Similar notify_page_fault() definitions are being used by architectures duplicating much of the same code. This attempts to unify them into a single implementation, generalize it and then move it to a common place. kprobes_built_in() can detect CONFIG_KPROBES, hence notify_page_fault() need not be wrapped again within CONFIG_KPROBES. Trap number argument can now contain upto an 'unsigned int' accommodating all possible platforms. Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Cc: linux-ia64@xxxxxxxxxxxxxxx Cc: linuxppc-dev@xxxxxxxxxxxxxxxx Cc: linux-s390@xxxxxxxxxxxxxxx Cc: linux-sh@xxxxxxxxxxxxxxx Cc: sparclinux@xxxxxxxxxxxxxxx Cc: x86@xxxxxxxxxx Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxx> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> --- Testing: - Build and boot tested on arm64 and x86 - Build tested on some other archs (arm, sparc64, alpha, powerpc etc) Changes in RFC V2: - Changed generic notify_page_fault() per Mathew Wilcox - Changed x86 to use new generic notify_page_fault() - s/must not/need not/ in commit message per Matthew Wilcox Changes in RFC V1: (https://patchwork.kernel.org/patch/10968273/) arch/arm/mm/fault.c | 22 ---------------------- arch/arm64/mm/fault.c | 22 ---------------------- arch/ia64/mm/fault.c | 22 ---------------------- arch/powerpc/mm/fault.c | 23 ++--------------------- arch/s390/mm/fault.c | 16 +--------------- arch/sh/mm/fault.c | 14 -------------- arch/sparc/mm/fault_64.c | 16 +--------------- arch/x86/mm/fault.c | 21 ++------------------- include/linux/mm.h | 1 + mm/memory.c | 16 ++++++++++++++++ 10 files changed, 23 insertions(+), 150 deletions(-) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 58f69fa..1bc3b18 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -30,28 +30,6 @@ #ifdef CONFIG_MMU -#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'. diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index a30818e..152f1f1 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -70,28 +70,6 @@ static inline const struct fault_info *esr_to_debug_fault_info(unsigned int esr) return debug_fault_info + DBG_ESR_EVT(esr); } -#ifdef CONFIG_KPROBES -static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) -{ - int ret = 0; - - /* kprobe_running() needs smp_processor_id() */ - if (!user_mode(regs)) { - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, esr)) - ret = 1; - preempt_enable(); - } - - return ret; -} -#else -static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) -{ - return 0; -} -#endif - static void data_abort_decode(unsigned int esr) { pr_alert("Data abort info:\n"); diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c index 5baeb02..64283d2 100644 --- a/arch/ia64/mm/fault.c +++ b/arch/ia64/mm/fault.c @@ -21,28 +21,6 @@ extern int 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() && kprobe_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. diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index b5d3578..5a0d71f 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -46,26 +46,6 @@ #include <asm/debug.h> #include <asm/kup.h> -static inline bool notify_page_fault(struct pt_regs *regs) -{ - bool ret = false; - -#ifdef CONFIG_KPROBES - /* kprobe_running() needs smp_processor_id() */ - if (!user_mode(regs)) { - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, 11)) - ret = true; - preempt_enable(); - } -#endif /* CONFIG_KPROBES */ - - if (unlikely(debugger_fault_handler(regs))) - ret = true; - - return ret; -} - /* * Check whether the instruction inst is a store using * an update addressing form which will update r1. @@ -466,8 +446,9 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, int is_write = page_fault_is_write(error_code); vm_fault_t fault, major = 0; bool must_retry = false; + int kprobe_fault = notify_page_fault(regs, 11); - if (notify_page_fault(regs)) + if (unlikely(debugger_fault_handler(regs) || kprobe_fault)) return 0; if (unlikely(page_fault_is_bad(error_code))) { diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index c220399..d317263 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -67,20 +67,6 @@ static int __init fault_init(void) } early_initcall(fault_init); -static inline int notify_page_fault(struct pt_regs *regs) -{ - int ret = 0; - - /* kprobe_running() needs