Commit graph

24 commits

Author SHA1 Message Date
Linus Torvalds
512b7931ad Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "257 patches.

  Subsystems affected by this patch series: scripts, ocfs2, vfs, and
  mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
  gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
  pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
  memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
  vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
  cleanups, kfence, and damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits)
  mm/damon: remove return value from before_terminate callback
  mm/damon: fix a few spelling mistakes in comments and a pr_debug message
  mm/damon: simplify stop mechanism
  Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
  Docs/admin-guide/mm/damon/start: simplify the content
  Docs/admin-guide/mm/damon/start: fix a wrong link
  Docs/admin-guide/mm/damon/start: fix wrong example commands
  mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
  mm/damon: remove unnecessary variable initialization
  Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
  mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
  selftests/damon: support watermarks
  mm/damon/dbgfs: support watermarks
  mm/damon/schemes: activate schemes based on a watermarks mechanism
  tools/selftests/damon: update for regions prioritization of schemes
  mm/damon/dbgfs: support prioritization weights
  mm/damon/vaddr,paddr: support pageout prioritization
  mm/damon/schemes: prioritize regions within the quotas
  mm/damon/selftests: support schemes quotas
  mm/damon/dbgfs: support quotas of schemes
  ...
2021-11-06 14:08:17 -07:00
Stephen Kitt
53944f171a mm: remove HARDENED_USERCOPY_FALLBACK
This has served its purpose and is no longer used.  All usercopy
violations appear to have been handled by now, any remaining instances
(or new bugs) will cause copies to be rejected.

This isn't a direct revert of commit 2d891fbc3b ("usercopy: Allow
strict enforcement of whitelists"); since usercopy_fallback is
effectively 0, the fallback handling is removed too.

This also removes the usercopy_fallback module parameter on slab_common.

Link: https://github.com/KSPP/linux/issues/153
Link: https://lkml.kernel.org/r/20210921061149.1091163-1-steve@sk2.org
Signed-off-by: Stephen Kitt <steve@sk2.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>	[defconfig change]
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E . Hallyn" <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Joel Stanley
f22969a660 powerpc/64s: Default to 64K pages for 64 bit book3s
For 64-bit book3s the default should be 64K as that's what modern CPUs
are designed for.

The following defconfigs already set CONFIG_PPC_64K_PAGES:

 cell_defconfig
 pasemi_defconfig
 powernv_defconfig
 ppc64_defconfig
 pseries_defconfig
 skiroot_defconfig

The have the option removed from the defconfig, as it is now the
default.

The defconfigs that now need to set CONFIG_PPC_4K_PAGES to maintain
their existing behaviour are:

 g5_defconfig
 maple_defconfig
 microwatt_defconfig
 ps3_defconfig

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
BugLink: https://github.com/linuxppc/issues/issues/109
Link: https://lore.kernel.org/r/20211015001649.45591-1-joel@jms.id.au
2021-10-27 22:31:22 +11:00
Chris Packham
0488d32530 powerpc/configs: Remove CMDLINE_BOOL
Regenerate defconfigs to remove CONFIG_CMDLINE_BOOL and the default
CONFIG_CMDLINE where applicable.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200611224220.25066-3-chris.packham@alliedtelesis.co.nz
2020-06-22 10:37:57 +10:00
Diego Elio Pettenò
679b2ec8e0 scsi: sr: remove references to BLK_DEV_SR_VENDOR, leave it enabled
This kernel configuration is basically enabling/disabling sr driver quirks
detection. While these quirks are for fairly rare devices (very old CD
burners, and a glucometer), the additional detection of these models is a
very minimal amount of code.

The logic behind the quirks is always built into the sr driver.

This also removes the config from all the defconfig files that are enabling
this already.

Link: https://lore.kernel.org/r/20200223191144.726-1-flameeyes@flameeyes.com
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Diego Elio Pettenò <flameeyes@flameeyes.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-02-24 14:59:01 -05:00
Michael Ellerman
5e84dd547b powerpc/configs/skiroot: Enable some more hardening options
Enable more hardening options.

Note BUG_ON_DATA_CORRUPTION selects DEBUG_LIST and is essentially just
a synonym for it.

DEBUG_SG, DEBUG_NOTIFIERS, DEBUG_LIST, DEBUG_CREDENTIALS and
SCHED_STACK_END_CHECK should all be low overhead and just add a few
extra checks.

SLAB_FREELIST_RANDOM, and SLUB_DEBUG_ON will add some overhead to the
SLAB allocator, but nothing that should be meaningful for skiroot.

Unselecting SLAB_MERGE_DEFAULT causes the SLAB to use more memory, but
the skiroot kernel shouldn't be memory constrained on any of our
systems, all it does is run a small bootloader.

Disabling merging has some security/robustness benefit as it means a
user-after-free or overflow will be limited to the objects in that
slab, rather than potentially affecting objects from unrelated slabs
that have been merged.

Note also that slab merging is disabled anyway by enabling
SLUB_DEBUG_ON, because of the SLAB_NEVER_MERGE mask.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-9-mpe@ellerman.id.au
2020-01-31 21:20:35 +11:00
Michael Ellerman
3554c12d83 powerpc/configs/skiroot: Disable xmon default & enable reboot on panic
If the skiroot kernel crashes we don't want it sitting at an xmon
prompt forever. Instead it's more helpful to reboot and bring the
boot loader back up, and if the crash was transient we can then boot
successfully.

Similarly if we panic we should reboot, with a short timeout in case
someone is watching the console.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-8-mpe@ellerman.id.au
2020-01-31 21:20:31 +11:00
Joel Stanley
579baeece6 powerpc/configs/skiroot: Enable security features
This turns on HARDENED_USERCOPY with HARDENED_USERCOPY_PAGESPAN, and
FORTIFY_SOURCE.

It also enables SECURITY_LOCKDOWN_LSM with _EARLY and
LOCK_DOWN_KERNEL_FORCE_INTEGRITY options enabled. This still allows
xmon to be used in read-only mode.

MODULE_SIG is selected by lockdown, so it is still enabled.

Because we're setting LOCK_DOWN_KERNELFORCE_INTEGRITY=y we also need
to enable KEXEC_FILE=y so that kexec continues to work.

Signed-off-by: Joel Stanley <joel@jms.id.au>
[mpe: Switch to lockdown integrity mode per oohal, enable KEXEC_FILE
      as reported by jms]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-7-mpe@ellerman.id.au
2020-01-31 21:20:17 +11:00
Michael Ellerman
cdc7b23f1e powerpc/configs/skiroot: Update for symbol movement only
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-6-mpe@ellerman.id.au
2020-01-31 21:20:09 +11:00
Michael Ellerman
81881e0998 powerpc/configs/skiroot: Drop default n CONFIG_CRYPTO_ECHAINIV
It's default n so we don't need to disable it.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-5-mpe@ellerman.id.au
2020-01-31 21:20:00 +11:00
Michael Ellerman
028fb6ded7 powerpc/configs/skiroot: Drop HID_LOGITECH
Commit bdd08fff49 ("HID: logitech: Add depends on LEDS_CLASS to
Logitech Kconfig entry") made HID_LOGITECH depend on LEDS_CLASS which
we do not enable, meaning we are not actually enabling those drivers
any more.

The Kconfig help text suggests USB HID compliant Logictech devices
will continue to work without HID_LOGITECH, so just drop it.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-4-mpe@ellerman.id.au
2020-01-31 21:19:52 +11:00
Michael Ellerman
7115bf789c powerpc/configs: Drop NET_VENDOR_HP which moved to staging
The HP network driver moved to staging in commit 52340b82cf ("hp100:
Move 100BaseVG AnyLAN driver to staging") meaning we don't need to
disable it any more in our defconfigs.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-3-mpe@ellerman.id.au
2020-01-31 21:19:41 +11:00
Michael Ellerman
f3e96a71aa powerpc/configs: NET_CADENCE became NET_VENDOR_CADENCE
The NET_CADENCE symbol was renamed to NET_VENDOR_CADENCE, so we don't
need to disable the former, see commit 0df5f81c48 ("net: ethernet:
Add missing VENDOR to Cadence and Packet Engines symbols").

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-2-mpe@ellerman.id.au
2020-01-31 21:19:30 +11:00
Michael Ellerman
76e4bd9336 powerpc/configs: Drop CONFIG_QLGE which moved to staging
The QLGE driver moved to staging in commit 955315b0dc ("qlge: Move
drivers/net/ethernet/qlogic/qlge/ to drivers/staging/qlge/"), meaning
our defconfigs that enable it have no effect as we don't enable
CONFIG_STAGING.

