| From: |
| Josh Poimboeuf <jpoimboe-AT-redhat.com> |
| To: |
| Al Viro <viro-AT-zeniv.linux.org.uk> |
| Subject: |
| [PATCH v4 0/4] x86/uaccess: Use pointer masking to limit uaccess speculation |
| Date: |
| Tue, 04 May 2021 22:54:28 -0500 |
| Message-ID: |
| <cover.1620186182.git.jpoimboe@redhat.com> |
| Cc: |
| x86-AT-kernel.org, linux-kernel-AT-vger.kernel.org, Linus Torvalds <torvalds-AT-linux-foundation.org>, Will Deacon <will-AT-kernel.org>, Dan Williams <dan.j.williams-AT-intel.com>, Andrea Arcangeli <aarcange-AT-redhat.com>, Waiman Long <longman-AT-redhat.com>, Peter Zijlstra <peterz-AT-infradead.org>, Thomas Gleixner <tglx-AT-linutronix.de>, Andrew Cooper <andrew.cooper3-AT-citrix.com>, Andy Lutomirski <luto-AT-kernel.org>, Christoph Hellwig <hch-AT-lst.de>, David Laight <David.Laight-AT-aculab.com>, Mark Rutland <mark.rutland-AT-arm.com>, Borislav Petkov <bp-AT-alien8.de> |
| Archive-link: |
| Article |
This one managed to fall through the cracks back in September. Here's a
fresh new version.
Ideally, we'd switch all access_ok() users to access_ok_mask() or
something, but that's a much bigger change.
I dropped all the ack/review tags because the rebase was significant.
Please review carefully :-)
v4 changes:
- Rebased on the latest.
- Split up into multiple logical patches.
- Renamed "force_user_ptr()" -> "mask_user_ptr()" to prevent confusing
it with '__force' casting. [based on Dan's comment]
- Instead of reusing array_index_nospec(), made a new separate inline
asm statement. Otherwise it fails the build on recent toolchains
and/or kernels because the "g" constraint in array_index_mask_nospec()
isn't big enough for TASK_SIZE_MAX. I could have changed "g" to "r",
but that would negatively impact code generation for the other users.
v3 was here:
https://lore.kernel.org/lkml/1d06ed6485b66b9f674900368b63...
Josh Poimboeuf (4):
uaccess: Always inline strn*_user() helper functions
uaccess: Fix __user annotations for copy_mc_to_user()
x86/uaccess: Use pointer masking to limit uaccess speculation
x86/nospec: Remove barrier_nospec()
Documentation/admin-guide/hw-vuln/spectre.rst | 6 +--
arch/x86/include/asm/barrier.h | 3 --
arch/x86/include/asm/futex.h | 5 ++
arch/x86/include/asm/uaccess.h | 48 +++++++++++++------
arch/x86/include/asm/uaccess_64.h | 12 ++---
arch/x86/kernel/cpu/sgx/virt.c | 6 ++-
arch/x86/lib/copy_mc.c | 10 ++--
arch/x86/lib/csum-wrappers_64.c | 5 +-
arch/x86/lib/getuser.S | 16 ++-----
arch/x86/lib/putuser.S | 8 ++++
arch/x86/lib/usercopy_32.c | 6 +--
arch/x86/lib/usercopy_64.c | 7 +--
lib/iov_iter.c | 2 +-
lib/strncpy_from_user.c | 6 ++-
lib/strnlen_user.c | 4 +-
15 files changed, 89 insertions(+), 55 deletions(-)
--
2.31.1
