{clock_type}(ha_mon,
> {inv.env}_{self.name}, time_ns, {value})"
>
> - def __start_to_conv(self, constr: str) -> str:
> - """
> - Undo the storage conversion done by ha_start_timer_
> - """
> - return "ha_inv_to_guard" + constr[constr.find("("):]
> -
> - def __parse_timer_constraint(self, rule: dict, value: str) ->
> str:
> - # by default assume the timer has ns expiration
> - clock_type = "ns"
> - if self.env_types.get(rule["env"]) == "j":
> - clock_type = "jiffy"
> -
> - return (f"ha_start_timer_{clock_type}(ha_mon,
> {rule["env"]}{self.enum_suffix},"
> - f" {value}, time_ns)")
> -
> def __parse_invariant(self, inv):
> # by default assume the timer has ns expiration
> clock_type = "ns"
^ permalink raw reply
* Re: [PATCH v2 06/13] verification/rvgen: Convert __fill_verify_guards_func() to Lark
From: Gabriele Monaco @ 2026-06-03 16:00 UTC (permalink / raw)
To: Nam Cao, Wander Lairson Costa, Steven Rostedt, linux-trace-kernel,
linux-kernel
In-Reply-To: <2157c2e5fe34251c403604f0d58a3a686a6f6a8b.1779956342.git.namcao@linutronix.de>
On Thu, 2026-05-28 at 10:27 +0200, Nam Cao wrote:
> Prepare to remove self.guards and self.__parse_constraints(), convert
> __fill_verify_guards_func() to use the parsed transitions from Lark.
>
> Signed-off-by: Nam Cao <namcao@linutronix.de>
> ---
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
> v2:
> - fix up the ';' separator [Gabriele]
> - make return type consistent with the function's signature
> [Wander]
> - fix up __parse_guard_rule()'s signature
> ---
> tools/verification/rvgen/rvgen/dot2k.py | 38 +++++++++++++++++++----
> --
> 1 file changed, 30 insertions(+), 8 deletions(-)
>
> diff --git a/tools/verification/rvgen/rvgen/dot2k.py
> b/tools/verification/rvgen/rvgen/dot2k.py
> index d9f8e1c7737a..ebaa6c9135c2 100644
> --- a/tools/verification/rvgen/rvgen/dot2k.py
> +++ b/tools/verification/rvgen/rvgen/dot2k.py
> @@ -221,6 +221,19 @@ class ha2k(dot2k):
> def __parse_single_constraint(self, rule: dict, value: str) ->
> str:
> return f"ha_get_env(ha_mon, {rule["env"]}{self.enum_suffix},
> time_ns) {rule["op"]} {value}"
>
> + def __parse_guard_rule(self, rule) -> list[str]:
> + buff = []
> + for c, sep in rule.rules:
> + env = c.env + self.enum_suffix
> + op = c.op
> + val = self.__adjust_value(c.val, c.unit)
> +
> + cond = f"ha_get_env(ha_mon, {env}, time_ns) {op} {val}"
> + if sep:
> + cond += f" {sep}"
> + buff.append(cond)
> + return buff
> +
> def __get_constraint_env(self, constr: str) -> str:
> """Extract the second argument from an ha_ function"""
> env =
> constr.split("(")[1].split()[1].rstrip(")").rstrip(",")
> @@ -287,7 +300,7 @@ class ha2k(dot2k):
> rules = invalid_checks + rules
>
> separator = "\n\t\t " if sum(len(r) for r in rules) >
> 80 else " "
> - return ["res = " + separator.join(rules)]
> + return ["res = " + separator.join(rules) + ";"]
>
> def __validate_constraint(self, key: tuple[int, int] | int,
> constr: str,
> rule, reset) -> None:
> @@ -406,7 +419,8 @@ f"""static inline void
> ha_convert_inv_guard(struct ha_monitor *ha_mon,
>
> def __fill_verify_guards_func(self) -> list[str]:
> buff = []
> - if not self.guards:
> +
> + if not self.has_guard:
> return []
>
> buff.append(
> @@ -418,14 +432,22 @@ f"""static inline bool ha_verify_guards(struct
> ha_monitor *ha_mon,
> """)
>
> _else = ""
> - for edge, constr in sorted(self.guards.items()):
> + for transition in self.transitions:
> + if not transition.rule and not transition.reset:
> + continue
> +
> buff.append(f"\t{_else}if (curr_state == "
> - f"{self.states[edge[0]]}{self.enum_suffix}
> && "
> - f"event ==
> {self.events[edge[1]]}{self.enum_suffix})")
> - if constr.count(";") > 0:
> + f"{transition.src}{self.enum_suffix} && "
> + f"event ==
> {transition.event}{self.enum_suffix})")
> + rule = transition.rule
> + reset = transition.reset
> + if rule and reset:
> buff[-1] += " {"
> - buff += [f"\t\t{c};" for c in constr.split(";")]
> - if constr.count(";") > 0:
> + if rule:
> + buff.append("\t\t" +
> self.__format_guard_rules(self.__parse_guard_rule(rule))[0])
> + if reset:
> + buff.append(f"\t\tha_reset_env(ha_mon,
> {reset.env}{self.enum_suffix}, time_ns);")
> + if rule and reset:
> _else = "} else "
> else:
> _else = "else "
^ permalink raw reply
* Re: mm/memory-failure tracepoint change breaks userspace rasdaemon
From: Steven Rostedt @ 2026-06-03 16:17 UTC (permalink / raw)
To: David Hildenbrand (Arm)
Cc: Zhuo, Qiuxu, mchehab+huawei@kernel.org, Luck, Tony, bp@alien8.de,
akpm@linux-foundation.org, linmiaohe@huawei.com,
xieyuanbin1@huawei.com, Lai, Yi1, linux-kernel@vger.kernel.org,
linux-edac@vger.kernel.org, linux-mm@kvack.org,
linux-trace-kernel@vger.kernel.org, Linus Torvalds
In-Reply-To: <b930678d-a1ae-458c-8705-7ca9680d4cb6@kernel.org>
On Wed, 3 Jun 2026 15:44:54 +0200
"David Hildenbrand (Arm)" <david@kernel.org> wrote:
> Likely the latter. BPF [1] documents:
>
> Q: Are tracepoints part of the stable ABI?
