linux-kernel - [PATCH] irq/core: Fix boot crash when the irqaffinity= boot parameter is passed on CPUMASK

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: <20171101041451.12581-1-rakib.mullick@gmail.com>
Date:   Wed,  1 Nov 2017 10:14:51 +0600
From:   Rakib Mullick <rakib.mullick@...il.com>
To:     mingo@...nel.org, linux-kernel@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH]  irq/core: Fix boot crash when the irqaffinity= boot parameter is passed on CPUMASK_OFFSTACK=y kernels(v1)

When the irqaffinity= kernel parameter is passed in a CPUMASK_OFFSTACK=y
kernel, it fails to boot, because zalloc_cpumask_var() cannot be used before
initializing the slab allocator to allocate a cpumask.

So, use alloc_bootmem_cpumask_var() instead.

Also do some cleanups while at it: in init_irq_default_affinity() remove
an unnecessary #ifdef.

Change since v0:
	* Fix build warning.

Signed-off-by: Rakib Mullick <rakib.mullick@...il.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Link: http://lkml.kernel.org/r/20171026045800.27087-1-rakib.mullick@gmail.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
Patch created against -rc7 (commit 0b07194bb55ed836c2). I found tip had a merge
conflict, so used -rc7 instead.

 kernel/irq/irqdesc.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 82afb7e..e97bbae 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -27,7 +27,7 @@ static struct lock_class_key irq_desc_lock_class;
 #if defined(CONFIG_SMP)
 static int __init irq_affinity_setup(char *str)
 {
-	zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+	alloc_bootmem_cpumask_var(&irq_default_affinity);
 	cpulist_parse(str, irq_default_affinity);
 	/*
 	 * Set at least the boot cpu. We don't want to end up with
@@ -40,10 +40,8 @@ __setup("irqaffinity=", irq_affinity_setup);
 
 static void __init init_irq_default_affinity(void)
 {
-#ifdef CONFIG_CPUMASK_OFFSTACK
-	if (!irq_default_affinity)
+	if (!cpumask_available(irq_default_affinity))
 		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
-#endif
 	if (cpumask_empty(irq_default_affinity))
 		cpumask_setall(irq_default_affinity);
 }
-- 
2.9.3