From: Sandipan Das <sandipan.osd@gmail.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v5 11/23] powerpc/book3s64/pkeys: Store/restore userspace AMR/IAMR correctly on entry and exit from kernel
Date: Sun, 18 Oct 2020 09:19:09 +0530 [thread overview]
Message-ID: <ef174ccb-62b1-9385-b213-42c1718d5cfa@gmail.com> (raw)
In-Reply-To: <20200827040931.297759-12-aneesh.kumar@linux.ibm.com>
On 27/08/20 9:39 am, Aneesh Kumar K.V wrote:
> This prepare kernel to operate with a different value than userspace AMR/IAMR.
> For this, AMR/IAMR need to be saved and restored on entry and return from the
> kernel.
>
> With KUAP we modify kernel AMR when accessing user address from the kernel
> via copy_to/from_user interfaces. We don't need to modify IAMR value in
> similar fashion.
>
> If MMU_FTR_PKEY is enabled we need to save AMR/IAMR in pt_regs on entering
> kernel from userspace. If not we can assume that AMR/IAMR is not modified
> from userspace.
>
> We need to save AMR if we have MMU_FTR_KUAP feature enabled and we are
> interrupted within kernel. This is required so that if we get interrupted
> within copy_to/from_user we continue with the right AMR value.
>
> If we hae MMU_FTR_KUEP enabled we need to restore IAMR on return to userspace
> beause kernel will be running with a different IAMR value.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
> arch/powerpc/include/asm/book3s/64/kup.h | 177 ++++++++++++++++++++---
> arch/powerpc/include/asm/ptrace.h | 4 +-
> arch/powerpc/kernel/asm-offsets.c | 2 +
> arch/powerpc/kernel/entry_64.S | 6 +-
> arch/powerpc/kernel/exceptions-64s.S | 4 +-
> arch/powerpc/kernel/syscall_64.c | 30 +++-
> 6 files changed, 192 insertions(+), 31 deletions(-)
>
Reviewed-by: Sandipan Das <sandipan@linux.ibm.com>
next prev parent reply other threads:[~2020-10-18 3:50 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-27 4:09 [PATCH v5 00/23] Kernel userspace access/execution prevention with hash translation Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 01/23] powerpc: Add new macro to handle NESTED_IFCLR Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 02/23] KVM: PPC: BOOK3S: PR: Ignore UAMOR SPR Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 03/23] powerpc/book3s64/kuap/kuep: Make KUAP and KUEP a subfeature of PPC_MEM_KEYS Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 04/23] powerpc/book3s64/kuap/kuep: Move uamor setup to pkey init Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 05/23] powerpc/book3s64/kuap: Move KUAP related function outside radix Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 06/23] powerpc/book3s64/kup: Use the correct #ifdef when including headers Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 07/23] powerpc/book3s64/kuep: Move KUEP related function outside radix Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 08/23] powerpc/book3s64/kuap: Rename MMU_FTR_RADIX_KUAP to MMU_FTR_KUAP Aneesh Kumar K.V
2020-08-27 4:57 ` Christophe Leroy
2020-08-27 4:09 ` [PATCH v5 09/23] powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation Aneesh Kumar K.V
2020-10-18 3:46 ` Sandipan Das
2020-08-27 4:09 ` [PATCH v5 10/23] powerpc/exec: Set thread.regs early during exec Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 11/23] powerpc/book3s64/pkeys: Store/restore userspace AMR/IAMR correctly on entry and exit from kernel Aneesh Kumar K.V
2020-10-18 3:49 ` Sandipan Das [this message]
2020-08-27 4:09 ` [PATCH v5 12/23] powerpc/book3s64/pkeys: Inherit correctly on fork Aneesh Kumar K.V
2020-10-18 3:50 ` Sandipan Das
2020-08-27 4:09 ` [PATCH v5 13/23] powerpc/book3s64/pkeys: Reset userspace AMR correctly on exec Aneesh Kumar K.V
2020-10-18 3:50 ` Sandipan Das
2020-08-27 4:09 ` [PATCH v5 14/23] powerpc/ptrace-view: Use pt_regs values instead of thread_struct based one Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 15/23] powerpc/book3s64/pkeys: Don't update SPRN_AMR when in kernel mode Aneesh Kumar K.V
2020-10-18 3:52 ` Sandipan Das
2020-08-27 4:09 ` [PATCH v5 16/23] powerpc/book3s64/kuap: Restrict access to userspace based on userspace AMR Aneesh Kumar K.V
2020-10-18 4:00 ` Sandipan Das
2020-08-27 4:09 ` [PATCH v5 17/23] powerpc/book3s64/kuap: Improve error reporting with KUAP Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 18/23] powerpc/book3s64/kuap: Use Key 3 to implement KUAP with hash translation Aneesh Kumar K.V
2020-10-18 4:00 ` Sandipan Das
2020-08-27 4:09 ` [PATCH v5 19/23] powerpc/book3s64/kuep: Use Key 3 to implement KUEP " Aneesh Kumar K.V
2020-10-18 4:01 ` Sandipan Das
2020-08-27 4:09 ` [PATCH v5 20/23] powerpc/book3s64/hash/kuap: Enable kuap on hash Aneesh Kumar K.V
2020-09-12 11:54 ` Michael Ellerman
2020-10-18 4:02 ` Sandipan Das
2020-08-27 4:09 ` [PATCH v5 21/23] powerpc/book3s64/hash/kuep: Enable KUEP " Aneesh Kumar K.V
2020-10-18 4:03 ` Sandipan Das
2020-08-27 4:09 ` [PATCH v5 22/23] powerpc/book3s64/hash/kup: Don't hardcode kup key Aneesh Kumar K.V
2020-08-27 4:09 ` [PATCH v5 23/23] powerpc/book3s64/pkeys: Optimize FTR_KUAP and FTR_KUEP disabled case Aneesh Kumar K.V
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=ef174ccb-62b1-9385-b213-42c1718d5cfa@gmail.com \
--to=sandipan.osd@gmail.com \
--cc=aneesh.kumar@linux.ibm.com \
--cc=linuxppc-dev@lists.ozlabs.org \
/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).