Commit Graph

14 Commits

Author SHA1 Message Date
Borislav Petkov
d72e720a19 scripts/decodecode: add the capability to supply the program counter
So that comparing with objdump output from vmlinux can ease pinpointing
where the trapping instruction actually is.  An example is better than a
thousand words:

  $ PC=0xffffffff8329a927 ./scripts/decodecode < ~/tmp/syz/gfs2.splat
  [ 477.379104][T23917] Code: 48 83 ec 28 48 89 3c 24 48 89 54 24 08 e8 c1 b4 4a fe 48 8d bb 00 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 97 05 00 00 48 8b 9b 00 01 00 00 48 85 db 0f 84
  All code
  ========
  ffffffff8329a8fd:       48 83 ec 28             sub    $0x28,%rsp
  ffffffff8329a901:       48 89 3c 24             mov    %rdi,(%rsp)
  ffffffff8329a905:       48 89 54 24 08          mov    %rdx,0x8(%rsp)
  ffffffff8329a90a:       e8 c1 b4 4a fe          callq  0xffffffff81745dd0
  ffffffff8329a90f:       48 8d bb 00 01 00 00    lea    0x100(%rbx),%rdi
  ffffffff8329a916:       48 b8 00 00 00 00 00    movabs $0xdffffc0000000000,%rax
  ffffffff8329a91d:       fc ff df
  ffffffff8329a920:       48 89 fa                mov    %rdi,%rdx
  ffffffff8329a923:       48 c1 ea 03             shr    $0x3,%rdx
  ffffffff8329a927:*      80 3c 02 00             cmpb   $0x0,(%rdx,%rax,1)               <-- trapping instruction
  ffffffff8329a92b:       0f 85 97 05 00 00       jne    0xffffffff8329aec8
  ffffffff8329a931:       48 8b 9b 00 01 00 00    mov    0x100(%rbx),%rbx
  ffffffff8329a938:       48 85 db                test   %rbx,%rbx
  ffffffff8329a93b:       0f                      .byte 0xf
  ffffffff8329a93c:       84                      .byte 0x84

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Marc Zyngier <maz@misterjones.org>
Cc: Will Deacon <will@kernel.org>
Cc: Rabin Vincent <rabin@rab.in>
Link: https://lkml.kernel.org/r/20200930111416.GF6810@zn.tnic
Link: https://lkml.kernel.org/r/20200929113238.GC21110@zn.tnic
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:26 -07:00
Ivan Delalande
e08df079b2 scripts/decodecode: fix trapping instruction formatting
If the trapping instruction contains a ':', for a memory access through
segment registers for example, the sed substitution will insert the '*'
marker in the middle of the instruction instead of the line address:

	2b:   65 48 0f c7 0f          cmpxchg16b %gs:*(%rdi)          <-- trapping instruction

I started to think I had forgotten some quirk of the assembly syntax
before noticing that it was actually coming from the script.  Fix it to
add the address marker at the right place for these instructions:

	28:   49 8b 06                mov    (%r14),%rax
	2b:*  65 48 0f c7 0f          cmpxchg16b %gs:(%rdi)           <-- trapping instruction
	30:   0f 94 c0                sete   %al

Fixes: 18ff44b189 ("scripts/decodecode: make faulting insn ptr more robust")
Signed-off-by: Ivan Delalande <colona@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20200419223653.GA31248@visor
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-07 19:27:20 -07:00
Marc Zyngier
c5cfb62f2b scripts/decodecode: set ARCH when running natively on arm/arm64
When running decodecode natively on arm64, ARCH is likely not to be set,
and we end-up with .4byte instead of .inst when generating the
disassembly.

Similar effects would occur if running natively on a 32bit ARM platform,
although that's even less popular.

A simple workaround is to populate ARCH when it is not set and that we're
running on an arm/arm64 system.

