cregit-Linux how code gets into the kernel

Release 4.10 kernel/kprobes.c

Directory: kernel
/*
 *  Kernel Probes (KProbes)
 *  kernel/kprobes.c
 *
 * 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) IBM Corporation, 2002, 2004
 *
 * 2002-Oct     Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
 *              Probes initial implementation (includes suggestions from
 *              Rusty Russell).
 * 2004-Aug     Updated by Prasanna S Panchamukhi <prasanna@in.ibm.com> with
 *              hlists and exceptions notifier as suggested by Andi Kleen.
 * 2004-July    Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
 *              interface to access function arguments.
 * 2004-Sep     Prasanna S Panchamukhi <prasanna@in.ibm.com> Changed Kprobes
 *              exceptions notifier to be first on the priority list.
 * 2005-May     Hien Nguyen <hien@us.ibm.com>, Jim Keniston
 *              <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
 *              <prasanna@in.ibm.com> added function-return probes.
 */
#include <linux/kprobes.h>
#include <linux/hash.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/stddef.h>
#include <linux/export.h>
#include <linux/moduleloader.h>
#include <linux/kallsyms.h>
#include <linux/freezer.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/sysctl.h>
#include <linux/kdebug.h>
#include <linux/memory.h>
#include <linux/ftrace.h>
#include <linux/cpu.h>
#include <linux/jump_label.h>

#include <asm/sections.h>
#include <asm/cacheflush.h>
#include <asm/errno.h>
#include <linux/uaccess.h>


#define KPROBE_HASH_BITS 6

#define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS)


/*
 * Some oddball architectures like 64bit powerpc have function descriptors
 * so this must be overridable.
 */
#ifndef kprobe_lookup_name

#define kprobe_lookup_name(name, addr) \
	addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name)))
#endif


static int kprobes_initialized;

static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];

static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];

/* NOTE: change this value only with kprobe_mutex held */

static bool kprobes_all_disarmed;

/* This protects kprobe_table and optimizing_list */
static DEFINE_MUTEX(kprobe_mutex);
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
static struct {
	
raw_spinlock_t lock ____cacheline_aligned_in_smp;
} 
kretprobe_table_locks[KPROBE_TABLE_SIZE];


static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) { return &(kretprobe_table_locks[hash].lock); }

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srinivasa d ssrinivasa d s2195.45%150.00%
thomas gleixnerthomas gleixner14.55%150.00%
Total22100.00%2100.00%

/* Blacklist -- list of struct kprobe_blacklist_entry */ static LIST_HEAD(kprobe_blacklist); #ifdef __ARCH_WANT_KPROBES_INSN_SLOT /* * kprobe->ainsn.insn points to the copy of the instruction to be * single-stepped. x86_64, POWER4 and above have no-exec support and * stepping on the instruction on a vmalloced/kmalloced/data page * is a recipe for disaster */ struct kprobe_insn_page { struct list_head list; kprobe_opcode_t *insns; /* Page of instruction slots */ struct kprobe_insn_cache *cache; int nused; int ngarbage; char slot_used[]; }; #define KPROBE_INSN_PAGE_SIZE(slots) \ (offsetof(struct kprobe_insn_page, slot_used) + \ (sizeof(char) * (slots)))
static int slots_per_page(struct kprobe_insn_cache *c) { return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t)); }

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masami hiramatsumasami hiramatsu25100.00%1100.00%
Total25100.00%1100.00%

enum kprobe_slot_state { SLOT_CLEAN = 0, SLOT_DIRTY = 1, SLOT_USED = 2, };
static void *alloc_insn_page(void) { return module_alloc(PAGE_SIZE); }

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heiko carstensheiko carstens15100.00%1100.00%
Total15100.00%1100.00%


static void free_insn_page(void *page) { module_memfree(page); }

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heiko carstensheiko carstens1493.33%150.00%
rusty russellrusty russell16.67%150.00%
Total15100.00%2100.00%

struct kprobe_insn_cache kprobe_insn_slots = { .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex), .alloc = alloc_insn_page, .free = free_insn_page, .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), .insn_size = MAX_INSN_SIZE, .nr_garbage = 0, }; static int collect_garbage_slots(struct kprobe_insn_cache *c); /** * __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. */
kprobe_opcode_t *__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)) { int i; for (i = 0; i < slots_per_page(c); i++) { if (kip->slot_used[i] == SLOT_CLEAN) { kip->slot_used[i] = SLOT_USED; kip->nused++; slot = kip->insns + (i * c->insn_size); goto out; } } /* kip->nused is broken. Fix it. */ kip->nused = slots_per_page(c); WARN_ON(1); } } /* If there are any garbage slots, collect it and try again. */ if (c->nr_garbage && collect_garbage_slots(c) == 0) goto retry; /* All out of space. Need to allocate a new page. */ kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL); if (!kip) goto out; /* * Use module_alloc so this page is within +/- 2GB of where the * kernel image and loaded module images reside. This is required * so x86_64 can correctly handle the %rip-relative fixups. */ kip->insns = c->alloc(); if (!kip->insns) { kfree(kip); goto out; } INIT_LIST_HEAD(&kip->list); memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c)); kip->slot_used[0] = SLOT_USED; kip->nused = 1; kip->ngarbage = 0; kip->cache = c; list_add(&kip->list, &c->pages); slot = kip->insns; out: mutex_unlock(&c->mutex); return slot; }

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ananth n. mavinakayanahalliananth n. mavinakayanahalli14450.70%111.11%
masami hiramatsumasami hiramatsu9332.75%555.56%
heiko carstensheiko carstens4415.49%222.22%
christoph hellwigchristoph hellwig31.06%111.11%
Total284100.00%9100.00%

/* Return 1 if all garbages are collected, otherwise 0. */
static int collect_one_slot(struct kprobe_insn_page *kip, int idx) { kip->slot_used[idx] = SLOT_CLEAN; kip->nused--; if (kip->nused == 0) { /* * Page is no longer in use. Free it unless * it's the last one. We keep the last one * so as not to have to set it up again the * next time somebody inserts a probe. */ if (!list_is_singular(&kip->list)) { list_del(&kip->list); kip->cache->free(kip->insns); kfree(kip); } return 1; } return 0; }

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masami hiramatsumasami hiramatsu7793.90%480.00%
heiko carstensheiko carstens56.10%120.00%
Total82100.00%5100.00%


static int collect_garbage_slots(struct kprobe_insn_cache *c) { struct kprobe_insn_page *kip, *next; /* Ensure no-one is interrupted on the garbages */ synchronize_sched(); list_for_each_entry_safe(kip, next, &c->pages, list) { int i; if (kip->ngarbage == 0) continue; kip->ngarbage = 0; /* we will collect all garbages */ for (i = 0; i < slots_per_page(c); i++) { if (kip->slot_used[i] == SLOT_DIRTY && collect_one_slot(kip, i)) break; } } c->nr_garbage = 0; return 0; }

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masami hiramatsumasami hiramatsu9797.00%685.71%
christoph hellwigchristoph hellwig33.00%114.29%
Total100100.00%7100.00%


void __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)); if (idx >= 0 && idx < slots_per_page(c)) { WARN_ON(kip->slot_used[idx] != SLOT_USED); if (dirty) { kip->slot_used[idx] = SLOT_DIRTY; kip->ngarbage++; if (++c->nr_garbage > slots_per_page(c)) collect_garbage_slots(c); } else collect_one_slot(kip, idx); goto out; } } /* Could not free this slot. */ WARN_ON(1); out: mutex_unlock(&c->mutex); }

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masami hiramatsumasami hiramatsu9660.38%666.67%
ananth n. mavinakayanahalliananth n. mavinakayanahalli4427.67%111.11%
heiko carstensheiko carstens1610.06%111.11%
christoph hellwigchristoph hellwig31.89%111.11%
Total159100.00%9100.00%

#ifdef CONFIG_OPTPROBES /* For optimized_kprobe buffer */ struct kprobe_insn_cache kprobe_optinsn_slots = { .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex), .alloc = alloc_insn_page, .free = free_insn_page, .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), /* .insn_size is initialized later */ .nr_garbage = 0, }; #endif #endif /* We have preemption disabled.. so it is safe to use __ versions */
static inline void set_kprobe_instance(struct kprobe *kp) { __this_cpu_write(kprobe_instance, kp); }

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ananth n. mavinakayanahalliananth n. mavinakayanahalli1684.21%150.00%
christoph lameterchristoph lameter315.79%150.00%
Total19100.00%2100.00%


static inline void reset_kprobe_instance(void) { __this_cpu_write(kprobe_instance, NULL); }

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ananth n. mavinakayanahalliananth n. mavinakayanahalli1381.25%150.00%
christoph lameterchristoph lameter318.75%150.00%
Total16100.00%2100.00%

/* * This routine is called either: * - under the kprobe_mutex - during kprobe_[un]register() * OR * - with preemption disabled - from arch/xxx/kernel/kprobes.c */
struct kprobe *get_kprobe(void *addr) { struct hlist_head *head; struct kprobe *p; head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; hlist_for_each_entry_rcu(p, head, hlist) { if (p->addr == addr) return p; } return NULL; }

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ananth n. mavinakayanahalliananth n. mavinakayanahalli58100.00%2100.00%
Total58100.00%2100.00%

NOKPROBE_SYMBOL(get_kprobe); static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); /* Return true if the kprobe is an aggregator */
static inline int kprobe_aggrprobe(struct kprobe *p) { return p->pre_handler == aggr_pre_handler; }

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masami hiramatsumasami hiramatsu19100.00%2100.00%
Total19100.00%2100.00%

/* Return true(!0) if the kprobe is unused */
static inline int kprobe_unused(struct kprobe *p) { return kprobe_aggrprobe(p) && kprobe_disabled(p) && list_empty(&p->list); }

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masami hiramatsumasami hiramatsu31100.00%1100.00%
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/* * Keep all fields in the kprobe consistent */
static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p) { memcpy(&p->opcode, &ap->opcode, sizeof(kprobe_opcode_t)); memcpy(&p->ainsn, &ap->ainsn, sizeof(struct arch_specific_insn)); }

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masami hiramatsumasami hiramatsu54100.00%3100.00%
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#ifdef CONFIG_OPTPROBES /* NOTE: change this value only with kprobe_mutex held */ static bool kprobes_allow_optimization; /* * Call all pre_handler on the list, but ignores its return value. * This must be called from arch-dep optimized caller. */
void opt_pre_handler(struct kprobe *p, struct pt_regs *regs) { struct kprobe *kp; list_for_each_entry_rcu(kp, &p->list, list) { if (kp->pre_handler && likely(!kprobe_disabled(kp))) { set_kprobe_instance(kp); kp->pre_handler(kp, regs); } reset_kprobe_instance(); } }