It sounds like the device is obsolete, so drop the driver.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-1-mpe@ellerman.id.au
2020-01-31 21:19:14 +11:00
YueHaibing
93a1544ad4 powerpc/configs: remove obsolete CONFIG_INET_XFRM_MODE_* and CONFIG_INET6_XFRM_MODE_*
These Kconfig options has been removed in commit 4c145dce26 ("xfrm:
make xfrm modes builtin") So there is no point to keep it in
defconfigs any longer.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
[mpe: Extract from cross arch patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190612071901.21736-1-yuehaibing@huawei.com
2019-11-13 16:58:06 +11:00
Hari Bathini
aaa3515044 powerpc/configs: add FADump awareness to skiroot_defconfig
FADump is supported on PowerNV platform. To fulfill this support, the
petitboot kernel must be FADump aware. Enable config PRESERVE_FA_DUMP
to make the petitboot kernel FADump aware.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/157062986936.23016.10146169203560084401.stgit@hbathini.in.ibm.com
2019-10-11 18:49:17 +11:00
Daniel Axtens
7e04a46d84 powerpc/configs: Disable /dev/port in skiroot defconfig
While reviewing lockdown patches, I discovered that we still enable
/dev/port (CONFIG_DEVPORT) in skiroot.

/dev/port is used for old x86 style IO accesses. It's set up in
drivers/char/mem.c, and is only created if arch_has_dev_port() returns
true. Per arch/powerpc/include/asm/io.h, on PPC64 with PCI, this is
only true if there's a legacy ISA bridge.

Even if a system has a legacy ISA bridge installed, we have no
business accessing it in skiroot.

Deselect CONFIG_DEVPORT for skiroot.

Signed-off-by: Daniel Axtens <dja@axtens.net>
[mpe: Incorporate emailed comments into the change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190627053008.29315-1-dja@axtens.net
2019-08-22 23:12:48 +10:00
Krzysztof Kozlowski
14b2f7d908 powerpc/configs: Remove useless UEVENT_HELPER_PATH
Remove the CONFIG_UEVENT_HELPER_PATH because:
1. It is disabled since commit 1be01d4a57 ("driver: base: Disable
   CONFIG_UEVENT_HELPER by default") as its dependency (UEVENT_HELPER) was
   made default to 'n',
2. It is not recommended (help message: "This should not be used today
   [...] creates a high system load") and was kept only for ancient
   userland,
3. Certain userland specifically requests it to be disabled (systemd
   README: "Legacy hotplug slows down the system and confuses udev").

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-03 15:19:36 +10:00
Linus Torvalds
b970afcfca powerpc updates for 5.2
Highlights:
 
  - Support for Kernel Userspace Access/Execution Prevention (like
    SMAP/SMEP/PAN/PXN) on some 64-bit and 32-bit CPUs. This prevents the kernel
    from accidentally accessing userspace outside copy_to/from_user(), or
    ever executing userspace.
 
  - KASAN support on 32-bit.
 
  - Rework of where we map the kernel, vmalloc, etc. on 64-bit hash to use the
    same address ranges we use with the Radix MMU.
 
  - A rewrite into C of large parts of our idle handling code for 64-bit Book3S
    (ie. power8 & power9).
 
  - A fast path entry for syscalls on 32-bit CPUs, for a 12-17% speedup in the
    null_syscall benchmark.
 
  - On 64-bit bare metal we have support for recovering from errors with the time
    base (our clocksource), however if that fails currently we hang in __delay()
    and never crash. We now have support for detecting that case and short
    circuiting __delay() so we at least panic() and reboot.
 
  - Add support for optionally enabling the DAWR on Power9, which had to be
    disabled by default due to a hardware erratum. This has the effect of
    enabling hardware breakpoints for GDB, the downside is a badly behaved
    program could crash the machine by pointing the DAWR at cache inhibited
    memory. This is opt-in obviously.
 
  - xmon, our crash handler, gets support for a read only mode where operations
    that could change memory or otherwise disturb the system are disabled.
 
 Plus many clean-ups, reworks and minor fixes etc.
 
 Thanks to:
   Christophe Leroy, Akshay Adiga, Alastair D'Silva, Alexey Kardashevskiy, Andrew
   Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Ben Hutchings,
   Bo YU, Breno Leitao, Cédric Le Goater, Christopher M. Riedl, Christoph
   Hellwig, Colin Ian King, David Gibson, Ganesh Goudar, Gautham R. Shenoy,
   George Spelvin, Greg Kroah-Hartman, Greg Kurz, Horia Geantă, Jagadeesh
   Pagadala, Joel Stanley, Joe Perches, Julia Lawall, Laurentiu Tudor, Laurent
   Vivier, Lukas Bulwahn, Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu
   Malaterre, Michael Neuling, Mukesh Ojha, Nathan Fontenot, Nathan Lynch,
   Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Peng Hao, Qian Cai, Ravi
   Bangoria, Rick Lindsley, Russell Currey, Sachin Sant, Stewart Smith, Sukadev
   Bhattiprolu, Thomas Huth, Tobin C. Harding, Tyrel Datwyler, Valentin
   Schneider, Wei Yongjun, Wen Yang, YueHaibing.
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Merge tag 'powerpc-5.2-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Slightly delayed due to the issue with printk() calling
  probe_kernel_read() interacting with our new user access prevention
  stuff, but all fixed now.

