linux-stable.git/arch/powerpc/kernel/setup_64.c, branch v5.8

mm: reorder includes after introduction of linux/pgtable.h

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

The replacement of  with  made the include
of the latter in the middle of asm includes.  Fix this up with the aid of
the below script and manual adjustments here and there.

	import sys
	import re

	if len(sys.argv) is not 3:
	    print "USAGE: %s  " % (sys.argv[0])
	    sys.exit(1)

	hdr_to_move="#include " % sys.argv[2]
	moved = False
	in_hdrs = False

	with open(sys.argv[1], "r") as f:
	    lines = f.readlines()
	    for _line in lines:
		line = _line.rstrip('
')
		if line == hdr_to_move:
		    continue
		if line.startswith("#include 
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: 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/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds

mm: introduce include/linux/pgtable.h

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

The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.

Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.

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: 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/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds

Merge branch 'fixes' into next

2020-05-26T12:56:03+00:00

Merge our fixes branch from this cycle. It contains several important
fixes we need in next for testing purposes, and also some that will
conflict with upcoming changes.

powerpc/pseries: Limit machine check stack to 4GB

2020-05-18T14:10:34+00:00

This allows rtas_args to be put on the machine check stack, which
avoids a lot of complications with re-entrancy deadlocks.

Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Reviewed-by: Christophe Leroy 
Reviewed-by: Mahesh Salgaonkar 
Link: https://lore.kernel.org/r/20200508043408.886394-10-npiggin@gmail.com

powerpc/setup_64: Set cache-line-size based on cache-block-size

2020-04-21T08:01:06+00:00

If {i,d}-cache-block-size is set and {i,d}-cache-line-size is not, use
the block-size value for both. Per the devicetree spec cache-line-size
is only needed if it differs from the block size.

Originally the code would fallback from block size to line size. An
error message was printed if both properties were missing.

Later the code was refactored to use clearer names and logic but it
inadvertently made line size a required property, meaning on systems
without a line size property we fall back to the default from the
cputable.

On powernv (OPAL) platforms, since the introduction of device tree CPU
features (5a61ef74f269 ("powerpc/64s: Support new device tree binding
for discovering CPU features")), that has led to the wrong value being
used, as the fallback value is incorrect for Power8/Power9 CPUs.

The incorrect values flow through to the VDSO and also to the sysconf
values, SC_LEVEL1_ICACHE_LINESIZE etc.

Fixes: bd067f83b084 ("powerpc/64: Fix naming of cache block vs. cache line")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Chris Packham 
Reported-by: Qian Cai 
[mpe: Add even more detail to change log]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200416221908.7886-1-chris.packham@alliedtelesis.co.nz

powerpc/64: Prevent stack protection in early boot

2020-03-25T01:09:38+00:00

The previous commit reduced the amount of code that is run before we
setup a paca. However there are still a few remaining functions that
run with no paca, or worse, with an arbitrary value in r13 that will
be used as a paca pointer.

In particular the stack protector canary is stored in the paca, so if
stack protector is activated for any of these functions we will read
the stack canary from wherever r13 points. If r13 happens to point
outside of memory we will get a machine check / checkstop.

For example if we modify initialise_paca() to trigger stack
protection, and then boot in the mambo simulator with r13 poisoned in
skiboot before calling the kernel:

  DEBUG: 19952232: (19952232): INSTRUCTION: PC=0xC0000000191FC1E8: [0x3C4C006D]: addis   r2,r12,0x6D [fetch]
  DEBUG: 19952236: (19952236): INSTRUCTION: PC=0xC00000001807EAD8: [0x7D8802A6]: mflr    r12 [fetch]
  FATAL ERROR: 19952276: (19952276): Check Stop for 0:0: Machine Check with ME bit of MSR off
  DEBUG: 19952276: (19952276): INSTRUCTION: PC=0xC0000000191FCA7C: [0xE90D0CF8]: ld      r8,0xCF8(r13) [Instruction Failed]
  INFO: 19952276: (19952277): ** Execution stopped: Mambo Error, Machine Check Stop,  **
  systemsim % bt
  pc:                             0xC0000000191FCA7C      initialise_paca+0x54
  lr:                             0xC0000000191FC22C      early_setup+0x44
  stack:0x00000000198CBED0        0x0     +0x0
  stack:0x00000000198CBF00        0xC0000000191FC22C      early_setup+0x44
  stack:0x00000000198CBF90        0x1801C968      +0x1801C968

So annotate the relevant functions to ensure stack protection is never
enabled for them.

