Messages in this thread Patch in this message | | | From | Davidlohr Bueso <> | Subject | [PATCH 05/10] uprobes: share the i_mmap_rwsem | Date | Fri, 24 Oct 2014 15:06:15 -0700 |
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Both register and unregister call build_map_info() in order to create the list of mappings before installing or removing breakpoints for every mm which maps file backed memory. As such, there is no reason to hold the i_mmap_rwsem exclusively, so share it and allow concurrent readers to build the mapping data.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de> --- kernel/events/uprobes.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 045b649..7a9e620 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -724,7 +724,7 @@ build_map_info(struct address_space *mapping, loff_t offset, bool is_register) int more = 0; again: - i_mmap_lock_write(mapping); + i_mmap_lock_read(mapping); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { if (!valid_vma(vma, is_register)) continue; @@ -755,7 +755,7 @@ build_map_info(struct address_space *mapping, loff_t offset, bool is_register) info->mm = vma->vm_mm; info->vaddr = offset_to_vaddr(vma, offset); } - i_mmap_unlock_write(mapping); + i_mmap_unlock_read(mapping); if (!more) goto out; -- 1.8.4.5
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