diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/Kconfig | 12 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes-common.h | 11 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes-ftrace.c | 93 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes.c | 70 |
6 files changed, 120 insertions, 68 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 7f8f281f2585..97fb7d0365d1 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -76,6 +76,15 @@ config OPTPROBES depends on KPROBES && HAVE_OPTPROBES depends on !PREEMPT +config KPROBES_ON_FTRACE + def_bool y + depends on KPROBES && HAVE_KPROBES_ON_FTRACE + depends on DYNAMIC_FTRACE_WITH_REGS + help + If function tracer is enabled and the arch supports full + passing of pt_regs to function tracing, then kprobes can + optimize on top of function tracing. + config UPROBES bool "Transparent user-space probes (EXPERIMENTAL)" depends on UPROBE_EVENT && PERF_EVENTS @@ -158,6 +167,9 @@ config HAVE_KRETPROBES config HAVE_OPTPROBES bool +config HAVE_KPROBES_ON_FTRACE + bool + config HAVE_NMI_WATCHDOG bool # diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 996ccecc694c..be8b2b3ab979 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -40,6 +40,7 @@ config X86 select HAVE_DMA_CONTIGUOUS if !SWIOTLB select HAVE_KRETPROBES select HAVE_OPTPROBES + select HAVE_KPROBES_ON_FTRACE select HAVE_FTRACE_MCOUNT_RECORD select HAVE_FENTRY if X86_64 select HAVE_C_RECORDMCOUNT diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 34e923a53762..cc5d31f8830c 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -67,6 +67,7 @@ obj-$(CONFIG_KEXEC) += relocate_kernel_$(BITS).o crash.o obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_OPTPROBES) += kprobes-opt.o +obj-$(CONFIG_KPROBES_ON_FTRACE) += kprobes-ftrace.o obj-$(CONFIG_MODULES) += module.o obj-$(CONFIG_DOUBLEFAULT) += doublefault_32.o obj-$(CONFIG_KGDB) += kgdb.o diff --git a/arch/x86/kernel/kprobes-common.h b/arch/x86/kernel/kprobes-common.h index 3230b68ef29a..2e9d4b5af036 100644 --- a/arch/x86/kernel/kprobes-common.h +++ b/arch/x86/kernel/kprobes-common.h @@ -99,4 +99,15 @@ static inline unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsig return addr; } #endif + +#ifdef CONFIG_KPROBES_ON_FTRACE +extern int skip_singlestep(struct kprobe *p, struct pt_regs *regs, + struct kprobe_ctlblk *kcb); +#else +static inline int skip_singlestep(struct kprobe *p, struct pt_regs *regs, + struct kprobe_ctlblk *kcb) +{ + return 0; +} +#endif #endif diff --git a/arch/x86/kernel/kprobes-ftrace.c b/arch/x86/kernel/kprobes-ftrace.c new file mode 100644 index 000000000000..70a81c7aa0a7 --- /dev/null +++ b/arch/x86/kernel/kprobes-ftrace.c @@ -0,0 +1,93 @@ +/* + * Dynamic Ftrace based Kprobes Optimization + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright (C) Hitachi Ltd., 2012 + */ +#include <linux/kprobes.h> +#include <linux/ptrace.h> +#include <linux/hardirq.h> +#include <linux/preempt.h> +#include <linux/ftrace.h> + +#include "kprobes-common.h" + +static int __skip_singlestep(struct kprobe *p, struct pt_regs *regs, + struct kprobe_ctlblk *kcb) +{ + /* + * Emulate singlestep (and also recover regs->ip) + * as if there is a 5byte nop + */ + regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE; + if (unlikely(p->post_handler)) { + kcb->kprobe_status = KPROBE_HIT_SSDONE; + p->post_handler(p, regs, 0); + } + __this_cpu_write(current_kprobe, NULL); + return 1; +} + +int __kprobes skip_singlestep(struct kprobe *p, struct pt_regs *regs, + struct kprobe_ctlblk *kcb) +{ + if (kprobe_ftrace(p)) + return __skip_singlestep(p, regs, kcb); + else + return 