linux.git/arch/xtensa/include/asm/thread_info.h, branch v4.16.7

Merge tag 'xtensa-20180129' of git://github.com/jcmvbkbc/linux-xtensa

2018-01-30T00:40:28+00:00

Pull Xtensa updates from Max Filippov:

 - add SSP support

 - add KASAN support

 - improvements to xtensa-specific assembly:
    - use ENTRY and ENDPROC consistently
    - clean up and unify word alignment macros
    - clean up and unify fixup marking
    - use 'call' instead of 'callx' where possible

 - various cleanups:
    - consiolidate kernel stack size related definitions
    - replace #ifdef'fed/commented out debug printk statements with
      pr_debug
    - use struct exc_table instead of flat array for exception handling
      data

 - build kernel with -mtext-section-literals; simplify xtensa linker
   script

 - fix futex_atomic_cmpxchg_inatomic()

* tag 'xtensa-20180129' of git://github.com/jcmvbkbc/linux-xtensa: (21 commits)
  xtensa: fix futex_atomic_cmpxchg_inatomic
  xtensa: shut up gcc-8 warnings
  xtensa: print kernel sections info in mem_init
  xtensa: use generic strncpy_from_user with KASAN
  xtensa: use __memset in __xtensa_clear_user
  xtensa: add support for KASAN
  xtensa: move fixmap and kmap just above the KSEG
  xtensa: don't clear swapper_pg_dir in paging_init
  xtensa: extract init_kio
  xtensa: implement early_trap_init
  xtensa: clean up exception handling structure
  xtensa: clean up custom-controlled debug output
  xtensa: enable stack protector
  xtensa: print hardware config ID on startup
  xtensa: consolidate kernel stack size related definitions
  xtensa: clean up functions in assembly code
  xtensa: clean up word alignment macros in assembly code
  xtensa: clean up fixups in assembly code
  xtensa: use call instead of callx in assembly code
  xtensa: build kernel with text-section-literals
  ...

Construct init thread stack in the linker script rather than by union

2018-01-09T23:21:02+00:00

Construct the init thread stack in the linker script rather than doing it
by means of a union so that ia64's init_task.c can be got rid of.

The following symbols are then made available from INIT_TASK_DATA() linker
script macro:

	init_thread_union
	init_stack

INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
size of the init stack.  init_thread_union is given its own section so that
it can be placed into the stack space in the right order.  I'm assuming
that the ia64 ordering is correct and that the task_struct is first and the
thread_info second.

Signed-off-by: David Howells 
Tested-by: Tony Luck 
Tested-by: Will Deacon  (arm64)
Tested-by: Palmer Dabbelt 
Acked-by: Thomas Gleixner

xtensa: consolidate kernel stack size related definitions

2017-12-10T22:48:55+00:00

Define kernel stack size in kmem_layout and use it in
current_thread_info, GET_THREAD_INFO, THREAD_SIZE and THERAD_SIZE_ORDER
definitions.

Signed-off-by: Max Filippov

xtensa: support hardware breakpoints/watchpoints

2016-03-11T08:53:32+00:00

Use perf framework to manage hardware instruction and data breakpoints.
Add two new ptrace calls: PTRACE_GETHBPREGS and PTRACE_SETHBPREGS to
query and set instruction and data breakpoints.
Address bit 0 choose instruction (0) or data (1) break register, bits
31..1 are the register number.
Both calls transfer two 32-bit words: address (0) and control (1).
Instruction breakpoint contorl word is 0 to clear breakpoint, 1 to set.
Data breakpoint control word bit 31 is 'trigger on store', bit 30 is
'trigger on load, bits 29..0 are length. Length 0 is used to clear a
breakpoint. To set a breakpoint length must be a power of 2 in the range
1..64 and the address must be length-aligned.

Introduce new thread_info flag: TIF_DB_DISABLED. Set it if debug
exception is raised by the kernel code accessing watched userspace
address and disable corresponding data breakpoint. On exit to userspace
check that flag and, if set, restore all data breakpoints.

Handle debug exceptions raised with PS.EXCM set. This may happen when
window overflow/underflow handler or fast exception handler hits data
breakpoint, in which case save and disable all data breakpoints,
single-step faulting instruction and restore data breakpoints.

Signed-off-by: Max Filippov

xtensa: Remove signal translation and exec_domain

2015-04-12T19:03:29+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

xtensa: Autogenerate offsets in struct thread_info

2015-04-12T19:03:29+00:00

Maintaining offsets by hand is no fun.

Reported-by: Guenter Roeck 
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

preempt: Make PREEMPT_ACTIVE generic

2013-11-13T19:21:47+00:00

No point in having this bit defined by architecture.

Signed-off-by: Thomas Gleixner 
Acked-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20130917183629.090698799@linutronix.de

bury the rest of TIF_IRET

2012-10-01T13:58:13+00:00

Some architectures had blindly copied it for no reason whatsoever.

Signed-off-by: Al Viro

sanitize tsk_is_polling()

2012-10-01T13:58:13+00:00

Make default just return 0.  The current default (checking
TIF_POLLING_NRFLAG) is taken to architectures that need it;
ones that don't do polling in their idle threads don't need
to defined TIF_POLLING_NRFLAG at all.

ia64 defined both TS_POLLING (used by its tsk_is_polling())
and TIF_POLLING_NRFLAG (not used at all).  Killed the latter...

Signed-off-by: Al Viro