linux-kernel - [PATCH v2 12/14] x86/fault: Don't look for extable entries for SMEP violations

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Message-Id: <46160d8babce2abf1d6daa052146002efa24ac56.1612924255.git.luto@kernel.org>
Date:   Tue,  9 Feb 2021 18:33:44 -0800
From:   Andy Lutomirski <luto@...nel.org>
To:     x86@...nel.org
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Yonghong Song <yhs@...com>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH v2 12/14] x86/fault: Don't look for extable entries for SMEP violations

If we get a SMEP violation or a fault that would have been a SMEP
violation if we had SMEP, we shouldn't run fixups.  Just OOPS.

Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Signed-off-by: Andy Lutomirski <luto@...nel.org>
---
 arch/x86/mm/fault.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 9fb636b2a3da..466415bdf58c 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1249,12 +1249,12 @@ void do_user_addr_fault(struct pt_regs *regs,
 		 * user memory.  Unless this is AMD erratum #93, which
 		 * corrupts RIP such that it looks like a user address,
 		 * this is unrecoverable.  Don't even try to look up the
-		 * VMA.
+		 * VMA or look for extable entries.
 		 */
 		if (is_errata93(regs, address))
 			return;
 
-		bad_area_nosemaphore(regs, error_code, address);
+		page_fault_oops(regs, error_code, address);
 		return;
 	}
 
-- 
2.29.2