linux-kernel - invalidate caches before going into suspend

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-next>] [day] [month] [year] [list]

Message-ID: <200808131141.18003.mark.langsdorf@amd.com>
Date:	Wed, 13 Aug 2008 11:41:17 -0500
From:	Mark Langsdorf <mark.langsdorf@....com>
To:	linux-kernel@...r.kernel.org
Subject: invalidate caches before going into suspend

When a CPU core is shut down, all of its caches need to be flushed
to prevent stale data from causing errors if the core is resumed.
Current Linux suspend code performs an assignment after the flush,
which can add dirty data back to the cache.  On some AMD platforms,
additional speculative reads have caused crashes on resume because
of this dirty data.

Relocate the cache flush to be the very last thing done before 
halting.


Signed-off-by: Mark Langsdorf <mark.langsdorf@....com>
Acked-by: Mark Borden <mark.borden@....com>
Acked-by: Michael Hohmuth <michael.hohmuth@....com>

diff -r f3f819497a68 arch/x86/kernel/process_64.c
--- a/arch/x86/kernel/process_64.c	Thu Aug 07 04:24:53 2008 -0500
+++ b/arch/x86/kernel/process_64.c	Tue Aug 12 07:11:36 2008 -0500
@@ -93,11 +93,11 @@ static inline void play_dead(void)
 static inline void play_dead(void)
 {
 	idle_task_exit();
-	wbinvd();
 	mb();
 	/* Ack it */
 	__get_cpu_var(cpu_state) = CPU_DEAD;
 
+	wbinvd();
 	local_irq_disable();
 	while (1)
 		halt();


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/