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Simplify synchronization with JUMP_LABEL engine

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We don't need to introduce custom LKRG-counter lock to synchronize with JUMP_LABEL engine and avoid potential deadlock with FTRACE. We can check if jump_label lock is taken after acquiring ftrace lock and before taking text_mutex.
This simplification changes p_text_section_(un)lock API.

This also fixes problem reported by Jacek
This commit is contained in:
Adam_pi3 2020-11-02 16:09:07 -05:00
parent 83cb64640a
commit f98da1b17c
No known key found for this signature in database
GPG key ID: 7C0A38B52323F571
6 changed files with 26 additions and 34 deletions
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10
src/modules/database/CPU.c
View file

@ -138,9 +138,8 @@ int p_cpu_callback(struct notifier_block *p_block, unsigned long p_action, void
int p_cpu_online_action(unsigned int p_cpu) {
int tmp_online_CPUs = p_db.p_cpu.online_CPUs;
unsigned long p_flags;
p_text_section_lock(&p_flags);
p_text_section_lock();
spin_lock(&p_db_lock);
smp_call_function_single(p_cpu,p_dump_CPU_metadata,p_db.p_CPU_metadata_array,true);
@ -196,7 +195,7 @@ int p_cpu_online_action(unsigned int p_cpu) {
/* God mode off ;) */
// spin_unlock_irqrestore(&p_db_lock,p_db_flags);
spin_unlock(&p_db_lock);
p_text_section_unlock(&p_flags);
p_text_section_unlock();
return 0;
}
@ -204,9 +203,8 @@ int p_cpu_online_action(unsigned int p_cpu) {
int p_cpu_dead_action(unsigned int p_cpu) {
int tmp_online_CPUs = p_db.p_cpu.online_CPUs;
unsigned long p_flags;
p_text_section_lock(&p_flags);
p_text_section_lock();
spin_lock(&p_db_lock);
p_db.p_CPU_metadata_array[p_cpu].p_cpu_online = P_CPU_OFFLINE;
@ -270,7 +268,7 @@ int p_cpu_dead_action(unsigned int p_cpu) {
/* God mode off ;) */
// spin_unlock_irqrestore(&p_db_lock,p_db_flags);
spin_unlock(&p_db_lock);
p_text_section_unlock(&p_flags);
p_text_section_unlock();
return 0;
}

17
src/modules/database/p_database.c
View file

@ -190,10 +190,15 @@ int p_create_database(void) {
int p_tmp;
// int p_tmp_cpu;
unsigned long p_flags;
memset(&p_db,0x0,sizeof(p_hash_database));
if ( (P_SYM(p_jump_label_mutex) = (struct mutex *)P_SYM(p_kallsyms_lookup_name)("jump_label_mutex")) == NULL) {
p_print_log(P_LKRG_ERR,
"CREATING DATABASE: error! Can't find 'jump_label_mutex' variable :( Exiting...\n");
return P_LKRG_GENERAL_ERROR;
}
if ( (P_SYM(p_text_mutex) = (struct mutex *)P_SYM(p_kallsyms_lookup_name)("text_mutex")) == NULL) {
p_print_log(P_LKRG_ERR,
"CREATING DATABASE: error! Can't find 'text_mutex' variable :( Exiting...\n");
@ -307,7 +312,7 @@ int p_create_database(void) {
}
p_text_section_lock(&p_flags);
p_text_section_lock();
/*
* Memory allocation may fail... let's loop here!
@ -327,7 +332,7 @@ int p_create_database(void) {
(unsigned int)p_db.p_module_kobj_nr * sizeof(p_module_kobj_mem));
*/
p_text_section_unlock(&p_flags);
p_text_section_unlock();
/* Register module notification routine - must be outside p_text_section_(un)lock */
p_register_module_notifier();
@ -352,14 +357,14 @@ int p_create_database(void) {
#if !defined(CONFIG_GRKERNSEC)
p_text_section_lock(&p_flags);
p_text_section_lock();
if (hash_from_kernel_stext() != P_LKRG_SUCCESS) {
p_print_log(P_LKRG_CRIT,
"CREATING DATABASE ERROR: HASH FROM _STEXT!\n");
p_text_section_unlock(&p_flags);
p_text_section_unlock();
return P_LKRG_GENERAL_ERROR;
}
p_text_section_unlock(&p_flags);
p_text_section_unlock();
#endif
return P_LKRG_SUCCESS;

18
src/modules/database/p_database.h
View file

@ -178,33 +178,23 @@ int hash_from_kernel_stext(void);
int hash_from_kernel_rodata(void);
int hash_from_iommu_table(void);
static inline void p_text_section_lock(unsigned long *p_arg) {
static inline void p_text_section_lock(void) {
#if defined(CONFIG_FUNCTION_TRACER)
mutex_lock(P_SYM(p_ftrace_lock));
#endif
do {
while (!p_lkrg_counter_lock_trylock(&p_jl_lock, p_arg))
schedule();
if (p_lkrg_counter_lock_val_read(&p_jl_lock)) {
p_lkrg_counter_lock_unlock(&p_jl_lock, p_arg);
schedule();
continue;
} else {
break;
}
} while(1);
while (mutex_is_locked(P_SYM(p_jump_label_mutex)))
schedule();
mutex_lock(P_SYM(p_text_mutex));
/* We are heavily consuming module list here - take 'module_mutex' */
mutex_lock(&module_mutex);
}
static inline void p_text_section_unlock(unsigned long *p_arg) {
static inline void p_text_section_unlock(void) {
/* Release the 'module_mutex' */
mutex_unlock(&module_mutex);
mutex_unlock(P_SYM(p_text_mutex));
p_lkrg_counter_lock_unlock(&p_jl_lock, p_arg);
#if defined(CONFIG_FUNCTION_TRACER)
mutex_unlock(P_SYM(p_ftrace_lock));
#endif

7
src/modules/integrity_timer/p_integrity_timer.c
View file

@ -117,7 +117,6 @@ void p_check_integrity(struct work_struct *p_work) {
struct module *p_tmp_mod;
unsigned int p_tmp = 0;
int p_ret;
unsigned long p_flags;
if (!P_CTRL(p_kint_validate) || (!p_manual && P_CTRL(p_kint_validate) == 1))
goto p_check_integrity_tasks;
@ -212,7 +211,7 @@ void p_check_integrity(struct work_struct *p_work) {
p_tmp_hash = hash_from_CPU_data(p_tmp_cpus);
put_online_cpus();
p_text_section_lock(&p_flags);
p_text_section_lock();
/*
* Memory allocation may fail... let's loop here!
@ -229,7 +228,7 @@ void p_check_integrity(struct work_struct *p_work) {
schedule();
}
/*
p_text_section_unlock(&p_flags);
p_text_section_unlock();
*/
spin_lock_irqsave(&p_db_lock,p_db_flags);
@ -1772,7 +1771,7 @@ void p_check_integrity(struct work_struct *p_work) {
p_check_integrity_cancel:
p_text_section_unlock(&p_flags);
p_text_section_unlock();
if (p_tmp_cpus) {
kzfree(p_tmp_cpus);
p_tmp_cpus = NULL;

7
src/modules/kmod/p_kmod_notifier.c
View file

@ -57,7 +57,6 @@ static void p_module_notifier_wrapper(unsigned long p_event, struct module *p_km
static int p_module_event_notifier(struct notifier_block *p_this, unsigned long p_event, void *p_kmod) {
struct module *p_tmp = p_kmod;
unsigned long p_flags;
// STRONG_DEBUG
#ifdef P_LKRG_DEBUG
@ -110,7 +109,7 @@ static int p_module_event_notifier(struct notifier_block *p_this, unsigned long
* We must keep in track that information ;)
*/
p_text_section_lock(&p_flags);
p_text_section_lock();
/*
* First, synchronize possible database changes with other LKRG components...
* We want to be as fast as possible to get this lock! :)
@ -179,7 +178,7 @@ static int p_module_event_notifier(struct notifier_block *p_this, unsigned long
* and recalculate global module hashes...
*/
p_text_section_lock(&p_flags);
p_text_section_lock();
/*
* First, synchronize possible database changes with other LKRG components...
@ -233,7 +232,7 @@ p_module_event_notifier_unlock_out:
/* God mode off ;) */
// spin_unlock_irqrestore(&p_db_lock,p_db_flags);
spin_unlock(&p_db_lock);
p_text_section_unlock(&p_flags);
p_text_section_unlock();
p_module_event_notifier_activity_out:

1
src/p_lkrg_main.h
View file

@ -168,6 +168,7 @@ typedef struct _p_lkrg_global_symbols_structure {
#endif
int (*p_core_kernel_text)(unsigned long p_addr);
pmd_t *(*p_mm_find_pmd)(struct mm_struct *mm, unsigned long address);
struct mutex *p_jump_label_mutex;
struct mutex *p_text_mutex;
struct text_poke_loc **p_tp_vec;
int *p_tp_vec_nr;