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kprobes: Fix coding style issues 

Fix coding style issues reported by checkpatch.pl and update
comments to quote variable names and add "()" to function
name.
One TODO comment in __disarm_kprobe() is removed because
it has been done by following commit.

Link: https://lkml.kernel.org/r/163163037468.489837.4282347782492003960.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu 2021-09-14 23:39:34 +09:00 committed by Steven Rostedt (VMware)
parent 9c89bb8e32
commit 223a76b268
2 changed files with 145 additions and 131 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
include/linux/kprobes.h
View File

@ -3,7 +3,6 @@
#define _LINUX_KPROBES_H
/*
* Kernel Probes (KProbes)
* include/linux/kprobes.h
*
* Copyright (C) IBM Corporation, 2002, 2004
*
@ -39,7 +38,7 @@
#define KPROBE_REENTER 0x00000004
#define KPROBE_HIT_SSDONE 0x00000008
#else /* CONFIG_KPROBES */
#else /* !CONFIG_KPROBES */
#include <asm-generic/kprobes.h>
typedef int kprobe_opcode_t;
struct arch_specific_insn {
@ -228,7 +227,7 @@ static nokprobe_inline struct kretprobe *get_kretprobe(struct kretprobe_instance
return READ_ONCE(ri->rph->rp);
}
#else /* CONFIG_KRETPROBES */
#else /* !CONFIG_KRETPROBES */
static inline void arch_prepare_kretprobe(struct kretprobe *rp,
struct pt_regs *regs)
{
@ -239,11 +238,15 @@ static inline int arch_trampoline_kprobe(struct kprobe *p)
}
#endif /* CONFIG_KRETPROBES */
/* Markers of '_kprobe_blacklist' section */
extern unsigned long __start_kprobe_blacklist[];
extern unsigned long __stop_kprobe_blacklist[];
extern struct kretprobe_blackpoint kretprobe_blacklist[];
#ifdef CONFIG_KPROBES_SANITY_TEST
extern int init_test_probes(void);
#else
#else /* !CONFIG_KPROBES_SANITY_TEST */
static inline int init_test_probes(void)
{
return 0;
@ -303,7 +306,7 @@ static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
#define KPROBE_OPTINSN_PAGE_SYM "kprobe_optinsn_page"
int kprobe_cache_get_kallsym(struct kprobe_insn_cache *c, unsigned int *symnum,
unsigned long *value, char *type, char *sym);
#else /* __ARCH_WANT_KPROBES_INSN_SLOT */
#else /* !__ARCH_WANT_KPROBES_INSN_SLOT */
#define DEFINE_INSN_CACHE_OPS(__name) \
static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
{ \
@ -345,11 +348,12 @@ extern int sysctl_kprobes_optimization;
extern int proc_kprobes_optimization_handler(struct ctl_table *table,
int write, void *buffer,
size_t *length, loff_t *ppos);
#endif
#endif /* CONFIG_SYSCTL */
extern void wait_for_kprobe_optimizer(void);
#else
#else /* !CONFIG_OPTPROBES */
static inline void wait_for_kprobe_optimizer(void) { }
#endif /* CONFIG_OPTPROBES */
#ifdef CONFIG_KPROBES_ON_FTRACE
extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ops, struct ftrace_regs *fregs);
@ -359,7 +363,7 @@ static inline int arch_prepare_kprobe_ftrace(struct kprobe *p)
{
return -EINVAL;
}
#endif
#endif /* CONFIG_KPROBES_ON_FTRACE */
/* Get the kprobe at this addr (if any) - called with preemption disabled */
struct kprobe *get_kprobe(void *addr);
@ -367,7 +371,7 @@ struct kprobe *get_kprobe(void *addr);
/* kprobe_running() will just return the current_kprobe on this CPU */
static inline struct kprobe *kprobe_running(void)
{
return (__this_cpu_read(current_kprobe));
return __this_cpu_read(current_kprobe);
}
static inline void reset_current_kprobe(void)
@ -431,11 +435,11 @@ static inline struct kprobe *kprobe_running(void)
