linux.git/arch/arm64/kernel/probes, branch v4.20

arm64: kprobe: make page to RO mode when allocate it

2018-11-02T18:15:07+00:00

Commit 1404d6f13e47 ("arm64: dump: Add checking for writable and exectuable pages")
has successfully identified code that leaves a page with W+X
permissions.

[    3.245140] arm64/mm: Found insecure W+X mapping at address (____ptrval____)/0xffff000000d90000
[    3.245771] WARNING: CPU: 0 PID: 1 at ../arch/arm64/mm/dump.c:232 note_page+0x410/0x420
[    3.246141] Modules linked in:
[    3.246653] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc5-next-20180928-00001-ge70ae259b853-dirty #62
[    3.247008] Hardware name: linux,dummy-virt (DT)
[    3.247347] pstate: 80000005 (Nzcv daif -PAN -UAO)
[    3.247623] pc : note_page+0x410/0x420
[    3.247898] lr : note_page+0x410/0x420
[    3.248071] sp : ffff00000804bcd0
[    3.248254] x29: ffff00000804bcd0 x28: ffff000009274000
[    3.248578] x27: ffff00000921a000 x26: ffff80007dfff000
[    3.248845] x25: ffff0000093f5000 x24: ffff000009526f6a
[    3.249109] x23: 0000000000000004 x22: ffff000000d91000
[    3.249396] x21: ffff000000d90000 x20: 0000000000000000
[    3.249661] x19: ffff00000804bde8 x18: 0000000000000400
[    3.249924] x17: 0000000000000000 x16: 0000000000000000
[    3.250271] x15: ffffffffffffffff x14: 295f5f5f5f6c6176
[    3.250594] x13: 7274705f5f5f5f28 x12: 2073736572646461
[    3.250941] x11: 20746120676e6970 x10: 70616d20582b5720
[    3.251252] x9 : 6572756365736e69 x8 : 3039643030303030
[    3.251519] x7 : 306666666678302f x6 : ffff0000095467b2
[    3.251802] x5 : 0000000000000000 x4 : 0000000000000000
[    3.252060] x3 : 0000000000000000 x2 : ffffffffffffffff
[    3.252323] x1 : 4d151327adc50b00 x0 : 0000000000000000
[    3.252664] Call trace:
[    3.252953]  note_page+0x410/0x420
[    3.253186]  walk_pgd+0x12c/0x238
[    3.253417]  ptdump_check_wx+0x68/0xf8
[    3.253637]  mark_rodata_ro+0x68/0x98
[    3.253847]  kernel_init+0x38/0x160
[    3.254103]  ret_from_fork+0x10/0x18

kprobes allocates a writable executable page with module_alloc() in
order to store executable code.
Reworked to that when allocate a page it sets mode RO. Inspired by
commit 63fef14fc98a ("kprobes/x86: Make insn buffer always ROX and use text_poke()").

Suggested-by: Arnd Bergmann 
Suggested-by: Ard Biesheuvel 
Acked-by: Will Deacon 
Acked-by: Masami Hiramatsu 
Reviewed-by: Laura Abbott 
Signed-off-by: Anders Roxell 
[catalin.marinas@arm.com: removed unnecessary casts]
Signed-off-by: Catalin Marinas

arm64/kprobes: remove an extra semicolon in arch_prepare_kprobe

2018-10-01T13:36:49+00:00

There is an extra semicolon in arch_prepare_kprobe, remove it.

Signed-off-by: zhong jiang 
Signed-off-by: Catalin Marinas

kprobes/arm64: Fix %p uses in error messages

2018-06-21T15:33:42+00:00

Fix %p uses in error messages by removing it because
those are redundant or meaningless.

Signed-off-by: Masami Hiramatsu 
Acked-by: Will Deacon 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: Arnd Bergmann 
Cc: David Howells 
Cc: David S . Miller 
Cc: Heiko Carstens 
Cc: Jon Medhurst 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Thomas Richter 
Cc: Tobin C . Harding 
Cc: acme@kernel.org
Cc: akpm@linux-foundation.org
Cc: brueckner@linux.vnet.ibm.com
Cc: linux-arch@vger.kernel.org
Cc: rostedt@goodmis.org
Cc: schwidefsky@de.ibm.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/lkml/152491908405.9916.12425053035317241111.stgit@devbox
Signed-off-by: Ingo Molnar

bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe

2018-06-21T10:33:19+00:00

Clear current_kprobe and enable preemption in kprobe
even if pre_handler returns !0.

This simplifies function override using kprobes.

Jprobe used to require to keep the preemption disabled and
keep current_kprobe until it returned to original function
entry. For this reason kprobe_int3_handler() and similar
arch dependent kprobe handers checks pre_handler result
and exit without enabling preemption if the result is !0.

After removing the jprobe, Kprobes does not need to
keep preempt disabled even if user handler returns !0
anymore.

But since the function override handler in error-inject
and bpf is also returns !0 if it overrides a function,
to balancing the preempt count, it enables preemption
and reset current kprobe by itself.

That is a bad design that is very buggy. This fixes
such unbalanced preempt-count and current_kprobes setting
in kprobes, bpf and error-inject.

Note: for powerpc and x86, this removes all preempt_disable
from kprobe_ftrace_handler because ftrace callbacks are
called under preempt disabled.

Signed-off-by: Masami Hiramatsu 
Acked-by: Thomas Gleixner 
Acked-by: Naveen N. Rao 
Cc: Alexei Starovoitov 
Cc: Ananth N Mavinakayanahalli 
Cc: Andrew Morton 
Cc: Benjamin Herrenschmidt 
Cc: Catalin Marinas 
Cc: David S. Miller 
Cc: Fenghua Yu 
Cc: Heiko Carstens 
Cc: James Hogan 
Cc: Josef Bacik 
Cc: Linus Torvalds 
Cc: Martin Schwidefsky 
Cc: Michael Ellerman 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Ralf Baechle 
Cc: Rich Felker 
Cc: Russell King 
Cc: Steven Rostedt 
Cc: Tony Luck 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: https://lore.kernel.org/lkml/152942494574.15209.12323837825873032258.stgit@devbox
Signed-off-by: Ingo Molnar

arm64/kprobes: Don't call the ->break_handler() in arm64 kprobes code

2018-06-21T10:33:15+00:00

Don't call the ->break_handler() from the arm64 kprobes code,
because it was only used by jprobes which got removed.

Signed-off-by: Masami Hiramatsu 
Acked-by: Thomas Gleixner 
Acked-by: Will Deacon 
Cc: Ananth N Mavinakayanahalli 
Cc: Andrew Morton 
Cc: Catalin Marinas 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/lkml/152942474231.15209.17684808374429473004.stgit@devbox
Signed-off-by: Ingo Molnar

arm64/kprobes: Remove jprobe implementation

2018-06-21T10:33:07+00:00

Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/arm64.

Signed-off-by: Masami Hiramatsu 
Acked-by: Thomas Gleixner 
Acked-by: Will Deacon 
Cc: Ananth N Mavinakayanahalli 
Cc: Andrew Morton 
Cc: Catalin Marinas 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/lkml/152942442318.15209.17767976282305601884.stgit@devbox
Signed-off-by: Ingo Molnar

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

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 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

arm64: introduce separated bits for mm_context_t flags

2017-08-22T17:13:04+00:00

Currently mm->context.flags field uses thread_info flags which is not
the best idea for many reasons. For example, mm_context_t doesn't need
most of thread_info flags. And it would be difficult to add new mm-related
flag if needed because it may easily interfere with TIF ones.

To deal with it, the new MMCF_AARCH32 flag is introduced for
mm_context_t->flags, where MMCF prefix stands for mm_context_t flags.
Also, mm_context_t flag doesn't require atomicity and ordering of the
access, so using set/clear_bit() is replaced with simple masks.

Signed-off-by: Yury Norov 
Signed-off-by: Catalin Marinas

arm64: Call __show_regs directly

2017-05-30T10:07:41+00:00

Generic code expects show_regs() to also dump the stack, but arm64's
show_reg() does not do this. Some arm64 callers of show_regs() *only*
want the registers dumped, without the stack.

To enable generic code to work as expected, we need to make
show_regs() dump the stack. Where we only want the registers dumped,
we must use __show_regs().

This patch updates code to use __show_regs() where only registers are
desired. A subsequent patch will modify show_regs().

Acked-by: Mark Rutland 
Signed-off-by: Kefeng Wang 
Signed-off-by: Will Deacon

arm64: kprobes: remove kprobe_exceptions_notify

2017-03-10T17:41:19+00:00

Commit fc62d0207ae0 ("kprobes: Introduce weak variant of
kprobe_exceptions_notify()") introduces a generic empty version of the
function for architectures that don't need special handling, like arm64.
As such, remove the arch/arm64/ specific handler.

Signed-off-by: Naveen N. Rao 
Signed-off-by: Will Deacon