> A: NO. Tracepoints are tied to internal implementation details hence they are
> subject to change and can break with newer kernels. BPF programs need to change
> accordingly when this happens.
>
> The Kernel ABI document explicitly doesn't list them AFAIKS.
>
> There were previous discussions on the stability of tracepints [2], I don't know
> what changed in the meantime. CCing Steve
>
> [1] https://www.kernel.org/doc/html/latest/bpf/bpf_design_QA.html
> [2] https://lwn.net/Articles/747256/
> [3] https://www.kernel.org/doc/html/latest/admin-guide/abi.html
Tracepoints are not stable or BPF programs only. But other applications
they are[1].
Adding Linus as he's the Supreme Judge on the matter.
-- Steve
[1] https://lwn.net/Articles/442113/
^ permalink raw reply
* Re: mm/memory-failure tracepoint change breaks userspace rasdaemon
From: Borislav Petkov @ 2026-06-03 16:19 UTC (permalink / raw)
To: Steven Rostedt
Cc: David Hildenbrand (Arm), Zhuo, Qiuxu, mchehab+huawei@kernel.org,
Luck, Tony, akpm@linux-foundation.org, linmiaohe@huawei.com,
xieyuanbin1@huawei.com, Lai, Yi1, linux-kernel@vger.kernel.org,
linux-edac@vger.kernel.org, linux-mm@kvack.org,
linux-trace-kernel@vger.kernel.org, Linus Torvalds
In-Reply-To: <20260603121707.7eccb9fb@gandalf.local.home>
On Wed, Jun 03, 2026 at 12:17:07PM -0400, Steven Rostedt wrote:
> On Wed, 3 Jun 2026 15:44:54 +0200
> "David Hildenbrand (Arm)" <david@kernel.org> wrote:
>
> > Likely the latter. BPF [1] documents:
> >
> > Q: Are tracepoints part of the stable ABI?
> > A: NO. Tracepoints are tied to internal implementation details hence they are
> > subject to change and can break with newer kernels. BPF programs need to change
> > accordingly when this happens.
> >
> > The Kernel ABI document explicitly doesn't list them AFAIKS.
> >
> > There were previous discussions on the stability of tracepints [2], I don't know
> > what changed in the meantime. CCing Steve
> >
> > [1] https://www.kernel.org/doc/html/latest/bpf/bpf_design_QA.html
> > [2] https://lwn.net/Articles/747256/
> > [3] https://www.kernel.org/doc/html/latest/admin-guide/abi.html
>
> Tracepoints are not stable or BPF programs only. But other applications
> they are[1].
>
> Adding Linus as he's the Supreme Judge on the matter.
I *think* tools or libtraceevent can't really anticipate the TP namespace
change so we might have to revert, I'm afraid...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
^ permalink raw reply
* Re: mm/memory-failure tracepoint change breaks userspace rasdaemon
From: David Hildenbrand (Arm) @ 2026-06-03 16:26 UTC (permalink / raw)
To: Borislav Petkov, Steven Rostedt
Cc: Zhuo, Qiuxu, mchehab+huawei@kernel.org, Luck, Tony,
akpm@linux-foundation.org, linmiaohe@huawei.com,
xieyuanbin1@huawei.com, Lai, Yi1, linux-kernel@vger.kernel.org,
linux-edac@vger.kernel.org, linux-mm@kvack.org,
linux-trace-kernel@vger.kernel.org, Linus Torvalds
In-Reply-To: <20260603161947.GBaiBUI7C8WWPwD84S@fat_crate.local>
On 6/3/26 18:19, Borislav Petkov wrote:
> On Wed, Jun 03, 2026 at 12:17:07PM -0400, Steven Rostedt wrote:
>> On Wed, 3 Jun 2026 15:44:54 +0200
>> "David Hildenbrand (Arm)" <david@kernel.org> wrote:
>>
>>> Likely the latter. BPF [1] documents:
>>>
>>> Q: Are tracepoints part of the stable ABI?
>>> A: NO. Tracepoints are tied to internal implementation details hence they are
>>> subject to change and can break with newer kernels. BPF programs need to change
>>> accordingly when this happens.
>>>
>>> The Kernel ABI document explicitly doesn't list them AFAIKS.
>>>
>>> There were previous discussions on the stability of tracepints [2], I don't know
>>> what changed in the meantime. CCing Steve
>>>
>>> [1] https://www.kernel.org/doc/html/latest/bpf/bpf_design_QA.html
>>> [2] https://lwn.net/Articles/747256/
>>> [3] https://www.kernel.org/doc/html/latest/admin-guide/abi.html
>>
>> Tracepoints are not stable or BPF programs only. But other applications
>> they are[1].
>>
>> Adding Linus as he's the Supreme Judge on the matter.
>
> I *think* tools or libtraceevent can't really anticipate the TP namespace
> change so we might have to revert, I'm afraid...
Yeah, I was fearing that when I read in [2]:
"It has become clear in the past that this promise extends to
tracepoints, most notably in 2011 when a tracepoint change broke
powertop and had to be reverted."
Which means that I now also fully understand
"Some kernel maintainers prohibit or severely restrict the addition of
tracepoints to their subsystems out of fear that a similar thing could
happen to them. "
Whatever the result of this discussion will be, I'll try to document it.
