[PATCH v2 1/2] kprobes: Allow architectures to override optinsn page allocation
From: Christophe Leroy <hidden>
Date: 2021-05-13 09:08:11
Also in:
lkml
Subsystem:
kprobes, the rest · Maintainers:
Naveen N Rao, "David S. Miller", Masami Hiramatsu, Linus Torvalds
Some architectures like powerpc require a non standard allocation of optinsn page, because module pages are too far from the kernel for direct branches. Define weak alloc_optinsn_page() and free_optinsn_page(), that fall back on alloc_insn_page() and free_insn_page() when not overriden by the architecture. Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Christophe Leroy <redacted> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> --- v2: Added missing prototypes in linux/kprobes.h --- include/linux/kprobes.h | 3 +++ kernel/kprobes.c | 14 ++++++++++++-- 2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 1883a4a9f16a..02d4020615a7 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h@@ -409,6 +409,9 @@ void dump_kprobe(struct kprobe *kp); void *alloc_insn_page(void); void free_insn_page(void *page); +void *alloc_optinsn_page(void); +void free_optinsn_page(void *page); + int kprobe_get_kallsym(unsigned int symnum, unsigned long *value, char *type, char *sym);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 745f08fdd7a6..8c0a6fdef771 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c@@ -321,11 +321,21 @@ int kprobe_cache_get_kallsym(struct kprobe_insn_cache *c, unsigned int *symnum, } #ifdef CONFIG_OPTPROBES +void __weak *alloc_optinsn_page(void) +{ + return alloc_insn_page(); +} + +void __weak free_optinsn_page(void *page) +{ + free_insn_page(page); +} + /* For optimized_kprobe buffer */ struct kprobe_insn_cache kprobe_optinsn_slots = { .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex), - .alloc = alloc_insn_page, - .free = free_insn_page, + .alloc = alloc_optinsn_page, + .free = free_optinsn_page, .sym = KPROBE_OPTINSN_PAGE_SYM, .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), /* .insn_size is initialized later */
--
2.25.0