linux-kernel - [PATCH] MIPS: Remove incorrect NULL check in local_flush_tlb

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: <1404602638-16447-1-git-send-email-emilgoode@gmail.com>
Date:	Sun,  6 Jul 2014 01:23:58 +0200
From:	Emil Goode <emilgoode@...il.com>
To:	Ralf Baechle <ralf@...ux-mips.org>,
	Paul Gortmaker <paul.gortmaker@...driver.com>,
	John Crispin <blogic@...nwrt.org>,
	Jonas Gorski <jogo@...nwrt.org>
Cc:	linux-mips@...ux-mips.org, linux-kernel@...r.kernel.org,
	kernel-janitors@...r.kernel.org, Emil Goode <emilgoode@...il.com>
Subject: [PATCH] MIPS: Remove incorrect NULL check in local_flush_tlb_page()

We check that the struct vm_area_struct pointer vma is NULL and then
dereference it a few lines below. The intent was to make sure vma is
not NULL but this is not necessary since the bug pre-dates GIT history
and seem to never have caused a problem. The tlb-4k and tlb-8k versions
of local_flush_tlb_page() don't bother checking if vma is NULL, also
vma is dereferenced before being passed to local_flush_tlb_page(),
thus it is safe to remove this NULL check.

Signed-off-by: Emil Goode <emilgoode@...il.com>
---
 arch/mips/mm/tlb-r3k.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/mm/tlb-r3k.c b/arch/mips/mm/tlb-r3k.c
index d657493..4094bbd 100644
--- a/arch/mips/mm/tlb-r3k.c
+++ b/arch/mips/mm/tlb-r3k.c
@@ -158,7 +158,7 @@ void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 {
 	int cpu = smp_processor_id();
 
-	if (!vma || cpu_context(cpu, vma->vm_mm) != 0) {
+	if (cpu_context(cpu, vma->vm_mm) != 0) {
 		unsigned long flags;
 		int oldpid, newpid, idx;
 
-- 
1.7.10.4

--
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/