}
static inline int register_kprobe(struct kprobe *p)
{
return -ENOSYS;
return -EOPNOTSUPP;
}
static inline int register_kprobes(struct kprobe **kps, int num)
{
return -ENOSYS;
return -EOPNOTSUPP;
}
static inline void unregister_kprobe(struct kprobe *p)
{
@ -445,11 +449,11 @@ static inline void unregister_kprobes(struct kprobe **kps, int num)
}
static inline int register_kretprobe(struct kretprobe *rp)
{
return -ENOSYS;
return -EOPNOTSUPP;
}
static inline int register_kretprobes(struct kretprobe **rps, int num)
{
return -ENOSYS;
return -EOPNOTSUPP;
}
static inline void unregister_kretprobe(struct kretprobe *rp)
{
@ -465,11 +469,11 @@ static inline void kprobe_free_init_mem(void)
}
static inline int disable_kprobe(struct kprobe *kp)
{
return -ENOSYS;
return -EOPNOTSUPP;
}
static inline int enable_kprobe(struct kprobe *kp)
{
return -ENOSYS;
return -EOPNOTSUPP;
}
static inline bool within_kprobe_blacklist(unsigned long addr)
@ -482,6 +486,7 @@ static inline int kprobe_get_kallsym(unsigned int symnum, unsigned long *value,
return -ERANGE;
}
#endif /* CONFIG_KPROBES */
static inline int disable_kretprobe(struct kretprobe *rp)
{
return disable_kprobe(&rp->kp);
@ -496,13 +501,14 @@ static inline bool is_kprobe_insn_slot(unsigned long addr)
{
return false;
}
#endif
#endif /* !CONFIG_KPROBES */
#ifndef CONFIG_OPTPROBES
static inline bool is_kprobe_optinsn_slot(unsigned long addr)
{
return false;
}
#endif
#endif /* !CONFIG_OPTPROBES */
/* Returns true if kprobes handled the fault */
static nokprobe_inline bool kprobe_page_fault(struct pt_regs *regs,

236
kernel/kprobes.c
View File

@ -1,7 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Kernel Probes (KProbes)
* kernel/kprobes.c
*
* Copyright (C) IBM Corporation, 2002, 2004
*
@ -52,18 +51,18 @@
static int kprobes_initialized;
/* kprobe_table can be accessed by
* - Normal hlist traversal and RCU add/del under kprobe_mutex is held.
* - Normal hlist traversal and RCU add/del under 'kprobe_mutex' is held.
* Or
* - RCU hlist traversal under disabling preempt (breakpoint handlers)
*/
static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];
/* NOTE: change this value only with kprobe_mutex held */
/* NOTE: change this value only with 'kprobe_mutex' held */
static bool kprobes_all_disarmed;
/* This protects kprobe_table and optimizing_list */
/* This protects 'kprobe_table' and 'optimizing_list' */
static DEFINE_MUTEX(kprobe_mutex);
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance);
kprobe_opcode_t * __weak kprobe_lookup_name(const char *name,
unsigned int __unused)
@ -71,12 +70,15 @@ kprobe_opcode_t * __weak kprobe_lookup_name(const char *name,
return ((kprobe_opcode_t *)(kallsyms_lookup_name(name)));
}
/* Blacklist -- list of struct kprobe_blacklist_entry */
/*
* Blacklist -- list of 'struct kprobe_blacklist_entry' to store info where
* kprobes can not probe.
*/
static LIST_HEAD(kprobe_blacklist);
#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
/*
* kprobe->ainsn.insn points to the copy of the instruction to be
* '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
@ -107,6 +109,12 @@ enum kprobe_slot_state {
void __weak *alloc_insn_page(void)
{
/*
* Use module_alloc() so this page is within +/- 2GB of where the
* kernel image and loaded module images reside. This is required
* for most of the architectures.
* (e.g. x86-64 needs this to handle the %rip-relative fixups.)