Link: http://lkml.kernel.org/r/20181210174659.31054-2-marc.zyngier@arm.com
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:44 -08:00
Andy Shevchenko
7e68b36145 scripts/decodecode: make it take multiline Code line
In case of running scripts/decodecode without any parameters in order to
give a copy'n'pasted Code line from, for example, email it would parse
only first line of it, while in emails it's split to few.

ie, when you have a file out of oops the Code line looks like

  Code: hh hh ... <hh> ... hh\n

When copy'n'paste from, for example, email where sender or some middle
MTA split it, the line looks like:

  Code: hh hh ... hh\n
  hh ... <hh> ... hh\n
  hh hh ... hh\n

The Code line followed by another oops line usually contains characters
out of hex digit + space + < + > set.

So add logic to join this split back if and only if the following lines
have hex digits, or spaces, or '<', or '>' characters.  It will be quite
unlikely to have a broken input in well formed Oops or dmesg, thus a
simple regex is being used.

Link: http://lkml.kernel.org/r/20171212100323.33201-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31 17:18:34 -08:00
Will Deacon
be9fa663d3 scripts/decodecode: fix decoding for AArch64 (arm64) instructions
There are a couple of problems with the decodecode script and arm64:

1. AArch64 objdump refuses to disassemble .4byte directives as instructions,
   insisting that they are data values and displaying them as:

	a94153f3	.word	0xa94153f3		<-- trapping instruction

   This is resolved by using the .inst directive instead.

2. Disassembly of branch instructions attempts to provide the target as
   an offset from a symbol, e.g.:

   0:	34000082	cbz	w2, 10 <.text+0x10>

  however this falls foul of the grep -v, which matches lines containing
  ".text" and ends up removing all branch instructions from the dump.

This patch resolves both issues by using the .inst directive for 4-byte
quantities on arm64 and stripping the resulting binaries (as is done on
arm already) to remove the mapping symbols.

Link: http://lkml.kernel.org/r/1506596147-23630-1-git-send-email-will.deacon@arm.com
Signed-off-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-19 10:09:41 -08:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Borislav Petkov
18ff44b189 scripts/decodecode: make faulting insn ptr more robust
It can accidentally happen that the faulting insn (the exact instruction
bytes) is repeated a little further on in the trace.  This causes that
same instruction to be tagged twice, see example below.

What we want to do, however, is to track back from the end of the whole
disassembly so many lines as the slice which starts with the faulting
instruction is long.  This leads us to the actual faulting instruction
and *then* we tag it.

While we're at it, we can drop the sed "g" flag because we address only
this one line.

Also, if we point to an instruction which changes decoding depending on
the slice being objdumped, like a Jcc insn, for example, we do not even
tag it as a faulting instruction because the instruction decode changes
in the second slice but we use that second format as a regex on the
fsrst disassembled buffer and more often than not that instruction
doesn't match.

Again, simply tag the line which is deduced from the original "<>"
marking we've received from the kernel.

This also solves the pathologic issue of multiple tagging like this:

  29:*  0f 0b                   ud2         <-- trapping instruction
  2b:*  0f 0b                   ud2         <-- trapping instruction
  2d:*  0f 0b                   ud2         <-- trapping instruction

Double tagging example:

Code: 34 dd 40 30 ad 81 48 c7 c0 80 f6 00 00 48 8b 3c 30 48 01 c6 b8 ff ff ff ff 48 8d 57 f0 48 39 f7 74 2f 49 8b 4c 24 08 48 8b 47 f0 <48> 39 48 08 75 0e eb 2a 66 90 48 8b 40 f0 48 39 48 08 74 1e 48
All code
========
   0:   34 dd                   xor    $0xdd,%al
   2:   40 30 ad 81 48 c7 c0    xor    %bpl,-0x3f38b77f(%rbp)
   9:   80 f6 00                xor    $0x0,%dh
   c:   00 48 8b                add    %cl,-0x75(%rax)
   f:   3c 30                   cmp    $0x30,%al
  11:   48 01 c6                add    %rax,%rsi
  14:   b8 ff ff ff ff          mov    $0xffffffff,%eax
  19:   48 8d 57 f0             lea    -0x10(%rdi),%rdx
  1d:   48 39 f7                cmp    %rsi,%rdi
  20:   74 2f                   je     0x51
  22:   49 8b 4c 24 08          mov    0x8(%r12),%rcx
  27:   48 8b 47 f0             mov    -0x10(%rdi),%rax
  2b:*  48 39 48 08             cmp    %rcx,0x8(%rax)     <-- trapping instruction
  2f:   75 0e                   jne    0x3f
  31:   eb 2a                   jmp    0x5d
  33:   66 90                   xchg   %ax,%ax
  35:   48 8b 40 f0             mov    -0x10(%rax),%rax
  39:*  48 39 48 08             cmp    %rcx,0x8(%rax)     <-- trapping instruction
  3d:   74 1e                   je     0x5d
  3f:   48                      rex.W

