Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753899AbaBDMHQ (ORCPT ); Tue, 4 Feb 2014 07:07:16 -0500 Received: from mail-pa0-f45.google.com ([209.85.220.45]:52428 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750937AbaBDMHO (ORCPT ); Tue, 4 Feb 2014 07:07:14 -0500 Message-ID: <52F0D7F3.7000901@gmail.com> Date: Tue, 04 Feb 2014 20:07:15 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Masami Hiramatsu CC: ananth@in.ibm.com, anil.s.keshavamurthy@intel.com, =?UTF-8?B?SMOldmFy?= =?UTF-8?B?ZCBTa2lubmVtb2Vu?= , David Miller , "linux-kernel@vger.kernel.org" , Hans-Christian Egtvedt , "yrl.pp-manager.tt@hitachi.com" Subject: Re: [PATCH] kernel: kprobe: move all *kretprobe* generic implementation to CONFIG_KRETPROBES enabled area References: <52ECE5D8.6090209@gmail.com> <52EDB022.5070101@hitachi.com> <52EF8222.6030709@gmail.com> <52EFB8F4.6010207@hitachi.com> <52F04FA8.8040008@gmail.com> <52F077A1.3020701@gmail.com> <52F09404.3060502@hitachi.com> In-Reply-To: <52F09404.3060502@hitachi.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/04/2014 03:17 PM, Masami Hiramatsu wrote: > (2014/02/04 14:16), Chen Gang wrote: >> When CONFIG_KRETPROBES disabled, all *kretprobe* generic implementation >> are useless, so need move them to CONFIG_KPROBES enabled area. >> >> Now, *kretprobe* generic implementation are all implemented in 2 files: >> >> - in "include/linux/kprobes.h": >> >> move inline kretprobe*() to CONFIG_KPROBES area and dummy outside. >> move some *kprobe() declarations which kretprobe*() call, to front. >> not touch kretprobe_blacklist[] which is architecture's variable. >> >> - in "kernel/kprobes.c": >> >> move all kretprobe* to CONFIG_KPROBES area and dummy outside. >> define kretprobe_flush_task() to let kprobe_flush_task() call. >> define init_kretprobes() to let init_kprobes() call. >> >> The patch passes compiling (get "kernel/kprobes.o" and "kernel/built- >> in.o") under avr32 and x86_64 allmodconfig, and passes building (get >> bzImage and Modpost modules) under x86_64 defconfig. > > Thanks for the fix! and I have some comments below. > >> Signed-off-by: Chen Gang >> --- >> include/linux/kprobes.h | 58 +++++---- >> kernel/kprobes.c | 328 +++++++++++++++++++++++++++--------------------- >> 2 files changed, 222 insertions(+), 164 deletions(-) >> >> diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h >> index 925eaf2..c0d1212 100644 >> --- a/include/linux/kprobes.h >> +++ b/include/linux/kprobes.h >> @@ -223,10 +223,36 @@ static inline int kprobes_built_in(void) >> return 1; >> } >> >> +int disable_kprobe(struct kprobe *kp); >> +int enable_kprobe(struct kprobe *kp); >> + >> +void dump_kprobe(struct kprobe *kp); >> + >> +extern struct kretprobe_blackpoint kretprobe_blacklist[]; >> + >> #ifdef CONFIG_KRETPROBES >> extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, >> struct pt_regs *regs); >> extern int arch_trampoline_kprobe(struct kprobe *p); >> +static inline void kretprobe_assert(struct kretprobe_instance *ri, >> + unsigned long orig_ret_address, unsigned long trampoline_address) >> +{ >> + if (!orig_ret_address || (orig_ret_address == trampoline_address)) { >> + printk(KERN_ERR >> + "kretprobe BUG!: Processing kretprobe %p @ %p\n", >> + ri->rp, ri->rp->kp.addr); >> + BUG(); >> + } >> +} >> +static inline int disable_kretprobe(struct kretprobe *rp) >> +{ >> + return disable_kprobe(&rp->kp); >> +} >> +static inline int enable_kretprobe(struct kretprobe *rp) >> +{ >> + return enable_kprobe(&rp->kp); >> +} >> + >> #else /* CONFIG_KRETPROBES */ >> static inline void arch_prepare_kretprobe(struct kretprobe *rp, >> struct pt_regs *regs) >> @@ -236,19 +262,20 @@ static inline int arch_trampoline_kprobe(struct kprobe *p) >> { >> return 0; >> } >> -#endif /* CONFIG_KRETPROBES */ >> - >> -extern struct kretprobe_blackpoint kretprobe_blacklist[]; >> - >> static inline void kretprobe_assert(struct kretprobe_instance *ri, >> unsigned long orig_ret_address, unsigned long trampoline_address) >> { >> - if (!orig_ret_address || (orig_ret_address == trampoline_address)) { >> - printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", >> - ri->rp, ri->rp->kp.addr); >> - BUG(); >> - } >> } >> +static inline int disable_kretprobe(struct kretprobe *rp) >> +{ >> + return 0; >> +} >> +static inline int enable_kretprobe(struct kretprobe *rp) >> +{ >> + return 0; >> +} > > No, these should returns -EINVAL or -ENOSYS, since these are user API. OK, thanks, it sounds reasonable to me. > Anyway, I don't think those inlined functions to be changed, because > most of them are internal functions. If CONFIG_KRETPROBES=n, it just > be ignored. > In original implementation, if CONFIG_KRETPROBES=n, kretprobe_assert(), disable_kretprobe(), and enable_kretprobe() are not ignored. > So, I think you don't need to change kprobes.h. > So "kprobes.h" still need be changed. >> + >> +#endif /* CONFIG_KRETPROBES */ >> >> #ifdef CONFIG_KPROBES_SANITY_TEST >> extern int init_test_probes(void); >> @@ -379,11 +406,6 @@ void unregister_kretprobes(struct kretprobe **rps, int num); >> void kprobe_flush_task(struct task_struct *tk); >> void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); >> >> -int disable_kprobe(struct kprobe *kp); >> -int enable_kprobe(struct kprobe *kp); >> - >> -void dump_kprobe(struct kprobe *kp); >> - >> #else /* !CONFIG_KPROBES: */ >> >> static inline int kprobes_built_in(void) >> @@ -459,14 +481,6 @@ static inline int enable_kprobe(struct kprobe *kp) >> return -ENOSYS; >> } >> #endif /* CONFIG_KPROBES */ >> -static inline int disable_kretprobe(struct kretprobe *rp) >> -{ >> - return disable_kprobe(&rp->kp); >> -} >> -static inline int enable_kretprobe(struct kretprobe *rp) >> -{ >> - return enable_kprobe(&rp->kp); >> -} >> static inline int disable_jprobe(struct jprobe *jp) >> { >> return disable_kprobe(&jp->kp); >> diff --git a/kernel/kprobes.c b/kernel/kprobes.c >> index ceeadfc..e305a81 100644 >> --- a/kernel/kprobes.c >> +++ b/kernel/kprobes.c > [...] >> @@ -1936,8 +1955,44 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p, >> return 0; >> } >> >> +void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, >> + struct hlist_head *head) >> +{ >> +} >> + >> +void __kprobes kretprobe_hash_lock(struct task_struct *tsk, >> + struct hlist_head **head, unsigned long *flags) >> +__acquires(hlist_lock) >> +{ >> +} >> + >> +void __kprobes kretprobe_hash_unlock(struct task_struct *tsk, >> + unsigned long *flags) >> +__releases(hlist_lock) >> +{ >> +} >> + > >> +static void __kprobes kretprobe_flush_task(struct task_struct *tk) >> +{ >> +} >> + >> +static void __init init_kretprobes(void) >> +{ >> +} > > These should be macros, as I did for optprobe functions > with !CONFIG_OPTPROBES. > OK, thanks, it sounds reasonable to me. - For new added static functions: kretprobe_flush_task(), and init_kretprobes() need be changed to macros - For extern functions: recycle_rp_inst(), kretprobe_hash_lock(), and kretprobe_has_unlock(), need use dummy functions. - For original static function: pre_handler_kretprobe(), need still use dummy function (for function pointer comparing). > Other parts looks good to me!;) > > Thank you! > > Thanks. -- Chen Gang Open, share and attitude like air, water and life which God blessed -- 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/