From: Peter Zijlstra <peterz@infradead.org>
To: Julien Thierry <jthierry@redhat.com>
Cc: catalin.marinas@arm.com, linux-kernel@vger.kernel.org,
raphael.gault@arm.com, jpoimboe@redhat.com, will@kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC v5 11/57] objtool: Abstract alternative special case handling
Date: Mon, 20 Jan 2020 15:54:01 +0100 [thread overview]
Message-ID: <20200120145401.GB14897@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200109160300.26150-12-jthierry@redhat.com>
On Thu, Jan 09, 2020 at 04:02:14PM +0000, Julien Thierry wrote:
> diff --git a/tools/objtool/arch/x86/arch_special.c b/tools/objtool/arch/x86/arch_special.c
> new file mode 100644
> index 000000000000..6dba31f419d0
> --- /dev/null
> +++ b/tools/objtool/arch/x86/arch_special.c
> @@ -0,0 +1,34 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +#include "../../special.h"
> +#include "../../builtin.h"
> +
> +void arch_handle_alternative(unsigned short feature, struct special_alt *alt)
> +{
> + /*
> + * If UACCESS validation is enabled; force that alternative;
> + * otherwise force it the other way.
> + *
> + * What we want to avoid is having both the original and the
> + * alternative code flow at the same time, in that case we can
> + * find paths that see the STAC but take the NOP instead of
> + * CLAC and the other way around.
> + */
That comment ^,
> + switch (feature) {
> + case X86_FEATURE_SMAP:
goes here >
> + if (uaccess)
> + alt->skip_orig = true;
> + else
> + alt->skip_alt = true;
> + break;
> + case X86_FEATURE_POPCNT:
> + /*
> + * It has been requested that we don't validate the !POPCNT
> + * feature path which is a "very very small percentage of
> + * machines".
> + */
> + alt->skip_orig = true;
> + break;
> + default:
> + break;
> + }
> +}
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-01-20 14:54 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-09 16:02 [RFC v5 00/57] objtool: Add support for arm64 Julien Thierry
2020-01-09 16:02 ` [RFC v5 01/57] objtool: check: Remove redundant checks on operand type Julien Thierry
2020-01-09 16:02 ` [RFC v5 02/57] objtool: check: Clean instruction state before each function validation Julien Thierry
2020-01-09 16:02 ` [RFC v5 03/57] objtool: check: Use arch specific values in restore_reg() Julien Thierry
2020-01-09 16:02 ` [RFC v5 04/57] objtool: check: Ignore empty alternative groups Julien Thierry
2020-01-21 16:30 ` Josh Poimboeuf
2020-01-23 11:45 ` Julien Thierry
2020-01-09 16:02 ` [RFC v5 05/57] objtool: Add abstraction for computation of symbols offsets Julien Thierry
2020-01-09 16:02 ` [RFC v5 06/57] objtool: Give ORC functions consistent name Julien Thierry
2020-01-09 16:02 ` [RFC v5 07/57] objtool: orc: Refactor ORC API for other architectures to implement Julien Thierry
2020-01-09 16:02 ` [RFC v5 08/57] objtool: Make ORC support optional Julien Thierry
2020-01-21 16:37 ` Josh Poimboeuf
2020-01-23 11:45 ` Julien Thierry
2020-01-09 16:02 ` [RFC v5 09/57] objtool: Move registers and control flow to arch-dependent code Julien Thierry
2020-01-09 16:02 ` [RFC v5 10/57] objtool: Split generic and arch specific CFI definitions Julien Thierry
2020-01-09 16:02 ` [RFC v5 11/57] objtool: Abstract alternative special case handling Julien Thierry
2020-01-20 14:54 ` Peter Zijlstra [this message]
2020-01-23 11:45 ` Julien Thierry
2020-01-09 16:02 ` [RFC v5 12/57] objtool: check: Allow jumps from an alternative group to itself Julien Thierry
2020-01-20 14:56 ` Peter Zijlstra
2020-01-21 10:30 ` Will Deacon
2020-01-21 17:33 ` Josh Poimboeuf
2020-01-23 13:42 ` Julien Thierry
2020-01-09 16:02 ` [RFC v5 13/57] objtool: Refactor switch-tables code to support other architectures Julien Thierry
2020-01-09 16:02 ` [RFC v5 14/57] objtool: Do not look for STT_NOTYPE symbols Julien Thierry
2020-01-13 10:20 ` Julien Thierry
2020-01-09 16:02 ` [RFC v5 15/57] objtool: Support addition to set frame pointer Julien Thierry
2020-01-09 16:02 ` [RFC v5 16/57] objtool: Support restoring BP from the stack without POP Julien Thierry
2020-01-09 16:02 ` [RFC v5 17/57] objtool: Make stack validation more generic Julien Thierry
2020-01-09 16:02 ` [RFC v5 18/57] objtool: Support multiple stack_op per instruction Julien Thierry
2020-01-09 16:02 ` [RFC v5 19/57] objtool: arm64: Add required implementation for supporting the aarch64 architecture in objtool Julien Thierry
2020-01-09 16:02 ` [RFC v5 20/57] objtool: arm64: Decode unknown instructions Julien Thierry
2020-01-09 16:02 ` [RFC v5 21/57] objtool: arm64: Decode simple data processing instructions Julien Thierry
2020-01-09 16:02 ` [RFC v5 22/57] objtool: arm64: Decode add/sub immediate instructions Julien Thierry