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:27 -07:00
Borislav Petkov
2a95e37c12 scripts/decodecode: Fixup trapping instruction marker
When dumping "Code: " sections from an oops, the trapping instruction
%rip points to can be a string copy

  2b:*  f3 a5                   rep movsl %ds:(%rsi),%es:(%rdi)

and the line contain a bunch of ":".  Current "cut" selects only the and
the second field output looks funnily overlaid this:

  2b:*  f3 a5                   rep movsl %ds     <-- trapping instruction:(%rsi),%es:(%rdi

Fix this by selecting the remaining fields too.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-16 11:15:09 -07:00
Rabin Vincent
b396aa0308 scripts: decodecode: remove bashisms
Remove bashisms to make scripts/decodecode work with other shells.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-06-04 10:26:35 +02:00
Rabin Vincent
5358db0b0e scripts: add ARM support to decodecode
This patch adds support for decoding ARM oopses to scripts/decodecode.
The following things are handled:

 - ARCH and CROSS_COMPILE environment variables are respected.

 - The Code: in x86 oopses is in bytes, while it is in either words (4
   bytes) or halfwords for ARM.

 - Some versions of ARM objdump refuse to disassemble instructions
   generated by literal constants (".word 0x...").  The workaround is to
   strip the object file first.

 - The faulting instruction is marked (liked so) in ARM, but <like so>
   in x86.

 - ARM mnemonics may include characters such as [] which need to be
   escaped before being passed to sed for the "<- trapping instruction"
   substitution.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-02-02 14:33:54 +01:00
Arjan van de Ven
846442c8dd scripts: improve the decodecode script
kerneloops.org has been using an improved "decodecode" script,
specifically it has a special marker that shows which line in the assembly
the oops happened at, like this:

  20:	83 e0 03             	and    $0x3,%eax
  23:	09 d8                	or     %ebx,%eax
  25:	85 db                	test   %ebx,%ebx
  27:	89 02                	mov    %eax,(%edx)
  29:	74 0f                	je     0x3a
  2b:*	3b 73 04             	cmp    0x4(%ebx),%esi     <-- trapping instruction
  2e:	75 05                	jne    0x35
  30:	89 53 04             	mov    %edx,0x4(%ebx)
  33:	eb 07                	jmp    0x3c
  35:	89 53 08             	mov    %edx,0x8(%ebx)

this patch updates the kernel copy to also have this functionality.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Reviewed-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-12-03 22:36:39 +01:00
Linus Torvalds
14d03fd98e Mark 'scripts/decodecode' executable
.. because it is.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-30 14:02:21 -07:00
Randy Dunlap
fa220d89ad kbuild: minor scripts/decodecode update
Remove the tmp file when exiting.  Noticed by Arjan van de Ven.
Catch mktemp failure and exit with message.
Trap kill or other signals and exit cleanly.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-01-28 23:14:40 +01:00
Randy Dunlap
dcecc6c700 doc/oops-tracing: add Code: decode info
Add info that the Code: bytes line contains <xy> or (wxyz) in some
architecture oops reports and what that means.

Add a script by Andi Kleen that reads the Code: line from an Oops report
file and generates assembly code from the hex bytes.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:48 -07:00