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| author | Ravi Bangoria <ravi.bangoria@linux.ibm.com> | 2018-08-20 10:12:48 +0530 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-09-24 04:44:54 -0400 |
| commit | 22bad38286d9a652d7061a02f9743bb2ebb84e59 (patch) | |
| tree | a43f88655fda4bdaf5470133c9b0fd367f22d3f6 /kernel/events | |
| parent | 1cc33161a83d20b5462b1e93f95d3ce6388079ee (diff) | |
| download | lwn-22bad38286d9a652d7061a02f9743bb2ebb84e59.tar.gz lwn-22bad38286d9a652d7061a02f9743bb2ebb84e59.zip | |
uprobes/sdt: Prevent multiple reference counter for same uprobe
We assume to have only one reference counter for one uprobe.
Don't allow user to register multiple uprobes having same
inode+offset but different reference counter.
Link: http://lkml.kernel.org/r/20180820044250.11659-3-ravi.bangoria@linux.ibm.com
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Song Liu <songliubraving@fb.com>
Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/uprobes.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 934feb39f6be..96fb51f3994f 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -679,6 +679,16 @@ static struct uprobe *insert_uprobe(struct uprobe *uprobe) return u; } +static void +ref_ctr_mismatch_warn(struct uprobe *cur_uprobe, struct uprobe *uprobe) +{ + pr_warn("ref_ctr_offset mismatch. inode: 0x%lx offset: 0x%llx " + "ref_ctr_offset(old): 0x%llx ref_ctr_offset(new): 0x%llx\n", + uprobe->inode->i_ino, (unsigned long long) uprobe->offset, + (unsigned long long) cur_uprobe->ref_ctr_offset, + (unsigned long long) uprobe->ref_ctr_offset); +} + static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset, loff_t ref_ctr_offset) { @@ -698,6 +708,12 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset, cur_uprobe = insert_uprobe(uprobe); /* a uprobe exists for this inode:offset combination */ if (cur_uprobe) { + if (cur_uprobe->ref_ctr_offset != uprobe->ref_ctr_offset) { + ref_ctr_mismatch_warn(cur_uprobe, uprobe); + put_uprobe(cur_uprobe); + kfree(uprobe); + return ERR_PTR(-EINVAL); + } kfree(uprobe); uprobe = cur_uprobe; } @@ -1112,6 +1128,9 @@ static int __uprobe_register(struct inode *inode, loff_t offset, uprobe = alloc_uprobe(inode, offset, ref_ctr_offset); if (!uprobe) return -ENOMEM; + if (IS_ERR(uprobe)) + return PTR_ERR(uprobe); + /* * We can race with uprobe_unregister()->delete_uprobe(). * Check uprobe_is_active() and retry if it is false. |