linux.git/arch/powerpc/kernel/traps.c, branch v5.1

powerpc/64s: Include header file to fix a warning

2019-03-13T04:03:13+00:00

Make sure to include  to provide the following prototype:
hv_nmi_check_nonrecoverable.

Remove the following warning treated as error (W=1):

  arch/powerpc/kernel/traps.c:393:6: error: no previous prototype for 'hv_nmi_check_nonrecoverable'

Fixes: ccd477028a20 ("powerpc/64s: Fix HV NMI vs HV interrupt recoverability test")
Signed-off-by: Mathieu Malaterre 
Reviewed-by: Christophe Leroy 
Signed-off-by: Michael Ellerman

powerpc/64s: Fix unrelocated interrupt trampoline address test

2019-03-01T13:25:47+00:00

The recent commit got this test wrong, it declared the assembler
symbols the wrong way, and also used the wrong symbol name
(xxx_start rather than start_xxx, see asm/head-64.h).

Fixes: ccd477028a ("powerpc/64s: Fix HV NMI vs HV interrupt recoverability test")
Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman

powerpc/64s: system reset interrupt preserve HSRRs

2019-02-26T12:28:25+00:00

Code that uses HSRR registers is not required to clear MSR[RI] by
convention, however the system reset NMI itself may use HSRR
registers (e.g., to call OPAL) and clobber them.

Rather than introduce the requirement to clear RI in order to use
HSRRs, have system reset interrupt save and restore HSRRs.

Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman

powerpc/64s: Fix HV NMI vs HV interrupt recoverability test

2019-02-26T12:28:24+00:00

HV interrupts that use HSRR registers do not enter with MSR[RI] clear,
but their entry code is not recoverable vs NMI, due to shared use of
HSPRG1 as a scratch register to save r13.

This means that a system reset or machine check that hits in HSRR
interrupt entry can cause r13 to be silently corrupted.

Fix this by marking NMIs non-recoverable if they land in HV interrupt
ranges.

Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman

powerpc/traps: fix recoverability of machine check handling on book3s/32

2019-02-21T13:10:16+00:00

Looks like book3s/32 doesn't set RI on machine check, so
checking RI before calling die() will always be fatal
allthought this is not an issue in most cases.

Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt")
Fixes: daf00ae71dad ("powerpc/traps: restore recoverability of machine_check interrupts")
Signed-off-by: Christophe Leroy 
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman

powerpc/traps: Fix the message printed when stack overflows

2019-01-30T12:31:44+00:00

Today's message is useless:

  [   42.253267] Kernel stack overflow in process (ptrval), r1=c65500b0

This patch fixes it:

  [   66.905235] Kernel stack overflow in process sh[356], r1=c65560b0

Fixes: ad67b74d2469 ("printk: hash addresses printed with %p")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Christophe Leroy 
[mpe: Use task_pid_nr()]
Signed-off-by: Michael Ellerman

powerpc/64s: Add MMU type to __die() output

2019-01-15T00:17:10+00:00

On Power9 machines (64-bit Book3S), we can be running with either the
Hash table or Radix tree MMU enabled. So add some text to the __die()
output to tell us which is enabled, for the case where all you have is
the oops output and no other information.

Example output:

  kernel BUG at drivers/misc/lkdtm/bugs.c:63!
  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: kvm vmx_crypto binfmt_misc ip_tables x_tables

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

powerpc: Show PAGE_SIZE in __die() output

2019-01-15T00:17:09+00:00

The page size the kernel is built with is useful info when debugging a
crash, so add it to the output in __die().

Result looks like eg:

  kernel BUG at drivers/misc/lkdtm/bugs.c:63!
  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: vmx_crypto kvm binfmt_misc ip_tables

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

powerpc: Stop using pr_cont() in __die()

2019-01-15T00:17:09+00:00

Using pr_cont() risks having our output interleaved with other output
from other CPUs. Instead print everything in a single printk() call.

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

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57+00:00

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds