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From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH v2 46/52] powerpc/64s/exception: fix machine check early should not set AMR
Date: Thu, 20 Jun 2019 15:14:53 +1000	[thread overview]
Message-ID: <20190620051459.29573-47-npiggin@gmail.com> (raw)
In-Reply-To: <20190620051459.29573-1-npiggin@gmail.com>

The early machine check runs in real mode, so locking is unnecessary.
Worse, the windup does not restore AMR, so this can result in a false
KUAP fault after a recoverable machine check hits inside a user copy
operation.

Fix this similarly to HMI by just avoiding the kuap lock in the
early machine check handler (it will be set by the late handler that
runs in virtual mode if that runs).

Fixes: 890274c2dc4c0 ("powerpc/64s: Implement KUAP for Radix MMU")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index ab22af2509d8..8ed787dc579c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1012,7 +1012,7 @@ TRAMP_REAL_BEGIN(machine_check_common_early)
 	mfspr	r11,SPRN_DSISR		/* Save DSISR */
 	std	r11,_DSISR(r1)
 	std	r9,_CCR(r1)		/* Save CR in stackframe */
-	kuap_save_amr_and_lock r9, r10, cr1
+	/* We don't touch AMR here, we never go to virtual mode */
 	/* Save r9 through r13 from EXMC save area to stack frame. */
 	EXCEPTION_PROLOG_COMMON_2(PACA_EXMC)
 	mfmsr	r11			/* get MSR value */
-- 
2.20.1


  parent reply	other threads:[~2019-06-20  6:53 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-20  5:14 [PATCH v2 00/52] powerpc/64s interrupt handler cleanups, gasification Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 01/52] powerpc/64s/exception: fix line wrap and semicolon inconsistencies in macros Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 02/52] powerpc/64s/exception: remove H concatenation for EXC_HV variants Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 03/52] powerpc/64s/exception: consolidate EXCEPTION_PROLOG_2 with _NORI variant Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 04/52] powerpc/64s/exception: move and tidy EXCEPTION_PROLOG_2 variants Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 05/52] powerpc/64s/exception: fix sreset KVM test code Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 06/52] powerpc/64s/exception: remove the "extra" macro parameter Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 07/52] powerpc/64s/exception: consolidate maskable and non-maskable prologs Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 08/52] powerpc/64s/exception: merge KVM handler and skip variants Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 09/52] powerpc/64s/exception: KVM handler can set the HSRR trap bit Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 10/52] powerpc/64s/exception: Make EXCEPTION_PROLOG_0 a gas macro for consistency with others Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 11/52] powerpc/64s/exception: Move EXCEPTION_COMMON handler and return branches into callers Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 12/52] powerpc/64s/exception: Move EXCEPTION_COMMON additions " Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 13/52] powerpc/64s/exception: unwind exception-64s.h macros Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 14/52] powerpc/64s/exception: improve 0x500 handler code Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 15/52] powerpc/64s/exception: move EXCEPTION_PROLOG_2* to a more logical place Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 16/52] powerpc/64s/exception: remove STD_EXCEPTION_COMMON variants Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 17/52] powerpc/64s/exception: move KVM related code together Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 18/52] powerpc/64s/exception: move exception-64s.h code to exception-64s.S where it is used Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 19/52] powerpc/64s/exception: move head-64.h " Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 20/52] powerpc/64s/exception: remove __BRANCH_TO_KVM Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 21/52] powerpc/64s/exception: remove unused BRANCH_TO_COMMON Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 22/52] powerpc/64s/exception: use a gas macro for system call handler code Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 23/52] powerpc/64s/exception: fix indenting irregularities Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 24/52] powerpc/64s/exception: generate regs clear instructions using .rept Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 25/52] powerpc/64s/exception: remove bad stack branch Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 26/52] powerpc/64s/exception: remove pointless EXCEPTION_PROLOG macro indirection Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 27/52] powerpc/64s/exception: move paca save area offsets into exception-64s.S Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 28/52] powerpc/64s/exception: clean up system call entry Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 29/52] powerpc/64s/exception: avoid SPR RAW scoreboard stall in real mode entry Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 30/52] powerpc/64s/exception: optimise system_reset for idle, clean up non-idle case Nicholas Piggin
2019-06-20  5:41   ` Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 31/52] powerpc/64s/exception: mtmsrd L=1 cleanup Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 32/52] powerpc/64s/exception: windup use r9 consistently to restore SPRs Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 33/52] powerpc/64s/exception: move machine check windup in_mce handling Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 34/52] powerpc/64s/exception: simplify hmi windup code Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 35/52] powerpc/64s/exception: shuffle windup code around Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 36/52] powerpc/64s/exception: use common macro for windup Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 37/52] powerpc/64s/exception: add dar and dsisr options to exception macro Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 38/52] powerpc/64s/exception: machine check use standard macros to save dar/dsisr Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 39/52] powerpc/64s/exception: denorm handler use standard scratch save macro Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 40/52] powerpc/64s/exception: move SET_SCRATCH0 into EXCEPTION_PROLOG_0 Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 41/52] powerpc/tm: update comment about interrupt re-entrancy Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 42/52] powerpc/64s/exception: machine check fwnmi does not trigger when in HV mode Nicholas Piggin
2019-06-20  9:26   ` Mahesh Jagannath Salgaonkar
2019-06-20  9:50     ` Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 43/52] powerpc/64s/exception: machine check early only runs " Nicholas Piggin
2019-06-20  9:53   ` Mahesh J Salgaonkar
2019-06-20 10:16     ` Nicholas Piggin
2019-06-20 10:57       ` Mahesh Jagannath Salgaonkar
2019-06-20  5:14 ` [PATCH v2 44/52] powerpc/64s/exception: separate pseries and powernv mce delivery paths Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 45/52] powerpc/64s/exception: machine check windup restore cfar for host delivery Nicholas Piggin
2019-06-20  5:14 ` Nicholas Piggin [this message]
2019-06-20  5:14 ` [PATCH v2 47/52] powerpc/64s/exception: machine check restructure handler to be more regular Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 48/52] powerpc/64s/exception: simplify machine check early path Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 49/52] powerpc/64s/exceptions: machine check move unrecoverable handling out of line Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 50/52] powerpc/64s/exception: untangle early machine check handler Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 51/52] powerpc/64s/exception: machine check improve branch labels Nicholas Piggin
2019-06-20  5:14 ` [PATCH v2 52/52] powerpc/64s/exception: add missing branch to self after RFI Nicholas Piggin

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