*/
return module_alloc(PAGE_SIZE);
}
@ -142,6 +150,7 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c)
list_for_each_entry_rcu(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;
@ -167,11 +176,6 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c)
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);
@ -233,6 +237,7 @@ static int collect_garbage_slots(struct kprobe_insn_cache *c)
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 */
@ -313,7 +318,7 @@ int kprobe_cache_get_kallsym(struct kprobe_insn_cache *c, unsigned int *symnum,
list_for_each_entry_rcu(kip, &c->pages, list) {
if ((*symnum)--)
continue;
strlcpy(sym, c->sym, KSYM_NAME_LEN);
strscpy(sym, c->sym, KSYM_NAME_LEN);
*type = 't';
*value = (unsigned long)kip->insns;
ret = 0;
@ -361,9 +366,9 @@ static inline void reset_kprobe_instance(void)
/*
* This routine is called either:
* - under the kprobe_mutex - during kprobe_[un]register()
* OR
* - with preemption disabled - from arch/xxx/kernel/kprobes.c
* - under the 'kprobe_mutex' - during kprobe_[un]register().
* OR
* - with preemption disabled - from architecture specific code.
*/
struct kprobe *get_kprobe(void *addr)
{
@ -383,22 +388,20 @@ NOKPROBE_SYMBOL(get_kprobe);
static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs);
/* Return true if the kprobe is an aggregator */
/* Return true if 'p' is an aggregator */
static inline int kprobe_aggrprobe(struct kprobe *p)
{
return p->pre_handler == aggr_pre_handler;
}
/* Return true(!0) if the kprobe is unused */
/* Return true if 'p' is unused */
static inline int kprobe_unused(struct kprobe *p)
{
return kprobe_aggrprobe(p) && kprobe_disabled(p) &&
list_empty(&p->list);
}
/*
* Keep all fields in the kprobe consistent
*/
/* 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));
@ -406,11 +409,11 @@ static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p)
}
#ifdef CONFIG_OPTPROBES
/* NOTE: change this value only with kprobe_mutex held */
/* NOTE: This is protected by 'kprobe_mutex'. */
static bool kprobes_allow_optimization;
/*
* Call all pre_handler on the list, but ignores its return value.
* Call all 'kprobe::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)
@ -438,7 +441,7 @@ static void free_aggr_kprobe(struct kprobe *p)
kfree(op);
}
/* Return true(!0) if the kprobe is ready for optimization. */
/* Return true if the kprobe is ready for optimization. */
static inline int kprobe_optready(struct kprobe *p)
{
struct optimized_kprobe *op;
@ -451,7 +454,7 @@ static inline int kprobe_optready(struct kprobe *p)
return 0;
}
/* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */
/* Return true if the kprobe is disarmed. Note: p must be on hash list */
static inline int kprobe_disarmed(struct kprobe *p)
{
struct optimized_kprobe *op;
@ -465,7 +468,7 @@ static inline int kprobe_disarmed(struct kprobe *p)
return kprobe_disabled(p) && list_empty(&op->list);
}
/* Return true(!0) if the probe is queued on (un)optimizing lists */
/* Return true if the probe is queued on (un)optimizing lists */
static int kprobe_queued(struct kprobe *p)
{
struct optimized_kprobe *op;
@ -480,7 +483,7 @@ static int kprobe_queued(struct kprobe *p)
/*
* Return an optimized kprobe whose optimizing code replaces
* instructions including addr (exclude breakpoint).
* instructions including 'addr' (exclude breakpoint).
*/
static struct kprobe *get_optimized_kprobe(unsigned long addr)
{
@ -501,7 +504,7 @@ static struct kprobe *get_optimized_kprobe(unsigned long addr)
return NULL;
}
/* Optimization staging list, protected by kprobe_mutex */
/* Optimization staging list, protected by 'kprobe_mutex' */
static LIST_HEAD(optimizing_list);
static LIST_HEAD(unoptimizing_list);
static LIST_HEAD(freeing_list);
@ -512,20 +515,20 @@ static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
/*
* Optimize (replace a breakpoint with a jump) kprobes listed on
* optimizing_list.
* 'optimizing_list'.
*/
static void do_optimize_kprobes(void)
{
lockdep_assert_held(&text_mutex);
/*
* 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, caller must have locked cpu hotplug
* for preventing cpu-hotplug outside of text_mutex locking.
* The optimization/unoptimization refers 'online_cpus' via
* stop_machine() and cpu-hotplug modifies the 'online_cpus'.
* And same time, 'text_mutex' will be held in cpu-hotplug and here.
* This combination can cause a deadlock (cpu-hotplug tries to lock
* 'text_mutex' but stop_machine() can not be done because
* the 'online_cpus' has been changed)
* To avoid this deadlock, caller must have locked cpu-hotplug
* for preventing cpu-hotplug outside of 'text_mutex' locking.
*/
lockdep_assert_cpus_held();
@ -539,7 +542,7 @@ static void do_optimize_kprobes(void)
/*
* Unoptimize (replace a jump with a breakpoint and remove the breakpoint
* if need) kprobes listed on unoptimizing_list.
* if need) kprobes listed on 'unoptimizing_list'.
*/
static void do_unoptimize_kprobes(void)
{
@ -554,7 +557,7 @@ static void do_unoptimize_kprobes(void)
return;
arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list);
/* Loop free_list for disarming */
/* Loop on 'freeing_list' for disarming */
list_for_each_entry_safe(op, tmp, &freeing_list, list) {
/* Switching from detour code to origin */
op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
@ -565,7 +568,7 @@ static void do_unoptimize_kprobes(void)
/*
* Remove unused probes from hash list. After waiting
* for synchronization, these probes are reclaimed.
* (reclaiming is done by do_free_cleaned_kprobes.)
* (reclaiming is done by do_free_cleaned_kprobes().)
*/
hlist_del_rcu(&op->kp.hlist);
} else
@ -573,7 +576,7 @@ static void do_unoptimize_kprobes(void)
}
}
/* Reclaim all kprobes on the free_list */
/* Reclaim all kprobes on the 'freeing_list' */
static void do_free_cleaned_kprobes(void)
{
struct optimized_kprobe *op, *tmp;
@ -645,9 +648,9 @@ void wait_for_kprobe_optimizer(void)
while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) {
mutex_unlock(&kprobe_mutex);
/* this will also make optimizing_work execute immmediately */
/* This will also make 'optimizing_work' execute immmediately */
flush_delayed_work(&optimizing_work);
/* @optimizing_work might not have been queued yet, relax */
/* 'optimizing_work' might not have been queued yet, relax */
cpu_relax();
mutex_lock(&kprobe_mutex);
@ -678,7 +681,7 @@ static void optimize_kprobe(struct kprobe *p)
(kprobe_disabled(p) || kprobes_all_disarmed))
return;
/* kprobes with post_handler can not be optimized */
/* kprobes with 'post_handler' can not be optimized */
if (p->post_handler)
return;
@ -698,7 +701,10 @@ static void optimize_kprobe(struct kprobe *p)
}
op->kp.flags |= KPROBE_FLAG_OPTIMIZED;
/* On unoptimizing/optimizing_list, op must have OPTIMIZED flag */
/*
* On the 'unoptimizing_list' and 'optimizing_list',
* 'op' must have OPTIMIZED flag
*/
if (WARN_ON_ONCE(!list_empty(&op->list)))
return;
@ -768,7 +774,7 @@ static int reuse_unused_kprobe(struct kprobe *ap)
WARN_ON_ONCE(list_empty(&op->list));
/* Enable the probe again */
ap->flags &= ~KPROBE_FLAG_DISABLED;
/* Optimize it again (remove from op->list) */
/* Optimize it again. (remove from 'op->list') */
if (!kprobe_optready(ap))
return -EINVAL;