--
Cheers,
David
^ permalink raw reply
* Re: mm/memory-failure tracepoint change breaks userspace rasdaemon
From: Steven Rostedt @ 2026-06-03 17:00 UTC (permalink / raw)
To: David Hildenbrand (Arm)
Cc: Borislav Petkov, Zhuo, Qiuxu, mchehab+huawei@kernel.org,
Luck, Tony, akpm@linux-foundation.org, linmiaohe@huawei.com,
xieyuanbin1@huawei.com, Lai, Yi1, linux-kernel@vger.kernel.org,
linux-edac@vger.kernel.org, linux-mm@kvack.org,
linux-trace-kernel@vger.kernel.org, Linus Torvalds
In-Reply-To: <0c16bf3d-7c6d-4e28-b200-03b7d0ef714a@kernel.org>
On Wed, 3 Jun 2026 18:26:24 +0200
"David Hildenbrand (Arm)" <david@kernel.org> wrote:
> Yeah, I was fearing that when I read in [2]:
>
> "It has become clear in the past that this promise extends to
> tracepoints, most notably in 2011 when a tracepoint change broke
> powertop and had to be reverted."
Technically the issue is with trace events and not tracepoints. The
difference is that a trace event is created via the TRACE_EVENT() macro
which defines what is to be collected from the tracepoint and exposes that
information to tracefs which applications can easily see.
A tracepoint is simply the hook in the code that you can attach to. Trace
events create a callback from that hook to extract the data from the
tracepoint to fill in the fields.
>
> Which means that I now also fully understand
>
> "Some kernel maintainers prohibit or severely restrict the addition of
> tracepoints to their subsystems out of fear that a similar thing could
> happen to them. "
>
> Whatever the result of this discussion will be, I'll try to document it.
You can still create a tracepoint without creating a trace event by using
the DECLARE_TRACE() macro. The scheduler subsystem uses that quite
extensively. That creates a tracepoint without exposing it to tracefs. The
runtime verifier uses these hooks to monitor the scheduler.
But you can still connect to these tracepoints from tracefs via a tprobe. A
tprobe hooks to tracepoints that you need the source code to find (just
like a fprobe hooks to any function). Thus applications *can't* rely on
them because there's nothing there to tell you it exists or not.
For example, for the given tracepoint:
# cd /sys/kernel/tracing
# echo 't:rfail memory_failure_event pfn=pfn type=type result=result' > dynamic_events
# cat events/tracepoints/rfail/format
name: rfail
ID: 1894
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:unsigned long __probe_ip; offset:8; size:8; signed:0;
field:u64 pfn; offset:16; size:8; signed:0;
field:s32 type; offset:24; size:4; signed:1;
field:s32 result; offset:28; size:4; signed:1;
print fmt: "(%lx) pfn=%Lu type=%d result=%d", REC->__probe_ip, REC->pfn, REC->type, REC->result
It requires that BTF exists and the above doesn't annotate the result as
nicely. But you can get data directly from tracepoints this way.
-- Steve
^ permalink raw reply
* Re: mm/memory-failure tracepoint change breaks userspace rasdaemon
From: David Hildenbrand (Arm) @ 2026-06-03 19:13 UTC (permalink / raw)
To: Steven Rostedt
Cc: Borislav Petkov, Zhuo, Qiuxu, mchehab+huawei@kernel.org,
Luck, Tony, akpm@linux-foundation.org, linmiaohe@huawei.com,
xieyuanbin1@huawei.com, Lai, Yi1, linux-kernel@vger.kernel.org,
linux-edac@vger.kernel.org, linux-mm@kvack.org,
linux-trace-kernel@vger.kernel.org, Linus Torvalds
In-Reply-To: <20260603130006.7d2c4a62@gandalf.local.home>
On 6/3/26 19:00, Steven Rostedt wrote:
> On Wed, 3 Jun 2026 18:26:24 +0200
> "David Hildenbrand (Arm)" <david@kernel.org> wrote:
>
>> Yeah, I was fearing that when I read in [2]:
>>
>> "It has become clear in the past that this promise extends to
>> tracepoints, most notably in 2011 when a tracepoint change broke
>> powertop and had to be reverted."
>
> Technically the issue is with trace events and not tracepoints. The
> difference is that a trace event is created via the TRACE_EVENT() macro
> which defines what is to be collected from the tracepoint and exposes that
> information to tracefs which applications can easily see.
>
> A tracepoint is simply the hook in the code that you can attach to. Trace
> events create a callback from that hook to extract the data from the
> tracepoint to fill in the fields.
>
>>
>> Which means that I now also fully understand
>>
>> "Some kernel maintainers prohibit or severely restrict the addition of
>> tracepoints to their subsystems out of fear that a similar thing could
>> happen to them. "
>>
>> Whatever the result of this discussion will be, I'll try to document it.
>
> You can still create a tracepoint without creating a trace event by using
> the DECLARE_TRACE() macro. The scheduler subsystem uses that quite
> extensively. That creates a tracepoint without exposing it to tracefs. The
> runtime verifier uses these hooks to monitor the scheduler.
>
> But you can still connect to these tracepoints from tracefs via a tprobe. A
> tprobe hooks to tracepoints that you need the source code to find (just
> like a fprobe hooks to any function). Thus applications *can't* rely on
> them because there's nothing there to tell you it exists or not.
Thanks, that makes sense!
So, would it be fair to say that, in general, what's exposed through
/sys/kernel/tracing/events/
is stable ABI?
