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From: Peter Zijlstra <peterz@infradead.org>
To: mhiramat@kernel.org
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	mingo@kernel.org, rostedt@goodmis.org,
	naveen.n.rao@linux.vnet.ibm.com, ananth@linux.ibm.com,
	x86@kernel.org
Subject: [PATCH 2/2] x86,kprobes: WARN if kprobes tries to handle a fault
Date: Tue, 25 May 2021 09:25:20 +0200	[thread overview]
Message-ID: <20210525073213.660594073@infradead.org> (raw)
In-Reply-To: 20210525072518.791889911@infradead.org

With the removal of kprobe::handle_fault there is no reason left that
kprobe_page_fault() would ever return true on x86, make sure it
doesn't happen by accident.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/mm/fault.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1186,7 +1186,7 @@ do_kern_addr_fault(struct pt_regs *regs,
 		return;
 
 	/* kprobes don't want to hook the spurious faults: */
-	if (kprobe_page_fault(regs, X86_TRAP_PF))
+	if (WARN_ON_ONCE(kprobe_page_fault(regs, X86_TRAP_PF)))
 		return;
 
 	/*
@@ -1239,7 +1239,7 @@ void do_user_addr_fault(struct pt_regs *
 	}
 
 	/* kprobes don't want to hook the spurious faults: */
-	if (unlikely(kprobe_page_fault(regs, X86_TRAP_PF)))
+	if (WARN_ON_ONCE(kprobe_page_fault(regs, X86_TRAP_PF)))
 		return;
 
 	/*



  parent reply	other threads:[~2021-05-25  7:33 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-25  7:25 [PATCH 0/2] kprobes: Remove kprobe::fault_handler Peter Zijlstra
2021-05-25  7:25 ` [PATCH 1/2] " Peter Zijlstra
2021-05-25 14:06   ` Masami Hiramatsu
2021-05-26 10:50   ` Naveen N. Rao
2021-05-26 13:51     ` Masami Hiramatsu
2021-06-01 12:01   ` [PATCH] kprobes: Do not increment probe miss count in the fault handler Naveen N. Rao
2021-06-01 13:20     ` Peter Zijlstra
2021-06-01 23:48       ` Masami Hiramatsu
2021-06-04 13:38     ` [tip: perf/core] " tip-bot2 for Naveen N. Rao
2021-06-01 14:04   ` [tip: perf/core] kprobes: Remove kprobe::fault_handler tip-bot2 for Peter Zijlstra
2021-05-25  7:25 ` Peter Zijlstra [this message]
2021-05-25 14:21   ` [PATCH 2/2] x86,kprobes: WARN if kprobes tries to handle a fault Masami Hiramatsu
2021-06-01 14:04   ` [tip: perf/core] " tip-bot2 for Peter Zijlstra

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