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ananth n. mavinakayanahalliananth n. mavinakayanahalli5179.69%342.86%
masami hiramatsumasami hiramatsu1218.75%342.86%
prasanna s panchamukhiprasanna s panchamukhi11.56%114.29%
Total64100.00%7100.00%

NOKPROBE_SYMBOL(opt_pre_handler); /* Free optimized instructions and optimized_kprobe */
static void free_aggr_kprobe(struct kprobe *p) { struct optimized_kprobe *op; op = container_of(p, struct optimized_kprobe, kp); arch_remove_optimized_kprobe(op); arch_remove_kprobe(p); kfree(op); }

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masami hiramatsumasami hiramatsu43100.00%1100.00%
Total43100.00%1100.00%

/* Return true(!0) if the kprobe is ready for optimization. */
static inline int kprobe_optready(struct kprobe *p) { struct optimized_kprobe *op; if (kprobe_aggrprobe(p)) { op = container_of(p, struct optimized_kprobe, kp); return arch_prepared_optinsn(&op->optinsn); } return 0; }

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masami hiramatsumasami hiramatsu4182.00%133.33%
ananth n. mavinakayanahalliananth n. mavinakayanahalli816.00%133.33%
hien nguyenhien nguyen12.00%133.33%
Total50100.00%3100.00%

/* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */
static inline int kprobe_disarmed(struct kprobe *p) { struct optimized_kprobe *op; /* If kprobe is not aggr/opt probe, just return kprobe is disabled */ if (!kprobe_aggrprobe(p)) return kprobe_disabled(p); op = container_of(p, struct optimized_kprobe, kp); return kprobe_disabled(p) && list_empty(&op->list); }

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masami hiramatsumasami hiramatsu58100.00%1100.00%
Total58100.00%1100.00%

/* Return true(!0) if the probe is queued on (un)optimizing lists */
static int kprobe_queued(struct kprobe *p) { struct optimized_kprobe *op; if (kprobe_aggrprobe(p)) { op = container_of(p, struct optimized_kprobe, kp); if (!list_empty(&op->list)) return 1; } return 0; }

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masami hiramatsumasami hiramatsu54100.00%1100.00%
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/* * Return an optimized kprobe whose optimizing code replaces * instructions including addr (exclude breakpoint). */
static struct kprobe *get_optimized_kprobe(unsigned long addr) { int i; struct kprobe *p = NULL; struct optimized_kprobe *op; /* Don't check i == 0, since that is a breakpoint case. */ for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++) p = get_kprobe((void *)(addr - i)); if (p && kprobe_optready(p)) { op = container_of(p, struct optimized_kprobe, kp); if (arch_within_optimized_kprobe(op, addr)) return p; } return NULL; }

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masami hiramatsumasami hiramatsu9698.97%150.00%
namhyung kimnamhyung kim11.03%150.00%
Total97100.00%2100.00%

/* Optimization staging list, protected by kprobe_mutex */ static LIST_HEAD(optimizing_list); static LIST_HEAD(unoptimizing_list); static LIST_HEAD(freeing_list); static void kprobe_optimizer(struct work_struct *work); static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); #define OPTIMIZE_DELAY 5 /* * Optimize (replace a breakpoint with a jump) kprobes listed on * optimizing_list. */
static void do_optimize_kprobes(void) { /* Optimization never be done when disarmed */ if (kprobes_all_disarmed || !kprobes_allow_optimization || list_empty(&optimizing_list)) return; /* * The optimization/unoptimization refers online_cpus via * stop_machine() and cpu-hotplug modifies online_cpus. * And same time, text_mutex will be held in cpu-hotplug and here. * This combination can cause a deadlock (cpu-hotplug try to lock * text_mutex but stop_machine can not be done because online_cpus * has been changed) * To avoid this deadlock, we need to call get_online_cpus() * for preventing cpu-hotplug outside of text_mutex locking. */ get_online_cpus(); mutex_lock(&text_mutex); arch_optimize_kprobes(&optimizing_list); mutex_unlock(&text_mutex); put_online_cpus(); }

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masami hiramatsumasami hiramatsu48100.00%4100.00%
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/* * Unoptimize (replace a jump with a breakpoint and remove the breakpoint * if need) kprobes listed on unoptimizing_list. */
static void do_unoptimize_kprobes(void) { struct optimized_kprobe *op, *tmp; /* Unoptimization must be done anytime */ if (list_empty(&unoptimizing_list)) return; /* Ditto to do_optimize_kprobes */ get_online_cpus(); mutex_lock(&text_mutex); arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list); /* Loop free_list for disarming */ list_for_each_entry_safe(op, tmp, &freeing_list, list) { /* Disarm probes if marked disabled */ if (kprobe_disabled(&op->kp)) arch_disarm_kprobe(&op->kp); if (kprobe_unused(&op->kp)) { /* * Remove unused probes from hash list. After waiting * for synchronization, these probes are reclaimed. * (reclaiming is done by do_free_cleaned_kprobes.) */ hlist_del_rcu(&op->kp.hlist); } else list_del_init(&op->list); } mutex_unlock(&text_mutex); put_online_cpus(); }

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masami hiramatsumasami hiramatsu118100.00%4100.00%
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/* Reclaim all kprobes on the free_list */
static void do_free_cleaned_kprobes(void) { struct optimized_kprobe *op, *tmp; list_for_each_entry_safe(op, tmp, &freeing_list, list) { BUG_ON(!kprobe_unused(&op->kp)); list_del_init(&op->list); free_aggr_kprobe(&op->kp); } }

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masami hiramatsumasami hiramatsu56100.00%3100.00%
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/* Start optimizer after OPTIMIZE_DELAY passed */
static void kick_kprobe_optimizer(void) { schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); }

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masami hiramatsumasami hiramatsu16100.00%1100.00%
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/* Kprobe jump optimizer */
static void kprobe_optimizer(struct work_struct *work) { mutex_lock(&kprobe_mutex); /* Lock modules while optimizing kprobes */ mutex_lock(&module_mutex); /* * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed) * kprobes before waiting for quiesence period. */ do_unoptimize_kprobes(); /* * Step 2: Wait for quiesence period to ensure all running interrupts * are done. Because optprobe may modify multiple instructions * there is a chance that Nth instruction is interrupted. In that * case, running interrupt can return to 2nd-Nth byte of jump * instruction. This wait is for avoiding it. */ synchronize_sched(); /* Step 3: Optimize kprobes after quiesence period */ do_optimize_kprobes(); /* Step 4: Free cleaned kprobes after quiesence period */ do_free_cleaned_kprobes(); mutex_unlock(&module_mutex); mutex_unlock(&kprobe_mutex); /* Step 5: Kick optimizer again if needed */ if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) kick_kprobe_optimizer(); }

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masami hiramatsumasami hiramatsu6793.06%685.71%
steven rostedtsteven rostedt56.94%114.29%
Total72100.00%7100.00%

/* Wait for completing optimization and unoptimization */
static void wait_for_kprobe_optimizer(void) { mutex_lock(&kprobe_mutex); while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) { mutex_unlock(&kprobe_mutex); /* this will also make optimizing_work execute immmediately */ flush_delayed_work(&optimizing_work); /* @optimizing_work might not have been queued yet, relax */ cpu_relax(); mutex_lock(&kprobe_mutex); } mutex_unlock(&kprobe_mutex); }

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tejun heotejun heo4472.13%133.33%
masami hiramatsumasami hiramatsu1727.87%266.67%
Total61100.00%3100.00%

/* Optimize kprobe if p is ready to be optimized */
static void optimize_kprobe(struct kprobe *p) { struct optimized_kprobe *op; /* Check if the kprobe is disabled or not ready for optimization. */ if (!kprobe_optready(p) || !kprobes_allow_optimization || (kprobe_disabled(p) || kprobes_all_disarmed)) return; /* Both of break_handler and post_handler are not supported. */ if (p->break_handler || p->post_handler) return; op = container_of(p, struct optimized_kprobe, kp); /* Check there is no other kprobes at the optimized instructions */ if (arch_check_optimized_kprobe(op) < 0) return; /* Check if it is already optimized. */ if (op->kp.flags & KPROBE_FLAG_OPTIMIZED) return; op->kp.flags |= KPROBE_FLAG_OPTIMIZED; if (!list_empty(&op->list)) /* This is under unoptimizing. Just dequeue the probe */ list_del_init(&op->list); else { list_add(&op->list, &optimizing_list); kick_kprobe_optimizer(); } }

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masami hiramatsumasami hiramatsu130100.00%3100.00%
Total130100.00%3100.00%

/* Short cut to direct unoptimizing */
static void force_unoptimize_kprobe(struct optimized_kprobe *op) { get_online_cpus(); arch_unoptimize_kprobe(op); put_online_cpus(); if (kprobe_disabled(&op->kp)) arch_disarm_kprobe(&op->kp); }

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masami hiramatsumasami hiramatsu40100.00%2100.00%
Total40100.00%2100.00%

/* Unoptimize a kprobe if p is optimized */
static void unoptimize_kprobe(struct kprobe *p, bool force) { struct optimized_kprobe *op; if (!kprobe_aggrprobe(p) || kprobe_disarmed(p)) return; /* This is not an optprobe nor optimized */ op = container_of(p, struct optimized_kprobe, kp); if (!kprobe_optimized(p)) { /* Unoptimized or unoptimizing case */ if (force && !list_empty(&op->list)) { /* * Only if this is unoptimizing kprobe and forced, * forcibly unoptimize it. (No need to unoptimize * unoptimized kprobe again :) */ list_del_init(&op->list); force_unoptimize_kprobe(op); } return; } op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; if (!list_empty(&op->list)) { /* Dequeue from the optimization queue */ list_del_init(&op->list); return; } /* Optimized kprobe case */ if (force) /* Forcibly update the code: this is a special case */ force_unoptimize_kprobe(op); else { list_add(&op->list, &unoptimizing_list); kick_kprobe_optimizer(); } }

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masami hiramatsumasami hiramatsu147100.00%2100.00%
Total147100.00%2100.00%

