linux.git/arch/arm/include/asm/thread_info.h, branch v4.4.300

ARM: 8791/1: vfp: use __copy_to_user() when saving VFP state

2019-11-10T10:21:33+00:00

Commit 3aa2df6ec2ca6bc143a65351cca4266d03a8bc41 upstream.

Use __copy_to_user() rather than __put_user_error() for individual
members when saving VFP state.
This has the benefit of disabling/enabling PAN once per copied struct
intead of once per write.

Signed-off-by: Julien Thierry 
Signed-off-by: Russell King 
Signed-off-by: David A. Long 
Reviewed-by: Julien Thierry 
Signed-off-by: Sasha Levin 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Greg Kroah-Hartman

ARM: vfp: use __copy_from_user() when restoring VFP state

2019-11-10T10:21:30+00:00

Commit 42019fc50dfadb219f9e6ddf4c354f3837057d80 upstream.

__get_user_error() is used as a fast accessor to make copying structure
members in the signal handling path as efficient as possible.  However,
with software PAN and the recent Spectre variant 1, the efficiency is
reduced as these are no longer fast accessors.

In the case of software PAN, it has to switch the domain register around
each access, and with Spectre variant 1, it would have to repeat the
access_ok() check for each access.

Use __copy_from_user() rather than __get_user_err() for individual
members when restoring VFP state.

Acked-by: Mark Rutland 
Signed-off-by: Russell King 
Signed-off-by: David A. Long 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

2015-09-14T19:24:10+00:00

Pull ARM fixes from Russell King:
 "A number of fixes for the merge window, fixing a number of cases
  missed when testing the uaccess code, particularly cases which only
  show up with certain compiler versions"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8431/1: fix alignement of __bug_table section entries
  arm/xen: Enable user access to the kernel before issuing a privcmd call
  ARM: domains: add memory dependencies to get_domain/set_domain
  ARM: domains: thread_info.h no longer needs asm/domains.h
  ARM: uaccess: fix undefined instruction on ARMv7M/noMMU
  ARM: uaccess: remove unneeded uaccess_save_and_disable macro
  ARM: swpan: fix nwfpe for uaccess changes
  ARM: 8429/1: disable GCC SRA optimization

ARM: domains: thread_info.h no longer needs asm/domains.h

2015-09-11T15:07:47+00:00

As of 1eef5d2f1b46 ("ARM: domains: switch to keeping domain value in
register") we no longer need to include asm/domains.h into
asm/thread_info.h.  Remove it.

Tested-by: Robert Jarzmik 
Signed-off-by: Russell King

Merge branches 'cleanup', 'fixes', 'misc', 'omap-barrier' and 'uaccess' into for-linus

2015-09-03T14:28:37+00:00

ARM: entry: efficiency cleanups

2015-08-25T09:32:48+00:00

Make the "fast" syscall return path fast again.  The addition of IRQ
tracing and context tracking has made this path grossly inefficient.
We can do much better if these options are enabled if we save the
syscall return code on the stack - we then don't need to save a bunch
of registers around every single callout to C code.

Acked-by: Will Deacon 
Signed-off-by: Russell King

ARM: domains: switch to keeping domain value in register

2015-08-21T12:55:49+00:00

Rather than modifying both the domain access control register and our
per-thread copy, modify only the domain access control register, and
use the per-thread copy to save and restore the register over context
switches.  We can also avoid the explicit initialisation of the
init thread_info structure.

This allows us to avoid needing to gain access to the thread information
at the uaccess control sites.

Signed-off-by: Russell King

arm: Remove signal translation and exec_domain

2015-04-12T18:58:24+00:00

As execution domain support is gone we can remove
signal translation from the signal code and remove
exec_domain from thread_info.

Signed-off-by: Richard Weinberger

all arches, signal: move restart_block to struct task_struct

2015-02-13T02:54:12+00:00

If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski 
Cc: Thomas Gleixner 
Cc: Al Viro 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Kees Cook 
Cc: David Miller 
Acked-by: Richard Weinberger 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Vineet Gupta 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Haavard Skinnemoen 
Cc: Hans-Christian Egtvedt 
Cc: Steven Miao 
Cc: Mark Salter 
Cc: Aurelien Jacquiot 
Cc: Mikael Starvik 
Cc: Jesper Nilsson 
Cc: David Howells 
Cc: Richard Kuo 
Cc: "Luck, Tony" 
Cc: Geert Uytterhoeven 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: Jonas Bonn 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Acked-by: Michael Ellerman  (powerpc)
Tested-by: Michael Ellerman  (powerpc)
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Chen Liqin 
Cc: Lennox Wu 
Cc: Chris Metcalf 
Cc: Guan Xuetao 
Cc: Chris Zankel 
Cc: Max Filippov 
Cc: Oleg Nesterov 
Cc: Guenter Roeck 
Signed-off-by: James Hogan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branches 'fixes', 'misc', 'pm' and 'sa1100' into for-next

2014-12-05T16:30:47+00:00