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Message-Id: <163681302d7380fde6717daa26739965295f636a.1535629099.git.andreyknvl@google.com>
Date: Thu, 30 Aug 2018 13:41:09 +0200
From: Andrey Konovalov <andreyknvl@...gle.com>
To: Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Mark Rutland <mark.rutland@....com>,
Robin Murphy <robin.murphy@....com>,
Al Viro <viro@...iv.linux.org.uk>,
Andrey Konovalov <andreyknvl@...gle.com>,
Kees Cook <keescook@...omium.org>,
Kate Stewart <kstewart@...uxfoundation.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Andrew Morton <akpm@...ux-foundation.org>,
Ingo Molnar <mingo@...nel.org>,
"Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
Shuah Khan <shuah@...nel.org>,
linux-arm-kernel@...ts.infradead.org, linux-doc@...r.kernel.org,
linux-mm@...ck.org, linux-arch@...r.kernel.org,
linux-kselftest@...r.kernel.org, linux-kernel@...r.kernel.org
Cc: Dmitry Vyukov <dvyukov@...gle.com>,
Kostya Serebryany <kcc@...gle.com>,
Evgeniy Stepanov <eugenis@...gle.com>,
Lee Smith <Lee.Smith@....com>,
Ramana Radhakrishnan <Ramana.Radhakrishnan@....com>,
Jacob Bramley <Jacob.Bramley@....com>,
Ruben Ayrapetyan <Ruben.Ayrapetyan@....com>,
Chintan Pandya <cpandya@...eaurora.org>
Subject: [PATCH v6 04/11] mm, arm64: untag user addresses in mm/gup.c
mm/gup.c provides a kernel interface that accepts user addresses and
manipulates user pages directly (for example get_user_pages, that is used
by the futex syscall). Since a user can provided tagged addresses, we need
to handle such case.
Add untagging to gup.c functions that use user addresses for vma lookup.
Signed-off-by: Andrey Konovalov <andreyknvl@...gle.com>
---
mm/gup.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/mm/gup.c b/mm/gup.c
index 1abc8b4afff6..6f09132c654e 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -666,6 +666,8 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
if (!nr_pages)
return 0;
+ start = untagged_addr(start);
+
VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET));
/*
@@ -820,6 +822,8 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
struct vm_area_struct *vma;
vm_fault_t ret, major = 0;
+ address = untagged_addr(address);
+
if (unlocked)
fault_flags |= FAULT_FLAG_ALLOW_RETRY;
--
2.19.0.rc0.228.g281dcd1b4d0-goog
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