Would the following be sufficient to avoid a full revert and the dependency on CONFIG_RAS?
diff --git a/include/trace/events/memory-failure.h b/include/trace/events/memory-failure.h
index aa57cc8f896b..c46b17602578 100644
--- a/include/trace/events/memory-failure.h
+++ b/include/trace/events/memory-failure.h
@@ -1,6 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM
-#define TRACE_SYSTEM memory_failure
+/* Some user space relies on ras/memory_failure_event */
+#define TRACE_SYSTEM ras
#define TRACE_INCLUDE_FILE memory-failure
#if !defined(_TRACE_MEMORY_FAILURE_H) || defined(TRACE_HEADER_MULTI_READ)
--
Cheers,
David
^ permalink raw reply related
* Re: mm/memory-failure tracepoint change breaks userspace rasdaemon
From: Steven Rostedt @ 2026-06-03 19:30 UTC (permalink / raw)
To: David Hildenbrand (Arm)
Cc: Borislav Petkov, Zhuo, Qiuxu, mchehab+huawei@kernel.org,
Luck, Tony, akpm@linux-foundation.org, linmiaohe@huawei.com,
xieyuanbin1@huawei.com, Lai, Yi1, linux-kernel@vger.kernel.org,
linux-edac@vger.kernel.org, linux-mm@kvack.org,
linux-trace-kernel@vger.kernel.org, Linus Torvalds
In-Reply-To: <b637ede2-73da-49f0-a7eb-70ec79e79624@kernel.org>
On Wed, 3 Jun 2026 21:13:30 +0200
"David Hildenbrand (Arm)" <david@kernel.org> wrote:
> Would the following be sufficient to avoid a full revert and the dependency on CONFIG_RAS?
>
> diff --git a/include/trace/events/memory-failure.h b/include/trace/events/memory-failure.h
> index aa57cc8f896b..c46b17602578 100644
> --- a/include/trace/events/memory-failure.h
> +++ b/include/trace/events/memory-failure.h
> @@ -1,6 +1,7 @@
> /* SPDX-License-Identifier: GPL-2.0 */
> #undef TRACE_SYSTEM
> -#define TRACE_SYSTEM memory_failure
> +/* Some user space relies on ras/memory_failure_event */
> +#define TRACE_SYSTEM ras
If that puts back the original path then yeah, all would be good.
-- Steve
> #define TRACE_INCLUDE_FILE memory-failure
>
> #if !defined(_TRACE_MEMORY_FAILURE_H) || defined(TRACE_HEADER_MULTI_READ)
^ permalink raw reply
* Re: mm/memory-failure tracepoint change breaks userspace rasdaemon
From: Steven Rostedt @ 2026-06-03 19:31 UTC (permalink / raw)
To: David Hildenbrand (Arm)
Cc: Borislav Petkov, Zhuo, Qiuxu, mchehab+huawei@kernel.org,
Luck, Tony, akpm@linux-foundation.org, linmiaohe@huawei.com,
xieyuanbin1@huawei.com, Lai, Yi1, linux-kernel@vger.kernel.org,
linux-edac@vger.kernel.org, linux-mm@kvack.org,
linux-trace-kernel@vger.kernel.org, Linus Torvalds
In-Reply-To: <b637ede2-73da-49f0-a7eb-70ec79e79624@kernel.org>
On Wed, 3 Jun 2026 21:13:30 +0200
"David Hildenbrand (Arm)" <david@kernel.org> wrote:
> Thanks, that makes sense!
>
> So, would it be fair to say that, in general, what's exposed through
>
> /sys/kernel/tracing/events/
>
> is stable ABI?
It's only stable if something depends on it. It changes all the time.
It's only when someone complains about it that it becomes "stable"!
-- Steve
^ permalink raw reply
* Re: mm/memory-failure tracepoint change breaks userspace rasdaemon
From: Andrew Morton @ 2026-06-03 19:54 UTC (permalink / raw)
To: Steven Rostedt
Cc: David Hildenbrand (Arm), Borislav Petkov, Zhuo, Qiuxu,
mchehab+huawei@kernel.org, Luck, Tony, linmiaohe@huawei.com,
xieyuanbin1@huawei.com, Lai, Yi1, linux-kernel@vger.kernel.org,
linux-edac@vger.kernel.org, linux-mm@kvack.org,
linux-trace-kernel@vger.kernel.org, Linus Torvalds
In-Reply-To: <20260603130006.7d2c4a62@gandalf.local.home>
On Wed, 3 Jun 2026 13:00:06 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> On Wed, 3 Jun 2026 18:26:24 +0200
> "David Hildenbrand (Arm)" <david@kernel.org> wrote:
>
> > Yeah, I was fearing that when I read in [2]:
> >
> > "It has become clear in the past that this promise extends to
> > tracepoints, most notably in 2011 when a tracepoint change broke
> > powertop and had to be reverted."
>
> Technically the issue is with trace events and not tracepoints. The
> difference is that a trace event is created via the TRACE_EVENT() macro
> which defines what is to be collected from the tracepoint and exposes that
> information to tracefs which applications can easily see.
>
> A tracepoint is simply the hook in the code that you can attach to. Trace
> events create a callback from that hook to extract the data from the
> tracepoint to fill in the fields.
The problem here appears to be that "ras:memory_failure_event" became
"memory_failure:memory_failure_event".
Perhaps we can add infrastructure to permit aliasing "ras" onto
"memory_failure". So if we make these namespace alterations we can
easily preserve back-compatibility?
^ permalink raw reply
* Re: [PATCH v7 00/42] guest_memfd: In-place conversion support
From: Ackerley Tng @ 2026-06-03 21:27 UTC (permalink / raw)
To: Ackerley Tng via B4 Relay, aik, andrew.jones, binbin.wu, brauner,
chao.p.peng, david, ira.weiny, jmattson, jthoughton, michael.roth,
oupton, pankaj.gupta, qperret, rick.p.edgecombe, rientjes,
shivankg, steven.price, tabba, willy, wyihan, yan.y.zhao,
forkloop, pratyush, suzuki.poulose, aneesh.kumar, liam,
Paolo Bonzini, Sean Christopherson, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, Dave Hansen, x86, H. Peter Anvin, Steven Rostedt,
Masami Hiramatsu, Mathieu Desnoyers, Jonathan Corbet, Shuah Khan,
Shuah Khan, Vishal Annapurve, Andrew Morton, Chris Li,
Kairui Song, Kemeng Shi, Nhat Pham, Baoquan He, Barry Song,
Axel Rasmussen, Yuanchu Xie, Wei Xu, Youngjun Park, Qi Zheng,
Shakeel Butt, Kiryl Shutsemau, Jason Gunthorpe, Vlastimil Babka
Cc: kvm, linux-kernel, linux-trace-kernel, linux-doc, linux-kselftest,
linux-mm, linux-coco
In-Reply-To: <20260522-gmem-inplace-conversion-v7-0-2f0fae496530@google.com>
Ackerley Tng via B4 Relay <devnull+ackerleytng.google.com@kernel.org>
writes:
> This is v7 of guest_memfd in-place conversion support.
