From fa5e5dc39669b4427830c546ede8709323b8276c Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 6 May 2021 21:33:58 +0200 Subject: jump_label, x86: Introduce jump_entry_size() This allows architectures to have variable sized jumps. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210506194157.786777050@infradead.org --- kernel/jump_label.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/jump_label.c b/kernel/jump_label.c index ba39fbb1f8e7..521cafcfcb69 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -309,7 +309,7 @@ EXPORT_SYMBOL_GPL(jump_label_rate_limit); static int addr_conflict(struct jump_entry *entry, void *start, void *end) { if (jump_entry_code(entry) <= (unsigned long)end && - jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE > (unsigned long)start) + jump_entry_code(entry) + jump_entry_size(entry) > (unsigned long)start) return 1; return 0; -- cgit v1.2.3-70-g09d2 From 5af0ea293d78c8b8f0b87ae2b13f7ac584057bc3 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 6 May 2021 21:34:00 +0200 Subject: jump_label: Free jump_entry::key bit1 for build use Have jump_label_init() set jump_entry::key bit1 to either 0 ot 1 unconditionally. This makes it available for build-time games. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210506194157.906893264@infradead.org --- include/linux/jump_label.h | 7 +++++-- kernel/jump_label.c | 10 ++++++---- 2 files changed, 11 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 8c45f58292ac..48b9b2a82767 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -171,9 +171,12 @@ static inline bool jump_entry_is_init(const struct jump_entry *entry) return (unsigned long)entry->key & 2UL; } -static inline void jump_entry_set_init(struct jump_entry *entry) +static inline void jump_entry_set_init(struct jump_entry *entry, bool set) { - entry->key |= 2; + if (set) + entry->key |= 2; + else + entry->key &= ~2; } static inline int jump_entry_size(struct jump_entry *entry) diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 521cafcfcb69..bdb0681bece8 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -483,13 +483,14 @@ void __init jump_label_init(void) for (iter = iter_start; iter < iter_stop; iter++) { struct static_key *iterk; + bool in_init; /* rewrite NOPs */ if (jump_label_type(iter) == JUMP_LABEL_NOP) arch_jump_label_transform_static(iter, JUMP_LABEL_NOP); - if (init_section_contains((void *)jump_entry_code(iter), 1)) - jump_entry_set_init(iter); + in_init = init_section_contains((void *)jump_entry_code(iter), 1); + jump_entry_set_init(iter, in_init); iterk = jump_entry_key(iter); if (iterk == key) @@ -634,9 +635,10 @@ static int jump_label_add_module(struct module *mod) for (iter = iter_start; iter < iter_stop; iter++) { struct static_key *iterk; + bool in_init; - if (within_module_init(jump_entry_code(iter), mod)) - jump_entry_set_init(iter); + in_init = within_module_init(jump_entry_code(iter), mod); + jump_entry_set_init(iter, in_init); iterk = jump_entry_key(iter); if (iterk == key) -- cgit v1.2.3-70-g09d2