<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/arch/powerpc/Kconfig, branch linux-5.10.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.10.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.10.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2022-06-14T16:32:39Z</updated>
<entry>
<title>powerpc/kasan: Force thread size increase with KASAN</title>
<updated>2022-06-14T16:32:39Z</updated>
<author>
<name>Michael Ellerman</name>
</author>
<published>2022-06-01T14:31:14Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=7fd03e34f01fef1d060b5fb7bedb6831be3cb42f'/>
<id>urn:sha1:7fd03e34f01fef1d060b5fb7bedb6831be3cb42f</id>
<content type='text'>
[ Upstream commit 3e8635fb2e072672cbc650989ffedf8300ad67fb ]

KASAN causes increased stack usage, which can lead to stack overflows.

The logic in Kconfig to suggest a larger default doesn't work if a user
has CONFIG_EXPERT enabled and has an existing .config with a smaller
value.

Follow the lead of x86 and arm64, and force the thread size to be
increased when KASAN is enabled.

That also has the effect of enlarging the stack for 64-bit KASAN builds,
which is also desirable.

Fixes: edbadaf06710 ("powerpc/kasan: Fix stack overflow by increasing THREAD_SHIFT")
Reported-by: Erhard Furtner &lt;erhard_f@mailbox.org&gt;
Reported-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
[mpe: Use MIN_THREAD_SHIFT as suggested by Christophe]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220601143114.133524-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc: Fix HAVE_HARDLOCKUP_DETECTOR_ARCH build configuration</title>
<updated>2021-05-14T07:50:31Z</updated>
<author>
<name>Chen Huang</name>
</author>
<published>2021-03-27T09:49:00Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=19c990c9fad3eaafbf3d7dbc9c8f62679ab63726'/>
<id>urn:sha1:19c990c9fad3eaafbf3d7dbc9c8f62679ab63726</id>
<content type='text'>
[ Upstream commit 4fe529449d85e78972fa327999961ecc83a0b6db ]

When compiling the powerpc with the SMP disabled, it shows the issue:

arch/powerpc/kernel/watchdog.c: In function ‘watchdog_smp_panic’:
arch/powerpc/kernel/watchdog.c:177:4: error: implicit declaration of function ‘smp_send_nmi_ipi’; did you mean ‘smp_send_stop’? [-Werror=implicit-function-declaration]
  177 |    smp_send_nmi_ipi(c, wd_lockup_ipi, 1000000);
      |    ^~~~~~~~~~~~~~~~
      |    smp_send_stop
cc1: all warnings being treated as errors
make[2]: *** [scripts/Makefile.build:273: arch/powerpc/kernel/watchdog.o] Error 1
make[1]: *** [scripts/Makefile.build:534: arch/powerpc/kernel] Error 2
make: *** [Makefile:1980: arch/powerpc] Error 2
make: *** Waiting for unfinished jobs....

We found that powerpc used ipi to implement hardlockup watchdog, so the
HAVE_HARDLOCKUP_DETECTOR_ARCH should depend on the SMP.

Fixes: 2104180a5369 ("powerpc/64s: implement arch-specific hardlockup watchdog")
Reported-by: Hulk Robot &lt;hulkci@huawei.com&gt;
Signed-off-by: Chen Huang &lt;chenhuang5@huawei.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20210327094900.938555-1-chenhuang5@huawei.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc/47x: Disable 256k page size</title>
<updated>2021-03-04T10:38:01Z</updated>
<author>
<name>Christophe Leroy</name>
</author>
<published>2021-01-20T07:49:13Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=f6ba4a84b9e0907951c2a9e25b2d5a1643a74846'/>
<id>urn:sha1:f6ba4a84b9e0907951c2a9e25b2d5a1643a74846</id>
<content type='text'>
[ Upstream commit 910a0cb6d259736a0c86e795d4c2f42af8d0d775 ]

PPC47x_TLBE_SIZE isn't defined for 256k pages, leading to a build
break if 256k pages is selected.

So change the kconfig so that 256k pages can't be selected for 47x.

Fixes: e7f75ad01d59 ("powerpc/47x: Base ppc476 support")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
[mpe: Expand change log to mention build break]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/2fed79b1154c872194f98bac4422c23918325e61.1611128938.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>kbuild: Hoist '--orphan-handling' into Kconfig</title>
<updated>2020-12-01T13:45:36Z</updated>
<author>
<name>Nathan Chancellor</name>
</author>
<published>2020-11-19T20:46:56Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=59612b24f78a0b61fe078ec9dff2e48e9cec52c0'/>
<id>urn:sha1:59612b24f78a0b61fe078ec9dff2e48e9cec52c0</id>
<content type='text'>
Currently, '--orphan-handling=warn' is spread out across four different
architectures in their respective Makefiles, which makes it a little
unruly to deal with in case it needs to be disabled for a specific
linker version (in this case, ld.lld 10.0.1).

To make it easier to control this, hoist this warning into Kconfig and
the main Makefile so that disabling it is simpler, as the warning will
only be enabled in a couple places (main Makefile and a couple of
compressed boot folders that blow away LDFLAGS_vmlinx) and making it
conditional is easier due to Kconfig syntax. One small additional
benefit of this is saving a call to ld-option on incremental builds
because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN.

