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-rw-r--r--kernel/events/uprobes.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index a2ed82b..1f02e3b 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1530,14 +1530,26 @@ static void handle_swbp(struct pt_regs *regs)
struct uprobe_task *utask;
struct uprobe *uprobe;
unsigned long bp_vaddr;
- int is_swbp;
+ int uninitialized_var(is_swbp);
bp_vaddr = uprobe_get_swbp_addr(regs);
uprobe = find_active_uprobe(bp_vaddr, &is_swbp);
if (!uprobe) {
- /* No matching uprobe; signal SIGTRAP. */
- send_sig(SIGTRAP, current, 0);
+ if (is_swbp > 0) {
+ /* No matching uprobe; signal SIGTRAP. */
+ send_sig(SIGTRAP, current, 0);
+ } else {
+ /*
+ * Either we raced with uprobe_unregister() or we can't
+ * access this memory. The latter is only possible if
+ * another thread plays with our ->mm. In both cases
+ * we can simply restart. If this vma was unmapped we
+ * can pretend this insn was not executed yet and get
+ * the (correct) SIGSEGV after restart.
+ */
+ instruction_pointer_set(regs, bp_vaddr);
+ }
return;
}
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