  The only out-of-area changes are the addition of a cpuhp_state, small
  additions to Documentation and MAINTAINERS updates.

  Highlights:

   - Support for Kernel Userspace Access/Execution Prevention (like
     SMAP/SMEP/PAN/PXN) on some 64-bit and 32-bit CPUs. This prevents
     the kernel from accidentally accessing userspace outside
     copy_to/from_user(), or ever executing userspace.

   - KASAN support on 32-bit.

   - Rework of where we map the kernel, vmalloc, etc. on 64-bit hash to
     use the same address ranges we use with the Radix MMU.

   - A rewrite into C of large parts of our idle handling code for
     64-bit Book3S (ie. power8 & power9).

   - A fast path entry for syscalls on 32-bit CPUs, for a 12-17% speedup
     in the null_syscall benchmark.

   - On 64-bit bare metal we have support for recovering from errors
     with the time base (our clocksource), however if that fails
     currently we hang in __delay() and never crash. We now have support
     for detecting that case and short circuiting __delay() so we at
     least panic() and reboot.

   - Add support for optionally enabling the DAWR on Power9, which had
     to be disabled by default due to a hardware erratum. This has the
     effect of enabling hardware breakpoints for GDB, the downside is a
     badly behaved program could crash the machine by pointing the DAWR
     at cache inhibited memory. This is opt-in obviously.

   - xmon, our crash handler, gets support for a read only mode where
     operations that could change memory or otherwise disturb the system
     are disabled.

  Plus many clean-ups, reworks and minor fixes etc.

  Thanks to: Christophe Leroy, Akshay Adiga, Alastair D'Silva, Alexey
  Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar,
  Anton Blanchard, Ben Hutchings, Bo YU, Breno Leitao, Cédric Le Goater,
  Christopher M. Riedl, Christoph Hellwig, Colin Ian King, David Gibson,
  Ganesh Goudar, Gautham R. Shenoy, George Spelvin, Greg Kroah-Hartman,
  Greg Kurz, Horia Geantă, Jagadeesh Pagadala, Joel Stanley, Joe
  Perches, Julia Lawall, Laurentiu Tudor, Laurent Vivier, Lukas Bulwahn,
  Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre, Michael
  Neuling, Mukesh Ojha, Nathan Fontenot, Nathan Lynch, Nicholas Piggin,
  Nick Desaulniers, Oliver O'Halloran, Peng Hao, Qian Cai, Ravi
  Bangoria, Rick Lindsley, Russell Currey, Sachin Sant, Stewart Smith,
  Sukadev Bhattiprolu, Thomas Huth, Tobin C. Harding, Tyrel Datwyler,
  Valentin Schneider, Wei Yongjun, Wen Yang, YueHaibing"

* tag 'powerpc-5.2-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (205 commits)
  powerpc/64s: Use early_mmu_has_feature() in set_kuap()
  powerpc/book3s/64: check for NULL pointer in pgd_alloc()
  powerpc/mm: Fix hugetlb page initialization
  ocxl: Fix return value check in afu_ioctl()
  powerpc/mm: fix section mismatch for setup_kup()
  powerpc/mm: fix redundant inclusion of pgtable-frag.o in Makefile
  powerpc/mm: Fix makefile for KASAN
  powerpc/kasan: add missing/lost Makefile
  selftests/powerpc: Add a signal fuzzer selftest
  powerpc/booke64: set RI in default MSR
  ocxl: Provide global MMIO accessors for external drivers
  ocxl: move event_fd handling to frontend
  ocxl: afu_irq only deals with IRQ IDs, not offsets
  ocxl: Allow external drivers to use OpenCAPI contexts
  ocxl: Create a clear delineation between ocxl backend & frontend
  ocxl: Don't pass pci_dev around
  ocxl: Split pci.c
  ocxl: Remove some unused exported symbols
  ocxl: Remove superfluous 'extern' from headers
  ocxl: read_pasid never returns an error, so make it void
  ...
2019-05-10 05:29:27 -07:00
Joel Stanley
e1619e89c9 powerpc/configs: Add (back) MLX5 ethernet support to skiroot_defconfig
It turns out that some defconfig changes and kernel config option
changes meant we accidentally dropped Ethernet support for Mellanox
CLX5 cards.