To keep the list of supported architectures the same, introduce
CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to
gain this automatically after all of the sections are specified and size
asserted. A special thanks to Kees Cook for the help text on this
config.

Link: https://github.com/ClangBuiltLinux/linux/issues/1187
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Tested-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'powerpc-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2020-10-16T19:21:15Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2020-10-16T19:21:15Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=96685f8666714233d34abb71b242448c80077536'/>
<id>urn:sha1:96685f8666714233d34abb71b242448c80077536</id>
<content type='text'>
Pull powerpc updates from Michael Ellerman:

 - A series from Nick adding ARCH_WANT_IRQS_OFF_ACTIVATE_MM &amp; selecting
   it for powerpc, as well as a related fix for sparc.

 - Remove support for PowerPC 601.

 - Some fixes for watchpoints &amp; addition of a new ptrace flag for
   detecting ISA v3.1 (Power10) watchpoint features.

 - A fix for kernels using 4K pages and the hash MMU on bare metal
   Power9 systems with &gt; 16TB of RAM, or RAM on the 2nd node.

 - A basic idle driver for shallow stop states on Power10.

 - Tweaks to our sched domains code to better inform the scheduler about
   the hardware topology on Power9/10, where two SMT4 cores can be
   presented by firmware as an SMT8 core.

 - A series doing further reworks &amp; cleanups of our EEH code.

 - Addition of a filter for RTAS (firmware) calls done via sys_rtas(),
   to prevent root from overwriting kernel memory.

 - Other smaller features, fixes &amp; cleanups.

Thanks to: Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
Athira Rajeev, Biwen Li, Cameron Berkenpas, Cédric Le Goater, Christophe
Leroy, Christoph Hellwig, Colin Ian King, Daniel Axtens, David Dai, Finn
Thain, Frederic Barrat, Gautham R. Shenoy, Greg Kurz, Gustavo Romero,
Ira Weiny, Jason Yan, Joel Stanley, Jordan Niethe, Kajol Jain, Konrad
Rzeszutek Wilk, Laurent Dufour, Leonardo Bras, Liu Shixin, Luca
Ceresoli, Madhavan Srinivasan, Mahesh Salgaonkar, Nathan Lynch, Nicholas
Mc Guire, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Pedro
Miraglia Franco de Carvalho, Pratik Rajesh Sampat, Qian Cai, Qinglang
Miao, Ravi Bangoria, Russell Currey, Satheesh Rajendran, Scott Cheloha,
Segher Boessenkool, Srikar Dronamraju, Stan Johnson, Stephen Kitt,
Stephen Rothwell, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain,
Vaidyanathan Srinivasan, Vasant Hegde, Wang Wensheng, Wolfram Sang, Yang
Yingliang, zhengbin.

* tag 'powerpc-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (228 commits)
  Revert "powerpc/pci: unmap legacy INTx interrupts when a PHB is removed"
  selftests/powerpc: Fix eeh-basic.sh exit codes
  cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier
  powerpc/time: Make get_tb() common to PPC32 and PPC64
  powerpc/time: Make get_tbl() common to PPC32 and PPC64
  powerpc/time: Remove get_tbu()
  powerpc/time: Avoid using get_tbl() and get_tbu() internally
  powerpc/time: Make mftb() common to PPC32 and PPC64
  powerpc/time: Rename mftbl() to mftb()
  powerpc/32s: Remove #ifdef CONFIG_PPC_BOOK3S_32 in head_book3s_32.S
  powerpc/32s: Rename head_32.S to head_book3s_32.S
  powerpc/32s: Setup the early hash table at all time.
  powerpc/time: Remove ifdef in get_dec() and set_dec()
  powerpc: Remove get_tb_or_rtc()
  powerpc: Remove __USE_RTC()
  powerpc: Tidy up a bit after removal of PowerPC 601.
  powerpc: Remove support for PowerPC 601
  powerpc: Remove PowerPC 601
  powerpc: Drop SYNC_601() ISYNC_601() and SYNC()
  powerpc: Remove CONFIG_PPC601_SYNC_FIX
  ...
</content>
</entry>
<entry>
<title>Merge tag 'seccomp-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux</title>
<updated>2020-10-13T23:33:43Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2020-10-13T23:33:43Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=8b05418b252166be6df3766dafdb25341488ab95'/>
<id>urn:sha1:8b05418b252166be6df3766dafdb25341488ab95</id>
<content type='text'>
Pull seccomp updates from Kees Cook:
 "The bulk of the changes are with the seccomp selftests to accommodate
  some powerpc-specific behavioral characteristics. Additional cleanups,
  fixes, and improvements are also included:

   - heavily refactor seccomp selftests (and clone3 selftests
     dependency) to fix powerpc (Kees Cook, Thadeu Lima de Souza
     Cascardo)

   - fix style issue in selftests (Zou Wei)

   - upgrade "unknown action" from KILL_THREAD to KILL_PROCESS (Rich
     Felker)