>
Here's the outstanding items after going over everyone's comments
including Sashiko's:
+ KVM: TDX: Make source page optional for KVM_TDX_INIT_MEM_REGION
+ Need to move page clearing into __kvm_gmem_get_pfn to resolve
leak where populate can put initialized kernel memory into TDX
guest
+ See suggested fix at [1]
+ KVM: guest_memfd: Only prepare folios for private pages,
+ s/non-CoCo/CoCo in commit message "INIT_SHARED is about to be
supported for non-CoCo VMs in a later patch in this series
+ Use Suggested-by: Michael Roth <michael.roth@amd.com>
+ KVM: selftests: Test that shared/private status is consistent across
processes
+ Improve test reliability using pthread_mutex
+ I have a fixup patch offline.
I would like feedback on these:
+ KVM: selftests: Test conversion with elevated page refcount
+ Askar pointed out that soon vmsplice may not pin pages. Should I
pin pages through CONFIG_GUP_TEST like in [2]? I prefer not to
take a dependency on CONFIG_GUP_TEST.
+ KVM: selftests: Add script to exercise private_mem_conversions_test
+ Would like to know what people think of a wrapper script before
I address Sashiko's comments.
[1] https://lore.kernel.org/all/CAEvNRgEVC=fFuKVgZYvWyZD7t_zvUZihFG8hrACjvtkD5cwugw@mail.gmail.com/
[2] https://lore.kernel.org/all/baa8838f623102931e755cf34c86314b305af49c.1747264138.git.ackerleytng@google.com/
>
> [...snip...]
>
^ permalink raw reply
* Re: [PATCH bpf-next v2 2/3] tracing: Expose tracepoint BTF ids via tracefs
From: Andrii Nakryiko @ 2026-06-03 22:41 UTC (permalink / raw)
To: Steven Rostedt
Cc: Mykyta Yatsenko, bpf, Mykyta Yatsenko, linux-trace-kernel,
Andrii Nakryiko, Alexei Starovoitov
In-Reply-To: <20260526215741.1e5b3e42@fedora>
On Tue, May 26, 2026 at 6:57 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Tue, 26 May 2026 11:07:56 +0100
> Mykyta Yatsenko <mykyta.yatsenko5@gmail.com> wrote:
>
> > Hi Steven,
> >
> > Gentle ping on this patch from the series.
> >
> > Since this part touches tracing, I’d appreciate your thoughts on the
> > tracing changes whenever you have a chance.
> >
>
> Hi,
>
> I've been looking at this and was wondering if there are ways to not
> extend the trace_event_class structure. It's added for most trace
> events (actually each DECLARE_EVENT_CLASS). Although when things like
> BTF is enabled, this is a very small amount of extra memory.
>
> I haven't been ignoring this. I've just been thinking about other
> approaches, but haven't come up with anything. Of course, I haven't
> been spending that much time on it, as I've been focused on other
> things.
Just in theory, what alternative would there be besides having one
extra pointer in trace_event_class struct? Some sort of lookup by name
or something? E.g., if we know "call" part at runtime for any given
tracepoint for
.btf_ids = __bpf_trace_btf_ids_##call,
we can probably lookup symbol from kallsyms and fetch BTF IDs that way
without extending the struct?
FWIW, this type info for tracepoints (classic and raw both) are very
useful, because right now one needs to do a bunch of work (subject to
break due to kernel type/name changes, etc) to find this, and for
various generic tracing tooling this type information is actually a
necessity to be useful.
That's just to say that it would be great to have this in some form of
shape, so please help getting this into acceptable form, thanks!
>
> -- Steve
^ permalink raw reply
* Re: [PATCH bpf-next v2 2/3] tracing: Expose tracepoint BTF ids via tracefs
From: Steven Rostedt @ 2026-06-03 22:50 UTC (permalink / raw)
To: Andrii Nakryiko
Cc: Mykyta Yatsenko, bpf, Mykyta Yatsenko, linux-trace-kernel,
Andrii Nakryiko, Alexei Starovoitov
In-Reply-To: <CAEf4BzY5MTGJyys369qDS3b63-tKq3okCpFMqUdfzy0dXk7vLg@mail.gmail.com>
On Wed, 3 Jun 2026 15:41:50 -0700
Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:
> That's just to say that it would be great to have this in some form of
> shape, so please help getting this into acceptable form, thanks!
As I said, I'm not against it. I was hoping to find something to help
alleviate the memory usage.
I'll likely take these as is, but I'm currently on vacation and it will
have to wait until next week.