2020-01-09 16:02 ` [RFC v5 23/57] objtool: arm64: Decode logical data processing instructions Julien Thierry
2020-01-09 16:02 ` [RFC v5 24/57] objtool: arm64: Decode system instructions not affecting the flow Julien Thierry
2020-01-09 16:02 ` [RFC v5 25/57] objtool: arm64: Decode calls to higher EL Julien Thierry
2020-01-09 16:02 ` [RFC v5 26/57] objtool: arm64: Decode brk instruction Julien Thierry
2020-01-09 16:02 ` [RFC v5 27/57] objtool: arm64: Decode instruction triggering context switch Julien Thierry
2020-01-09 16:02 ` [RFC v5 28/57] objtool: arm64: Decode branch instructions with PC relative immediates Julien Thierry
2020-01-09 16:02 ` [RFC v5 29/57] objtool: arm64: Decode branch to register instruction Julien Thierry
2020-01-09 16:02 ` [RFC v5 30/57] objtool: arm64: Decode basic load/stores Julien Thierry
2020-01-09 16:02 ` [RFC v5 31/57] objtool: arm64: Decode load/store with register offset Julien Thierry
2020-01-09 16:02 ` [RFC v5 32/57] objtool: arm64: Decode load/store register pair instructions Julien Thierry
2020-01-09 16:02 ` [RFC v5 33/57] objtool: arm64: Decode FP/SIMD load/store instructions Julien Thierry
2020-01-09 16:02 ` [RFC v5 34/57] objtool: arm64: Decode load/store exclusive Julien Thierry
2020-01-09 16:02 ` [RFC v5 35/57] objtool: arm64: Decode atomic load/store Julien Thierry
2020-01-09 16:02 ` [RFC v5 36/57] objtool: arm64: Decode pointer auth load instructions Julien Thierry
2020-01-09 16:02 ` [RFC v5 37/57] objtool: arm64: Decode load acquire/store release Julien Thierry
2020-01-09 16:02 ` [RFC v5 38/57] objtool: arm64: Decode load/store with memory tag Julien Thierry
2020-01-09 16:02 ` [RFC v5 39/57] objtool: arm64: Decode load literal Julien Thierry
2020-01-09 16:02 ` [RFC v5 40/57] objtool: arm64: Decode register data processing instructions Julien Thierry
2020-01-09 16:02 ` [RFC v5 41/57] objtool: arm64: Decode FP/SIMD " Julien Thierry
2020-01-09 16:02 ` [RFC v5 42/57] objtool: arm64: Decode SVE instructions Julien Thierry
2020-01-09 16:02 ` [RFC v5 43/57] gcc-plugins: objtool: Add plugin to detect switch table on arm64 Julien Thierry
2020-01-09 16:02 ` [RFC v5 44/57] objtool: arm64: Implement functions to add switch tables alternatives Julien Thierry
2020-01-15 16:37 ` Raphael Gault
2020-01-17 8:28 ` Julien Thierry
2020-01-09 16:02 ` [RFC v5 45/57] objtool: arm64: Enable stack validation for arm64 Julien Thierry
2020-01-09 16:02 ` [RFC v5 46/57] arm64: alternative: Mark .altinstr_replacement as containing executable instructions Julien Thierry
2020-01-09 16:02 ` [RFC v5 47/57] arm64: assembler: Add macro to annotate asm function having non standard stack-frame Julien Thierry
2020-01-21 10:30 ` Will Deacon
2020-01-23 13:45 ` Julien Thierry
2020-01-23 14:40 ` Will Deacon
2020-01-09 16:02 ` [RFC v5 48/57] arm64: sleep: Prevent stack frame warnings from objtool Julien Thierry
2020-01-09 16:02 ` [RFC v5 49/57] arm64: kvm: Annotate non-standard stack frame functions Julien Thierry
2020-01-09 16:02 ` [RFC v5 50/57] arm64: kernel: Add exception on kuser32 to prevent stack analysis Julien Thierry
2020-01-09 16:02 ` [RFC v5 51/57] arm64: crypto: Add exceptions for crypto object " Julien Thierry
2020-01-09 16:02 ` [RFC v5 52/57] arm64: kernel: Annotate non-standard stack frame functions Julien Thierry
2020-01-09 16:02 ` [RFC v5 53/57] arm64: Generate no-ops to pad executable section Julien Thierry
2020-01-09 16:02 ` [RFC v5 54/57] arm64: Move constant to rodata Julien Thierry
2020-01-09 16:02 ` [RFC v5 55/57] arm64: Mark sigreturn32.o as containing non standard code Julien Thierry
2020-01-09 16:02 ` [RFC v5 56/57] arm64: entry: Avoid empty alternatives entries Julien Thierry
2020-01-09 16:51 ` Mark Rutland
2020-01-21 10:30 ` Will Deacon
2020-01-09 16:03 ` [RFC v5 57/57] arm64: crypto: Remove redundant branch Julien Thierry
2020-01-12 8:42 ` [RFC v5 00/57] objtool: Add support for arm64 Nathan Chancellor
2020-01-13 7:57 ` Julien Thierry
2020-01-21 10:31 ` Will Deacon
2020-01-21 17:08 ` Nick Desaulniers
2020-01-21 18:06 ` Will Deacon
2020-01-21 18:30 ` Josh Poimboeuf
2020-01-22 14:47 ` Will Deacon
2020-01-13 17:18 ` Nick Desaulniers
2020-01-20 15:07 ` Peter Zijlstra
2020-01-21 17:50 ` Josh Poimboeuf
2020-01-23 13:56 ` Julien Thierry
2020-01-21 10:30 ` Will Deacon
2020-01-23 13:52 ` Julien Thierry
2020-01-23 14:35 ` Will Deacon
2020-01-23 15:11 ` Julien Thierry
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=20200120145401.GB14897@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=catalin.marinas@arm.com \
--cc=jpoimboe@redhat.com \
--cc=jthierry@redhat.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=raphael.gault@arm.com \
--cc=will@kernel.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).