smp_processor_id() */ - if (kprobes_built_in() && !user_mode(regs)) { - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, 14)) - ret = 1; - preempt_enable(); - } - return ret; -} - /* * Find out which address space caused the exception. * Access register mode is impossible, ignore space == 3. @@ -409,7 +395,7 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) */ clear_pt_regs_flag(regs, PIF_PER_TRAP); - if (notify_page_fault(regs)) + if (notify_page_fault(regs, 14)) return 0; mm = tsk->mm; diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c index 6defd2c6..94bdfcb 100644 --- a/arch/sh/mm/fault.c +++ b/arch/sh/mm/fault.c @@ -24,20 +24,6 @@ #include <asm/tlbflush.h> #include <asm/traps.h> -static inline int notify_page_fault(struct pt_regs *regs, int trap) -{ - int ret = 0; - - if (kprobes_built_in() && !user_mode(regs)) { - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, trap)) - ret = 1; - preempt_enable(); - } - - return ret; -} - static void force_sig_info_fault(int si_signo, int si_code, unsigned long address, struct task_struct *tsk) diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c index 8f8a604..e5557a1 100644 --- a/arch/sparc/mm/fault_64.c +++ b/arch/sparc/mm/fault_64.c @@ -38,20 +38,6 @@ int show_unhandled_signals = 1; -static inline __kprobes int notify_page_fault(struct pt_regs *regs) -{ - int ret = 0; - - /* kprobe_running() needs smp_processor_id() */ - if (kprobes_built_in() && !user_mode(regs)) { - preempt_disable(); - if (kprobe_running() && kprobe_fault_handler(regs, 0)) - ret = 1; - preempt_enable(); - } - return ret; -} - static void __kprobes unhandled_fault(unsigned long address, struct task_struct *tsk, struct pt_regs *regs) @@ -285,7 +271,7 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs) fault_code = get_thread_fault_code(); - if (notify_page_fault(regs)) + if (notify_page_fault(regs, 0)) goto exit_exception; si_code = SEGV_MAPERR; diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 46df4c6..1790859 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -46,23 +46,6 @@ kmmio_fault(struct pt_regs *regs, unsigned long addr) return 0; } -static nokprobe_inline int kprobes_fault(struct pt_regs *regs) -{ - if (!kprobes_built_in()) - return 0; - if (user_mode(regs)) - return 0; - /* - * To be potentially processing a kprobe fault and to be allowed to call - * kprobe_running(), we have to be non-preemptible. - */ - if (preemptible()) - return 0; - if (!kprobe_running()) - return 0; - return kprobe_fault_handler(regs, X86_TRAP_PF); -} - /* * Prefetch quirks: * @@ -1280,7 +1263,7 @@ do_kern_addr_fault(struct pt_regs *regs, unsigned long hw_error_code, return; /* kprobes don't want to hook the spurious faults: */ - if (kprobes_fault(regs)) + if (notify_page_fault(regs, X86_TRAP_PF)) return; /* @@ -1311,7 +1294,7 @@ void do_user_addr_fault(struct pt_regs *regs, mm = tsk->mm; /* kprobes don't want to hook the spurious faults: */ - if (unlikely(kprobes_fault(regs))) + if (unlikely(notify_page_fault(regs, X86_TRAP_PF))) return; /* diff --git a/include/linux/mm.h b/include/linux/mm.h index 0e8834a..c5a8dcf 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1778,6 +1778,7 @@ static inline int pte_devmap(pte_t pte) } #endif +int notify_page_fault(struct pt_regs *regs, unsigned int trap); int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot); extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr, diff --git a/mm/memory.c b/mm/memory.c index ddf20bd..b6bae8f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -52,6 +52,7 @@ #include <linux/pagemap.h> #include <linux/memremap.h> #include <linux/ksm.h> +#include <linux/kprobes.h> #include <linux/rmap.h> #include <linux/export.h> #include <linux/delayacct.h> @@ -141,6 +142,21 @@ static int __init init_zero_pfn(void) core_initcall(init_zero_pfn); +int __kprobes notify_page_fault(struct pt_regs *regs, unsigned int trap) +{ + int ret = 0; + + /* + * To be potentially processing a kprobe fault and to be allowed + * to call kprobe_running(), we have to be non-preemptible. + */ + if (kprobes_built_in() && !preemptible() && !user_mode(regs)) { + if (kprobe_running() && kprobe_fault_handler(regs, trap)) + ret = 1; + } + return ret; +} + #if defined(SPLIT_RSS_COUNTING) void sync_mm_rss(struct mm_struct *mm) -- 2.7.4
