From: Keshavamurthy Anil S <anil.s.keshavamurthy@intel.com>
Date: Mon, 25 Sep 2006 23:32:20 +0000 (-0700)
Subject: [IA64] kprobes: fixup the pagefault exception caused by probehandlers
X-Git-Tag: firefly_0821_release~33275^2~13
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=fd32cb3a9c9f9399421408e8734cd8a6d9d1a09f;p=firefly-linux-kernel-4.4.55.git

[IA64] kprobes: fixup the pagefault exception caused by probehandlers

If the user-specified kprobe handler causes the page fault when accessing
user space address, fixup this fault since do_page_fault() should not
continue as the kprobe handler are run with preemption disabled.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---

diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
index 320cb7a91c9d..169ec3a7156c 100644
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -771,6 +771,12 @@ static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr)
 		 */
 		if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
 			return 1;
+		/*
+		 * In case the user-specified fault handler returned
+		 * zero, try to fix up.
+		 */
+		if (ia64_done_with_exception(regs))
+			return 1;
 
 		/*
 		 * Let ia64_do_page_fault() fix it.