From: Santosh Sivaraj <santosh@fossix.org>
To: Michael Ellerman <mpe@ellerman.id.au>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Linux Kernel <linux-kernel@vger.kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
Mahesh Salgaonkar <mahesh@linux.ibm.com>,
Nicholas Piggin <npiggin@gmail.com>,
Chandan Rajendra <chandan@linux.vnet.ibm.com>,
Reza Arbab <arbab@linux.ibm.com>
Subject: Re: [PATCH v8 7/7] powerpc: add machine check safe copy_to_user
Date: Sun, 11 Aug 2019 07:05:09 +0530 [thread overview]
Message-ID: <87mugg8oxe.fsf@santosiv.in.ibm.com> (raw)
In-Reply-To: <87lfw1s6u0.fsf@concordia.ellerman.id.au>
Michael Ellerman <mpe@ellerman.id.au> writes:
> Santosh Sivaraj <santosh@fossix.org> writes:
>> Use memcpy_mcsafe() implementation to define copy_to_user_mcsafe()
>>
>> Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
>> ---
>> arch/powerpc/Kconfig | 1 +
>> arch/powerpc/include/asm/uaccess.h | 14 ++++++++++++++
>> 2 files changed, 15 insertions(+)
>>
>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index 77f6ebf97113..4316e36095a2 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -137,6 +137,7 @@ config PPC
>> select ARCH_HAS_STRICT_KERNEL_RWX if ((PPC_BOOK3S_64 || PPC32) && !RELOCATABLE && !HIBERNATION)
>> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
>> select ARCH_HAS_UACCESS_FLUSHCACHE if PPC64
>> + select ARCH_HAS_UACCESS_MCSAFE if PPC64
>> select ARCH_HAS_UBSAN_SANITIZE_ALL
>> select ARCH_HAVE_NMI_SAFE_CMPXCHG
>> select ARCH_KEEP_MEMBLOCK
>> diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
>> index 8b03eb44e876..15002b51ff18 100644
>> --- a/arch/powerpc/include/asm/uaccess.h
>> +++ b/arch/powerpc/include/asm/uaccess.h
>> @@ -387,6 +387,20 @@ static inline unsigned long raw_copy_to_user(void __user *to,
>> return ret;
>> }
>>
>> +static __always_inline unsigned long __must_check
>> +copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n)
>> +{
>> + if (likely(check_copy_size(from, n, true))) {
>> + if (access_ok(to, n)) {
>> + allow_write_to_user(to, n);
>> + n = memcpy_mcsafe((void *)to, from, n);
>> + prevent_write_to_user(to, n);
>> + }
>> + }
>> +
>> + return n;
>> +}
>
> This looks OK to me.
>
> It would be nice though if copy_to_user_mcsafe() followed the pattern of
> the other copy_to_user() etc. routines where the arch code is only
> responsible for the actual arch details, and all the checks are done in
> the generic code. That would be a good cleanup to do after this has gone
> in, as the 2nd implementation of the API.
Sure, will do that.
>
> cheers
prev parent reply other threads:[~2019-08-11 1:37 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-07 14:56 [PATCH v8 0/7] powerpc: implement machine check safe memcpy Santosh Sivaraj
2019-08-07 14:56 ` [PATCH v8 1/7] powerpc/mce: Schedule work from irq_work Santosh Sivaraj
2019-08-09 18:55 ` Mahesh Jagannath Salgaonkar
2019-08-07 14:56 ` [PATCH v8 2/7] powerpc/mce: Make machine_check_ue_event() static Santosh Sivaraj
2019-08-07 14:56 ` [PATCH v8 3/7] powerpc/mce: Fix MCE handling for huge pages Santosh Sivaraj
2019-08-09 19:06 ` Mahesh Jagannath Salgaonkar
2019-08-11 1:32 ` Santosh Sivaraj
2019-08-07 14:56 ` [PATCH v8 4/7] extable: Add function to search only kernel exception table Santosh Sivaraj
2019-08-07 14:56 ` [PATCH v8 5/7] powerpc/memcpy: Add memcpy_mcsafe for pmem Santosh Sivaraj
2019-08-07 14:56 ` [PATCH v8 6/7] powerpc/mce: Handle UE event for memcpy_mcsafe Santosh Sivaraj
2019-08-07 14:57 ` [PATCH v8 7/7] powerpc: add machine check safe copy_to_user Santosh Sivaraj
2019-08-10 9:33 ` Michael Ellerman
2019-08-11 1:35 ` Santosh Sivaraj [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87mugg8oxe.fsf@santosiv.in.ibm.com \
--to=santosh@fossix.org \
--cc=aneesh.kumar@linux.ibm.com \
--cc=arbab@linux.ibm.com \
--cc=chandan@linux.vnet.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mahesh@linux.ibm.com \
--cc=mpe@ellerman.id.au \
--cc=npiggin@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).