0; +} + +/* Ftrace callback handler for kprobes */ +void __kprobes kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *ops, struct pt_regs *regs) +{ + struct kprobe *p; + struct kprobe_ctlblk *kcb; + unsigned long flags; + + /* Disable irq for emulating a breakpoint and avoiding preempt */ + local_irq_save(flags); + + p = get_kprobe((kprobe_opcode_t *)ip); + if (unlikely(!p) || kprobe_disabled(p)) + goto end; + + kcb = get_kprobe_ctlblk(); + if (kprobe_running()) { + kprobes_inc_nmissed_count(p); + } else { + /* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */ + regs->ip = ip + sizeof(kprobe_opcode_t); + + __this_cpu_write(current_kprobe, p); + kcb->kprobe_status = KPROBE_HIT_ACTIVE; + if (!p->pre_handler || !p->pre_handler(p, regs)) + __skip_singlestep(p, regs, kcb); + /* + * If pre_handler returns !0, it sets regs->ip and + * resets current kprobe. + */ + } +end: + local_irq_restore(flags); +} + +int __kprobes arch_prepare_kprobe_ftrace(struct kprobe *p) +{ + p->ainsn.insn = NULL; + p->ainsn.boostable = -1; + return 0; +} diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c index 57916c0d3cf6..18114bfb10f3 100644 --- a/arch/x86/kernel/kprobes.c +++ b/arch/x86/kernel/kprobes.c @@ -541,23 +541,6 @@ reenter_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb return 1; } -#ifdef KPROBES_CAN_USE_FTRACE -static void __kprobes skip_singlestep(struct kprobe *p, struct pt_regs *regs, - struct kprobe_ctlblk *kcb) -{ - /* - * Emulate singlestep (and also recover regs->ip) - * as if there is a 5byte nop - */ - regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE; - if (unlikely(p->post_handler)) { - kcb->kprobe_status = KPROBE_HIT_SSDONE; - p->post_handler(p, regs, 0); - } - __this_cpu_write(current_kprobe, NULL); -} -#endif - /* * Interrupts are disabled on entry as trap3 is an interrupt gate and they * remain disabled throughout this function. @@ -616,13 +599,8 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) } else if (kprobe_running()) { p = __this_cpu_read(current_kprobe); if (p->break_handler && p->break_handler(p, regs)) { -#ifdef KPROBES_CAN_USE_FTRACE - if (kprobe_ftrace(p)) { - skip_singlestep(p, regs, kcb); - return 1; - } -#endif - setup_singlestep(p, regs, kcb, 0); + if (!skip_singlestep(p, regs, kcb)) + setup_singlestep(p, regs, kcb, 0); return 1; } } /* else: not a kprobe fault; let the kernel handle it */ @@ -1075,50 +1053,6 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) return 0; } -#ifdef KPROBES_CAN_USE_FTRACE -/* Ftrace callback handler for kprobes */ -void __kprobes kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ops, struct pt_regs *regs) -{ - struct kprobe *p; - struct kprobe_ctlblk *kcb; - unsigned long flags; - - /* Disable irq for emulating a breakpoint and avoiding preempt */ - local_irq_save(flags); - - p = get_kprobe((kprobe_opcode_t *)ip); - if (unlikely(!p) || kprobe_disabled(p)) - goto end; - - kcb = get_kprobe_ctlblk(); - if (kprobe_running()) { - kprobes_inc_nmissed_count(p); - } else { - /* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */ - regs->ip = ip + sizeof(kprobe_opcode_t); - - __this_cpu_write(current_kprobe, p); - kcb->kprobe_status = KPROBE_HIT_ACTIVE; - if (!p->pre_handler || !p->pre_handler(p, regs)) - skip_singlestep(p, regs, kcb); - /* - * If pre_handler returns !0, it sets regs->ip and - * resets current kprobe. - */ - } -end: - local_irq_restore(flags); -} - -int __kprobes arch_prepare_kprobe_ftrace(struct kprobe *p) -{ - p->ainsn.insn = NULL; - p->ainsn.boostable = -1; - return 0; -} -#endif - int __init arch_init_kprobes(void) { return arch_init_optprobes(); |