@ -818,7 +824,7 @@ static void prepare_optimized_kprobe(struct kprobe *p)
__prepare_optimized_kprobe(op, p);
}
/* Allocate new optimized_kprobe and try to prepare optimized instructions */
/* Allocate new optimized_kprobe and try to prepare optimized instructions. */
static struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
{
struct optimized_kprobe *op;
@ -837,19 +843,19 @@ static struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
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
* 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 */
/* Impossible to optimize ftrace-based kprobe. */
if (kprobe_ftrace(p))
return;
/* For preparing optimization, jump_label_text_reserved() is called */
/* For preparing optimization, jump_label_text_reserved() is called. */
cpus_read_lock();
jump_label_lock();
mutex_lock(&text_mutex);
@ -860,14 +866,14 @@ static void try_to_optimize_kprobe(struct kprobe *p)
op = container_of(ap, struct optimized_kprobe, kp);
if (!arch_prepared_optinsn(&op->optinsn)) {
/* If failed to setup optimizing, fallback to kprobe */
/* 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 */
optimize_kprobe(ap); /* This just kicks optimizer thread. */
out:
mutex_unlock(&text_mutex);
@ -882,7 +888,7 @@ static void optimize_all_kprobes(void)
unsigned int i;
mutex_lock(&kprobe_mutex);
/* If optimization is already allowed, just return */
/* If optimization is already allowed, just return. */
if (kprobes_allow_optimization)
goto out;
@ -908,7 +914,7 @@ static void unoptimize_all_kprobes(void)
unsigned int i;
mutex_lock(&kprobe_mutex);
/* If optimization is already prohibited, just return */
/* If optimization is already prohibited, just return. */
if (!kprobes_allow_optimization) {
mutex_unlock(&kprobe_mutex);
return;
@ -926,7 +932,7 @@ static void unoptimize_all_kprobes(void)
cpus_read_unlock();
mutex_unlock(&kprobe_mutex);
/* Wait for unoptimizing completion */
/* Wait for unoptimizing completion. */
wait_for_kprobe_optimizer();
pr_info("kprobe jump-optimization is disabled. All kprobes are based on software breakpoint.\n");
}
@ -953,12 +959,12 @@ int proc_kprobes_optimization_handler(struct ctl_table *table, int write,
}
#endif /* CONFIG_SYSCTL */
/* Put a breakpoint for a probe. Must be called with text_mutex locked */
/* 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 */
/* Find the overlapping optimized kprobes. */
_p = get_optimized_kprobe((unsigned long)p->addr);
if (unlikely(_p))
/* Fallback to unoptimized kprobe */
@ -968,7 +974,7 @@ static void __arm_kprobe(struct kprobe *p)
optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */
}
/* Remove the breakpoint of a probe. Must be called with text_mutex locked */
/* 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;
@ -978,12 +984,17 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt)
if (!kprobe_queued(p)) {
arch_disarm_kprobe(p);
/* If another kprobe was blocked, optimize it. */
/* If another kprobe was blocked, re-optimize it. */
_p = get_optimized_kprobe((unsigned long)p->addr);
if (unlikely(_p) && reopt)
optimize_kprobe(_p);
}
/* TODO: reoptimize others after unoptimized this probe */
/*
* TODO: Since unoptimization and real disarming will be done by
* the worker thread, we can not check whether another probe are
* unoptimized because of this probe here. It should be re-optimized
* by the worker thread.