-- Steve
^ permalink raw reply
* Re: [GIT PULL] rv fixes for v7.1
From: Steven Rostedt @ 2026-06-03 23:16 UTC (permalink / raw)
To: Gabriele Monaco; +Cc: linux-kernel, linux-trace-kernel, unknownbbqrx, Wen Yang
In-Reply-To: <20260603125056.75559-1-gmonaco@redhat.com>
On Wed, 3 Jun 2026 14:50:56 +0200
Gabriele Monaco <gmonaco@redhat.com> wrote:
> unknownbbqrx (1):
> tools/rv: Ensure monitor name and desc are NUL-terminated
Hi Gabriele,
What is this? All commits need to be authored by and signed off by from
a real person with their official name.
https://docs.kernel.org/process/submitting-patches.html#sign-your-work-the-developer-s-certificate-of-origin
-- Steve
^ permalink raw reply
* Re: [PATCH v3] tracing: fix CFI violation in probestub test
From: Masami Hiramatsu @ 2026-06-03 23:47 UTC (permalink / raw)
To: Eva Kurchatova
Cc: rostedt, linux-trace-kernel, linux-kernel, mathieu.desnoyers,
peterz, jpoimboe, samitolvanen
In-Reply-To: <20260603153147.573589-1-eva.kurchatova@virtuozzo.com>
On Wed, 3 Jun 2026 18:31:42 +0300
Eva Kurchatova <eva.kurchatova@virtuozzo.com> wrote:
> When multiple callbacks are registered on the same tracepoint,
> callbacks will be indirectly called via traceiter helper.
>
> Pointers to __probestub_* callbacks reside in __tracepoints section,
> which is excluded from ENDBR checks in objtool, causing objtool to
> assume those functions are never indirectly called.
>
> Registering multiple callbacks using sched_wakeup test will result
> in #CP exception due to missing ENDBR in __probestub_sched_wakeup
> on a CFI-enabled machine.
>
> Fix this by adding CFI_NOSEAL annotation to probestub declaration.
Thanks for update, this looks good to me.
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Peter, will you pick this fix because it fixes objtool change?
Thank you,
>
> Fixes: d5173f753750 ("objtool: Exclude __tracepoints data from ENDBR checks")
> Signed-off-by: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
> ---
> include/linux/tracepoint.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
> index 763eea4d80d8..2d2b9f8cdda4 100644
> --- a/include/linux/tracepoint.h
> +++ b/include/linux/tracepoint.h
> @@ -20,6 +20,7 @@
> #include <linux/rcupdate_trace.h>
> #include <linux/tracepoint-defs.h>
> #include <linux/static_call.h>
> +#include <linux/cfi.h>
>
> struct module;
> struct tracepoint;
> @@ -389,6 +390,13 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
> void __probestub_##_name(void *__data, proto) \
> { \
> } \
> + /* \
> + * Annotate the probestub 'CFI_NOSEAL' to stop objtool from \
> + * requesting the kernel remove the ENDBR, because the only \
> + * references to the function are in the __tracepoint section, \
> + * that objtool doesn't scan. \
> + */ \
> + CFI_NOSEAL(__probestub_##_name); \
> DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); \
> DEFINE_RUST_DO_TRACE(_name, TP_PROTO(proto), TP_ARGS(args))
>
> --
> 2.54.0
>
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply
* Re: [PATCH bpf-next v2 2/3] tracing: Expose tracepoint BTF ids via tracefs
From: Andrii Nakryiko @ 2026-06-03 23:51 UTC (permalink / raw)
To: Steven Rostedt
Cc: Mykyta Yatsenko, bpf, Mykyta Yatsenko, linux-trace-kernel,
Andrii Nakryiko, Alexei Starovoitov
In-Reply-To: <20260603185057.4a85d5df@fedora>
On Wed, Jun 3, 2026 at 3:51 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Wed, 3 Jun 2026 15:41:50 -0700
> Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:
>
> > That's just to say that it would be great to have this in some form of
> > shape, so please help getting this into acceptable form, thanks!
>
> As I said, I'm not against it. I was hoping to find something to help
> alleviate the memory usage.
>
> I'll likely take these as is, but I'm currently on vacation and it will
> have to wait until next week.
>
Yeah, no worries, I was just going through my backlog and trying to
think if we can avoid extending the tracepoint class struct. Besides
the somewhat dirty kallsyms symbol lookup logic, I don't see any other
way.
Enjoy your vacation!
> -- Steve
>
^ permalink raw reply
* Re: [LSF/MM/BPF TOPIC][RFC PATCH v4 00/27] Private Memory Nodes (w/ Compressed RAM)
From: Balbir Singh @ 2026-06-04 1:43 UTC (permalink / raw)
To: Gregory Price
Cc: lsf-pc, linux-kernel, linux-cxl, cgroups, linux-mm,
linux-trace-kernel, damon, kernel-team, gregkh, rafael, dakr,
dave, jonathan.cameron, dave.jiang, alison.schofield,
vishal.l.verma, ira.weiny, dan.j.williams, longman, akpm, david,
lorenzo.stoakes, Liam.Howlett, vbabka, rppt, surenb, mhocko,
osalvador, ziy, matthew.brost, joshua.hahnjy, rakie.kim,
byungchul, ying.huang, apopple, axelrasmussen, yuanchu, weixugc,
yury.norov, linux, mhiramat, mathieu.desnoyers, tj, hannes,
mkoutny, jackmanb, sj, baolin.wang, npache, ryan.roberts,
dev.jain, baohua, lance.yang, muchun.song, xu.xin16,
chengming.zhou, jannh, linmiaohe, nao.horiguchi, pfalcato,
rientjes, shakeel.butt, riel, harry.yoo, cl, roman.gushchin,
chrisl, kasong, shikemeng, nphamcs, bhe, zhengqi.arch,
terry.bowman
In-Reply-To: <ah_RcTU8SpQG7hab@gourry-fedora-PF4VCD3F>
On Wed, Jun 03, 2026 at 08:02:09AM +0100, Gregory Price wrote:
> On Wed, Jun 03, 2026 at 03:00:01PM +1000, Balbir Singh wrote:
> > On Tue, Jun 02, 2026 at 09:57:48AM +0100, Gregory Price wrote:
> > > On Tue, Jun 02, 2026 at 12:16:50PM +1000, Balbir Singh wrote:
> > > >
> > > > I was think we wouldn't need explicit flags and that allocations would
> > > > happen from user space using __GFP_THISNODE to the node or via a nodemask
> > > > based on nodes of interest. Is there a reason to add this flag, a system
> > > > might have more than one source of N_MEMORY_PRIVATE?