/* Cancel unoptimizing for reusing */
static void reuse_unused_kprobe(struct kprobe *ap) { struct optimized_kprobe *op; BUG_ON(!kprobe_unused(ap)); /* * Unused kprobe MUST be on the way of delayed unoptimizing (means * there is still a relative jump) and disabled. */ op = container_of(ap, struct optimized_kprobe, kp); if (unlikely(list_empty(&op->list))) printk(KERN_WARNING "Warning: found a stray unused " "aggrprobe@%p\n", ap->addr); /* Enable the probe again */ ap->flags &= ~KPROBE_FLAG_DISABLED; /* Optimize it again (remove from op->list) */ BUG_ON(!kprobe_optready(ap)); optimize_kprobe(ap); }

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masami hiramatsumasami hiramatsu85100.00%1100.00%
Total85100.00%1100.00%

/* Remove optimized instructions */
static void kill_optimized_kprobe(struct kprobe *p) { struct optimized_kprobe *op; op = container_of(p, struct optimized_kprobe, kp); if (!list_empty(&op->list)) /* Dequeue from the (un)optimization queue */ list_del_init(&op->list); op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; if (kprobe_unused(p)) { /* Enqueue if it is unused */ list_add(&op->list, &freeing_list); /* * Remove unused probes from the hash list. After waiting * for synchronization, this probe is reclaimed. * (reclaiming is done by do_free_cleaned_kprobes().) */ hlist_del_rcu(&op->kp.hlist); } /* Don't touch the code, because it is already freed. */ arch_remove_optimized_kprobe(op); }

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masami hiramatsumasami hiramatsu95100.00%3100.00%
Total95100.00%3100.00%

/* Try to prepare optimized instructions */
static void prepare_optimized_kprobe(struct kprobe *p) { struct optimized_kprobe *op; op = container_of(p, struct optimized_kprobe, kp); arch_prepare_optimized_kprobe(op, p); }

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masami hiramatsumasami hiramatsu35100.00%2100.00%
Total35100.00%2100.00%

/* Allocate new optimized_kprobe and try to prepare optimized instructions */
static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) { struct optimized_kprobe *op; op = kzalloc(sizeof(struct optimized_kprobe), GFP_KERNEL); if (!op) return NULL; INIT_LIST_HEAD(&op->list); op->kp.addr = p->addr; arch_prepare_optimized_kprobe(op, p); return &op->kp; }

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masami hiramatsumasami hiramatsu70100.00%3100.00%
Total70100.00%3100.00%

static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); /* * Prepare an optimized_kprobe and optimize it * NOTE: p must be a normal registered kprobe */
static void try_to_optimize_kprobe(struct kprobe *p) { struct kprobe *ap; struct optimized_kprobe *op; /* Impossible to optimize ftrace-based kprobe */ if (kprobe_ftrace(p)) return; /* For preparing optimization, jump_label_text_reserved() is called */ jump_label_lock(); mutex_lock(&text_mutex); ap = alloc_aggr_kprobe(p); if (!ap) goto out; op = container_of(ap, struct optimized_kprobe, kp); if (!arch_prepared_optinsn(&op->optinsn)) { /* If failed to setup optimizing, fallback to kprobe */ arch_remove_optimized_kprobe(op); kfree(op); goto out; } init_aggr_kprobe(ap, p); optimize_kprobe(ap); /* This just kicks optimizer thread */ out: mutex_unlock(&text_mutex); jump_label_unlock(); }

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masami hiramatsumasami hiramatsu118100.00%4100.00%
Total118100.00%4100.00%

#ifdef CONFIG_SYSCTL
static void optimize_all_kprobes(void) { struct hlist_head *head; struct kprobe *p; unsigned int i; mutex_lock(&kprobe_mutex); /* If optimization is already allowed, just return */ if (kprobes_allow_optimization) goto out; kprobes_allow_optimization = true; for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, head, hlist) if (!kprobe_disabled(p)) optimize_kprobe(p); } printk(KERN_INFO "Kprobes globally optimized\n"); out: mutex_unlock(&kprobe_mutex); }

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masami hiramatsumasami hiramatsu98100.00%2100.00%
Total98100.00%2100.00%


static void unoptimize_all_kprobes(void) { struct hlist_head *head; struct kprobe *p; unsigned int i; mutex_lock(&kprobe_mutex); /* If optimization is already prohibited, just return */ if (!kprobes_allow_optimization) { mutex_unlock(&kprobe_mutex); return; } kprobes_allow_optimization = false; for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, head, hlist) { if (!kprobe_disabled(p)) unoptimize_kprobe(p, false); } } mutex_unlock(&kprobe_mutex); /* Wait for unoptimizing completion */ wait_for_kprobe_optimizer(); printk(KERN_INFO "Kprobes globally unoptimized\n"); }

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masami hiramatsumasami hiramatsu111100.00%3100.00%
Total111100.00%3100.00%

static DEFINE_MUTEX(kprobe_sysctl_mutex); int sysctl_kprobes_optimization;
int proc_kprobes_optimization_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) { int ret; mutex_lock(&kprobe_sysctl_mutex); sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0; ret = proc_dointvec_minmax(table, write, buffer, length, ppos); if (sysctl_kprobes_optimization) optimize_all_kprobes(); else unoptimize_all_kprobes(); mutex_unlock(&kprobe_sysctl_mutex); return ret; }

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masami hiramatsumasami hiramatsu78100.00%2100.00%
Total78100.00%2100.00%

#endif /* CONFIG_SYSCTL */ /* Put a breakpoint for a probe. Must be called with text_mutex locked */
static void __arm_kprobe(struct kprobe *p) { struct kprobe *_p; /* Check collision with other optimized kprobes */ _p = get_optimized_kprobe((unsigned long)p->addr); if (unlikely(_p)) /* Fallback to unoptimized kprobe */ unoptimize_kprobe(_p, true); arch_arm_kprobe(p); optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ }

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PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu56100.00%3100.00%
Total56100.00%3100.00%

/* Remove the breakpoint of a probe. Must be called with text_mutex locked */
static void __disarm_kprobe(struct kprobe *p, bool reopt) { struct kprobe *_p; /* Try to unoptimize */ unoptimize_kprobe(p, kprobes_all_disarmed); if (!kprobe_queued(p)) { arch_disarm_kprobe(p); /* If another kprobe was blocked, optimize it. */ _p = get_optimized_kprobe((unsigned long)p->addr); if (unlikely(_p) && reopt) optimize_kprobe(_p); } /* TODO: reoptimize others after unoptimized this probe */ }

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masami hiramatsumasami hiramatsu6997.18%375.00%
wang nanwang nan22.82%125.00%
Total71100.00%4100.00%

#else /* !CONFIG_OPTPROBES */ #define optimize_kprobe(p) do {} while (0) #define unoptimize_kprobe(p, f) do {} while (0) #define kill_optimized_kprobe(p) do {} while (0) #define prepare_optimized_kprobe(p) do {} while (0) #define try_to_optimize_kprobe(p) do {} while (0) #define __arm_kprobe(p) arch_arm_kprobe(p) #define __disarm_kprobe(p, o) arch_disarm_kprobe(p) #define kprobe_disarmed(p) kprobe_disabled(p) #define wait_for_kprobe_optimizer() do {} while (0) /* There should be no unused kprobes can be reused without optimization */
static void reuse_unused_kprobe(struct kprobe *ap) { printk(KERN_ERR "Error: There should be no unused kprobe here.\n"); BUG_ON(kprobe_unused(ap)); }

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masami hiramatsumasami hiramatsu25100.00%1100.00%
Total25100.00%1100.00%


static void free_aggr_kprobe(struct kprobe *p) { arch_remove_kprobe(p); kfree(p); }

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masami hiramatsumasami hiramatsu21100.00%2100.00%
Total21100.00%2100.00%


static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) { return kzalloc(sizeof(struct kprobe), GFP_KERNEL); }

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masami hiramatsumasami hiramatsu25100.00%2100.00%
Total25100.00%2100.00%

#endif /* CONFIG_OPTPROBES */ #ifdef CONFIG_KPROBES_ON_FTRACE static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { .func = kprobe_ftrace_handler, .flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY, }; static int kprobe_ftrace_enabled; /* Must ensure p->addr is really on ftrace */
static int prepare_kprobe(struct kprobe *p) { if (!kprobe_ftrace(p)) return arch_prepare_kprobe(p); return arch_prepare_kprobe_ftrace(p); }

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masami hiramatsumasami hiramatsu31100.00%1100.00%
Total31100.00%1100.00%

/* Caller must lock kprobe_mutex */
static void arm_kprobe_ftrace(struct kprobe *p) { int ret; ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, (unsigned long)p->addr, 0, 0); WARN(ret < 0, "Failed to arm kprobe-ftrace at %p (%d)\n", p->addr, ret); kprobe_ftrace_enabled++; if (kprobe_ftrace_enabled == 1) { ret = register_ftrace_function(&kprobe_ftrace_ops); WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret); } }

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masami hiramatsumasami hiramatsu79100.00%1100.00%
Total79100.00%1100.00%

/* Caller must lock kprobe_mutex */
static void disarm_kprobe_ftrace(struct kprobe *p) { int ret; kprobe_ftrace_enabled--; if (kprobe_ftrace_enabled == 0) { ret = unregister_ftrace_function(&kprobe_ftrace_ops); WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret); } ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, (unsigned long)p->addr, 1, 0); WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p->addr, ret); }

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PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu79100.00%1100.00%
Total79100.00%1100.00%

#else /* !CONFIG_KPROBES_ON_FTRACE */ #define prepare_kprobe(p) arch_prepare_kprobe(p) #define arm_kprobe_ftrace(p) do {} while (0) #define disarm_kprobe_ftrace(p) do {} while (0) #endif /* Arm a kprobe with text_mutex */
static void arm_kprobe(struct kprobe *kp) { if (unlikely(kprobe_ftrace(kp))) { arm_kprobe_ftrace(kp); return; } /* * Here, since __arm_kprobe() doesn't use stop_machine(), * this doesn't cause deadlock on text_mutex. So, we don't * need get_online_cpus(). */ mutex_lock(&text_mutex); __arm_kprobe(kp); mutex_unlock(&text_mutex); }

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masami hiramatsumasami hiramatsu47100.00%2100.00%
Total47100.00%2100.00%

/* Disarm a kprobe with text_mutex */
static void disarm_kprobe(struct kprobe *kp, bool reopt) { if (unlikely(kprobe_ftrace(kp))) { disarm_kprobe_ftrace(kp); return; } /* Ditto */ mutex_lock(&text_mutex); __disarm_kprobe(kp, reopt); mutex_unlock(&text_mutex); }

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masami hiramatsumasami hiramatsu52100.00%3100.00%
Total52100.00%3100.00%

