Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756023AbbBLMbr (ORCPT ); Thu, 12 Feb 2015 07:31:47 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:44495 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755857AbbBLM3l (ORCPT ); Thu, 12 Feb 2015 07:29:41 -0500 From: Wang Nan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: , , , Subject: [RFC PATCH v2 18/26] early kprobes: allows __alloc_insn_slot() from early kprobes slots. Date: Thu, 12 Feb 2015 20:20:55 +0800 Message-ID: <1423743655-12803-1-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1423743476-11927-1-git-send-email-wangnan0@huawei.com> References: <1423743476-11927-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.197.247] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4224 Lines: 132 Introduces early_slots_start/end and bitmap for struct kprobe_insn_cache then uses previous introduced macro to generate allocator. This patch makes get/free_insn_slot() and get/free_optinsn_slot() transparent to early kprobes. Signed-off-by: Wang Nan --- include/linux/kprobes.h | 40 ++++++++++++++++++++++++++++++++++++++++ kernel/kprobes.c | 14 ++++++++++++++ 2 files changed, 54 insertions(+) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index cd7a2a5..6100678 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -319,6 +319,17 @@ static inline int ek_free_##__name(__t *__s) \ (__ek_##__name##_bitmap)); \ } +/* + * Start and end of early kprobes area, including code area and + * insn_slot area. + */ +extern char __early_kprobes_start[]; +extern char __early_kprobes_end[]; + +extern kprobe_opcode_t __early_kprobes_code_area_start[]; +extern kprobe_opcode_t __early_kprobes_code_area_end[]; +extern kprobe_opcode_t __early_kprobes_insn_slot_start[]; +extern kprobe_opcode_t __early_kprobes_insn_slot_end[]; #else #define __DEFINE_EKPROBE_ALLOC_OPS(__t, __name) \ @@ -348,6 +359,8 @@ static inline int ek_free_##__name(__t *__s) \ #endif +__DEFINE_EKPROBE_ALLOC_OPS(kprobe_opcode_t, opcode) + struct kprobe_insn_cache { struct mutex mutex; void *(*alloc)(void); /* allocate insn page */ @@ -355,8 +368,35 @@ struct kprobe_insn_cache { struct list_head pages; /* list of kprobe_insn_page */ size_t insn_size; /* size of instruction slot */ int nr_garbage; +#ifdef CONFIG_EARLY_KPROBES +# define slots_start(c) ((c)->early_slots_start) +# define slots_end(c) ((c)->early_slots_end) +# define slots_bitmap(c) ((c)->early_slots_bitmap) + kprobe_opcode_t *early_slots_start; + kprobe_opcode_t *early_slots_end; + unsigned long early_slots_bitmap[EARLY_KPROBES_BITMAP_SZ]; +#else +# define slots_start(c) NULL +# define slots_end(c) NULL +# define slots_bitmap(c) NULL +#endif }; +static inline kprobe_opcode_t * +__get_insn_slot_early(struct kprobe_insn_cache *c) +{ + return __ek_alloc_opcode(slots_start(c), + slots_end(c), slots_bitmap(c)); +} + +static inline int +__free_insn_slot_early(struct kprobe_insn_cache *c, + kprobe_opcode_t *slot) +{ + return __ek_free_opcode(slot, slots_start(c), + slots_end(c), slots_bitmap(c)); +} + extern kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c); extern void __free_insn_slot(struct kprobe_insn_cache *c, kprobe_opcode_t *slot, int dirty); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 647c95a..fa1e422 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -143,6 +143,10 @@ struct kprobe_insn_cache kprobe_insn_slots = { .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), .insn_size = MAX_INSN_SIZE, .nr_garbage = 0, +#ifdef CONFIG_EARLY_KPROBES + .early_slots_start = __early_kprobes_insn_slot_start, + .early_slots_end = __early_kprobes_insn_slot_end, +#endif }; static int collect_garbage_slots(struct kprobe_insn_cache *c); @@ -155,6 +159,9 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c) struct kprobe_insn_page *kip; kprobe_opcode_t *slot = NULL; + if (kprobes_is_early()) + return __get_insn_slot_early(c); + mutex_lock(&c->mutex); retry: list_for_each_entry(kip, &c->pages, list) { @@ -255,6 +262,9 @@ void __free_insn_slot(struct kprobe_insn_cache *c, { struct kprobe_insn_page *kip; + if (unlikely(__free_insn_slot_early(c, slot))) + return; + mutex_lock(&c->mutex); list_for_each_entry(kip, &c->pages, list) { long idx = ((long)slot - (long)kip->insns) / @@ -286,6 +296,10 @@ struct kprobe_insn_cache kprobe_optinsn_slots = { .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), /* .insn_size is initialized later */ .nr_garbage = 0, +#ifdef CONFIG_EARLY_KPROBES + .early_slots_start = __early_kprobes_code_area_start, + .early_slots_end = __early_kprobes_code_area_end, +#endif }; #endif #endif -- 1.8.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/