*/
}
#else /* !CONFIG_OPTPROBES */
@ -1036,7 +1047,7 @@ static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = {
static int kprobe_ipmodify_enabled;
static int kprobe_ftrace_enabled;
/* Caller must lock kprobe_mutex */
/* Caller must lock 'kprobe_mutex' */
static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
int *cnt)
{
@ -1073,7 +1084,7 @@ static int arm_kprobe_ftrace(struct kprobe *p)
ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled);
}
/* Caller must lock kprobe_mutex */
/* Caller must lock 'kprobe_mutex'. */
static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
int *cnt)
{
@ -1122,7 +1133,7 @@ static int prepare_kprobe(struct kprobe *p)
return arch_prepare_kprobe(p);
}
/* Arm a kprobe with text_mutex */
/* Arm a kprobe with 'text_mutex'. */
static int arm_kprobe(struct kprobe *kp)
{
if (unlikely(kprobe_ftrace(kp)))
@ -1137,7 +1148,7 @@ static int arm_kprobe(struct kprobe *kp)
return 0;
}
/* Disarm a kprobe with text_mutex */
/* Disarm a kprobe with 'text_mutex'. */
static int disarm_kprobe(struct kprobe *kp, bool reopt)
{
if (unlikely(kprobe_ftrace(kp)))
@ -1187,17 +1198,17 @@ static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs,
}
NOKPROBE_SYMBOL(aggr_post_handler);
/* Walks the list and increments nmissed count for multiprobe case */
/* Walks the list and increments 'nmissed' if 'p' has child probes. */
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;
}
NOKPROBE_SYMBOL(kprobes_inc_nmissed_count);
@ -1215,9 +1226,9 @@ static void recycle_rp_inst(struct kretprobe_instance *ri)
{
struct kretprobe *rp = get_kretprobe(ri);
if (likely(rp)) {
if (likely(rp))
freelist_add(&ri->freelist, &rp->freelist);
} else
else
call_rcu(&ri->rcu, free_rp_inst_rcu);
}
NOKPROBE_SYMBOL(recycle_rp_inst);
@ -1243,8 +1254,8 @@ void kprobe_busy_end(void)
}
/*
* This function is called from finish_task_switch when task tk becomes dead,
* so that we can recycle any function-return probe instances associated
* This function is called from finish_task_switch() when task 'tk' becomes
* dead, so that we can recycle any kretprobe instances associated
* with this task. These left over instances represent probed functions
* that have been called but will never return.
*/
@ -1292,7 +1303,7 @@ static inline void free_rp_inst(struct kretprobe *rp)
}
}
/* Add the new probe to ap->list */
/* Add the new probe to 'ap->list'. */
static int add_new_kprobe(struct kprobe *ap, struct kprobe *p)
{
if (p->post_handler)
@ -1306,12 +1317,12 @@ static int add_new_kprobe(struct kprobe *ap, struct kprobe *p)
}
/*
* Fill in the required fields of the "manager kprobe". Replace the
* earlier kprobe in the hlist with the manager kprobe
* Fill in the required fields of the aggregator kprobe. Replace the
* earlier kprobe in the hlist with the aggregator kprobe.
*/
static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p)
{
/* Copy p's insn slot to ap */
/* Copy the insn slot of 'p' to 'ap'. */
copy_kprobe(p, ap);
flush_insn_slot(ap);
ap->addr = p->addr;
@ -1329,8 +1340,7 @@ static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p)
}
/*
* This is the second or subsequent kprobe at the address - handle
* the intricacies
* This registers the second or subsequent kprobe at the same address.
*/
static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p)
{
@ -1344,7 +1354,7 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p)
mutex_lock(&text_mutex);
if (!kprobe_aggrprobe(orig_p)) {
/* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */
/* If 'orig_p' is not an 'aggr_kprobe', create new one. */
ap = alloc_aggr_kprobe(orig_p);
if (!ap) {
ret = -ENOMEM;
@ -1369,8 +1379,8 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p)
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.
* free the 'ap'. It will be used next time, or
* freed by unregister_kprobe().