/* * Aggregate handlers for multiple kprobes support - these handlers * take care of invoking the individual kprobe handlers on p->list */
static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) { struct kprobe *kp; list_for_each_entry_rcu(kp, &p->list, list) { if (kp->pre_handler && likely(!kprobe_disabled(kp))) { set_kprobe_instance(kp); if (kp->pre_handler(kp, regs)) return 1; } reset_kprobe_instance(); } return 0; }

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masami hiramatsumasami hiramatsu73100.00%1100.00%
Total73100.00%1100.00%

NOKPROBE_SYMBOL(aggr_pre_handler);
static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs, unsigned long flags) { struct kprobe *kp; list_for_each_entry_rcu(kp, &p->list, list) { if (kp->post_handler && likely(!kprobe_disabled(kp))) { set_kprobe_instance(kp); kp->post_handler(kp, regs, flags); reset_kprobe_instance(); } } }

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PersonTokensPropCommitsCommitProp
ananth n. mavinakayanahalliananth n. mavinakayanahalli4157.75%350.00%
masami hiramatsumasami hiramatsu3042.25%350.00%
Total71100.00%6100.00%

NOKPROBE_SYMBOL(aggr_post_handler);
static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, int trapnr) { struct kprobe *cur = __this_cpu_read(kprobe_instance); /* * if we faulted "during" the execution of a user specified * probe handler, invoke just that probe's fault handler */ if (cur && cur->fault_handler) { if (cur->fault_handler(cur, regs, trapnr)) return 1; } return 0; }

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PersonTokensPropCommitsCommitProp
ananth n. mavinakayanahalliananth n. mavinakayanahalli4372.88%250.00%
hien nguyenhien nguyen1525.42%125.00%
christoph lameterchristoph lameter11.69%125.00%
Total59100.00%4100.00%

NOKPROBE_SYMBOL(aggr_fault_handler);
static int aggr_break_handler(struct kprobe *p, struct pt_regs *regs) { struct kprobe *cur = __this_cpu_read(kprobe_instance); int ret = 0; if (cur && cur->break_handler) { if (cur->break_handler(cur, regs)) ret = 1; } reset_kprobe_instance(); return ret; }

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PersonTokensPropCommitsCommitProp
prasanna s panchamukhiprasanna s panchamukhi4369.35%133.33%
ananth n. mavinakayanahalliananth n. mavinakayanahalli1829.03%133.33%
christoph lameterchristoph lameter11.61%133.33%
Total62100.00%3100.00%

NOKPROBE_SYMBOL(aggr_break_handler); /* Walks the list and increments nmissed count for multiprobe case */
void kprobes_inc_nmissed_count(struct kprobe *p) { struct kprobe *kp; if (!kprobe_aggrprobe(p)) { p->nmissed++; } else { list_for_each_entry_rcu(kp, &p->list, list) kp->nmissed++; } return; }

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PersonTokensPropCommitsCommitProp
anil keshavamurthyanil keshavamurthy4391.49%150.00%
masami hiramatsumasami hiramatsu48.51%150.00%
Total47100.00%2100.00%

NOKPROBE_SYMBOL(kprobes_inc_nmissed_count);
void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head) { struct kretprobe *rp = ri->rp; /* remove rp inst off the rprobe_inst_table */ hlist_del(&ri->hlist); INIT_HLIST_NODE(&ri->hlist); if (likely(rp)) { raw_spin_lock(&rp->lock); hlist_add_head(&ri->hlist, &rp->free_instances); raw_spin_unlock(&rp->lock); } else /* Unregistering */ hlist_add_head(&ri->hlist, head); }

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PersonTokensPropCommitsCommitProp
hien nguyenhien nguyen4953.85%125.00%
srinivasa d ssrinivasa d s2931.87%125.00%
bibo maobibo mao1112.09%125.00%
thomas gleixnerthomas gleixner22.20%125.00%
Total91100.00%4100.00%

NOKPROBE_SYMBOL(recycle_rp_inst);
void kretprobe_hash_lock(struct task_struct *tsk, struct hlist_head **head, unsigned long *flags) __acquires (hlist_lock) { unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); raw_spinlock_t *hlist_lock; *head = &kretprobe_inst_table[hash]; hlist_lock = kretprobe_table_lock_ptr(hash); raw_spin_lock_irqsave(hlist_lock, *flags); }

Contributors

PersonTokensPropCommitsCommitProp
srinivasa d ssrinivasa d s4875.00%125.00%
hien nguyenhien nguyen1015.62%125.00%
namhyung kimnamhyung kim46.25%125.00%
thomas gleixnerthomas gleixner23.12%125.00%
Total64100.00%4100.00%

NOKPROBE_SYMBOL(kretprobe_hash_lock);
static void kretprobe_table_lock(unsigned long hash, unsigned long *flags) __acquires (hlist_lock) { raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); raw_spin_lock_irqsave(hlist_lock, *flags); }

Contributors

PersonTokensPropCommitsCommitProp
srinivasa d ssrinivasa d s2980.56%125.00%
namhyung kimnamhyung kim411.11%125.00%
thomas gleixnerthomas gleixner25.56%125.00%
adrian bunkadrian bunk12.78%125.00%
Total36100.00%4100.00%

NOKPROBE_SYMBOL(kretprobe_table_lock);
void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags) __releases (hlist_lock) { unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); raw_spinlock_t *hlist_lock; hlist_lock = kretprobe_table_lock_ptr(hash); raw_spin_unlock_irqrestore(hlist_lock, *flags); }

Contributors

PersonTokensPropCommitsCommitProp
srinivasa d ssrinivasa d s3775.51%125.00%
hien nguyenhien nguyen612.24%125.00%
namhyung kimnamhyung kim48.16%125.00%
thomas gleixnerthomas gleixner24.08%125.00%
Total49100.00%4100.00%

NOKPROBE_SYMBOL(kretprobe_hash_unlock);
static void kretprobe_table_unlock(unsigned long hash, unsigned long *flags) __releases (hlist_lock) { raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); raw_spin_unlock_irqrestore(hlist_lock, *flags); }

Contributors

PersonTokensPropCommitsCommitProp
srinivasa d ssrinivasa d s2877.78%120.00%
namhyung kimnamhyung kim513.89%240.00%
thomas gleixnerthomas gleixner25.56%120.00%
hien nguyenhien nguyen12.78%120.00%
Total36100.00%5100.00%

NOKPROBE_SYMBOL(kretprobe_table_unlock); /* * This function is called from finish_task_switch when task tk becomes dead, * so that we can recycle any function-return probe instances associated * with this task. These left over instances represent probed functions * that have been called but will never return. */
void kprobe_flush_task(struct task_struct *tk) { struct kretprobe_instance *ri; struct hlist_head *head, empty_rp; struct hlist_node *tmp; unsigned long hash, flags = 0; if (unlikely(!kprobes_initialized)) /* Early boot. kretprobe_table_locks not yet initialized. */ return; INIT_HLIST_HEAD(&empty_rp); hash = hash_ptr(tk, KPROBE_HASH_BITS); head = &kretprobe_inst_table[hash]; kretprobe_table_lock(hash, &flags); hlist_for_each_entry_safe(ri, tmp, head, hlist) { if (ri->task == tk) recycle_rp_inst(ri, &empty_rp); } kretprobe_table_unlock(hash, &flags); hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { hlist_del(&ri->hlist); kfree(ri); } }

Contributors

PersonTokensPropCommitsCommitProp
hien nguyenhien nguyen4633.58%233.33%
bibo maobibo mao3223.36%116.67%
srinivasa d ssrinivasa d s2921.17%116.67%
rusty lynchrusty lynch2417.52%116.67%
ananth n. mavinakayanahalliananth n. mavinakayanahalli64.38%116.67%
Total137100.00%6100.00%

NOKPROBE_SYMBOL(kprobe_flush_task);
static inline void free_rp_inst(struct kretprobe *rp) { struct kretprobe_instance *ri; struct hlist_node *next; hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) { hlist_del(&ri->hlist); kfree(ri); } }

Contributors

PersonTokensPropCommitsCommitProp
hien nguyenhien nguyen3063.83%125.00%
christoph hellwigchristoph hellwig1225.53%125.00%
ananth n. mavinakayanahalliananth n. mavinakayanahalli36.38%125.00%
srinivasa d ssrinivasa d s24.26%125.00%
Total47100.00%4100.00%


static void cleanup_rp_inst(struct kretprobe *rp) { unsigned long flags, hash; struct kretprobe_instance *ri; struct hlist_node *next; struct hlist_head *head; /* No race here */ for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { kretprobe_table_lock(hash, &flags); head = &kretprobe_inst_table[hash]; hlist_for_each_entry_safe(ri, next, head, hlist) { if (ri->rp == rp) ri->rp = NULL; } kretprobe_table_unlock(hash, &flags); } free_rp_inst(rp); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu6260.19%233.33%
srinivasa d ssrinivasa d s3231.07%116.67%
ananth n. mavinakayanahalliananth n. mavinakayanahalli76.80%116.67%
prasanna s panchamukhiprasanna s panchamukhi10.97%116.67%
rusty lynchrusty lynch10.97%116.67%
Total103100.00%6100.00%

NOKPROBE_SYMBOL(cleanup_rp_inst); /* * Add the new probe to ap->list. Fail if this is the * second jprobe at the address - two jprobes can't coexist */
static int add_new_kprobe(struct kprobe *ap, struct kprobe *p) { BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); if (p->break_handler || p->post_handler) unoptimize_kprobe(ap, true); /* Fall back to normal kprobe */ if (p->break_handler) { if (ap->break_handler) return -EEXIST; list_add_tail_rcu(&p->list, &ap->list); ap->break_handler = aggr_break_handler; } else list_add_rcu(&p->list, &ap->list); if (p->post_handler && !ap->post_handler) ap->post_handler = aggr_post_handler; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
prasanna s panchamukhiprasanna s panchamukhi5849.15%114.29%
masami hiramatsumasami hiramatsu3832.20%457.14%
bibo maobibo mao2016.95%114.29%
ananth n. mavinakayanahalliananth n. mavinakayanahalli21.69%114.29%
Total118100.00%7100.00%

/* * Fill in the required fields of the "manager kprobe". Replace the * earlier kprobe in the hlist with the manager kprobe */
static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) { /* Copy p's insn slot to ap */ copy_kprobe(p, ap); flush_insn_slot(ap); ap->addr = p->addr; ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED; ap->pre_handler = aggr_pre_handler; ap->fault_handler = aggr_fault_handler; /* We don't care the kprobe which has gone. */ if (p->post_handler && !kprobe_gone(p)) ap->post_handler = aggr_post_handler; if (p->break_handler && !kprobe_gone(p)) ap->break_handler = aggr_break_handler; INIT_LIST_HEAD(&ap->list); INIT_HLIST_NODE(&ap->hlist); list_add_rcu(&p->list, &ap->list); hlist_replace_rcu(&p->hlist, &ap->hlist); }

