linux-stable.git/arch/powerpc/kernel/process.c, branch v5.8

Merge tag 'powerpc-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2020-06-21T17:02:53+00:00

Pull powerpc fixes from Michael Ellerman:

 - One fix for the interrupt rework we did last release which broke
   KVM-PR

 - Three commits fixing some fallout from the READ_ONCE() changes
   interacting badly with our 8xx 16K pages support, which uses a pte_t
   that is a structure of 4 actual PTEs

 - A cleanup of the 8xx pte_update() to use the newly added pmd_off()

 - A fix for a crash when handling an oops if CONFIG_DEBUG_VIRTUAL is
   enabled

 - A minor fix for the SPU syscall generation

Thanks to Aneesh Kumar K.V, Christian Zigotzky, Christophe Leroy, Mike
Rapoport, Nicholas Piggin.

* tag 'powerpc-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/8xx: Provide ptep_get() with 16k pages
  mm: Allow arches to provide ptep_get()
  mm/gup: Use huge_ptep_get() in gup_hugepte()
  powerpc/syscalls: Use the number when building SPU syscall table
  powerpc/8xx: use pmd_off() to access a PMD entry in pte_update()
  powerpc/64s: Fix KVM interrupt using wrong save area
  powerpc: Fix kernel crash in show_instructions() w/DEBUG_VIRTUAL

maccess: rename probe_kernel_address to get_kernel_nofault

2020-06-18T18:14:40+00:00

Better describe what this helper does, and match the naming of
copy_from_kernel_nofault.

Also switch the argument order around, so that it acts and looks
like get_user().

Signed-off-by: Christoph Hellwig 
Signed-off-by: Linus Torvalds

maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault

2020-06-17T17:57:41+00:00

Better describe what these functions do.

Suggested-by: Linus Torvalds 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Linus Torvalds

powerpc: Fix kernel crash in show_instructions() w/DEBUG_VIRTUAL

2020-06-15T12:37:03+00:00

With CONFIG_DEBUG_VIRTUAL=y, we can hit a BUG() if we take a hard
lockup watchdog interrupt when in OPAL mode.

This happens in show_instructions() if the kernel takes the watchdog
NMI IPI, or any other interrupt, with MSR_IR == 0. show_instructions()
updates the variable pc in the loop and the second iteration will
result in BUG().

We hit the BUG_ON due the below check in  __va()

  #define __va(x)
  ({
  	VIRTUAL_BUG_ON((unsigned long)(x) >= PAGE_OFFSET);
  	(void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET);
  })

Fix it by moving the check out of the loop. Also update nip so that
the nip == pc check still matches.

Fixes: 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va and __pa addresses")
Signed-off-by: Aneesh Kumar K.V 
[mpe: Use IS_ENABLED(), massage change log]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200524093822.423487-1-aneesh.kumar@linux.ibm.com

mm: don't include asm/pgtable.h if linux/mm.h is already included

2020-06-09T16:39:13+00:00

Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once.  For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
        return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
        return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes  to allow inlining of the
functions involving page table manipulations, e.g.  pte_alloc() and
pmd_alloc().  So, there is no point to explicitly include 
in the files that include .

The include statements in such cases are remove with a simple loop:

	for f in $(git grep -l "include ") ; do
		sed -i -e '/include / d' $f
	done

Signed-off-by: Mike Rapoport 
Signed-off-by: Andrew Morton 
Cc: Arnd Bergmann 
Cc: Borislav Petkov 
Cc: Brian Cain 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Ungerer 
Cc: Guan Xuetao 
Cc: Guo Ren 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Ingo Molnar 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Matthew Wilcox 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Mike Rapoport 
Cc: Nick Hu 
Cc: Paul Walmsley 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vincent Chen 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds

kernel: rename show_stack_loglvl() => show_stack()

2020-06-09T16:39:13+00:00

Now the last users of show_stack() got converted to use an explicit log
level, show_stack_loglvl() can drop it's redundant suffix and become once
again well known show_stack().

Signed-off-by: Dmitry Safonov 
Signed-off-by: Andrew Morton 
Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.com
Signed-off-by: Linus Torvalds

powerpc: add show_stack_loglvl()

2020-06-09T16:39:11+00:00

Currently, the log-level of show_stack() depends on a platform
realization.  It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).

Furthermore, it forces the logic decision from user to an architecture
side.  In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages.  And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.

Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers.  Also, it will consolidate
printings with headers.

Introduce show_stack_loglvl(), that eventually will substitute
show_stack().

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u

Signed-off-by: Dmitry Safonov 
Signed-off-by: Andrew Morton 
Acked-by: Michael Ellerman  (powerpc)
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Link: http://lkml.kernel.org/r/20200418201944.482088-27-dima@arista.com
Signed-off-by: Linus Torvalds

powerpc/watchpoint: Prepare handler to handle more than one watchpoint

2020-05-18T14:14:37+00:00

Currently we assume that we have only one watchpoint supported by hw.
Get rid of that assumption and use dynamic loop instead. This should
make supporting more watchpoints very easy.

With more than one watchpoint, exception handler needs to know which
DAWR caused the exception, and hw currently does not provide it. So
we need sw logic for the same. To figure out which DAWR caused the
exception, check all different combinations of user specified range,
DAWR address range, actual access range and DAWRX constrains. For ex,
if user specified range and actual access range overlaps but DAWRX is
configured for readonly watchpoint and the instruction is store, this
DAWR must not have caused exception.

Signed-off-by: Ravi Bangoria 
Reviewed-by: Michael Neuling 
[mpe: Unsplit multi-line printk() strings, fix some sparse warnings]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200514111741.97993-14-ravi.bangoria@linux.ibm.com

powerpc/watchpoint: Use builtin ALIGN*() macros

2020-05-18T14:11:05+00:00

Currently we calculate hw aligned start and end addresses manually.
Replace them with builtin ALIGN_DOWN() and ALIGN() macros.

So far end_addr was inclusive but this patch makes it exclusive (by
avoiding -1) for better readability.

Suggested-by: Christophe Leroy 
Signed-off-by: Ravi Bangoria 
Signed-off-by: Michael Ellerman 
Reviewed-by: Michael Neuling 
Link: https://lore.kernel.org/r/20200514111741.97993-13-ravi.bangoria@linux.ibm.com

powerpc/watchpoint: Use loop for thread_struct->ptrace_bps

2020-05-18T14:11:05+00:00

ptrace_bps is already an array of size HBP_NUM_MAX. But we use
hardcoded index 0 while fetching/updating it. Convert such code
to loop over array.

ptrace interface to use multiple watchpoint remains same. eg:
two PPC_PTRACE_SETHWDEBUG calls will create two watchpoint if
underneath hw supports it.

Signed-off-by: Ravi Bangoria 
Signed-off-by: Michael Ellerman 
Reviewed-by: Michael Neuling 
Link: https://lore.kernel.org/r/20200514111741.97993-11-ravi.bangoria@linux.ibm.com