Subject: + kprobes-unify-insn-caches.patch added to -mm tree To: heiko.carstens@xxxxxxxxxx,ananth@xxxxxxxxxx,masami.hiramatsu.pt@xxxxxxxxxxx,mingo@xxxxxxxxxx,schwidefsky@xxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Fri, 23 Aug 2013 15:52:49 -0700 The patch titled Subject: kprobes: unify insn caches has been added to the -mm tree. Its filename is kprobes-unify-insn-caches.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/kprobes-unify-insn-caches.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/kprobes-unify-insn-caches.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Subject: kprobes: unify insn caches The two insn caches (insn, and optinsn) each have an own mutex and alloc/free functions (get_[opt]insn_slot() / free_[opt]insn_slot()). Since there is the need for yet another insn cache which satifies dma allocations on s390, unify and simplify the current implementation: - Move the per insn cache mutex into struct kprobe_insn_cache. - Move the alloc/free functions to kprobe.h so they are simply wrappers for the generic __get_insn_slot/__free_insn_slot functions. The implementation is done with a DEFINE_INSN_CACHE_OPS() macro which provides the alloc/free functions for each cache if needed. - move the struct kprobe_insn_cache to kprobe.h which allows to generate architecture specific insn slot caches outside of the core kprobes code. Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx> Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/kprobes.h | 32 ++++++++++++++-- kernel/kprobes.c | 75 ++++++++++---------------------------- 2 files changed, 49 insertions(+), 58 deletions(-) diff -puN include/linux/kprobes.h~kprobes-unify-insn-caches include/linux/kprobes.h --- a/include/linux/kprobes.h~kprobes-unify-insn-caches +++ a/include/linux/kprobes.h @@ -264,10 +264,34 @@ extern void arch_arm_kprobe(struct kprob extern void arch_disarm_kprobe(struct kprobe *p); extern int arch_init_kprobes(void); extern void show_registers(struct pt_regs *regs); -extern kprobe_opcode_t *get_insn_slot(void); -extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); extern void kprobes_inc_nmissed_count(struct kprobe *p); +struct kprobe_insn_cache { + struct mutex mutex; + struct list_head pages; /* list of kprobe_insn_page */ + size_t insn_size; /* size of instruction slot */ + int nr_garbage; +}; + +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); + +#define DEFINE_INSN_CACHE_OPS(__name) \ +extern struct kprobe_insn_cache kprobe_##__name##_slots; \ + \ +static inline kprobe_opcode_t *get_##__name##_slot(void) \ +{ \ + return __get_insn_slot(&kprobe_##__name##_slots); \ +} \ + \ +static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\ +{ \ + __free_insn_slot(&kprobe_##__name##_slots, slot, dirty); \ +} \ + +DEFINE_INSN_CACHE_OPS(insn); + #ifdef CONFIG_OPTPROBES /* * Internal structure for direct jump optimized probe @@ -287,13 +311,13 @@ extern void arch_optimize_kprobes(struct extern void arch_unoptimize_kprobes(struct list_head *oplist, struct list_head *done_list); extern void arch_unoptimize_kprobe(struct optimized_kprobe *op); -extern kprobe_opcode_t *get_optinsn_slot(void); -extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty); extern int arch_within_optimized_kprobe(struct optimized_kprobe *op, unsigned long addr); extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs); +DEFINE_INSN_CACHE_OPS(optinsn); + #ifdef CONFIG_SYSCTL extern int sysctl_kprobes_optimization; extern int proc_kprobes_optimization_handler(struct ctl_table *table, diff -puN kernel/kprobes.c~kprobes-unify-insn-caches kernel/kprobes.c --- a/kernel/kprobes.c~kprobes-unify-insn-caches +++ a/kernel/kprobes.c @@ -121,12 +121,6 @@ struct kprobe_insn_page { (offsetof(struct kprobe_insn_page, slot_used) + \ (sizeof(char) * (slots))) -struct kprobe_insn_cache { - struct list_head pages; /* list of kprobe_insn_page */ - size_t insn_size; /* size of instruction slot */ - int nr_garbage; -}; - static int slots_per_page(struct kprobe_insn_cache *c) { return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t)); @@ -138,8 +132,8 @@ enum kprobe_slot_state { SLOT_USED = 2, }; -static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_slots */ -static struct kprobe_insn_cache kprobe_insn_slots = { +struct kprobe_insn_cache kprobe_insn_slots = { + .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex), .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), .insn_size = MAX_INSN_SIZE, .nr_garbage = 0, @@ -150,10 +144,12 @@ static int __kprobes collect_garbage_slo * __get_insn_slot() - Find a slot on an executable page for an instruction. * We allocate an executable page if there's no room on existing ones. */ -static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c) +kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c) { struct kprobe_insn_page *kip; + kprobe_opcode_t *slot = NULL; + mutex_lock(&c->mutex); retry: list_for_each_entry(kip, &c->pages, list) { if (kip->nused < slots_per_page(c)) { @@ -162,7 +158,8 @@ static kprobe_opcode_t __kprobes *__get_ if (kip->slot_used[i] == SLOT_CLEAN) { kip->slot_used[i] = SLOT_USED; kip->nused++; - return kip->insns + (i * c->insn_size); + slot = kip->insns + (i * c->insn_size); + goto out; } } /* kip->nused is broken. Fix it. */ @@ -178,7 +175,7 @@ static kprobe_opcode_t __kprobes *__get_ /* All out of space. Need to allocate a new page. */ kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL); if (!kip) - return NULL; + goto out; /* * Use module_alloc so this page is within +/- 2GB of where the @@ -188,7 +185,7 @@ static kprobe_opcode_t __kprobes *__get_ kip->insns = module_alloc(PAGE_SIZE); if (!kip->insns) { kfree(kip); - return NULL; + goto out; } INIT_LIST_HEAD(&kip->list); memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c)); @@ -196,19 +193,10 @@ static kprobe_opcode_t __kprobes *__get_ kip->nused = 1; kip->ngarbage = 0; list_add(&kip->list, &c->pages); - return kip->insns; -} - - -kprobe_opcode_t __kprobes *get_insn_slot(void) -{ - kprobe_opcode_t *ret = NULL; - - mutex_lock(&kprobe_insn_mutex); - ret = __get_insn_slot(&kprobe_insn_slots); - mutex_unlock(&kprobe_insn_mutex); - - return ret; + slot = kip->insns; +out: + mutex_unlock(&c->mutex); + return slot; } /* Return 1 if all garbages are collected, otherwise 0. */ @@ -255,11 +243,12 @@ static int __kprobes collect_garbage_slo return 0; } -static void __kprobes __free_insn_slot(struct kprobe_insn_cache *c, - kprobe_opcode_t *slot, int dirty) +void __kprobes __free_insn_slot(struct kprobe_insn_cache *c, + kprobe_opcode_t *slot, int dirty) { struct kprobe_insn_page *kip; + mutex_lock(&c->mutex); list_for_each_entry(kip, &c->pages, list) { long idx = ((long)slot - (long)kip->insns) / (c->insn_size * sizeof(kprobe_opcode_t)); @@ -272,45 +261,23 @@ static void __kprobes __free_insn_slot(s collect_garbage_slots(c); } else collect_one_slot(kip, idx); - return; + goto out; } } /* Could not free this slot. */ WARN_ON(1); +out: + mutex_unlock(&c->mutex); } -void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) -{ - mutex_lock(&kprobe_insn_mutex); - __free_insn_slot(&kprobe_insn_slots, slot, dirty); - mutex_unlock(&kprobe_insn_mutex); -} #ifdef CONFIG_OPTPROBES /* For optimized_kprobe buffer */ -static DEFINE_MUTEX(kprobe_optinsn_mutex); /* Protects kprobe_optinsn_slots */ -static struct kprobe_insn_cache kprobe_optinsn_slots = { +struct kprobe_insn_cache kprobe_optinsn_slots = { + .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex), .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), /* .insn_size is initialized later */ .nr_garbage = 0, }; -/* Get a slot for optimized_kprobe buffer */ -kprobe_opcode_t __kprobes *get_optinsn_slot(void) -{ - kprobe_opcode_t *ret = NULL; - - mutex_lock(&kprobe_optinsn_mutex); - ret = __get_insn_slot(&kprobe_optinsn_slots); - mutex_unlock(&kprobe_optinsn_mutex); - - return ret; -} - -void __kprobes free_optinsn_slot(kprobe_opcode_t * slot, int dirty) -{ - mutex_lock(&kprobe_optinsn_mutex); - __free_insn_slot(&kprobe_optinsn_slots, slot, dirty); - mutex_unlock(&kprobe_optinsn_mutex); -} #endif #endif _ Patches currently in -mm which might be from heiko.carstens@xxxxxxxxxx are kprobes-unify-insn-caches.patch kprobes-allow-to-specify-custum-allocator-for-insn-caches.patch s390-kprobes-add-support-for-pc-relative-long-displacement-instructions.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html