x86/tools/insn_sanity: Convert to insn_decode()

Simplify code, no functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210304174237.31945-19-bp@alien8.de

x86/insn: Support big endian cross-compiles

The x86 instruction decoder code is shared across the kernel source and
the tools. Currently objtool seems to be the only tool from build tools
needed which breaks x86 cross-compilation on big endian systems. Make
the x86 instruction decoder build host endianness agnostic to support
x86 cross-compilation and enable objtool to implement endianness
awareness for big endian architectures support.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Co-developed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/paravirt: Standardize 'insn_buff' variable names

We currently have 6 (!) separate naming variants to name temporary instruction
buffers that are used for code patching:

- insnbuf
- insnbuff
- insn_buff
- insn_buffer
- ibuf
- ibuffer

These are used as local variables, percpu fields and function parameters.

Standardize all the names to a single variant: 'insn_buff'.

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/decoder: Use stderr if insn sanity test fails

If the instruction sanity test fails, it prints a "Failure" message to
stdout. Make this program behave like the rest of the build and print
that message to stderr.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1477428965-20548-3-git-send-email-pebolle@tiscali.nl
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86: Remove arbitrary instruction size limit in instruction decoder

The current x86 instruction decoder steps along through the
instruction stream but always ensures that it never steps farther
than the largest possible instruction size (MAX_INSN_SIZE).

The MPX code is now going to be doing some decoding of userspace
instructions. We copy those from userspace in to the kernel and
they're obviously completely untrusted coming from userspace. In
addition to the constraint that instructions can only be so long,
we also have to be aware of how long the buffer is that came in
from userspace. This _looks_ to be similar to what the perf and
kprobes is doing, but it's unclear to me whether they are
affected.

The whole reason we need this is that it is perfectly valid to be
executing an instruction within MAX_INSN_SIZE bytes of an
unreadable page. We should be able to gracefully handle short
reads in those cases.

This adds support to the decoder to record how long the buffer
being decoded is and to refuse to "validate" the instruction if
we would have gone over the end of the buffer to decode it.

The kprobes code probably needs to be looked at here a bit more
carefully. This patch still respects the MAX_INSN_SIZE limit
there but the kprobes code does look like it might be able to
be a bit more strict than it currently is.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: x86@kernel.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20141114153957.E6B01535@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/tools/insn_sanity.c: Identify source of messages

The kernel build prints:

Building modules, stage 2.
TEST posttest
MODPOST 3821 modules
TEST posttest
Success: decoded and checked 1000000 random instructions with 0
errors (seed:0xaac4bc47) CC arch/x86/boot/a20.o
CC arch/x86/boot/cmdline.o
AS arch/x86/boot/copy.o
HOSTCC arch/x86/boot/mkcpustr
CC arch/x86/boot/cpucheck.o
CC arch/x86/boot/early_serial_console.o

which is irritating because you don't know what program is
proudly pronouncing its success.

So, as described in "console mode programming user interface
guidelines version 101" which doesn't exist, change this program
to identify the source of its messages.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/tools: Add decoded instruction dump mode

Add instruction dump mode to insn_sanity tool for
checking decoder really decoded instructions.

This mode is enabled when passing double -v (-vv) to
insn_sanity. It is useful for who wants to check whether
the decoder can decode some instructions correctly.
e.g.
$ echo 0f 73 10 11 | ./insn_sanity -y -vv -i -
Instruction = {
.prefixes = {
.value = 0, bytes[] = {0, 0, 0, 0},
.got = 1, .nbytes = 0},
.rex_prefix = {
.value = 0, bytes[] = {0, 0, 0, 0},
.got = 1, .nbytes = 0},
.vex_prefix = {
.value = 0, bytes[] = {0, 0, 0, 0},
.got = 1, .nbytes = 0},
.opcode = {
.value = 29455, bytes[] = {f, 73, 0, 0},
.got = 1, .nbytes = 2},
.modrm = {
.value = 16, bytes[] = {10, 0, 0, 0},
.got = 1, .nbytes = 1},
.sib = {
.value = 0, bytes[] = {0, 0, 0, 0},
.got = 1, .nbytes = 0},
.displacement = {
.value = 0, bytes[] = {0, 0, 0, 0},
.got = 1, .nbytes = 0},
.immediate1 = {
.value = 17, bytes[] = {11, 0, 0, 0},
.got = 1, .nbytes = 1},
.immediate2 = {
.value = 0, bytes[] = {0, 0, 0, 0},
.got = 0, .nbytes = 0},
.attr = 44800, .opnd_bytes = 4, .addr_bytes = 8,
.length = 4, .x86_64 = 1, .kaddr = 0x7fff0f7d9430}
Success: decoded and checked 1 given instructions with 0 errors (seed:0x0)

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20111205120603.15475.91192.stgit@cloud
Signed-off-by: Ingo Molnar <mingo@elte.hu>

x86/tools: Fix insn_sanity message outputs

Fix x86 instruction decoder test to dump all error messages
to stderr and others to stdout.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20111205120550.15475.70149.stgit@cloud
Signed-off-by: Ingo Molnar <mingo@elte.hu>

x86/tools: Fix instruction decoder message output

Fix instruction decoder test (insn_sanity), so that
it doesn't show both info and error messages twice on
same instruction. (In that case, show only error message)

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20111205120545.15475.7928.stgit@cloud
Signed-off-by: Ingo Molnar <mingo@elte.hu>

x86, perf: Add a build-time sanity test to the x86 decoder

Add a sanity test of x86 insn decoder against a stream
of randomly generated input, at build time.

This test is also able to reproduce any bug that might
trigger by allowing the passing of random-seed and
iteration-number to the test, or by passing input
which has invalid byte code.

Changes in V2:
- Code cleanup.
- Show how to reproduce the error by insn_sanity test.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: acme@redhat.com
Cc: ming.m.lin@intel.com
Cc: robert.richter@amd.com
Cc: ravitillo@lbl.gov
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20111020140109.20938.92572.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@elte.hu>