> > > >
> > >
> > > There's a few things to unpack here. I discussed this many times on
> > > list and at LSF, but to reiterate.
> > >
> > > 1) __GFP_THISNODE is insufficient to enforce isolation and otherwise
> > > not particularly useful. Additionally, from userland, it's not
> > > something you can actually set.
> >
> > I was thinking mbind()/mempolicy() is how we get to it. It already
> > accepts a nodemask.
> >
>
> First let me say: I want to enable mbind access to these nodes.
>
> But let me caveat: I think that needs more time to develop, and
> in the meantime, we can enable the /dev/xxx pattern somewhat trivially.
>
> First let me address a few things about mbind/mempolicy and how it
> interacts with page_alloc.c, I gave this overview at LSF but I don't
> remember if I posted it in any of my follow ups.
>
>
> 1) Fallback lists are filtered by nodemask, the nodemask does not replace
> the fallback list.
>
> Here is how the page allocator fallback lists and nodemasks interact:
>
> Fallbacks A: A B
> Fallbacks B: B A
> Fallbacks C: C A B (Private)
> Fallbacks D: D B A (Private)
>
Do we want regular memory (N_MEMORY) in the fallback list of device private nodes?
The assumption is that we have ATS translation enabled? Assumiung A and
B are N_MEMORY here or am I misreading your illustraion?
> Lets say you pass:
>
> alloc_pages_node(C, ..., nodemask(A,C,D))
>
> So we get
>
> Fallback(C,A,B) & nodemask(A,C,D) -> iterate(C,A)
>
> If we wanted to change this behavior, realistically we'd be looking for
> a way to add specific nodes to certain fallback lists - rather than
> modify the nodemask interaction in some way.
Yes, that is what we did with CDM, control the fallback for
N_MEMORY_PRIVATE, but there is a design decision to be made here.
>
> I think this is out of scope for the first iteration - so supporting
> anything other than mbind() from the start is just pointless.
>
> The only feasible mempolicy you can apply is single-node bind, so
> realistically you can only support mbind.
>
>
> 2) full mempolicy support doesn't really make sense
>
> task mempolicy PROBABLY should never really touch private nodes,
> while VMA policy certainly can. Assuming we're able to support
> multi-private-node masks, none of the non-bind mempolicies even
> make sense for most private nodes (interleave? weighted interleave?)
>
Yes, mostly, but is that baked into the design? If so, why?
> I haven't worked through all the implications of a task policy having
> a private node attached, but the longer I think about it, the less it
> makes sense to just support this outright.
>
>
> 3) Introducing mbind support is not just a simple nodemask on a VMA,
> It also implies migration, cgroup/cpuset, and UAPI interactions.
>
> a) migration:
>
> mbind/mempolicy can and will engage migration when it is called
> with certain flags. Migration has subtle LRU interactions, but
> the patch set I have at least allows this to work.
>
> b) cgroup/cpuset:
>
> cpuset.mems rebinding will cause private nodes to be quietly
> rebound to non-private nodes within a nodemask.
>
> c) between A and B - we really want MPOL_F_STATIC to be required
> for mbind to be applied to private node so that it is never
> forcefully remapped.
>
> That's a UAPI semantic change specific for private nodes we
> should really take time to consider.
>
>
> 4) File VMA interactions don't entirely make sense with mbind
>
> In theory you might want:
>
> fd = open("somefile", ...);
> mem = mmap(fd, ...);
> mbind(mem, ..., private_node);
> for page in mem:
> mem[page_off] /* fault file into private memory */
>
> In reality: This does not work the way you want.
Why not? Just curious about what you found?
>
> I went digging and we need a few mild extensions to allow
> migration on mbind to work for pagecache pages, and the fault
> path does not necessarily respect the vma mempolicy always.
>
> You also start getting into the question of "what happens when
> the node is out of memory and you don't have reclaim support?".
Yes, we should discuss reclaim support, I think we should allow for
reclaim. It allows you to overcommit private memory the way we can
with regular memory.
> The OOM implications jump out at you pretty aggressively.
>
> Moreover other tasks can force the page cache pages to be moved
> as well. So the programming model here just kind of sucks.
>
> Works great for anon memory though :]
>
> For all these reasons, I think the be mbind/mempolicy support with
> private nodes needs to be brought in with follow up work - not
> introduced as part of the baseline set.
>
I am not opposed to the follow up work, but I feel mbind() should
be the fundamental work and user space API.
> > >
> > > for node in possible_nodes:
> > > alloc_pages_node(private_node, __GFP_THISNODE)
> > >
> > > In fact it's the opposite semantic of what we want.
> > > THISNODE says: "Do not fallback back to OTHER nodes".
> > >
> >
> > That's why we need to control the fallback nodes carefully for
> > N_MEMORY_PRIVATE
> >
>
> My point is that __GFP_THISNODE is not actually useful.
>
> If we go by nodemask, submitting a single-node nodemask is the
> equivalent of an empty fallback list.
>
> If we gate access to a private node by __GFP_THISNODE... this is the
> same as just providing a single-node nodelist (putting aside the OOM
> implications for a moment).
>
> And it doesn't even buy you any new filtering ability against existing
> nodemask iterators that may already utilize __GFP_THISNODE. i.e.
>
> for node in online_nodes:
> alloc_pages_node(node, __GFP_THISNODE, ...)
> /* Alloc per-node resources */
>
> This pattern is undesirable, but completely valid.
>
> So overloading/requiring __GFP_THISNODE is just not useful.
>
> I will follow up soon with a new version that limits the private node
> interface to just nodemask and fallback list controls.