Contributors

PersonTokensPropCommitsCommitProp
ananth n. mavinakayanahalliananth n. mavinakayanahalli4733.81%222.22%
prasanna s panchamukhiprasanna s panchamukhi3525.18%111.11%
masami hiramatsumasami hiramatsu3424.46%333.33%
bibo maobibo mao2115.11%222.22%
anil keshavamurthyanil keshavamurthy21.44%111.11%
Total139100.00%9100.00%

/* * This is the second or subsequent kprobe at the address - handle * the intricacies */
static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) { int ret = 0; struct kprobe *ap = orig_p; /* For preparing optimization, jump_label_text_reserved() is called */ jump_label_lock(); /* * Get online CPUs to avoid text_mutex deadlock.with stop machine, * which is invoked by unoptimize_kprobe() in add_new_kprobe() */ get_online_cpus(); mutex_lock(&text_mutex); if (!kprobe_aggrprobe(orig_p)) { /* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */ ap = alloc_aggr_kprobe(orig_p); if (!ap) { ret = -ENOMEM; goto out; } init_aggr_kprobe(ap, orig_p); } else if (kprobe_unused(ap)) /* This probe is going to die. Rescue it */ reuse_unused_kprobe(ap); if (kprobe_gone(ap)) { /* * Attempting to insert new probe at the same location that * had a probe in the module vaddr area which already * freed. So, the instruction slot has already been * released. We need a new slot for the new probe. */ ret = arch_prepare_kprobe(ap); if (ret) /* * Even if fail to allocate new slot, don't need to * free aggr_probe. It will be used next time, or * freed by unregister_kprobe. */ goto out; /* Prepare optimized instructions if possible. */ prepare_optimized_kprobe(ap); /* * Clear gone flag to prevent allocating new slot again, and * set disabled flag because it is not armed yet. */ ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) | KPROBE_FLAG_DISABLED; } /* Copy ap's insn slot to p */ copy_kprobe(ap, p); ret = add_new_kprobe(ap, p); out: mutex_unlock(&text_mutex); put_online_cpus(); jump_label_unlock(); if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) { ap->flags &= ~KPROBE_FLAG_DISABLED; if (!kprobes_all_disarmed) /* Arm the breakpoint again. */ arm_kprobe(ap); } return ret; }

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PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu16175.23%872.73%
ananth n. mavinakayanahalliananth n. mavinakayanahalli4521.03%19.09%
prasanna s panchamukhiprasanna s panchamukhi83.74%218.18%
Total214100.00%11100.00%


bool __weak arch_within_kprobe_blacklist(unsigned long addr) { /* The __kprobes marked functions and entry code must not be probed */ return addr >= (unsigned long)__kprobes_text_start && addr < (unsigned long)__kprobes_text_end; }

Contributors

PersonTokensPropCommitsCommitProp
prasanna s panchamukhiprasanna s panchamukhi2175.00%150.00%
masami hiramatsumasami hiramatsu725.00%150.00%
Total28100.00%2100.00%


bool within_kprobe_blacklist(unsigned long addr) { struct kprobe_blacklist_entry *ent; if (arch_within_kprobe_blacklist(addr)) return true; /* * If there exists a kprobe_blacklist, verify and * fail any probe registration in the prohibited area */ list_for_each_entry(ent, &kprobe_blacklist, list) { if (addr >= ent->start_addr && addr < ent->end_addr) return true; } return false; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu3360.00%250.00%
srinivasa d ssrinivasa d s1629.09%125.00%
prasanna s panchamukhiprasanna s panchamukhi610.91%125.00%
Total55100.00%4100.00%

/* * If we have a symbol_name argument, look it up and add the offset field * to it. This way, we can specify a relative address to a symbol. * This returns encoded errors if it fails to look up symbol or invalid * combination of parameters. */
static kprobe_opcode_t *kprobe_addr(struct kprobe *p) { kprobe_opcode_t *addr = p->addr; if ((p->symbol_name && p->addr) || (!p->symbol_name && !p->addr)) goto invalid; if (p->symbol_name) { kprobe_lookup_name(p->symbol_name, addr); if (!addr) return ERR_PTR(-ENOENT); } addr = (kprobe_opcode_t *)(((char *)addr) + p->offset); if (addr) return addr; invalid: return ERR_PTR(-EINVAL); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu6053.57%233.33%
ananth n. mavinakayanahalliananth n. mavinakayanahalli4237.50%116.67%
prasanna s panchamukhiprasanna s panchamukhi76.25%116.67%
bibo maobibo mao21.79%116.67%
anil keshavamurthyanil keshavamurthy10.89%116.67%
Total112100.00%6100.00%

/* Check passed kprobe is valid and return kprobe in kprobe_table. */
static struct kprobe *__get_valid_kprobe(struct kprobe *p) { struct kprobe *ap, *list_p; ap = get_kprobe(p->addr); if (unlikely(!ap)) return NULL; if (p != ap) { list_for_each_entry_rcu(list_p, &ap->list, list) if (list_p == p) /* kprobe p is a valid probe */ goto valid; return NULL; } valid: return ap; }

Contributors

PersonTokensPropCommitsCommitProp
ananth n. mavinakayanahalliananth n. mavinakayanahalli6992.00%150.00%
masami hiramatsumasami hiramatsu68.00%150.00%
Total75100.00%2100.00%

/* Return error if the kprobe is being re-registered */
static inline int check_kprobe_rereg(struct kprobe *p) { int ret = 0; mutex_lock(&kprobe_mutex); if (__get_valid_kprobe(p)) ret = -EINVAL; mutex_unlock(&kprobe_mutex); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
ananth n. mavinakayanahalliananth n. mavinakayanahalli4295.45%150.00%
masami hiramatsumasami hiramatsu24.55%150.00%
Total44100.00%2100.00%


int __weak arch_check_ftrace_location(struct kprobe *p) { unsigned long ftrace_addr; ftrace_addr = ftrace_location((unsigned long)p->addr); if (ftrace_addr) { #ifdef CONFIG_KPROBES_ON_FTRACE /* Given address is not on the instruction boundary */ if ((unsigned long)p->addr != ftrace_addr) return -EILSEQ; p->flags |= KPROBE_FLAG_FTRACE; #else /* !CONFIG_KPROBES_ON_FTRACE */ return -EINVAL; #endif } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu6691.67%480.00%
heiko carstensheiko carstens68.33%120.00%
Total72100.00%5100.00%


static int check_kprobe_address_safe(struct kprobe *p, struct module **probed_mod) { int ret; ret = arch_check_ftrace_location(p); if (ret) return ret; jump_label_lock(); preempt_disable(); /* Ensure it is not in reserved area nor out of text */ if (!kernel_text_address((unsigned long) p->addr) || within_kprobe_blacklist((unsigned long) p->addr) || jump_label_text_reserved(p->addr, p->addr)) { ret = -EINVAL; goto out; } /* Check if are we probing a module */ *probed_mod = __module_text_address((unsigned long) p->addr); if (*probed_mod) { /* * We must hold a refcount of the probed module while updating * its code to prohibit unexpected unloading. */ if (unlikely(!try_module_get(*probed_mod))) { ret = -ENOENT; goto out; } /* * If the module freed .init.text, we couldn't insert * kprobes in there. */ if (within_module_init((unsigned long)p->addr, *probed_mod) && (*probed_mod)->state != MODULE_STATE_COMING) { module_put(*probed_mod); *probed_mod = NULL; ret = -ENOENT; } } out: preempt_enable(); jump_label_unlock(); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu7439.57%741.18%
heiko carstensheiko carstens3317.65%15.88%
bibo maobibo mao2915.51%15.88%
jason baronjason baron126.42%211.76%
prasanna s panchamukhiprasanna s panchamukhi126.42%211.76%
steven rostedtsteven rostedt94.81%15.88%
anil keshavamurthyanil keshavamurthy73.74%15.88%
prashanth nageshappaprashanth nageshappa73.74%15.88%
christoph hellwigchristoph hellwig42.14%15.88%
Total187100.00%17100.00%


int register_kprobe(struct kprobe *p) { int ret; struct kprobe *old_p; struct module *probed_mod; kprobe_opcode_t *addr; /* Adjust probe address from symbol */ addr = kprobe_addr(p); if (IS_ERR(addr)) return PTR_ERR(addr); p->addr = addr; ret = check_kprobe_rereg(p); if (ret) return ret; /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ p->flags &= KPROBE_FLAG_DISABLED; p->nmissed = 0; INIT_LIST_HEAD(&p->list); ret = check_kprobe_address_safe(p, &probed_mod); if (ret) return ret; mutex_lock(&kprobe_mutex); old_p = get_kprobe(p->addr); if (old_p) { /* Since this may unoptimize old_p, locking text_mutex. */ ret = register_aggr_kprobe(old_p, p); goto out; } mutex_lock(&text_mutex); /* Avoiding text modification */ ret = prepare_kprobe(p); mutex_unlock(&text_mutex); if (ret) goto out; INIT_HLIST_NODE(&p->hlist); hlist_add_head_rcu(&p->hlist, &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); if (!kprobes_all_disarmed && !kprobe_disabled(p)) arm_kprobe(p); /* Try to optimize kprobe */ try_to_optimize_kprobe(p); out: mutex_unlock(&kprobe_mutex); if (probed_mod) module_put(probed_mod); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu13155.04%735.00%
prasanna s panchamukhiprasanna s panchamukhi5322.27%315.00%
ananth n. mavinakayanahalliananth n. mavinakayanahalli2510.50%315.00%
anil keshavamurthyanil keshavamurthy135.46%315.00%
bibo maobibo mao72.94%15.00%
christoph hellwigchristoph hellwig41.68%15.00%
mathieu desnoyersmathieu desnoyers41.68%15.00%
ingo molnaringo molnar10.42%15.00%
Total238100.00%20100.00%

EXPORT_SYMBOL_GPL(register_kprobe); /* Check if all probes on the aggrprobe are disabled */
static int aggr_kprobe_disabled(struct kprobe *ap) { struct kprobe *kp; list_for_each_entry_rcu(kp, &ap->list, list) if (!kprobe_disabled(kp)) /* * There is an active probe on the list. * We can't disable this ap. */ return 0; return 1; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu39100.00%1100.00%
Total39100.00%1100.00%

