Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 20 Mar 2019 15:51:26 +0100
In-Reply-To: <cover.1553093420.git.andreyknvl@google.com>
Message-Id: <88d5255400fc6536d6a6895dd2a3aef0f0ecc899.1553093421.git.andreyknvl@google.com>
Mime-Version: 1.0
References: <cover.1553093420.git.andreyknvl@google.com>
Subject: [PATCH v13 12/20] uprobes, arm64: untag user pointers in find_active_uprobe
From:   Andrey Konovalov <andreyknvl@google.com>
To:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Kees Cook <keescook@chromium.org>,
        Kate Stewart <kstewart@linuxfoundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Ingo Molnar <mingo@kernel.org>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Shuah Khan <shuah@kernel.org>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Eric Dumazet <edumazet@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Alex Deucher <alexander.deucher@amd.com>,
        "=?UTF-8?q?Christian=20K=C3=B6nig?=" <christian.koenig@amd.com>,
        "David (ChunMing) Zhou" <David1.Zhou@amd.com>,
        Yishai Hadas <yishaih@mellanox.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Jens Wiklander <jens.wiklander@linaro.org>,
        Alex Williamson <alex.williamson@redhat.com>,
        linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
        linux-arch@vger.kernel.org, netdev@vger.kernel.org,
        bpf@vger.kernel.org, amd-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org,
        linux-media@vger.kernel.org, kvm@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Dmitry Vyukov <dvyukov@google.com>,
        Kostya Serebryany <kcc@google.com>,
        Evgeniy Stepanov <eugenis@google.com>,
        Lee Smith <Lee.Smith@arm.com>,
        Ramana Radhakrishnan <Ramana.Radhakrishnan@arm.com>,
        Jacob Bramley <Jacob.Bramley@arm.com>,
        Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>,
        Chintan Pandya <cpandya@codeaurora.org>,
        Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
        Dave Martin <Dave.Martin@arm.com>,
        Kevin Brodsky <kevin.brodsky@arm.com>,
        Szabolcs Nagy <Szabolcs.Nagy@arm.com>,
        Andrey Konovalov <andreyknvl@google.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

This patch is a part of a series that extends arm64 kernel ABI to allow to
pass tagged user pointers (with the top byte set to something else other
than 0x00) as syscall arguments.

find_active_uprobe() uses user pointers (obtained via
instruction_pointer(regs)) for vma lookups, which can only by done with
untagged pointers.

Untag user pointers in this function.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 kernel/events/uprobes.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index c5cde87329c7..d3a2716a813a 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1992,6 +1992,8 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
 	struct uprobe *uprobe = NULL;
 	struct vm_area_struct *vma;
 
+	bp_vaddr = untagged_addr(bp_vaddr);
+
 	down_read(&mm->mmap_sem);
 	vma = find_vma(mm, bp_vaddr);
 	if (vma && vma->vm_start <= bp_vaddr) {
-- 
2.21.0.225.g810b269d1ac-goog