Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935601AbYBCDAc (ORCPT ); Sat, 2 Feb 2008 22:00:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932357AbYBCDAS (ORCPT ); Sat, 2 Feb 2008 22:00:18 -0500 Received: from rv-out-0910.google.com ([209.85.198.191]:4963 "EHLO rv-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753950AbYBCDAP (ORCPT ); Sat, 2 Feb 2008 22:00:15 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:content-type:date:message-id:mime-version:x-mailer:content-transfer-encoding; b=ov/yWQqY88QkUio/EM9j2cluDpYpoBqWzTVzJpEoNBkP/SKk+V2Pd1v/A0ckyMw7C7D8CtX4g5IFA/4SjreE9w/YhsLQsHmQID62kZtoHFwk9p6iooHdzm8z+JQUzRUOpt7EX0A2nzrXeniQ/tGUJ3fW0Fi7YaSbTuJy2iFUyzo= Subject: [PATCH 1/2] kprobes: Introduce kprobe_handle_fault() From: Harvey Harrison To: Andrew Morton Cc: linux-arch , LKML Content-Type: text/plain Date: Sat, 02 Feb 2008 19:00:23 -0800 Message-Id: <1202007623.1844.44.camel@brick> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9558 Lines: 376 Use a central kprobe_handle_fault() inline in kprobes.h to remove all of the arch-dependant, practically identical implementations in avr32, ia64, powerpc, s390, sparc64, and x86. avr32 was the only arch without the preempt_disable/enable pair in its notify_page_fault implementation. This uncovered a possible bug in the s390 version as that purely copied the x86 version unconditionally passing 14 as the trapnr rather than the error_code parameter. s390 is changed to pass error_code in this patch. Signed-off-by: Harvey Harrison --- Andrew, 1/2 is low risk, 2/2 has been tested on x86-32 and 64, but the !preemptible invariant seems correct. arch/arm/mm/fault.c | 25 +------------------------ arch/avr32/mm/fault.c | 21 +-------------------- arch/ia64/mm/fault.c | 24 +----------------------- arch/powerpc/mm/fault.c | 25 +------------------------ arch/s390/mm/fault.c | 25 +------------------------ arch/sparc64/mm/fault.c | 23 +---------------------- arch/x86/mm/fault.c | 26 ++------------------------ include/linux/kprobes.h | 20 ++++++++++++++++++++ 8 files changed, 28 insertions(+), 161 deletions(-) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 28ad7ab..5def64f 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -21,29 +21,6 @@ #include "fault.h" - -#ifdef CONFIG_KPROBES -static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr) -{ - int ret = 0; - - if (!user_mode(regs)) { - /* kprobe_running() needs smp_processor_id() */ - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, fsr)) - ret = 1; - preempt_enable(); - } - - return ret; -} -#else -static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr) -{ - return 0; -} -#endif - /* * This is useful to dump out the page tables associated with * 'addr' in mm 'mm'. @@ -246,7 +223,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) struct mm_struct *mm; int fault, sig, code; - if (notify_page_fault(regs, fsr)) + if (handle_kprobe_fault(regs, fsr)) return 0; tsk = current; diff --git a/arch/avr32/mm/fault.c b/arch/avr32/mm/fault.c index 6560cb1..e41953e 100644 --- a/arch/avr32/mm/fault.c +++ b/arch/avr32/mm/fault.c @@ -20,25 +20,6 @@ #include #include -#ifdef CONFIG_KPROBES -static inline int notify_page_fault(struct pt_regs *regs, int trap) -{ - int ret = 0; - - if (!user_mode(regs)) { - if (kprobe_running() && kprobe_fault_handler(regs, trap)) - ret = 1; - } - - return ret; -} -#else -static inline int notify_page_fault(struct pt_regs *regs, int trap) -{ - return 0; -} -#endif - int exception_trace = 1; /* @@ -66,7 +47,7 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs) int code; int fault; - if (notify_page_fault(regs, ecr)) + if (kprobe_handle_fault(regs, ecr)) return; address = sysreg_read(TLBEAR); diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c index 7571076..bfc83e8 100644 --- a/arch/ia64/mm/fault.c +++ b/arch/ia64/mm/fault.c @@ -18,28 +18,6 @@ extern void die (char *, struct pt_regs *, long); -#ifdef CONFIG_KPROBES -static inline int notify_page_fault(struct pt_regs *regs, int trap) -{ - int ret = 0; - - if (!user_mode(regs)) { - /* kprobe_running() needs smp_processor_id() */ - preempt_disable(); - if (kprobe_running() && kprobes_fault_handler(regs, trap)) - ret = 1; - preempt_enable(); - } - - return ret; -} -#else -static inline int notify_page_fault(struct pt_regs *regs, int trap) -{ - return 0; -} -#endif - /* * Return TRUE if ADDRESS points at a page in the kernel's mapped segment * (inside region 5, on ia64) and that page is present. @@ -106,7 +84,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re /* * This is to handle the kprobes on user space access instructions */ - if (notify_page_fault(regs, TRAP_BRKPT)) + if (kprobe_handle_fault(regs, TRAP_BRKPT)) return; down_read(&mm->mmap_sem); diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 