From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- scripts/kconfig/lkc.h | 139 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 scripts/kconfig/lkc.h (limited to 'scripts/kconfig/lkc.h') diff --git a/scripts/kconfig/lkc.h b/scripts/kconfig/lkc.h new file mode 100644 index 000000000..7e6f6ca29 --- /dev/null +++ b/scripts/kconfig/lkc.h @@ -0,0 +1,139 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2002 Roman Zippel + */ + +#ifndef LKC_H +#define LKC_H + +#include +#include +#include + +#include "expr.h" + +#ifdef __cplusplus +extern "C" { +#endif + +#include "lkc_proto.h" + +#define SRCTREE "srctree" + +#ifndef CONFIG_ +#define CONFIG_ "CONFIG_" +#endif +static inline const char *CONFIG_prefix(void) +{ + return getenv( "CONFIG_" ) ?: CONFIG_; +} +#undef CONFIG_ +#define CONFIG_ CONFIG_prefix() + +extern int yylineno; +void zconfdump(FILE *out); +void zconf_starthelp(void); +FILE *zconf_fopen(const char *name); +void zconf_initscan(const char *name); +void zconf_nextfile(const char *name); + +/* confdata.c */ +extern struct gstr autoconf_cmd; +const char *conf_get_configname(void); + +/* confdata.c and expr.c */ +static inline void xfwrite(const void *str, size_t len, size_t count, FILE *out) +{ + assert(len != 0); + + if (fwrite(str, len, count, out) != count) + fprintf(stderr, "Error in writing or end of file.\n"); +} + +/* util.c */ +const char *file_lookup(const char *name, + const char *parent_name, int parent_lineno); + +/* lexer.l */ +int yylex(void); + +struct gstr { + size_t len; + char *s; + /* + * when max_width is not zero long lines in string s (if any) get + * wrapped not to exceed the max_width value + */ + int max_width; +}; +struct gstr str_new(void); +void str_free(struct gstr *gs); +void str_append(struct gstr *gs, const char *s); +void str_printf(struct gstr *gs, const char *fmt, ...); +char *str_get(const struct gstr *gs); + +/* menu.c */ +struct menu *menu_next(struct menu *menu, struct menu *root); +#define menu_for_each_sub_entry(menu, root) \ + for (menu = menu_next(root, root); menu; menu = menu_next(menu, root)) +#define menu_for_each_entry(menu) \ + menu_for_each_sub_entry(menu, &rootmenu) +void _menu_init(void); +void menu_warn(const struct menu *menu, const char *fmt, ...); +struct menu *menu_add_menu(void); +void menu_end_menu(void); +void menu_add_entry(struct symbol *sym, enum menu_type type); +void menu_add_dep(struct expr *dep, struct expr *cond); +void menu_add_visibility(struct expr *dep); +struct property *menu_add_prompt(enum prop_type type, const char *prompt, + struct expr *dep); +void menu_add_expr(enum prop_type type, struct expr *expr, struct expr *dep); +void menu_add_symbol(enum prop_type type, struct symbol *sym, struct expr *dep); +void menu_finalize(void); +void menu_set_type(int type); + +extern struct menu rootmenu; + +bool menu_is_empty(struct menu *menu); +bool menu_is_visible(struct menu *menu); +bool menu_has_prompt(const struct menu *menu); +const char *menu_get_prompt(const struct menu *menu); +struct menu *menu_get_parent_menu(struct menu *menu); +struct menu *menu_get_menu_or_parent_menu(struct menu *menu); +int get_jump_key_char(void); +struct gstr get_relations_str(struct symbol **sym_arr, struct list_head *head); +void menu_get_ext_help(struct menu *menu, struct gstr *help); +void menu_dump(void); + +/* symbol.c */ +void sym_clear_all_valid(void); +struct symbol *sym_choice_default(struct menu *choice); +struct symbol *sym_calc_choice(struct menu *choice); +struct property *sym_get_range_prop(struct symbol *sym); +const char *sym_get_string_default(struct symbol *sym); +struct symbol *sym_check_deps(struct symbol *sym); +struct symbol *prop_get_symbol(const struct property *prop); + +static inline tristate sym_get_tristate_value(const struct symbol *sym) +{ + return sym->curr.tri; +} + +static inline bool sym_is_choice(const struct symbol *sym) +{ + /* A choice is a symbol with no name */ + return sym->name == NULL; +} + +bool sym_is_choice_value(const struct symbol *sym); + +static inline bool sym_has_value(const struct symbol *sym) +{ + return sym->flags & SYMBOL_DEF_USER ? true : false; +} + +#ifdef __cplusplus +} +#endif + +#endif /* LKC_H */ -- cgit v1.3.1