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authorOleg Nesterov <oleg@redhat.com>2012-12-28 11:58:38 -0500
committerOleg Nesterov <oleg@redhat.com>2013-02-08 11:47:10 -0500
commit8a7f2fa0dea3b019500961b86d765e6fdd4bffb2 (patch)
treec6c467e02da75a9e92f8541cf8889dbd0e2fe5fb /kernel/events
parent806a98bdf2a862fef0fc880399d677b35ba525ff (diff)
uprobes: Reintroduce uprobe_consumer->filter()
Finally add uprobe_consumer->filter() and change consumer_filter() to actually call this method. Note that ->filter() accepts mm_struct, not task_struct. Because: 1. We do not have for_each_mm_user(mm, task). 2. Even if we implement for_each_mm_user(), ->filter() can use it itself. 3. It is not clear who will actually need this interface to do the "nontrivial" filtering. Another argument is "enum uprobe_filter_ctx", consumer->filter() can use it to figure out why/where it was called. For example, perhaps we can add UPROBE_FILTER_PRE_REGISTER used by build_map_info() to quickly "nack" the unwanted mm's. In this case consumer should know that it is called under ->i_mmap_mutex. See the previous discussion at http://marc.info/?t=135214229700002 Perhaps we should pass more arguments, vma/vaddr? Note: this patch obviously can't help to filter out the child created by fork(), this will be addressed later. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/uprobes.c18
1 files changed, 11 insertions, 7 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 33912086d54e..c2737be3c4b8 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -579,19 +579,21 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file,
579 return ret; 579 return ret;
580} 580}
581 581
582static inline bool consumer_filter(struct uprobe_consumer *uc) 582static inline bool consumer_filter(struct uprobe_consumer *uc,
583 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
583{ 584{
584 return true; /* TODO: !uc->filter || uc->filter(...) */ 585 return !uc->filter || uc->filter(uc, ctx, mm);
585} 586}
586 587
587static bool filter_chain(struct uprobe *uprobe) 588static bool filter_chain(struct uprobe *uprobe,
589 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
588{ 590{
589 struct uprobe_consumer *uc; 591 struct uprobe_consumer *uc;
590 bool ret = false; 592 bool ret = false;
591 593
592 down_read(&uprobe->consumer_rwsem); 594 down_read(&uprobe->consumer_rwsem);
593 for (uc = uprobe->consumers; uc; uc = uc->next) { 595 for (uc = uprobe->consumers; uc; uc = uc->next) {
594 ret = consumer_filter(uc); 596 ret = consumer_filter(uc, ctx, mm);
595 if (ret) 597 if (ret)
596 break; 598 break;
597 } 599 }
@@ -772,10 +774,12 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
772 774
773 if (is_register) { 775 if (is_register) {
774 /* consult only the "caller", new consumer. */ 776 /* consult only the "caller", new consumer. */
775 if (consumer_filter(uprobe->consumers)) 777 if (consumer_filter(uprobe->consumers,
778 UPROBE_FILTER_REGISTER, mm))
776 err = install_breakpoint(uprobe, mm, vma, info->vaddr); 779 err = install_breakpoint(uprobe, mm, vma, info->vaddr);
777 } else if (test_bit(MMF_HAS_UPROBES, &mm->flags)) { 780 } else if (test_bit(MMF_HAS_UPROBES, &mm->flags)) {
778 if (!filter_chain(uprobe)) 781 if (!filter_chain(uprobe,
782 UPROBE_FILTER_UNREGISTER, mm))
779 err |= remove_breakpoint(uprobe, mm, info->vaddr); 783 err |= remove_breakpoint(uprobe, mm, info->vaddr);
780 } 784 }
781 785
@@ -968,7 +972,7 @@ int uprobe_mmap(struct vm_area_struct *vma)
968 */ 972 */
969 list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) { 973 list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
970 if (!fatal_signal_pending(current) && 974 if (!fatal_signal_pending(current) &&
971 filter_chain(uprobe)) { 975 filter_chain(uprobe, UPROBE_FILTER_MMAP, vma->vm_mm)) {
972 unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset); 976 unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset);
973 install_breakpoint(uprobe, vma->vm_mm, vma, vaddr); 977 install_breakpoint(uprobe, vma->vm_mm, vma, vaddr);
974 } 978 }