/* Disable one kprobe: Make sure called under kprobe_mutex is locked */
static struct kprobe *__disable_kprobe(struct kprobe *p) { struct kprobe *orig_p; /* Get an original kprobe for return */ orig_p = __get_valid_kprobe(p); if (unlikely(orig_p == NULL)) return NULL; if (!kprobe_disabled(p)) { /* Disable probe if it is a child probe */ if (p != orig_p) p->flags |= KPROBE_FLAG_DISABLED; /* Try to disarm and disable this/parent probe */ if (p == orig_p || aggr_kprobe_disabled(orig_p)) { /* * If kprobes_all_disarmed is set, orig_p * should have already been disarmed, so * skip unneed disarming process. */ if (!kprobes_all_disarmed) disarm_kprobe(orig_p, true); orig_p->flags |= KPROBE_FLAG_DISABLED; } } return orig_p; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu9193.81%266.67%
wang nanwang nan66.19%133.33%
Total97100.00%3100.00%

/* * Unregister a kprobe without a scheduler synchronization. */
static int __unregister_kprobe_top(struct kprobe *p) { struct kprobe *ap, *list_p; /* Disable kprobe. This will disarm it if needed. */ ap = __disable_kprobe(p); if (ap == NULL) return -EINVAL; if (ap == p) /* * This probe is an independent(and non-optimized) kprobe * (not an aggrprobe). Remove from the hash list. */ goto disarmed; /* Following process expects this probe is an aggrprobe */ WARN_ON(!kprobe_aggrprobe(ap)); if (list_is_singular(&ap->list) && kprobe_disarmed(ap)) /* * !disarmed could be happen if the probe is under delayed * unoptimizing. */ goto disarmed; else { /* If disabling probe has special handlers, update aggrprobe */ if (p->break_handler && !kprobe_gone(p)) ap->break_handler = NULL; if (p->post_handler && !kprobe_gone(p)) { list_for_each_entry_rcu(list_p, &ap->list, list) { if ((list_p != p) && (list_p->post_handler)) goto noclean; } ap->post_handler = NULL; } noclean: /* * Remove from the aggrprobe: this path will do nothing in * __unregister_kprobe_bottom(). */ list_del_rcu(&p->list); if (!kprobe_disabled(ap) && !kprobes_all_disarmed) /* * Try to optimize this probe again, because post * handler may have been changed. */ optimize_kprobe(ap); } return 0; disarmed: BUG_ON(!kprobe_disarmed(ap)); hlist_del_rcu(&ap->hlist); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu17588.38%763.64%
anil keshavamurthyanil keshavamurthy189.09%218.18%
prasanna s panchamukhiprasanna s panchamukhi31.52%19.09%
ananth n. mavinakayanahalliananth n. mavinakayanahalli21.01%19.09%
Total198100.00%11100.00%


static void __unregister_kprobe_bottom(struct kprobe *p) { struct kprobe *ap; if (list_empty(&p->list)) /* This is an independent kprobe */ arch_remove_kprobe(p); else if (list_is_singular(&p->list)) { /* This is the last child of an aggrprobe */ ap = list_entry(p->list.next, struct kprobe, list); list_del(&p->list); free_aggr_kprobe(ap); } /* Otherwise, do nothing. */ }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu5876.32%562.50%
anil keshavamurthyanil keshavamurthy1114.47%225.00%
ananth n. mavinakayanahalliananth n. mavinakayanahalli79.21%112.50%
Total76100.00%8100.00%


int register_kprobes(struct kprobe **kps, int num) { int i, ret = 0; if (num <= 0) return -EINVAL; for (i = 0; i < num; i++) { ret = register_kprobe(kps[i]); if (ret < 0) { if (i > 0) unregister_kprobes(kps, i); break; } } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu7086.42%375.00%
bibo maobibo mao1113.58%125.00%
Total81100.00%4100.00%

EXPORT_SYMBOL_GPL(register_kprobes);
void unregister_kprobe(struct kprobe *p) { unregister_kprobes(&p, 1); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu18100.00%1100.00%
Total18100.00%1100.00%

EXPORT_SYMBOL_GPL(unregister_kprobe);
void unregister_kprobes(struct kprobe **kps, int num) { int i; if (num <= 0) return; mutex_lock(&kprobe_mutex); for (i = 0; i < num; i++) if (__unregister_kprobe_top(kps[i]) < 0) kps[i]->addr = NULL; mutex_unlock(&kprobe_mutex); synchronize_sched(); for (i = 0; i < num; i++) if (kps[i]->addr) __unregister_kprobe_bottom(kps[i]); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu8380.58%133.33%
bibo maobibo mao1918.45%133.33%
prasanna s panchamukhiprasanna s panchamukhi10.97%133.33%
Total103100.00%3100.00%

EXPORT_SYMBOL_GPL(unregister_kprobes); static struct notifier_block kprobe_exceptions_nb = { .notifier_call = kprobe_exceptions_notify, .priority = 0x7fffffff /* we need to be notified first */ };
unsigned long __weak arch_deref_entry_point(void *entry) { return (unsigned long)entry; }

Contributors

PersonTokensPropCommitsCommitProp
michael ellermanmichael ellerman18100.00%1100.00%
Total18100.00%1100.00%


int register_jprobes(struct jprobe **jps, int num) { struct jprobe *jp; int ret = 0, i; if (num <= 0) return -EINVAL; for (i = 0; i < num; i++) { unsigned long addr, offset; jp = jps[i]; addr = arch_deref_entry_point(jp->entry); /* Verify probepoint is a function entry point */ if (kallsyms_lookup_size_offset(addr, NULL, &offset) && offset == 0) { jp->kp.pre_handler = setjmp_pre_handler; jp->kp.break_handler = longjmp_break_handler; ret = register_kprobe(&jp->kp); } else ret = -EINVAL; if (ret < 0) { if (i > 0) unregister_jprobes(jps, i); break; } } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu8557.05%350.00%
prasanna s panchamukhiprasanna s panchamukhi2818.79%116.67%
namhyung kimnamhyung kim2718.12%116.67%
michael ellermanmichael ellerman96.04%116.67%
Total149100.00%6100.00%

EXPORT_SYMBOL_GPL(register_jprobes);
int register_jprobe(struct jprobe *jp) { return register_jprobes(&jp, 1); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu1684.21%266.67%
prasanna s panchamukhiprasanna s panchamukhi315.79%133.33%
Total19100.00%3100.00%

EXPORT_SYMBOL_GPL(register_jprobe);
void unregister_jprobe(struct jprobe *jp) { unregister_jprobes(&jp, 1); }

Contributors

PersonTokensPropCommitsCommitProp
prasanna s panchamukhiprasanna s panchamukhi1266.67%150.00%
masami hiramatsumasami hiramatsu633.33%150.00%
Total18100.00%2100.00%

EXPORT_SYMBOL_GPL(unregister_jprobe);
void unregister_jprobes(struct jprobe **jps, int num) { int i; if (num <= 0) return; mutex_lock(&kprobe_mutex); for (i = 0; i < num; i++) if (__unregister_kprobe_top(&jps[i]->kp) < 0) jps[i]->kp.addr = NULL; mutex_unlock(&kprobe_mutex); synchronize_sched(); for (i = 0; i < num; i++) { if (jps[i]->kp.addr) __unregister_kprobe_bottom(&jps[i]->kp); } }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu11095.65%150.00%
prasanna s panchamukhiprasanna s panchamukhi54.35%150.00%
Total115100.00%2100.00%

EXPORT_SYMBOL_GPL(unregister_jprobes); #ifdef CONFIG_KRETPROBES /* * This kprobe pre_handler is registered with every kretprobe. When probe * hits it will set up the return probe. */
static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) { struct kretprobe *rp = container_of(p, struct kretprobe, kp); unsigned long hash, flags = 0; struct kretprobe_instance *ri; /* * To avoid deadlocks, prohibit return probing in NMI contexts, * just skip the probe and increase the (inexact) 'nmissed' * statistical counter, so that the user is informed that * something happened: */ if (unlikely(in_nmi())) { rp->nmissed++; return 0; } /* TODO: consider to only swap the RA after the last pre_handler fired */ hash = hash_ptr(current, KPROBE_HASH_BITS); raw_spin_lock_irqsave(&rp->lock, flags); if (!hlist_empty(&rp->free_instances)) { ri = hlist_entry(rp->free_instances.first, struct kretprobe_instance, hlist); hlist_del(&ri->hlist); raw_spin_unlock_irqrestore(&rp->lock, flags); ri->rp = rp; ri->task = current; if (rp->entry_handler && rp->entry_handler(ri, regs)) { raw_spin_lock_irqsave(&rp->lock, flags); hlist_add_head(&ri->hlist, &rp->free_instances); raw_spin_unlock_irqrestore(&rp->lock, flags); return 0; } arch_prepare_kretprobe(ri, regs); /* XXX(hch): why is there no hlist_move_head? */ INIT_HLIST_NODE(&ri->hlist); kretprobe_table_lock(hash, &flags); hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); kretprobe_table_unlock(hash, &flags); } else { rp->nmissed++; raw_spin_unlock_irqrestore(&rp->lock, flags); } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig6926.34%114.29%
srinivasa d ssrinivasa d s5922.52%114.29%
adrian bunkadrian bunk5822.14%114.29%
jiang liujiang liu3513.36%114.29%
masami hiramatsumasami hiramatsu207.63%114.29%
abhishek sagarabhishek sagar186.87%114.29%
thomas gleixnerthomas gleixner31.15%114.29%
Total262100.00%7100.00%

NOKPROBE_SYMBOL(pre_handler_kretprobe);
int register_kretprobe(struct kretprobe *rp) { int ret = 0; struct kretprobe_instance *inst; int i; void *addr; if (kretprobe_blacklist_size) { addr = kprobe_addr(&rp->kp); if (IS_ERR(addr)) return PTR_ERR(addr); for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { if (kretprobe_blacklist[i].addr == addr) return -EINVAL; } } rp->kp.pre_handler = pre_handler_kretprobe; rp->kp.post_handler = NULL; rp->kp.fault_handler = NULL; rp->kp.break_handler = NULL; /* Pre-allocate memory for max kretprobe instances */ if (rp->maxactive <= 0) { #ifdef CONFIG_PREEMPT rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); #else rp->maxactive = num_possible_cpus(); #endif } raw_spin_lock_init(&rp->lock); INIT_HLIST_HEAD(&rp->free_instances); for (i = 0; i < rp->maxactive; i++) { inst = kmalloc(sizeof(struct kretprobe_instance) + rp->data_size, GFP_KERNEL); if (inst == NULL) { free_rp_inst(rp); return -ENOMEM; } INIT_HLIST_NODE(&inst->hlist); hlist_add_head(&inst->hlist, &rp->free_instances); } rp->nmissed = 0; /* Establish function entry probe point */ ret = register_kprobe(&rp->kp); if (ret != 0) free_rp_inst(rp); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
hien nguyenhien nguyen16960.14%18.33%
masami hiramatsumasami hiramatsu7426.33%541.67%
ananth n. mavinakayanahalliananth n. mavinakayanahalli269.25%216.67%
abhishek sagarabhishek sagar41.42%18.33%
heiko carstensheiko carstens41.42%18.33%
srinivasa d ssrinivasa d s31.07%18.33%
thomas gleixnerthomas gleixner10.36%18.33%
Total281100.00%12100.00%

EXPORT_SYMBOL_GPL(register_kretprobe);
int register_kretprobes(struct kretprobe **rps, int num) { int ret = 0, i; if (num <= 0) return -EINVAL; for (i = 0; i < num; i++) { ret = register_kretprobe(rps[i]); if (ret < 0) { if (i > 0) unregister_kretprobes(rps, i); break; } } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu7086.42%375.00%
hien nguyenhien nguyen1113.58%125.00%
Total81100.00%4100.00%

EXPORT_SYMBOL_GPL(register_kretprobes);
void unregister_kretprobe(struct kretprobe *rp) { unregister_kretprobes(&rp, 1); }

Contributors

PersonTokensPropCommitsCommitProp
hien nguyenhien nguyen950.00%150.00%
masami hiramatsumasami hiramatsu950.00%150.00%
Total18100.00%2100.00%

EXPORT_SYMBOL_GPL(unregister_kretprobe);
void unregister_kretprobes(struct kretprobe **rps, int num) { int i; if (num <= 0) return; mutex_lock(&kprobe_mutex); for (i = 0; i < num; i++) if (__unregister_kprobe_top(&rps[i]->kp) < 0) rps[i]->kp.addr = NULL; mutex_unlock(&kprobe_mutex); synchronize_sched(); for (i = 0; i < num; i++) { if (rps[i]->kp.addr) { __unregister_kprobe_bottom(&rps[i]->kp); cleanup_rp_inst(rps[i]); } } }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu9878.40%125.00%
hien nguyenhien nguyen2016.00%125.00%
christoph hellwigchristoph hellwig43.20%125.00%
ananth n. mavinakayanahalliananth n. mavinakayanahalli32.40%125.00%
Total125100.00%4100.00%

EXPORT_SYMBOL_GPL(unregister_kretprobes); #else /* CONFIG_KRETPROBES */
int register_kretprobe(struct kretprobe *rp) { return -ENOSYS; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu14100.00%1100.00%
Total14100.00%1100.00%

EXPORT_SYMBOL_GPL(register_kretprobe);
int register_kretprobes(struct kretprobe **rps, int num) { return -ENOSYS; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu18100.00%1100.00%
Total18100.00%1100.00%

EXPORT_SYMBOL_GPL(register_kretprobes);
void unregister_kretprobe(struct kretprobe *rp) { }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu9100.00%1100.00%
Total9100.00%1100.00%

EXPORT_SYMBOL_GPL(unregister_kretprobe);
void unregister_kretprobes(struct kretprobe **rps, int num) { }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu13100.00%1100.00%
Total13100.00%1100.00%

EXPORT_SYMBOL_GPL(unregister_kretprobes);
static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) { return 0; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu19100.00%1100.00%
Total19100.00%1100.00%

NOKPROBE_SYMBOL(pre_handler_kretprobe); #endif /* CONFIG_KRETPROBES */ /* Set the kprobe gone and remove its instruction buffer. */
static void kill_kprobe(struct kprobe *p) { struct kprobe *kp; p->flags |= KPROBE_FLAG_GONE; if (kprobe_aggrprobe(p)) { /* * If this is an aggr_kprobe, we have to list all the * chained probes and mark them GONE. */ list_for_each_entry_rcu(kp, &p->list, list) kp->flags |= KPROBE_FLAG_GONE; p->post_handler = NULL; p->break_handler = NULL; kill_optimized_kprobe(p); } /* * Here, we can remove insn_slot safely, because no thread calls * the original probed function (which will be freed soon) any more. */ arch_remove_kprobe(p); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu69100.00%2100.00%
Total69100.00%2100.00%

/* Disable one kprobe */
int disable_kprobe(struct kprobe *kp) { int ret = 0; mutex_lock(&kprobe_mutex); /* Disable this kprobe */ if (__disable_kprobe(kp) == NULL) ret = -EINVAL; mutex_unlock(&kprobe_mutex); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu45100.00%3100.00%
Total45100.00%3100.00%

EXPORT_SYMBOL_GPL(disable_kprobe); /* Enable one kprobe */
int enable_kprobe(struct kprobe *kp) { int ret = 0; struct kprobe *p; mutex_lock(&kprobe_mutex); /* Check whether specified probe is valid. */ p = __get_valid_kprobe(kp); if (unlikely(p == NULL)) { ret = -EINVAL; goto out; } if (kprobe_gone(kp)) { /* This kprobe has gone, we couldn't enable it. */ ret = -EINVAL; goto out; } if (p != kp) kp->flags &= ~KPROBE_FLAG_DISABLED; if (!kprobes_all_disarmed && kprobe_disabled(p)) { p->flags &= ~KPROBE_FLAG_DISABLED; arm_kprobe(p); } out: mutex_unlock(&kprobe_mutex); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu8571.43%233.33%
srinivasa d ssrinivasa d s2924.37%350.00%
prasanna s panchamukhiprasanna s panchamukhi54.20%116.67%
Total119100.00%6100.00%

EXPORT_SYMBOL_GPL(enable_kprobe);
void dump_kprobe(struct kprobe *kp) { printk(KERN_WARNING "Dumping kprobe:\n"); printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n", kp->symbol_name, kp->addr, kp->offset); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu2779.41%150.00%
srinivasa d ssrinivasa d s720.59%150.00%
Total34100.00%2100.00%

NOKPROBE_SYMBOL(dump_kprobe); /* * Lookup and populate the kprobe_blacklist. * * Unlike the kretprobe blacklist, we'll need to determine * the range of addresses that belong to the said functions, * since a kprobe need not necessarily be at the beginning * of a function. */
static int __init populate_kprobe_blacklist(unsigned long *start, unsigned long *end) { unsigned long *iter; struct kprobe_blacklist_entry *ent; unsigned long entry, offset = 0, size = 0; for (iter = start; iter < end; iter++) { entry = arch_deref_entry_point((void *)*iter); if (!kernel_text_address(entry) || !kallsyms_lookup_size_offset(entry, &size, &offset)) { pr_err("Failed to find blacklist at %p\n", (void *)entry); continue; } ent = kmalloc(sizeof(*ent), GFP_KERNEL); if (!ent) return -ENOMEM; ent->start_addr = entry; ent->end_addr = entry + size; INIT_LIST_HEAD(&ent->list); list_add_tail(&ent->list, &kprobe_blacklist); } return 0; }

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PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu158100.00%2100.00%
Total158100.00%2100.00%

/* Module notifier call back, checking kprobes on the module */
static int kprobes_module_callback(struct notifier_block *nb, unsigned long val, void *data) { struct module *mod = data; struct hlist_head *head; struct kprobe *p; unsigned int i; int checkcore = (val == MODULE_STATE_GOING); if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) return NOTIFY_DONE; /* * When MODULE_STATE_GOING was notified, both of module .text and * .init.text sections would be freed. When MODULE_STATE_LIVE was * notified, only .init.text section would be freed. We need to * disable kprobes which have been inserted in the sections. */ mutex_lock(&kprobe_mutex); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, head, hlist) if (within_module_init((unsigned long)p->addr, mod) || (checkcore && within_module_core((unsigned long)p->addr, mod))) { /* * The vaddr this probe is installed will soon * be vfreed buy not synced to disk. Hence, * disarming the breakpoint isn't needed. */ kill_kprobe(p); } } mutex_unlock(&kprobe_mutex); return NOTIFY_DONE; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu12684.56%150.00%
srinivasa d ssrinivasa d s2315.44%150.00%
Total149100.00%2100.00%

static struct notifier_block kprobe_module_nb = { .notifier_call = kprobes_module_callback, .priority = 0 }; /* Markers of _kprobe_blacklist section */ extern unsigned long __start_kprobe_blacklist[]; extern unsigned long __stop_kprobe_blacklist[];
static int __init init_kprobes(void) { int i, err = 0; /* FIXME allocate the probe table, currently defined statically */ /* initialize all list heads */ for (i = 0; i < KPROBE_TABLE_SIZE; i++) { INIT_HLIST_HEAD(&kprobe_table[i]); INIT_HLIST_HEAD(&kretprobe_inst_table[i]); raw_spin_lock_init(&(kretprobe_table_locks[i].lock)); } err = populate_kprobe_blacklist(__start_kprobe_blacklist, __stop_kprobe_blacklist); if (err) { pr_err("kprobes: failed to populate blacklist: %d\n", err); pr_err("Please take care of using kprobes.\n"); } if (kretprobe_blacklist_size) { /* lookup the function address from its name */ for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { kprobe_lookup_name(kretprobe_blacklist[i].name, kretprobe_blacklist[i].addr); if (!kretprobe_blacklist[i].addr) printk("kretprobe: lookup failed: %s\n", kretprobe_blacklist[i].name); } } #if defined(CONFIG_OPTPROBES) #if defined(__ARCH_WANT_KPROBES_INSN_SLOT) /* Init kprobe_optinsn_slots */ kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; #endif /* By default, kprobes can be optimized */ kprobes_allow_optimization = true; #endif /* By default, kprobes are armed */ kprobes_all_disarmed = false; err = arch_init_kprobes(); if (!err) err = register_die_notifier(&kprobe_exceptions_nb); if (!err) err = register_module_notifier(&kprobe_module_nb); kprobes_initialized = (err == 0); if (!err) init_test_probes(); return err; }

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PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu20886.67%250.00%
srinivasa d ssrinivasa d s3112.92%125.00%
thomas gleixnerthomas gleixner10.42%125.00%
Total240100.00%4100.00%

