linux-kernel - [PATCH v4 1/8] arm64: Do not enable IRQs for ct_user

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1560245893-46998-2-git-send-email-julien.thierry@arm.com>
Date:   Tue, 11 Jun 2019 10:38:06 +0100
From:   Julien Thierry <julien.thierry@....com>
To:     linux-arm-kernel@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, rostedt@...dmis.org,
        marc.zyngier@....com, yuzenghui@...wei.com,
        wanghaibin.wang@...wei.com, james.morse@....com,
        will.deacon@....com, catalin.marinas@....com, mark.rutland@....com,
        liwei391@...wei.com, Julien Thierry <julien.thierry@....com>
Subject: [PATCH v4 1/8] arm64: Do not enable IRQs for ct_user_exit

For el0_dbg and el0_error, DAIF bits get explicitly cleared before
calling ct_user_exit.

When context tracking is disabled, DAIF gets set (almost) immediately
after. When context tracking is enabled, among the first things done
is disabling IRQs.

What is actually needed is:
- PSR.D = 0 so the system can be debugged (should be already the case)
- PSR.A = 0 so async error can be handled during context tracking

Do not clear PSR.I in those two locations.

Signed-off-by: Julien Thierry <julien.thierry@....com>
Reviewed-by: James Morse <james.morse@....com>
Cc:Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will.deacon@....com>
Cc: Mark Rutland <mark.rutland@....com>
Cc: Marc Zyngier <marc.zyngier@....com>
---
 arch/arm64/kernel/entry.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index cd0c7af..89ab6bd 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -870,7 +870,7 @@ el0_dbg:
 	mov	x1, x25
 	mov	x2, sp
 	bl	do_debug_exception
-	enable_daif
+	enable_da_f
 	ct_user_exit
 	b	ret_to_user
 el0_inv:
@@ -922,7 +922,7 @@ el0_error_naked:
 	enable_dbg
 	mov	x0, sp
 	bl	do_serror
-	enable_daif
+	enable_da_f
 	ct_user_exit
 	b	ret_to_user
 ENDPROC(el0_error)
--
1.9.1