From: Dave Hansen <dave.hansen@intel.com>
To: Andrey Konovalov <andreyknvl@google.com>,
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>,
linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
linux-mm@kvack.org, linux-arch@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>
Subject: Re: [PATCH v10 04/12] mm, arm64: untag user pointers passed to memory syscalls
Date: Fri, 22 Feb 2019 15:07:45 -0800 [thread overview]
Message-ID: <81ea4e77-90a4-4fd9-2bc8-135e0da30044@intel.com> (raw)
In-Reply-To: <3875fa863b755d8cb43afa7bb0fe543e5fd05a5d.1550839937.git.andreyknvl@google.com>
On 2/22/19 4:53 AM, Andrey Konovalov wrote:
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -578,6 +578,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
> SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
> unsigned long, prot)
> {
> + start = untagged_addr(start);
> return do_mprotect_pkey(start, len, prot, -1);
> }
>
> @@ -586,6 +587,7 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
> SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len,
> unsigned long, prot, int, pkey)
> {
> + start = untagged_addr(start);
> return do_mprotect_pkey(start, len, prot, pkey);
> }
This seems to have taken the approach of going as close as possible to
the syscall boundary and untagging the pointer there. I guess that's
OK, but it does lead to more churn than necessary. For instance, why
not just do the untagging in do_mprotect_pkey()?
I think that's an overall design question. I kinda asked the same thing
about patching call sites vs. VMA lookup functions.
next prev parent reply other threads:[~2019-02-22 23:07 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-22 12:53 [PATCH v10 00/12] arm64: untag user pointers passed to the kernel Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 01/12] uaccess: add untagged_addr definition for other arches Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 02/12] arm64: untag user pointers in access_ok and __uaccess_mask_ptr Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 03/12] lib, arm64: untag user pointers in strn*_user Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 04/12] mm, arm64: untag user pointers passed to memory syscalls Andrey Konovalov
2019-02-22 23:07 ` Dave Hansen [this message]
2019-02-26 14:41 ` Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 05/12] mm, arm64: untag user pointers in mm/gup.c Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 06/12] fs, arm64: untag user pointers in copy_mount_options Andrey Konovalov
2019-02-22 23:03 ` Dave Hansen
2019-02-26 14:35 ` Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 07/12] fs, arm64: untag user pointers in fs/userfaultfd.c Andrey Konovalov
2019-02-22 23:05 ` Dave Hansen
2019-02-26 14:39 ` Andrey Konovalov
2019-03-01 16:59 ` Catalin Marinas
2019-03-01 18:37 ` Dave Hansen
2019-03-05 17:47 ` Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 08/12] net, arm64: untag user pointers in tcp_zerocopy_receive Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 09/12] kernel, arm64: untag user pointers in prctl_set_mm* Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 10/12] tracing, arm64: untag user pointers in seq_print_user_ip Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 11/12] arm64: update Documentation/arm64/tagged-pointers.txt Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 12/12] selftests, arm64: add a selftest for passing tagged pointers to kernel Andrey Konovalov
2019-02-22 15:35 ` [PATCH v10 00/12] arm64: untag user pointers passed to the kernel Szabolcs Nagy
2019-02-22 15:40 ` Andrey Konovalov
2019-02-22 16:10 ` Szabolcs Nagy
2019-02-26 17:00 ` Andrey Konovalov
2019-02-22 22:54 ` Dave Hansen
2019-02-26 17:18 ` Andrey Konovalov
2019-02-26 17:35 ` Dave Hansen
2019-02-26 23:17 ` Luc Van Oostenryck
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