*/
goto out;
@ -1385,7 +1395,7 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p)
| KPROBE_FLAG_DISABLED;
}
/* Copy ap's insn slot to p */
/* Copy the insn slot of 'p' to 'ap'. */
copy_kprobe(ap, p);
ret = add_new_kprobe(ap, p);
@ -1411,7 +1421,7 @@ out:
bool __weak arch_within_kprobe_blacklist(unsigned long addr)
{
/* The __kprobes marked functions and entry code must not be probed */
/* The '__kprobes' functions and entry code must not be probed. */
return addr >= (unsigned long)__kprobes_text_start &&
addr < (unsigned long)__kprobes_text_end;
}
@ -1423,8 +1433,8 @@ static bool __within_kprobe_blacklist(unsigned long addr)
if (arch_within_kprobe_blacklist(addr))
return true;
/*
* If there exists a kprobe_blacklist, verify and
* fail any probe registration in the prohibited area
* If 'kprobe_blacklist' is defined, check the address and
* reject any probe registration in the prohibited area.
*/
list_for_each_entry(ent, &kprobe_blacklist, list) {
if (addr >= ent->start_addr && addr < ent->end_addr)
@ -1454,7 +1464,7 @@ bool within_kprobe_blacklist(unsigned long addr)
}
/*
* If we have a symbol_name argument, look it up and add the offset field
* If 'symbol_name' is specified, look it up and add the 'offset'
* 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.
@ -1484,7 +1494,10 @@ static kprobe_opcode_t *kprobe_addr(struct kprobe *p)
return _kprobe_addr(p->addr, p->symbol_name, p->offset);
}
/* Check passed kprobe is valid and return kprobe in kprobe_table. */
/*
* Check the 'p' is valid and return the aggregator kprobe
* at the same address.
*/
static struct kprobe *__get_valid_kprobe(struct kprobe *p)
{
struct kprobe *ap, *list_p;
@ -1561,7 +1574,7 @@ static int check_kprobe_address_safe(struct kprobe *p,
goto out;
}
/* Check if are we probing a module */
/* Check if 'p' is probing a module. */
*probed_mod = __module_text_address((unsigned long) p->addr);
if (*probed_mod) {
/*
@ -1574,7 +1587,7 @@ static int check_kprobe_address_safe(struct kprobe *p,
}
/*
* If the module freed .init.text, we couldn't insert
* If the module freed '.init.text', we couldn't insert
* kprobes in there.
*/
if (within_module_init((unsigned long)p->addr, *probed_mod) &&
@ -1621,7 +1634,7 @@ int register_kprobe(struct kprobe *p)
old_p = get_kprobe(p->addr);
if (old_p) {
/* Since this may unoptimize old_p, locking text_mutex. */
/* Since this may unoptimize 'old_p', locking 'text_mutex'. */
ret = register_aggr_kprobe(old_p, p);
goto out;
}
@ -1660,7 +1673,7 @@ out:
}
EXPORT_SYMBOL_GPL(register_kprobe);
/* Check if all probes on the aggrprobe are disabled */
/* Check if all probes on the 'ap' are disabled. */
static int aggr_kprobe_disabled(struct kprobe *ap)
{
struct kprobe *kp;
@ -1670,15 +1683,15 @@ static int aggr_kprobe_disabled(struct kprobe *ap)
list_for_each_entry(kp, &ap->list, list)
if (!kprobe_disabled(kp))
/*
* There is an active probe on the list.
* We can't disable this ap.
* Since there is an active probe on the list,
* we can't disable this 'ap'.
*/
return 0;
return 1;
}
/* Disable one kprobe: Make sure called under kprobe_mutex is locked */
/* Disable one kprobe: Make sure called under 'kprobe_mutex' is locked. */
static struct kprobe *__disable_kprobe(struct kprobe *p)
{
struct kprobe *orig_p;
@ -1697,7 +1710,7 @@ static struct kprobe *__disable_kprobe(struct kprobe *p)
/* 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
* If 'kprobes_all_disarmed' is set, 'orig_p'
* should have already been disarmed, so
* skip unneed disarming process.
