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From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>,
	"Naveen N . Rao" <naveen.n.rao@linux.vnet.ibm.com>,
	Ganesh Goudar <ganeshgr@linux.ibm.com>,
	Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH v3 14/15] powerpc/64s: system reset do not trace
Date: Tue,  7 Apr 2020 15:16:35 +1000	[thread overview]
Message-ID: <20200407051636.648369-15-npiggin@gmail.com> (raw)
In-Reply-To: <20200407051636.648369-1-npiggin@gmail.com>

Similarly to the previous patch, do not trace system reset. This code
is used when there is a crash or hang, and tracing disturbs the system
more and has been known to crash in the crash handling path.

Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/traps.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 9f221772eb73..1beae89bb871 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -443,6 +443,9 @@ void system_reset_exception(struct pt_regs *regs)
 	unsigned long hsrr0, hsrr1;
 	bool nested = in_nmi();
 	bool saved_hsrrs = false;
+	u8 ftrace_enabled = this_cpu_get_ftrace_enabled();
+
+	this_cpu_set_ftrace_enabled(0);
 
 	/*
 	 * Avoid crashes in case of nested NMI exceptions. Recoverability
@@ -524,6 +527,8 @@ void system_reset_exception(struct pt_regs *regs)
 	if (!nested)
 		nmi_exit();
 
+	this_cpu_set_ftrace_enabled(ftrace_enabled);
+
 	/* What should we do here? We could issue a shutdown or hard reset. */
 }
 
-- 
2.23.0


  parent reply	other threads:[~2020-04-07  5:45 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-07  5:16 [PATCH v3 00/15] powerpc/64: machine check and system reset fixes Nicholas Piggin
2020-04-07  5:16 ` [PATCH v3 01/15] powerpc/64s/exception: Fix machine check no-loss idle wakeup Nicholas Piggin
2020-04-07  5:16 ` [PATCH v3 02/15] powerpc/64s/exceptions: Fix in_mce accounting in unrecoverable path Nicholas Piggin
2020-04-07  5:16 ` [PATCH v3 03/15] powerpc/64s/exceptions: Change irq reconcile for NMIs from reusing _DAR to RESULT Nicholas Piggin
2020-04-07  5:16 ` [PATCH v3 04/15] powerpc/64s/exceptions: machine check reconcile irq state Nicholas Piggin
2020-04-07  5:16 ` [PATCH v3 05/15] powerpc/pseries/ras: avoid calling rtas_token in NMI paths Nicholas Piggin
2020-04-07  5:42   ` Christophe Leroy
2020-04-07  5:16 ` [PATCH v3 06/15] powerpc/pseries/ras: FWNMI_VALID off by one Nicholas Piggin
2020-04-07  5:16 ` [PATCH v3 07/15] powerpc/pseries/ras: fwnmi avoid modifying r3 in error case Nicholas Piggin
2020-04-07  5:16 ` [PATCH v3 08/15] powerpc/pseries/ras: fwnmi sreset should not interlock Nicholas Piggin
2020-04-07  5:41   ` Christophe Leroy
2020-04-07  5:16 ` [PATCH v3 09/15] powerpc/pseries: limit machine check stack to 4GB Nicholas Piggin
2020-04-07  5:38   ` Christophe Leroy
2020-04-07  5:16 ` [PATCH v3 10/15] powerpc/pseries: machine check use rtas_call_unlocked with args on stack Nicholas Piggin
2020-04-07  5:16 ` [PATCH v3 11/15] powerpc/64s: machine check interrupt update NMI accounting Nicholas Piggin
2020-04-07  5:37   ` Christophe Leroy
2020-05-06  3:50     ` Nicholas Piggin
2020-04-12  8:46   ` kbuild test robot
2020-04-07  5:16 ` [PATCH v3 12/15] powerpc: ftrace_enabled helper Nicholas Piggin
2020-04-07  5:45   ` Christophe Leroy
2020-04-07  5:16 ` [PATCH v3 13/15] powerpc/64s: machine check do not trace real-mode handler Nicholas Piggin
2020-04-07  5:45   ` Christophe Leroy
2020-04-07  5:16 ` Nicholas Piggin [this message]
2020-04-07  5:45   ` [PATCH v3 14/15] powerpc/64s: system reset do not trace Christophe Leroy
2020-04-07  5:16 ` [PATCH v3 15/15] powerpc: make unrecoverable NMIs die instead of panic Nicholas Piggin
2020-04-07  5:46   ` Christophe Leroy

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