Fixes: 06ec27aea9fc ("powerpc/64: add stack protector support")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200320032116.1024773-2-mpe@ellerman.id.au

powerpc/64: Setup a paca before parsing device tree etc.

2020-03-25T01:09:37+00:00

Currently we set up the paca after parsing the device tree for CPU
features. Prior to that, r13 contains random data, which means there
is random data in r13 while we're running the generic dt parsing code.

This random data varies depending on whether we boot through a vmlinux
or a zImage: for the vmlinux case it's usually around zero, but for
zImages we see random values like 912a72603d420015.

This is poor practice, and can also lead to difficult-to-debug
crashes. For example, when kcov is enabled, the kcov instrumentation
attempts to read preempt_count out of the current task, which goes via
the paca. This then crashes in the zImage case.

Similarly stack protector can cause crashes if r13 is bogus, by
reading from the stack canary in the paca.

To resolve this:

 - move the paca setup to before the CPU feature parsing.

 - because we no longer have access to CPU feature flags in paca
 setup, change the HV feature test in the paca setup path to consider
 the actual value of the MSR rather than the CPU feature.

Translations get switched on once we leave early_setup, so I think
we'd already catch any other cases where the paca or task aren't set
up.

Boot tested on a P9 guest and host.

Fixes: fb0b0a73b223 ("powerpc: Enable kcov")
Fixes: 06ec27aea9fc ("powerpc/64: add stack protector support")
Cc: stable@vger.kernel.org # v4.20+
Reviewed-by: Andrew Donnellan 
Suggested-by: Michael Ellerman 
Signed-off-by: Daniel Axtens 
[mpe: Reword comments & change log a bit to mention stack protector]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200320032116.1024773-1-mpe@ellerman.id.au

powerpc: align stack to 2 * THREAD_SIZE with VMAP_STACK

2020-01-26T11:15:09+00:00

In order to ease stack overflow detection, align
stack to 2 * THREAD_SIZE when using VMAP_STACK.
This allows overflow detection using a single bit check.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/60e9ae86b7d2cdcf21468787076d345663648f46.1576916812.git.christophe.leroy@c-s.fr

powerpc: Add support for GENERIC_EARLY_IOREMAP

2019-11-19T08:38:38+00:00

Add support for GENERIC_EARLY_IOREMAP.

Let's define 16 slots of 256Kbytes each for early ioremap.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/412c7eaa6a373d8f82a3c3ee01e6a65a1a6589de.1568295907.git.christophe.leroy@c-s.fr

powerpc/setup_64: fix -Wempty-body warnings

2019-10-11T08:33:25+00:00

At the beginning of setup_64.c, it has,

  #ifdef DEBUG
  #define DBG(fmt...) udbg_printf(fmt)
  #else
  #define DBG(fmt...)
  #endif

where DBG() could be compiled away, and generate warnings,

  arch/powerpc/kernel/setup_64.c: In function 'initialize_cache_info':
  arch/powerpc/kernel/setup_64.c:579:49: warning: suggest braces around
  empty body in an 'if' statement [-Wempty-body]
      DBG("Argh, can't find dcache properties !\n");
                                                 ^
  arch/powerpc/kernel/setup_64.c:582:49: warning: suggest braces around
  empty body in an 'if' statement [-Wempty-body]
      DBG("Argh, can't find icache properties !\n");

Fix it by using the suggestions from Michael:

  "Neither of those sites should use DBG(), that's not really early
  boot code, they should just use pr_warn().

  And the other uses of DBG() in initialize_cache_info() should just
  be removed.

  In smp_release_cpus() the entry/exit DBG's should just be removed,
  and the spinning_secondaries line should just be pr_debug().

  That would just leave the two calls in early_setup(). If we taught
  udbg_printf() to return early when udbg_putc is NULL, then we could
  just call udbg_printf() unconditionally and get rid of the DBG macro
  entirely."

Suggested-by: Michael Ellerman 
Signed-off-by: Qian Cai 
[mpe: Split udbg change out into previous patch]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/1563215552-8166-1-git-send-email-cai@lca.pw