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| author | Davidlohr Bueso <dave@stgolabs.net> | 2014-12-12 16:54:30 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-13 12:42:45 -0800 |
| commit | 4a23717a236b2ab31efb1651f586126789fc997f (patch) | |
| tree | d7123a21a93fff2ee555d76420504329f371a804 | |
| parent | 3dec0ba0be6a532cac949e02b853021bf6d57dad (diff) | |
| download | op-kernel-dev-4a23717a236b2ab31efb1651f586126789fc997f.zip op-kernel-dev-4a23717a236b2ab31efb1651f586126789fc997f.tar.gz | |
uprobes: share the i_mmap_rwsem
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>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/events/uprobes.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 1901dbf..995a95f 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; |