*/
@ -1984,7 +1997,7 @@ int register_kretprobe(struct kretprobe *rp)
if (ret)
return ret;
/* If only rp->kp.addr is specified, check reregistering kprobes */
/* If only 'rp->kp.addr' is specified, check reregistering kprobes */
if (rp->kp.addr && warn_kprobe_rereg(&rp->kp))
return -EINVAL;
@ -2089,13 +2102,13 @@ EXPORT_SYMBOL_GPL(unregister_kretprobes);
#else /* CONFIG_KRETPROBES */
int register_kretprobe(struct kretprobe *rp)
{
return -ENOSYS;
return -EOPNOTSUPP;
}
EXPORT_SYMBOL_GPL(register_kretprobe);
int register_kretprobes(struct kretprobe **rps, int num)
{
return -ENOSYS;
return -EOPNOTSUPP;
}
EXPORT_SYMBOL_GPL(register_kretprobes);
@ -2144,7 +2157,7 @@ static void kill_kprobe(struct kprobe *p)
/*
* The module is going away. We should disarm the kprobe which
* is using ftrace, because ftrace framework is still available at
* MODULE_STATE_GOING notification.
* 'MODULE_STATE_GOING' notification.
*/
if (kprobe_ftrace(p) && !kprobe_disabled(p) && !kprobes_all_disarmed)
disarm_kprobe_ftrace(p);
@ -2317,13 +2330,13 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
return ret;
}
/* Symbols in __kprobes_text are blacklisted */
/* Symbols in '__kprobes_text' are blacklisted */
ret = kprobe_add_area_blacklist((unsigned long)__kprobes_text_start,
(unsigned long)__kprobes_text_end);
if (ret)
return ret;
/* Symbols in noinstr section are blacklisted */
/* Symbols in 'noinstr' section are blacklisted */
ret = kprobe_add_area_blacklist((unsigned long)__noinstr_text_start,
(unsigned long)__noinstr_text_end);
@ -2395,9 +2408,9 @@ static int kprobes_module_callback(struct notifier_block *nb,
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
* 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);
@ -2414,9 +2427,9 @@ static int kprobes_module_callback(struct notifier_block *nb,
*
* Note, this will also move any optimized probes
* that are pending to be removed from their
* corresponding lists to the freeing_list and
* corresponding lists to the 'freeing_list' and
* will not be touched by the delayed
* kprobe_optimizer work handler.
* kprobe_optimizer() work handler.
*/
kill_kprobe(p);
}
@ -2432,10 +2445,6 @@ static struct notifier_block kprobe_module_nb = {
.priority = 0
};
/* Markers of _kprobe_blacklist section */
extern unsigned long __start_kprobe_blacklist[];
extern unsigned long __stop_kprobe_blacklist[];
void kprobe_free_init_mem(void)
{
void *start = (void *)(&__init_begin);
@ -2446,7 +2455,7 @@ void kprobe_free_init_mem(void)
mutex_lock(&kprobe_mutex);
/* Kill all kprobes on initmem */
/* Kill all kprobes on initmem because the target code has been freed. */
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
hlist_for_each_entry(p, head, hlist) {
@ -2469,9 +2478,8 @@ static int __init init_kprobes(void)
err = populate_kprobe_blacklist(__start_kprobe_blacklist,
__stop_kprobe_blacklist);
if (err) {
if (err)
pr_err("Failed to populate blacklist (error %d), kprobes not restricted, be careful using them!\n", err);
}
if (kretprobe_blacklist_size) {
/* lookup the function address from its name */
@ -2488,7 +2496,7 @@ static int __init init_kprobes(void)
kprobes_all_disarmed = false;
#if defined(CONFIG_OPTPROBES) && defined(__ARCH_WANT_KPROBES_INSN_SLOT)
/* Init kprobe_optinsn_slots for allocation */
/* Init 'kprobe_optinsn_slots' for allocation */
kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE;
#endif
@ -2622,7 +2630,7 @@ static int kprobe_blacklist_seq_show(struct seq_file *m, void *v)
list_entry(v, struct kprobe_blacklist_entry, list);
/*
* If /proc/kallsyms is not showing kernel address, we won't
* If '/proc/kallsyms' is not showing kernel address, we won't
* show them here either.
*/
if (!kallsyms_show_value(m->file->f_cred))