linux.git/arch/arm/kernel/vdso.c, branch v6.8

ARM: 9300/1: Replace all non-returning strlcpy with strscpy

2023-06-19T08:35:49+00:00

strlcpy() reads the entire source buffer first.  This read may exceed
the destination size limit.  This is both inefficient and can lead to
linear read overflows if a source string is not NUL-terminated [1].  In
an effort to remove strlcpy() completely [2], replace strlcpy() here
with strscpy().  No return values were used, so direct replacement is
safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

[ardb: submitting to the patch tracker on behalf of Azeem]

Signed-off-by: Azeem Shaikh 
Reviewed-by: Linus Walleij 
Reviewed-by: Kees Cook 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Russell King (Oracle)

mm: forbid splitting special mappings

2020-12-15T20:13:41+00:00

Don't allow splitting of vm_special_mapping's.  It affects vdso/vvar
areas.  Uprobes have only one page in xol_area so they aren't affected.

Those restrictions were enforced by checks in .mremap() callbacks.
Restrict resizing with generic .split() callback.

Link: https://lkml.kernel.org/r/20201013013416.390574-7-dima@arista.com
Signed-off-by: Dmitry Safonov 
Cc: Alexander Viro 
Cc: Andy Lutomirski 
Cc: Brian Geffon 
Cc: Catalin Marinas 
Cc: Dan Carpenter 
Cc: Dan Williams 
Cc: Dave Jiang 
Cc: Hugh Dickins 
Cc: Ingo Molnar 
Cc: Jason Gunthorpe 
Cc: John Hubbard 
Cc: "Kirill A. Shutemov" 
Cc: Mike Kravetz 
Cc: Minchan Kim 
Cc: Ralph Campbell 
Cc: Russell King 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Vishal Verma 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ARM: 8987/1: VDSO: Fix incorrect clock_gettime64

2020-07-21T15:32:55+00:00

__vdso_*() should be removed and fallback used if CNTCVT is not
available by cntvct_functional(). __vdso_clock_gettime64 when added
previous commit is using the incorrect CNTCVT value in that state.
__vdso_clock_gettime64 is also added to remove it's symbol.

Cc: stable@vger.kernel.org
Fixes: 74d06efb9c2f ("ARM: 8932/1: Add clock_gettime64 entry point")
Signed-off-by: Jaedon Shin 
Tested-by: Robin Murphy 
Signed-off-by: Robin Murphy 
Signed-off-by: Russell King

mmap locking API: convert mmap_sem comments

2020-06-09T16:39:14+00:00

Convert comments that reference mmap_sem to reference mmap_lock instead.

[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]

Signed-off-by: Michel Lespinasse 
Signed-off-by: Andrew Morton 
Reviewed-by: Vlastimil Babka 
Reviewed-by: Daniel Jordan 
Cc: Davidlohr Bueso 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Jason Gunthorpe 
Cc: Jerome Glisse 
Cc: John Hubbard 
Cc: Laurent Dufour 
Cc: Liam Howlett 
Cc: Matthew Wilcox 
Cc: Peter Zijlstra 
Cc: Ying Han 
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds

ARM: 8957/1: VDSO: Match ARMv8 timer in cntvct_functional()

2020-02-21T17:03:20+00:00

It is possible for a system with an ARMv8 timer to run a 32-bit kernel.
When this happens we will unconditionally have the vDSO code remove the
__vdso_gettimeofday and __vdso_clock_gettime symbols because
cntvct_functional() returns false since it does not match that
compatibility string.

Fixes: ecf99a439105 ("ARM: 8331/1: VDSO initialization, mapping, and synchronization")
Signed-off-by: Florian Fainelli 
Signed-off-by: Russell King

ARM: 8930/1: Add support for generic vDSO

2019-11-15T22:21:12+00:00

The arm vDSO library requires some adaptations to take advantage of
the newly introduced generic vDSO library.

Introduce the following changes:
 - Modification vdso.c to be compliant with the common vdso datapage
 - Use of lib/vdso for gettimeofday
 - Implementation of elf note

Signed-off-by: Vincenzo Frascino 
Signed-off-by: Russell King

ARM: 8896/1: VDSO: Don't leak kernel addresses

2019-08-23T10:39:32+00:00

Since commit ad67b74d2469d9b8 ("printk: hash addresses printed with
%p"), an obfuscated kernel pointer is printed at every boot if
debugging is enabled:

    vdso: 1 text pages at base (____ptrval____)

Remove the print completely, as it's useless without the address.

Based on commit 0f1bf7e39822476b ("arm64/vdso: don't leak kernel
addresses").

Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Russell King

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234

2019-06-19T15:09:07+00:00

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 version 2 as
  published by the free software foundation 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 see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Alexios Zavras 
Reviewed-by: Allison Randal 
Reviewed-by: Enrico Weigelt 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman

ARM: 8748/1: mm: Define vdso_start, vdso_end as array

2018-03-24T14:27:49+00:00

Define vdso_start, vdso_end as array to avoid compile-time analysis error
for the case of built with CONFIG_FORTIFY_SOURCE.

and, since vdso_start, vdso_end are used in vdso.c only,
move extern-declaration from vdso.h to vdso.c.

If kernel is built with CONFIG_FORTIFY_SOURCE,
compile-time error happens at this code.
- if (memcmp(&vdso_start, "177ELF", 4))

The size of "&vdso_start" is recognized as 1 byte, but n is 4,
So that compile-time error is reported.

Acked-by: Kees Cook 
Signed-off-by: Jinbum Park 
Signed-off-by: Russell King

ARM: 8683/1: ARM32: Support mremap() for sigpage/vDSO

2017-06-21T12:02:58+00:00

CRIU restores application mappings on the same place where they
were before Checkpoint. That means, that we need to move vDSO
and sigpage during restore on exactly the same place where
they were before C/R.

Make mremap() code update mm->context.{sigpage,vdso} pointers
during VMA move. Sigpage is used for landing after handling
a signal - if the pointer is not updated during moving, the
application might crash on any signal after mremap().

vDSO pointer on ARM32 is used only for setting auxv at this moment,
update it during mremap() in case of future usage.

Without those updates, current work of CRIU on ARM32 is not reliable.
Historically, we error Checkpointing if we find vDSO page on ARM32
and suggest user to disable CONFIG_VDSO.
But that's not correct - it goes from x86 where signal processing
is ended in vDSO blob. For arm32 it's sigpage, which is not disabled
with `CONFIG_VDSO=n'.

Looks like C/R was working by luck - because userspace on ARM32 at
this moment always sets SA_RESTORER.

Signed-off-by: Dmitry Safonov 
Acked-by: Andy Lutomirski 
Cc: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon 
Cc: Thomas Gleixner 
Cc: Cyrill Gorcunov 
Cc: Pavel Emelyanov 
Cc: Christopher Covington 
Signed-off-by: Russell King