Commit-ID: 9ae033aca8d600e36034d4d0743aad624cec92ed Gitweb: https://git.kernel.org/tip/9ae033aca8d600e36034d4d0743aad624cec92ed Author: Ard Biesheuvel <ard.biesheu...@linaro.org> AuthorDate: Tue, 18 Sep 2018 23:51:36 -0700 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Thu, 27 Sep 2018 17:56:46 +0200
jump_label: Abstract jump_entry member accessors In preparation of allowing architectures to use relative references in jump_label entries [which can dramatically reduce the memory footprint], introduce abstractions for references to the 'code' and 'key' members of struct jump_entry. Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: linux-arm-ker...@lists.infradead.org Cc: linux-s...@vger.kernel.org Cc: Arnd Bergmann <a...@arndb.de> Cc: Heiko Carstens <heiko.carst...@de.ibm.com> Cc: Kees Cook <keesc...@chromium.org> Cc: Will Deacon <will.dea...@arm.com> Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Martin Schwidefsky <schwidef...@de.ibm.com> Cc: Jessica Yu <j...@kernel.org> Link: https://lkml.kernel.org/r/20180919065144.25010-2-ard.biesheu...@linaro.org --- include/linux/jump_label.h | 34 ++++++++++++++++++++++++++++++++++ kernel/jump_label.c | 40 +++++++++++++++------------------------- 2 files changed, 49 insertions(+), 25 deletions(-) diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 1a0b6f17a5d6..2eadff9b3b90 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -119,6 +119,40 @@ struct static_key { #ifdef HAVE_JUMP_LABEL #include <asm/jump_label.h> + +#ifndef __ASSEMBLY__ + +static inline unsigned long jump_entry_code(const struct jump_entry *entry) +{ + return entry->code; +} + +static inline unsigned long jump_entry_target(const struct jump_entry *entry) +{ + return entry->target; +} + +static inline struct static_key *jump_entry_key(const struct jump_entry *entry) +{ + return (struct static_key *)((unsigned long)entry->key & ~1UL); +} + +static inline bool jump_entry_is_branch(const struct jump_entry *entry) +{ + return (unsigned long)entry->key & 1UL; +} + +static inline bool jump_entry_is_init(const struct jump_entry *entry) +{ + return entry->code == 0; +} + +static inline void jump_entry_set_init(struct jump_entry *entry) +{ + entry->code = 0; +} + +#endif #endif #ifndef __ASSEMBLY__ diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 2e62503bea0d..834e43de0daf 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -38,10 +38,10 @@ static int jump_label_cmp(const void *a, const void *b) const struct jump_entry *jea = a; const struct jump_entry *jeb = b; - if (jea->key < jeb->key) + if (jump_entry_key(jea) < jump_entry_key(jeb)) return -1; - if (jea->key > jeb->key) + if (jump_entry_key(jea) > jump_entry_key(jeb)) return 1; return 0; @@ -261,8 +261,8 @@ EXPORT_SYMBOL_GPL(jump_label_rate_limit); static int addr_conflict(struct jump_entry *entry, void *start, void *end) { - if (entry->code <= (unsigned long)end && - entry->code + JUMP_LABEL_NOP_SIZE > (unsigned long)start) + if (jump_entry_code(entry) <= (unsigned long)end && + jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE > (unsigned long)start) return 1; return 0; @@ -321,16 +321,6 @@ static inline void static_key_set_linked(struct static_key *key) key->type |= JUMP_TYPE_LINKED; } -static inline struct static_key *jump_entry_key(struct jump_entry *entry) -{ - return (struct static_key *)((unsigned long)entry->key & ~1UL); -} - -static bool jump_entry_branch(struct jump_entry *entry) -{ - return (unsigned long)entry->key & 1UL; -} - /*** * A 'struct static_key' uses a union such that it either points directly * to a table of 'struct jump_entry' or to a linked list of modules which in @@ -355,7 +345,7 @@ static enum jump_label_type jump_label_type(struct jump_entry *entry) { struct static_key *key = jump_entry_key(entry); bool enabled = static_key_enabled(key); - bool branch = jump_entry_branch(entry); + bool branch = jump_entry_is_branch(entry); /* See the comment in linux/jump_label.h */ return enabled ^ branch; @@ -370,12 +360,12 @@ static void __jump_label_update(struct static_key *key, * An entry->code of 0 indicates an entry which has been * disabled because it was in an init text area. */ - if (entry->code) { - if (kernel_text_address(entry->code)) + if (!jump_entry_is_init(entry)) { + if (kernel_text_address(jump_entry_code(entry))) arch_jump_label_transform(entry, jump_label_type(entry)); else WARN_ONCE(1, "can't patch jump_label at %pS", - (void *)(unsigned long)entry->code); + (void *)jump_entry_code(entry)); } } } @@ -430,8 +420,8 @@ void __init jump_label_invalidate_initmem(void) struct jump_entry *iter; for (iter = iter_start; iter < iter_stop; iter++) { - if (init_section_contains((void *)(unsigned long)iter->code, 1)) - iter->code = 0; + if (init_section_contains((void *)jump_entry_code(iter), 1)) + jump_entry_set_init(iter); } } @@ -441,7 +431,7 @@ static enum jump_label_type jump_label_init_type(struct jump_entry *entry) { struct static_key *key = jump_entry_key(entry); bool type = static_key_type(key); - bool branch = jump_entry_branch(entry); + bool branch = jump_entry_is_branch(entry); /* See the comment in linux/jump_label.h */ return type ^ branch; @@ -565,7 +555,7 @@ static int jump_label_add_module(struct module *mod) continue; key = iterk; - if (within_module(iter->key, mod)) { + if (within_module((unsigned long)key, mod)) { static_key_set_entries(key, iter); continue; } @@ -615,7 +605,7 @@ static void jump_label_del_module(struct module *mod) key = jump_entry_key(iter); - if (within_module(iter->key, mod)) + if (within_module((unsigned long)key, mod)) continue; /* No memory during module load */ @@ -659,8 +649,8 @@ static void jump_label_invalidate_module_init(struct module *mod) struct jump_entry *iter; for (iter = iter_start; iter < iter_stop; iter++) { - if (within_module_init(iter->code, mod)) - iter->code = 0; + if (within_module_init(jump_entry_code(iter), mod)) + jump_entry_set_init(iter); } }
