linux.git/arch/powerpc/kernel/entry_32.S, branch v5.4.30

powerpc/entry: Fix an #if which should be an #ifdef in entry_32.S

2020-02-28T16:22:18+00:00

commit 9eb425b2e04e0e3006adffea5bf5f227a896f128 upstream.

Fixes: 12c3f1fd87bf ("powerpc/32s: get rid of CPU_FTR_601 feature")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/a99fc0ad65b87a1ba51cfa3e0e9034ee294c3e07.1582034961.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman

powerpc/32s: Fix CPU wake-up from sleep mode

2020-02-11T12:35:18+00:00

commit 9933819099c4600b41a042f27a074470a43cf6b9 upstream.

Commit f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and
rename TI_CPU") broke the CPU wake-up from sleep mode (i.e. when
_TLF_SLEEPING is set) by delaying the tovirt(r2, r2).

This is because r2 is not restored by fast_exception_return. It used
to work (by chance ?) because CPU wake-up interrupt never comes from
user, so r2 is expected to point to 'current' on return.

Commit e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access
Protection") broke it even more by clobbering r0 which is not
restored by fast_exception_return either.

Use r6 instead of r0. This is possible because r3-r6 are restored by
fast_exception_return and only r3-r5 are used for exception arguments.

For r2 it could be converted back to virtual address, but stay on the
safe side and restore it from the stack instead. It should be live
in the cache at that moment, so loading from the stack should make
no difference compared to converting it from phys to virt.

Fixes: f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU")
Fixes: e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/6d02c3ae6ad77af34392e98117e44c2bf6d13ba1.1580121710.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman

powerpc/32s: get rid of CPU_FTR_601 feature

2019-08-28T13:19:33+00:00

Now that 601 is exclusive from other 6xx, CPU_FTR_601 and
associated fixups are useless.

Drop this feature and use #ifdefs instead.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/ecdb7194a17dbfa01865df6a82979533adc2c70b.1566834712.git.christophe.leroy@c-s.fr

powerpc/32: replace LOAD_MSR_KERNEL() by LOAD_REG_IMMEDIATE()

2019-08-27T03:03:36+00:00

LOAD_MSR_KERNEL() and LOAD_REG_IMMEDIATE() are doing the same thing
in the same way. Drop LOAD_MSR_KERNEL()

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/8f04a6df0bc8949517fd8236d50c15008ccf9231.1566311636.git.christophe.leroy@c-s.fr

powerpc: Wire up clone3 syscall

2019-07-28T23:34:27+00:00

Wire up the new clone3 syscall added in commit 7f192e3cd316 ("fork:
add clone3").

This requires a ppc_clone3 wrapper, in order to save the non-volatile
GPRs before calling into the generic syscall code. Otherwise we hit
the BUG_ON in CHECK_FULL_REGS in copy_thread().

Lightly tested using Christian's test code on a Power8 LE VM.

Signed-off-by: Michael Ellerman 
Acked-by: Christian Brauner 
Link: https://lore.kernel.org/r/20190724140259.23554-1-mpe@ellerman.id.au

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+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 as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

powerpc/entry: Remove unneeded need_resched() loop

2019-05-02T16:54:57+00:00

Since the enabling and disabling of IRQs within preempt_schedule_irq()
is contained in a need_resched() loop, we don't need the outer arch
code loop.

Signed-off-by: Valentin Schneider 
[mpe: Rebase since CURRENT_THREAD_INFO() removal]
Signed-off-by: Michael Ellerman

powerpc/32: Don't add dummy frames when calling trace_hardirqs_on/off

2019-05-02T15:20:28+00:00

No need to add dummy frames when calling trace_hardirqs_on or
trace_hardirqs_off. GCC properly handles empty stacks.

In addition, powerpc doesn't set CONFIG_FRAME_POINTER, therefore
__builtin_return_address(1..) returns NULL at all time. So the
dummy frames are definitely unneeded here.

In the meantime, avoid reading memory for loading r1 with a value
we already know.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman

powerpc/32: don't do syscall stuff in transfer_to_handler

2019-05-02T15:20:27+00:00

As syscalls are now handled via a fast entry path, syscall related
actions can be removed from the generic transfer_to_handler path.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman

powerpc/32: implement fast entry for syscalls on BOOKE

2019-05-02T15:20:27+00:00

This patch implements a fast entry for syscalls.

Syscalls don't have to preserve non volatile registers except LR.

This patch then implement a fast entry for syscalls, where
volatile registers get clobbered.

As this entry is dedicated to syscall it always sets MSR_EE
and warns in case MSR_EE was previously off

It also assumes that the call is always from user, system calls are
unexpected from kernel.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman