linux-stable.git/arch/xtensa/kernel/process.c, branch v4.4.232

xtensa: enable coprocessors that are being flushed

2018-12-13T08:21:26+00:00

commit 2958b66694e018c552be0b60521fec27e8d12988 upstream.

coprocessor_flush_all may be called from a context of a thread that is
different from the thread being flushed. In that case contents of the
cpenable special register may not match ti->cpenable of the target
thread, resulting in unhandled coprocessor exception in the kernel
context.
Set cpenable special register to the ti->cpenable of the target register
for the duration of the flush and restore it afterwards.
This fixes the following crash caused by coprocessor register inspection
in native gdb:

  (gdb) p/x $w0
  Illegal instruction in kernel: sig: 9 [#1] PREEMPT
  Call Trace:
    ___might_sleep+0x184/0x1a4
    __might_sleep+0x41/0xac
    exit_signals+0x14/0x218
    do_exit+0xc9/0x8b8
    die+0x99/0xa0
    do_illegal_instruction+0x18/0x6c
    common_exception+0x77/0x77
    coprocessor_flush+0x16/0x3c
    arch_ptrace+0x46c/0x674
    sys_ptrace+0x2ce/0x3b4
    system_call+0x54/0x80
    common_exception+0x77/0x77
  note: gdb[100] exited with preempt_count 1
  Killed

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov 
Signed-off-by: Greg Kroah-Hartman

xtensa: Use generic idle loop

2013-04-08T15:39:29+00:00

Signed-off-by: Thomas Gleixner 
Cc: Linus Torvalds 
Cc: Rusty Russell 
Cc: Paul McKenney 
Cc: Peter Zijlstra 
Reviewed-by: Srivatsa S. Bhat 
Cc: Magnus Damm 
Acked-by: Chris Zankel 
Link: http://lkml.kernel.org/r/20130321215235.546600507@linutronix.de
Signed-off-by: Thomas Gleixner

xtensa: add support for TLS

2013-02-24T03:35:57+00:00

The Xtensa architecture provides a global register called THREADPTR
for the purpose of Thread Local Storage (TLS) support. This allows us
to use a fairly simple implementation, keeping the thread pointer in
the regset and simply saving and restoring it upon entering/exiting
the from user space.

Signed-off-by: Chris Zankel

xtensa: clean up files to make them code-style compliant

2012-12-19T05:10:25+00:00

Remove heading and trailing spaces, trim trailing lines, and wrap lines
that are longer than 80 characters.

Signed-off-by: Chris Zankel

flagday: don't pass regs to copy_thread()

2012-11-29T04:43:42+00:00

Signed-off-by: Al Viro

xtensa: switch to generic clone()

2012-11-29T04:43:41+00:00

Signed-off-by: Al Viro

xtensa: switch to generic sys_execve()

2012-10-25T22:00:44+00:00

Signed-off-by: Max Filippov 
Signed-off-by: Chris Zankel

xtensa: switch to generic kernel_thread()

2012-10-25T22:00:03+00:00

Signed-off-by: Max Filippov 
Signed-off-by: Chris Zankel

xtensa: reset windowbase/windowstart when cloning the VM

2012-10-25T21:53:36+00:00

When we copy a user thread with CLONE_VM, we also have to reset
windowbase and windowstart to start a pristine stack frame. Otherwise,
overflows can happen using the address 0 as the stack pointer.
Also add a special case for vfork, which continues on the
parent stack until it calls execve. Because this could be a call8, we
need to spill the stack pointer of the previus frame (if still 'live' in
the register file).

Signed-off-by: Chris Zankel

xtensa: minor compiler warning fix

2012-10-19T17:24:20+00:00

Fix two compiler warnings complaining about truncating a value on
a 64-bit host, and about declaring an unused variable that is only
used for a specific configuration.

Signed-off-by: Chris Zankel