Fixes: cbc39809a3 ("powerpc/configs: Update skiroot defconfig")
Reported-by: Carol L Soto <clsoto@us.ibm.com>
Suggested-by: Carol L Soto <clsoto@us.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:54:58 +10:00
Michael Ellerman
8adddf349f powerpc/mm/radix: Make Radix require HUGETLB_PAGE
Joel reported weird crashes using skiroot_defconfig, in his case we
jumped into an NX page:

  kernel tried to execute exec-protected page (c000000002bff4f0) - exploit attempt? (uid: 0)
  BUG: Unable to handle kernel instruction fetch
  Faulting instruction address: 0xc000000002bff4f0

Looking at the disassembly, we had simply branched to that address:

  c000000000c001bc  49fff335    bl     c000000002bff4f0

But that didn't match the original kernel image:

  c000000000c001bc  4bfff335    bl     c000000000bff4f0 <kobject_get+0x8>

When STRICT_KERNEL_RWX is enabled, and we're using the radix MMU, we
call radix__change_memory_range() late in boot to change page
protections. We do that both to mark rodata read only and also to mark
init text no-execute. That involves walking the kernel page tables,
and clearing _PAGE_WRITE or _PAGE_EXEC respectively.

With radix we may use hugepages for the linear mapping, so the code in
radix__change_memory_range() uses eg. pmd_huge() to test if it has
found a huge mapping, and if so it stops the page table walk and
changes the PMD permissions.

However if the kernel is built without HUGETLBFS support, pmd_huge()
is just a #define that always returns 0. That causes the code in
radix__change_memory_range() to incorrectly interpret the PMD value as
a pointer to a PTE page rather than as a PTE at the PMD level.

We can see this using `dv` in xmon which also uses pmd_huge():

  0:mon> dv c000000000000000
  pgd  @ 0xc000000001740000
  pgdp @ 0xc000000001740000 = 0x80000000ffffb009
  pudp @ 0xc0000000ffffb000 = 0x80000000ffffa009
  pmdp @ 0xc0000000ffffa000 = 0xc00000000000018f   <- this is a PTE
  ptep @ 0xc000000000000100 = 0xa64bb17da64ab07d   <- kernel text

The end result is we treat the value at 0xc000000000000100 as a PTE
and clear _PAGE_WRITE or _PAGE_EXEC, potentially corrupting the code
at that address.

In Joel's specific case we cleared the sign bit in the offset of the
branch, causing a backward branch to turn into a forward branch which
caused us to branch into a non-executable page. However the exact
nature of the crash depends on kernel version, compiler version, and
other factors.

We need to fix radix__change_memory_range() to not use accessors that
depend on HUGETLBFS, but we also have radix memory hotplug code that
uses pmd_huge() etc that will also need fixing. So for now just
disallow the broken combination of Radix with HUGETLBFS disabled.

The only defconfig we have that is affected is skiroot_defconfig, so
turn on HUGETLBFS there so that it still gets Radix.

Fixes: 566ca99af0 ("powerpc/mm/radix: Add dummy radix_enabled()")
Cc: stable@vger.kernel.org # v4.7+
Reported-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-17 18:50:26 +10:00
Joel Stanley
805bf3b755 powerpc/configs: Sync skiroot defconfig
This updates the skiroot defconfig with the version from the OpenPower
firmwre build tree.

Important changes are the addition of QED and E1000E ethernet drivers.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-03-05 16:35:54 +11:00
Joel Stanley
cbc39809a3 powerpc/configs: Update skiroot defconfig
Disable new features from recent releases, and clean out some other
unused options:

  - Enable EXPERT, so we can disable some things
  - Disable non-powerpc BPF decoders
  - Disable TASKSTATS
  - Disable unused syscalls
  - Set more things to be modules
  - Turn off unused network vendors
  - PPC_OF_BOOT_TRAMPOLINE and FB_OF are unused on powernv
  - Drop unused Radeon and Matrox GPU drivers
  - IPV6 support landed in petitboot
  - Bringup related command line powersave=off dropped, switch to quiet

Set CONFIG_I2C_CHARDEV=y as the module is not loaded automatically, and
without this i2cget etc. will fail in the skiroot environment.

This defconfig gets us build coverage of KERNEL_XZ, which was broken in
the 4.19 merge window for powerpc.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Joel Stanley
c3dda4b0db powerpc/configs: Add Skiroot defconfig
This configuration is used by the OpenPower firmware for it's
Linux-as-bootloader implementation. Also known as the Petitboot
kernel, this configuration broke in 4.12 (CPU_HOTPLUG=n), so add it to
the upstream tree in order to get better coverage.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04 22:26:46 +11:00