#ifdef CONFIG_DEBUG_FS
static void report_probe(struct seq_file *pi, struct kprobe *p, const char *sym, int offset, char *modname, struct kprobe *pp) { char *kprobe_type; if (p->pre_handler == pre_handler_kretprobe) kprobe_type = "r"; else if (p->pre_handler == setjmp_pre_handler) kprobe_type = "j"; else kprobe_type = "k"; if (sym) seq_printf(pi, "%p %s %s+0x%x %s ", p->addr, kprobe_type, sym, offset, (modname ? modname : " ")); else seq_printf(pi, "%p %s %p ", p->addr, kprobe_type, p->addr); if (!pp) pp = p; seq_printf(pi, "%s%s%s%s\n", (kprobe_gone(p) ? "[GONE]" : ""), ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""), (kprobe_optimized(pp) ? "[OPTIMIZED]" : ""), (kprobe_ftrace(pp) ? "[FTRACE]" : "")); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu17495.60%360.00%
srinivasa d ssrinivasa d s73.85%120.00%
alexey dobriyanalexey dobriyan10.55%120.00%
Total182100.00%5100.00%


static void *kprobe_seq_start(struct seq_file *f, loff_t *pos) { return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu28100.00%2100.00%
Total28100.00%2100.00%


static void *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) { (*pos)++; if (*pos >= KPROBE_TABLE_SIZE) return NULL; return pos; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu39100.00%2100.00%
Total39100.00%2100.00%


static void kprobe_seq_stop(struct seq_file *f, void *v) { /* Nothing to do */ }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu16100.00%1100.00%
Total16100.00%1100.00%


static int show_kprobe_addr(struct seq_file *pi, void *v) { struct hlist_head *head; struct kprobe *p, *kp; const char *sym = NULL; unsigned int i = *(loff_t *) v; unsigned long offset = 0; char *modname, namebuf[KSYM_NAME_LEN]; head = &kprobe_table[i]; preempt_disable(); hlist_for_each_entry_rcu(p, head, hlist) { sym = kallsyms_lookup((unsigned long)p->addr, NULL, &offset, &modname, namebuf); if (kprobe_aggrprobe(p)) { list_for_each_entry_rcu(kp, &p->list, list) report_probe(pi, kp, sym, offset, modname, p); } else report_probe(pi, p, sym, offset, modname, NULL); } preempt_enable(); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu15899.37%375.00%
joe mariojoe mario10.63%125.00%
Total159100.00%4100.00%

static const struct seq_operations kprobes_seq_ops = { .start = kprobe_seq_start, .next = kprobe_seq_next, .stop = kprobe_seq_stop, .show = show_kprobe_addr };
static int kprobes_open(struct inode *inode, struct file *filp) { return seq_open(filp, &kprobes_seq_ops); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu25100.00%2100.00%
Total25100.00%2100.00%

static const struct file_operations debugfs_kprobes_operations = { .open = kprobes_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; /* kprobes/blacklist -- shows which functions can not be probed */
static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos) { return seq_list_start(&kprobe_blacklist, *pos); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu26100.00%1100.00%
Total26100.00%1100.00%


static void *kprobe_blacklist_seq_next(struct seq_file *m, void *v, loff_t *pos) { return seq_list_next(v, &kprobe_blacklist, pos); }

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PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu31100.00%1100.00%
Total31100.00%1100.00%


static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) { struct kprobe_blacklist_entry *ent = list_entry(v, struct kprobe_blacklist_entry, list); seq_printf(m, "0x%p-0x%p\t%ps\n", (void *)ent->start_addr, (void *)ent->end_addr, (void *)ent->start_addr); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu64100.00%1100.00%
Total64100.00%1100.00%

static const struct seq_operations kprobe_blacklist_seq_ops = { .start = kprobe_blacklist_seq_start, .next = kprobe_blacklist_seq_next, .stop = kprobe_seq_stop, /* Reuse void function */ .show = kprobe_blacklist_seq_show, };
static int kprobe_blacklist_open(struct inode *inode, struct file *filp) { return seq_open(filp, &kprobe_blacklist_seq_ops); }

Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu25100.00%1100.00%
Total25100.00%1100.00%

static const struct file_operations debugfs_kprobe_blacklist_ops = { .open = kprobe_blacklist_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, };
static void arm_all_kprobes(void) { struct hlist_head *head; struct kprobe *p; unsigned int i; mutex_lock(&kprobe_mutex); /* If kprobes are armed, just return */ if (!kprobes_all_disarmed) goto already_enabled; /* * optimize_kprobe() called by arm_kprobe() checks * kprobes_all_disarmed, so set kprobes_all_disarmed before * arm_kprobe. */ kprobes_all_disarmed = false; /* Arming kprobes doesn't optimize kprobe itself */ for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, head, hlist) if (!kprobe_disabled(p)) arm_kprobe(p); } printk(KERN_INFO "Kprobes globally enabled\n"); already_enabled: mutex_unlock(&kprobe_mutex); return; }

Contributors

PersonTokensPropCommitsCommitProp
ananth n. mavinakayanahalliananth n. mavinakayanahalli8381.37%114.29%
masami hiramatsumasami hiramatsu1413.73%571.43%
wang nanwang nan54.90%114.29%
Total102100.00%7100.00%


static void disarm_all_kprobes(void) { struct hlist_head *head; struct kprobe *p; unsigned int i; mutex_lock(&kprobe_mutex); /* If kprobes are already disarmed, just return */ if (kprobes_all_disarmed) { mutex_unlock(&kprobe_mutex); return; } kprobes_all_disarmed = true; printk(KERN_INFO "Kprobes globally disabled\n"); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, head, hlist) { if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) disarm_kprobe(p, false); } } mutex_unlock(&kprobe_mutex); /* Wait for disarming all kprobes by optimizer */ wait_for_kprobe_optimizer(); }

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PersonTokensPropCommitsCommitProp
ananth n. mavinakayanahalliananth n. mavinakayanahalli9178.45%116.67%
masami hiramatsumasami hiramatsu2521.55%583.33%
Total116100.00%6100.00%

/* * XXX: The debugfs bool file interface doesn't allow for callbacks * when the bool state is switched. We can reuse that facility when * available */
static ssize_t read_enabled_file_bool(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { char buf[3]; if (!kprobes_all_disarmed) buf[0] = '1'; else buf[0] = '0'; buf[1] = '\n'; buf[2] = 0x00; return simple_read_from_buffer(user_buf, count, ppos, buf, 2); }

Contributors

PersonTokensPropCommitsCommitProp
ananth n. mavinakayanahalliananth n. mavinakayanahalli7597.40%150.00%
masami hiramatsumasami hiramatsu22.60%150.00%
Total77100.00%2100.00%


static ssize_t write_enabled_file_bool(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos) { char buf[32]; size_t buf_size; buf_size = min(count, (sizeof(buf)-1)); if (copy_from_user(buf, user_buf, buf_size)) return -EFAULT; buf[buf_size] = '\0'; switch (buf[0]) { case 'y': case 'Y': case '1': arm_all_kprobes(); break; case 'n': case 'N': case '0': disarm_all_kprobes(); break; default: return -EINVAL; } return count; }

Contributors

PersonTokensPropCommitsCommitProp
ananth n. mavinakayanahalliananth n. mavinakayanahalli9986.84%125.00%
mathias krausemathias krause1210.53%125.00%
masami hiramatsumasami hiramatsu21.75%125.00%
stephen boydstephen boyd10.88%125.00%
Total114100.00%4100.00%

static const struct file_operations fops_kp = { .read = read_enabled_file_bool, .write = write_enabled_file_bool, .llseek = default_llseek, };
static int __init debugfs_kprobe_init(void) { struct dentry *dir, *file; unsigned int value = 1; dir = debugfs_create_dir("kprobes", NULL); if (!dir) return -ENOMEM; file = debugfs_create_file("list", 0444, dir, NULL, &debugfs_kprobes_operations); if (!file) goto error; file = debugfs_create_file("enabled", 0600, dir, &value, &fops_kp); if (!file) goto error; file = debugfs_create_file("blacklist", 0444, dir, NULL, &debugfs_kprobe_blacklist_ops); if (!file) goto error; return 0; error: debugfs_remove(dir); return -ENOMEM; }

Contributors

PersonTokensPropCommitsCommitProp
srinivasa d ssrinivasa d s5341.41%120.00%
ananth n. mavinakayanahalliananth n. mavinakayanahalli3829.69%120.00%
masami hiramatsumasami hiramatsu3628.12%240.00%
randy dunlaprandy dunlap10.78%120.00%
Total128100.00%5100.00%

late_initcall(debugfs_kprobe_init); #endif /* CONFIG_DEBUG_FS */ module_init(init_kprobes); /* defined in arch/.../kernel/kprobes.c */ EXPORT_SYMBOL_GPL(jprobe_return);

Overall Contributors

PersonTokensPropCommitsCommitProp
masami hiramatsumasami hiramatsu657865.91%5339.26%
ananth n. mavinakayanahalliananth n. mavinakayanahalli122412.26%128.89%
srinivasa d ssrinivasa d s5145.15%32.22%
hien nguyenhien nguyen3783.79%21.48%
prasanna s panchamukhiprasanna s panchamukhi3623.63%75.19%
heiko carstensheiko carstens1821.82%42.96%
bibo maobibo mao1531.53%53.70%
anil keshavamurthyanil keshavamurthy1071.07%85.93%
christoph hellwigchristoph hellwig1061.06%53.70%
adrian bunkadrian bunk600.60%21.48%
namhyung kimnamhyung kim450.45%32.22%
tejun heotejun heo440.44%10.74%
jiang liujiang liu350.35%10.74%
michael ellermanmichael ellerman270.27%10.74%
rusty lynchrusty lynch250.25%21.48%
abhishek sagarabhishek sagar220.22%10.74%
thomas gleixnerthomas gleixner200.20%21.48%
jason baronjason baron150.15%32.22%
steven rostedtsteven rostedt140.14%21.48%
wang nanwang nan130.13%21.48%
mathias krausemathias krause120.12%10.74%
christoph lameterchristoph lameter80.08%10.74%
prashanth nageshappaprashanth nageshappa70.07%10.74%
mathieu desnoyersmathieu desnoyers70.07%10.74%
arnd bergmannarnd bergmann50.05%10.74%
randy dunlaprandy dunlap40.04%10.74%
tim schmielautim schmielau30.03%10.74%
ingo molnaringo molnar20.02%10.74%
alexey dobriyanalexey dobriyan20.02%10.74%
rusty russellrusty russell10.01%10.74%
daniel guilakdaniel guilak10.01%10.74%
joe mariojoe mario10.01%10.74%
stephen boydstephen boyd10.01%10.74%
linus torvaldslinus torvalds10.01%10.74%
paul gortmakerpaul gortmaker10.01%10.74%
andrew mortonandrew morton10.01%10.74%
Total9981100.00%135100.00%
Directory: kernel
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