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From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>,
	Ganesh Goudar <ganeshgr@linux.ibm.com>,
	Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH v2 06/12] powerpc/pseries/ras: fwnmi avoid modifying r3 in error case
Date: Wed, 25 Mar 2020 20:34:04 +1000	[thread overview]
Message-ID: <20200325103410.157573-7-npiggin@gmail.com> (raw)
In-Reply-To: <20200325103410.157573-1-npiggin@gmail.com>

If there is some error with the fwnmi save area, r3 has already been
modified which doesn't help with debugging.

Only update r3 when to restore the saved value.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/platforms/pseries/ras.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index 9a37bda47468..a40598e6e525 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -423,18 +423,19 @@ static inline struct rtas_error_log *fwnmi_get_errlog(void)
  */
 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
 {
+	unsigned long savep_ra;
 	unsigned long *savep;
 	struct rtas_error_log *h;
 
 	/* Mask top two bits */
-	regs->gpr[3] &= ~(0x3UL << 62);
+	savep_ra = regs->gpr[3] & ~(0x3UL << 62);
 
-	if (!VALID_FWNMI_BUFFER(regs->gpr[3])) {
+	if (!VALID_FWNMI_BUFFER(savep_ra)) {
 		printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
 		return NULL;
 	}
 
-	savep = __va(regs->gpr[3]);
+	savep = __va(savep_ra);
 	regs->gpr[3] = be64_to_cpu(savep[0]);	/* restore original r3 */
 
 	h = (struct rtas_error_log *)&savep[1];
-- 
2.23.0


  parent reply	other threads:[~2020-03-25 10:49 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-25 10:33 [PATCH v2 00/12] powerpc/64: machine check and system reset fixes Nicholas Piggin
2020-03-25 10:33 ` [PATCH v2 01/12] powerpc/64s/exceptions: Fix in_mce accounting in unrecoverable path Nicholas Piggin
2020-03-27  3:43   ` Mahesh J Salgaonkar
2020-03-25 10:34 ` [PATCH v2 02/12] powerpc/64s/exceptions: Change irq reconcile for NMIs from reusing _DAR to RESULT Nicholas Piggin
2020-03-25 10:34 ` [PATCH v2 03/12] powerpc/64s/exceptions: machine check reconcile irq state Nicholas Piggin
2020-03-25 10:34 ` [PATCH v2 04/12] powerpc/pseries/ras: avoid calling rtas_token in NMI paths Nicholas Piggin
2020-03-27  3:50   ` Mahesh J Salgaonkar
2020-03-25 10:34 ` [PATCH v2 05/12] powerpc/pseries/ras: FWNMI_VALID off by one Nicholas Piggin
2020-03-27  3:51   ` Mahesh J Salgaonkar
2020-03-25 10:34 ` Nicholas Piggin [this message]
2020-03-25 10:34 ` [PATCH v2 07/12] powerpc/pseries/ras: fwnmi sreset should not interlock Nicholas Piggin
2020-03-25 10:34 ` [PATCH v2 08/12] powerpc/pseries: limit machine check stack to 4GB Nicholas Piggin
2020-03-27  5:24   ` Mahesh J Salgaonkar
2020-04-03 10:24     ` Nicholas Piggin
2020-03-25 10:34 ` [PATCH v2 09/12] powerpc/pseries: machine check use rtas_call_unlocked with args on stack Nicholas Piggin
2020-03-25 10:34 ` [PATCH v2 10/12] powerpc/64s: machine check interrupt update NMI accounting Nicholas Piggin
2020-03-25 10:34 ` [PATCH v2 11/12] powerpc/64s: machine check do not trace real-mode handler Nicholas Piggin
2020-03-25 10:34 ` [PATCH v2 12/12] powerpc/64s: system reset do not trace Nicholas Piggin
2020-03-26 17:23   ` Naveen N. Rao

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