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authorOleg Nesterov <oleg@redhat.com>2012-11-24 21:51:34 +0400
committerOleg Nesterov <oleg@redhat.com>2013-02-08 20:47:08 +0400
commitd4d3ccc6d1eb74bd315d49a3829c5ad6c48d21b0 (patch)
treee8ccc45b9b9f8c72aaea150bf93d4d56cf9dc8d4 /kernel
parentbb929284be40cbbdb347690742557d708fd504a9 (diff)
downloadlinux-d4d3ccc6d1eb74bd315d49a3829c5ad6c48d21b0.tar.xz
uprobes: Kill uprobe->copy_mutex
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> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/uprobes.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 7ec2eb278634..40ced98b2bc8 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;
}