>
> I need to test a few more things related to removing normal nodes from
> private node fallbacks before I feel comfortable shipping without
> __GFP_PRIVATE.
>
> > > The semantic we want is "Do not allow allocations from private
> > > nodes UNLESS we specifically request" (__GFP_PRIVATE).
> > >
> > > __GFP_THISNODE does not actually buy you anything here, AND it's
> > > worse, in the scenario where a private node makes its way into the
> > > preferred slot (via possible_nodes or some other nodemask), the
> > > allocator cannot fall back to a node it can access.
> > >
> > > __GFP_THISNODE cannot be overloaded to do anything useful here.
> >
> > Let me clarify, I meant to say, let's use a nodemask for allocation
> > and __GFP_THISNODE gets us to the node we desire, if that is the only
> > node. My earlier comment might not have been clear.
> >
>
> My point was that __GFP_THISNODE is pointless and reduces to providing a
> single node nodemask anyway.
>
> The contention over __GFP_PRIVATE is a bit ideological - do we want:
>
> 1) A hard guarantee that allocations to a private node are controlled
> (__GFP_PRIVATE implies the caller knows what it's doing)
>
> or
>
> 2) A soft guarantee (fallback list isolation only), and needing to
> deal with undesired behavior that's "not technically a bug"
> associated with existing users of global nodemasks (possible,
> online, etc).
>
> I am arguing for #1 - the community has argued for #2 and "fixing
> existing nodemask users". I think we can ship #2 and pivot to #1 if we
> find fixing existing users is infeasible or too much of a maintenance
> burden.
Again happy to discuss this, I'd like to make sure we agree on the
design. I am wondering if there is any experimental data to choose
between 1 and 2.
>
> >
> > Why not use mbind() API's? Do we want to gate allocation/privileges
> > via a /dev?
> >
>
> We want to eventually enable it, but we really need to treat these
> extensions as a separate step from the base so that the UAPI
> implications are given proper scrutiny.
>
> In the short term, /dev/xxx and driver-local/service-local control
> of a node is still very useful.
>
> For example, for my compressed memory work, I have found that if
> implemented as a swap backend - the kernel can manage the node without
> any UAPI implications at all :].
>
> A driver managing memory on a private node could do the same.
>
> ~Gregory
Thanks for the detailed answers, happy to iterate and experiment on
the design with you, my opinions come from way back when we tried
to do CDM (in it's first iteration)
Balbir
^ permalink raw reply
* Re: mm/memory-failure tracepoint change breaks userspace rasdaemon
From: Xie Yuanbin @ 2026-06-04 1:46 UTC (permalink / raw)
To: david, qiuxu.zhuo, bp, akpm, rostedt, linmiaohe
Cc: linux-edac, linux-kernel, linux-mm, linux-trace-kernel,
mchehab+huawei, tony.luck, torvalds, xieyuanbin1, yi1.lai
In-Reply-To: <b637ede2-73da-49f0-a7eb-70ec79e79624@kernel.org>
On Wed, 3 Jun 2026 21:13:30 +0200, David Hildenbrand (Arm) wrote:
> Would the following be sufficient to avoid a full revert and the dependency on CONFIG_RAS?
>
> diff --git a/include/trace/events/memory-failure.h b/include/trace/events/memory-failure.h
> index aa57cc8f896b..c46b17602578 100644
> --- a/include/trace/events/memory-failure.h
> +++ b/include/trace/events/memory-failure.h
> @@ -1,6 +1,7 @@
> /* SPDX-License-Identifier: GPL-2.0 */
> #undef TRACE_SYSTEM
> -#define TRACE_SYSTEM memory_failure
> +/* Some user space relies on ras/memory_failure_event */
> +#define TRACE_SYSTEM ras
> #define TRACE_INCLUDE_FILE memory-failure
>
> #if !defined(_TRACE_MEMORY_FAILURE_H) || defined(TRACE_HEADER_MULTI_READ)
Yes, it should be. In fact, when I sent the V2 patch, I had already
considered this issue, and that's exactly what I did:
Link: https://lore.kernel.org/20251104072306.100738-3-xieyuanbin1@huawei.com
However, David Hildenbrand advised me at that time to completely
remove the dependence on RAS:
Link: https://lore.kernel.org/01b44e0f-ea2e-406f-9f65-b698b5504f42@kernel.org
^ permalink raw reply
* [RFC PATCH 0/3] mm/compaction: honour compact_unevictable_allowed in mlock race and alloc_contig path
From: Wandun Chen @ 2026-06-04 2:38 UTC (permalink / raw)
To: linux-mm, linux-kernel, linux-trace-kernel, linux-rt-devel
Cc: akpm, vbabka, surenb, mhocko, jackmanb, hannes, ziy, rostedt,
mhiramat, mathieu.desnoyers, david, ljs, liam, rppt, bigeasy,
clrkwllms, Alexander.Krabler
From: Wandun Chen <chenwandun@lixiang.com>
vm.compact_unevictable_allowed=0 is meant to keep compaction from
touching unevictable folios. In practice there are still two paths
where it does not take effect. This series fixes them and adds a
tracepoint to make such issues easier to diagnose in the future.
Wandun Chen (3):
mm/compaction: skip isolate mlocked folios when
compact_unevictable_allowed=0
mm/compaction: add per-folio isolation tracepoint
mm/compaction: respect compact_unevictable_allowed in alloc_contig
path
include/linux/compaction.h | 6 ++++++
include/trace/events/compaction.h | 26 ++++++++++++++++++++++++++
mm/compaction.c | 14 +++++++++++---
mm/internal.h | 1 +
mm/page_alloc.c | 2 ++
5 files changed, 46 insertions(+), 3 deletions(-)
--
2.43.0
^ permalink raw reply
page: next (older) | prev (newer) | latest
- recent:[subjects (threaded)|topics (new)|topics (active)]
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox