Messages in this thread Patch in this message | | | Date | Sat, 24 Nov 2012 19:02:36 +0100 | From | Oleg Nesterov <> | Subject | [PATCH 4/4] uprobes: Kill uprobe->copy_mutex |
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Now that ->register_rwsem is safe under ->mmap_sem we can kill ->copy_mutex and abuse down_write(&uprobe->consumer_rwsem).
This makes prepare_uprobe() even more ugly, but we should kill it anyway.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- kernel/events/uprobes.c | 7 +++---- 1 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 97c3874..1e047f8 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -91,7 +91,6 @@ struct uprobe { atomic_t ref; struct rw_semaphore register_rwsem; struct rw_semaphore consumer_rwsem; - struct mutex copy_mutex; /* TODO: kill me and UPROBE_COPY_INSN */ struct list_head pending_list; struct uprobe_consumer *consumers; struct inode *inode; /* Also hold a ref to inode */ @@ -450,7 +449,6 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset) uprobe->offset = offset; init_rwsem(&uprobe->register_rwsem); init_rwsem(&uprobe->consumer_rwsem); - mutex_init(&uprobe->copy_mutex); /* For now assume that the instruction need not be single-stepped */ __set_bit(UPROBE_SKIP_SSTEP, &uprobe->flags); @@ -578,7 +576,8 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, if (test_bit(UPROBE_COPY_INSN, &uprobe->flags)) return ret; - mutex_lock(&uprobe->copy_mutex); + /* TODO: move this into _register, until then we abuse this sem. */ + down_write(&uprobe->consumer_rwsem); if (test_bit(UPROBE_COPY_INSN, &uprobe->flags)) goto out; @@ -602,7 +601,7 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, set_bit(UPROBE_COPY_INSN, &uprobe->flags); out: - mutex_unlock(&uprobe->copy_mutex); + up_write(&uprobe->consumer_rwsem); return ret; } -- 1.5.5.1
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