diff options
| -rw-r--r-- | include/linux/uprobes.h | 8 | ||||
| -rw-r--r-- | kernel/events/uprobes.c | 26 | ||||
| -rw-r--r-- | kernel/fork.c | 2 |
3 files changed, 33 insertions, 3 deletions
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 2615c4d7788d..4f628a6fc5b4 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -97,6 +97,8 @@ extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_con extern void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc); extern int uprobe_mmap(struct vm_area_struct *vma); extern void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end); +extern void uprobe_start_dup_mmap(void); +extern void uprobe_end_dup_mmap(void); extern void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm); extern void uprobe_free_utask(struct task_struct *t); extern void uprobe_copy_process(struct task_struct *t); @@ -127,6 +129,12 @@ static inline void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end) { } +static inline void uprobe_start_dup_mmap(void) +{ +} +static inline void uprobe_end_dup_mmap(void) +{ +} static inline void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm) { diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 5ce99cfd2e6e..dea7acfbb071 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -33,6 +33,7 @@ #include <linux/ptrace.h> /* user_enable_single_step */ #include <linux/kdebug.h> /* notifier mechanism */ #include "../../mm/internal.h" /* munlock_vma_page */ +#include <linux/percpu-rwsem.h> #include <linux/uprobes.h> @@ -71,6 +72,8 @@ static struct mutex uprobes_mutex[UPROBES_HASH_SZ]; static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ]; #define uprobes_mmap_hash(v) (&uprobes_mmap_mutex[((unsigned long)(v)) % UPROBES_HASH_SZ]) +static struct percpu_rw_semaphore dup_mmap_sem; + /* * uprobe_events allows us to skip the uprobe_mmap if there are no uprobe * events active at this time. Probably a fine grained per inode count is @@ -766,10 +769,13 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) struct map_info *info; int err = 0; + percpu_down_write(&dup_mmap_sem); info = build_map_info(uprobe->inode->i_mapping, uprobe->offset, is_register); - if (IS_ERR(info)) - return PTR_ERR(info); + if (IS_ERR(info)) { + err = PTR_ERR(info); + goto out; + } while (info) { struct mm_struct *mm = info->mm; @@ -799,7 +805,8 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) mmput(mm); info = free_map_info(info); } - + out: + percpu_up_write(&dup_mmap_sem); return err; } @@ -1131,6 +1138,16 @@ void uprobe_clear_state(struct mm_struct *mm) kfree(area); } +void uprobe_start_dup_mmap(void) +{ + percpu_down_read(&dup_mmap_sem); +} + +void uprobe_end_dup_mmap(void) +{ + percpu_up_read(&dup_mmap_sem); +} + void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm) { newmm->uprobes_state.xol_area = NULL; @@ -1597,6 +1614,9 @@ static int __init init_uprobes(void) mutex_init(&uprobes_mmap_mutex[i]); } + if (percpu_init_rwsem(&dup_mmap_sem)) + return -ENOMEM; + return register_die_notifier(&uprobe_exception_nb); } module_init(init_uprobes); diff --git a/kernel/fork.c b/kernel/fork.c index 8b20ab7d3aa2..c497e57aa654 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -352,6 +352,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) unsigned long charge; struct mempolicy *pol; + uprobe_start_dup_mmap(); down_write(&oldmm->mmap_sem); flush_cache_dup_mm(oldmm); uprobe_dup_mmap(oldmm, mm); @@ -469,6 +470,7 @@ out: up_write(&mm->mmap_sem); flush_tlb_mm(oldmm); up_write(&oldmm->mmap_sem); + uprobe_end_dup_mmap(); return retval; fail_nomem_anon_vma_fork: mpol_put(pol); |