linux-kernel - [PATCH 5.17 006/140] Revert "parisc: Mark sched_clock unstable only if clocks are not syncronized"

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: <20220510130741.788784661@linuxfoundation.org>
Date:   Tue, 10 May 2022 15:06:36 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Helge Deller <deller@....de>,
        John David Anglin <dave.anglin@...l.net>
Subject: [PATCH 5.17 006/140] Revert "parisc: Mark sched_clock unstable only if clocks are not syncronized"

From: Helge Deller <deller@....de>

commit 7962c0896429af2a0e00ec6bc15d992536453b2d upstream.

This reverts commit d97180ad68bdb7ee10f327205a649bc2f558741d.

It triggers RCU stalls at boot with a 32-bit kernel.

Signed-off-by: Helge Deller <deller@....de>
Noticed-by: John David Anglin <dave.anglin@...l.net>
Cc: stable@...r.kernel.org # v5.15+
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 arch/parisc/kernel/setup.c |    2 ++
 arch/parisc/kernel/time.c  |    7 ++++---
 2 files changed, 6 insertions(+), 3 deletions(-)

--- a/arch/parisc/kernel/setup.c
+++ b/arch/parisc/kernel/setup.c
@@ -161,6 +161,8 @@ void __init setup_arch(char **cmdline_p)
 #ifdef CONFIG_PA11
 	dma_ops_init();
 #endif
+
+	clear_sched_clock_stable();
 }
 
 /*
--- a/arch/parisc/kernel/time.c
+++ b/arch/parisc/kernel/time.c
@@ -265,9 +265,6 @@ static int __init init_cr16_clocksource(
 			    (cpu0_loc == per_cpu(cpu_data, cpu).cpu_loc))
 				continue;
 
-			/* mark sched_clock unstable */
-			clear_sched_clock_stable();
-
 			clocksource_cr16.name = "cr16_unstable";
 			clocksource_cr16.flags = CLOCK_SOURCE_UNSTABLE;
 			clocksource_cr16.rating = 0;
@@ -275,6 +272,10 @@ static int __init init_cr16_clocksource(
 		}
 	}
 
+	/* XXX: We may want to mark sched_clock stable here if cr16 clocks are
+	 *	in sync:
+	 *	(clocksource_cr16.flags == CLOCK_SOURCE_IS_CONTINUOUS) */
+
 	/* register at clocksource framework */
 	clocksource_register_hz(&clocksource_cr16,
 		100 * PAGE0->mem_10msec);