7b25107..3246953 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -39,29 +39,6 @@ #include #include - -#ifdef CONFIG_KPROBES -static inline int notify_page_fault(struct pt_regs *regs) -{ - int ret = 0; - - /* kprobe_running() needs smp_processor_id() */ - if (!user_mode(regs)) { - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, 11)) - ret = 1; - preempt_enable(); - } - - return ret; -} -#else -static inline int notify_page_fault(struct pt_regs *regs) -{ - return 0; -} -#endif - /* * Check whether the instruction at regs->nip is a store using * an update addressing form which will update r1. @@ -164,7 +141,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address, is_write = error_code & ESR_DST; #endif /* CONFIG_4xx || CONFIG_BOOKE */ - if (notify_page_fault(regs)) + if (kprobe_handle_fault(regs, 11)) return 0; if (unlikely(debugger_fault_handler(regs))) diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 2456b52..5a47295 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -51,29 +51,6 @@ extern int sysctl_userprocess_debug; extern void die(const char *,struct pt_regs *,long); -#ifdef CONFIG_KPROBES -static inline int notify_page_fault(struct pt_regs *regs, long err) -{ - int ret = 0; - - /* kprobe_running() needs smp_processor_id() */ - if (!user_mode(regs)) { - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, 14)) - ret = 1; - preempt_enable(); - } - - return ret; -} -#else -static inline int notify_page_fault(struct pt_regs *regs, long err) -{ - return 0; -} -#endif - - /* * Unlock any spinlocks which will prevent us from getting the * message out. @@ -309,7 +286,7 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int write) int si_code; int fault; - if (notify_page_fault(regs, error_code)) + if (kprobe_handle_fault(regs, error_code)) return; tsk = current; diff --git a/arch/sparc64/mm/fault.c b/arch/sparc64/mm/fault.c index e2027f2..8467dd6 100644 --- a/arch/sparc64/mm/fault.c +++ b/arch/sparc64/mm/fault.c @@ -31,27 +31,6 @@ #include #include -#ifdef CONFIG_KPROBES -static inline int notify_page_fault(struct pt_regs *regs) -{ - int ret = 0; - - /* kprobe_running() needs smp_processor_id() */ - if (!user_mode(regs)) { - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, 0)) - ret = 1; - preempt_enable(); - } - return ret; -} -#else -static inline int notify_page_fault(struct pt_regs *regs) -{ - return 0; -} -#endif - /* * To debug kernel to catch accesses to certain virtual/physical addresses. * Mode = 0 selects physical watchpoints, mode = 1 selects virtual watchpoints. @@ -280,7 +259,7 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs) fault_code = get_thread_fault_code(); - if (notify_page_fault(regs)) + if (kprobe_handle_fault(regs, 0)) return; si_code = SEGV_MAPERR; diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 3fff490..f0adbb0 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -49,29 +49,6 @@ #define PF_RSVD (1<<3) #define PF_INSTR (1<<4) -static inline int notify_page_fault(struct pt_regs *regs) -{ -#ifdef CONFIG_KPROBES - int ret = 0; - - /* kprobe_running() needs smp_processor_id() */ -#ifdef CONFIG_X86_32 - if (!user_mode_vm(regs)) { -#else - if (!user_mode(regs)) { -#endif - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, 14)) - ret = 1; - preempt_enable(); - } - - return ret; -#else - return 0; -#endif -} - /* * X86_32 * Sometimes AMD Athlon/Opteron CPUs report invalid exceptions on prefetch. @@ -589,7 +566,8 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) si_code = SEGV_MAPERR; - if (notify_page_fault(regs)) + /* Must not try to handle kprobes in v8086 mode */ + if (!v8086_mode(regs) && kprobe_handle_fault(regs, 14)) return; /* diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 6168c0a..e5ecb1e 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -36,6 +36,7 @@ #include #include #include +#include #ifdef CONFIG_KPROBES #include @@ -212,6 +213,21 @@ static inline struct kprobe *kprobe_running(void) return (__get_cpu_var(current_kprobe)); } +static inline int kprobe_handle_fault(struct pt_regs *regs, int trapnr) +{ + int ret = 0; + + /* kprobe_running() needs smp_processor_id() */ + if (!user_mode(regs)) { + preempt_disable(); + if (kprobe_running() && kprobe_fault_handler(regs, trapnr)) + ret = 1; + preempt_enable(); + } + + return ret; +} + static inline void reset_current_kprobe(void) { __get_cpu_var(current_kprobe) = NULL; @@ -247,6 +263,10 @@ static inline struct kprobe *kprobe_running(void) { return NULL; } +static inline int kprobe_handle_fault(struct pt_regs *regs, int trapnr) +{ + return 0; +} static inline int register_kprobe(struct kprobe *p) { return -ENOSYS; -- 1.5.4.rc4.1142.gf5a97 -- 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/