   - replace task_pt_regs(current) with current_pt_regs() (Denis
     Efremov)

   - fix corner-case race in USER_NOTIF (Jann Horn)

   - make CONFIG_SECCOMP no longer per-arch (YiFei Zhu)"

* tag 'seccomp-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (23 commits)
  seccomp: Make duplicate listener detection non-racy
  seccomp: Move config option SECCOMP to arch/Kconfig
  selftests/clone3: Avoid OS-defined clone_args
  selftests/seccomp: powerpc: Set syscall return during ptrace syscall exit
  selftests/seccomp: Allow syscall nr and ret value to be set separately
  selftests/seccomp: Record syscall during ptrace entry
  selftests/seccomp: powerpc: Fix seccomp return value testing
  selftests/seccomp: Remove SYSCALL_NUM_RET_SHARE_REG in favor of SYSCALL_RET_SET
  selftests/seccomp: Avoid redundant register flushes
  selftests/seccomp: Convert REGSET calls into ARCH_GETREG/ARCH_SETREG
  selftests/seccomp: Convert HAVE_GETREG into ARCH_GETREG/ARCH_SETREG
  selftests/seccomp: Remove syscall setting #ifdefs
  selftests/seccomp: mips: Remove O32-specific macro
  selftests/seccomp: arm64: Define SYSCALL_NUM_SET macro
  selftests/seccomp: arm: Define SYSCALL_NUM_SET macro
  selftests/seccomp: mips: Define SYSCALL_NUM_SET macro
  selftests/seccomp: Provide generic syscall setting macro
  selftests/seccomp: Refactor arch register macros to avoid xtensa special case
  selftests/seccomp: Use __NR_mknodat instead of __NR_mknod
  selftests/seccomp: Use bitwise instead of arithmetic operator for flags
  ...
</content>
</entry>
<entry>
<title>Merge tag 'x86-irq-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2020-10-12T18:40:41Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2020-10-12T18:40:41Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=cc7343724eb77ce0752b1097a275f22f6fe47057'/>
<id>urn:sha1:cc7343724eb77ce0752b1097a275f22f6fe47057</id>
<content type='text'>
Pull x86 irq updates from Thomas Gleixner:
 "Surgery of the MSI interrupt handling to prepare the support of
  upcoming devices which require non-PCI based MSI handling:

   - Cleanup historical leftovers all over the place

   - Rework the code to utilize more core functionality

   - Wrap XEN PCI/MSI interrupts into an irqdomain to make irqdomain
     assignment to PCI devices possible.

   - Assign irqdomains to PCI devices at initialization time which
     allows to utilize the full functionality of hierarchical
     irqdomains.

   - Remove arch_.*_msi_irq() functions from X86 and utilize the
     irqdomain which is assigned to the device for interrupt management.

   - Make the arch_.*_msi_irq() support conditional on a config switch
     and let the last few users select it"

* tag 'x86-irq-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  PCI: MSI: Fix Kconfig dependencies for PCI_MSI_ARCH_FALLBACKS
  x86/apic/msi: Unbreak DMAR and HPET MSI
  iommu/amd: Remove domain search for PCI/MSI
  iommu/vt-d: Remove domain search for PCI/MSI[X]
  x86/irq: Make most MSI ops XEN private
  x86/irq: Cleanup the arch_*_msi_irqs() leftovers
  PCI/MSI: Make arch_.*_msi_irq[s] fallbacks selectable
  x86/pci: Set default irq domain in pcibios_add_device()
  iommm/amd: Store irq domain in struct device
  iommm/vt-d: Store irq domain in struct device
  x86/xen: Wrap XEN MSI management into irqdomain
  irqdomain/msi: Allow to override msi_domain_alloc/free_irqs()
  x86/xen: Consolidate XEN-MSI init
  x86/xen: Rework MSI teardown
  x86/xen: Make xen_msi_init() static and rename it to xen_hvm_msi_init()
  PCI/MSI: Provide pci_dev_has_special_msi_domain() helper
  PCI_vmd_Mark_VMD_irqdomain_with_DOMAIN_BUS_VMD_MSI
  irqdomain/msi: Provide DOMAIN_BUS_VMD_MSI
  x86/irq: Initialize PCI/MSI domain at PCI init time
  x86/pci: Reducde #ifdeffery in PCI init code
  ...
</content>
</entry>
<entry>
<title>Merge tag 'ras_updates_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2020-10-12T17:14:38Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2020-10-12T17:14:38Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=ca1b66922a702316734bcd5ea2100e5fb8f3caa3'/>
<id>urn:sha1:ca1b66922a702316734bcd5ea2100e5fb8f3caa3</id>
<content type='text'>
Pull RAS updates from Borislav Petkov:

 - Extend the recovery from MCE in kernel space also to processes which
   encounter an MCE in kernel space but while copying from user memory
   by sending them a SIGBUS on return to user space and umapping the
   faulty memory, by Tony Luck and Youquan Song.

 - memcpy_mcsafe() rework by splitting the functionality into
   copy_mc_to_user() and copy_mc_to_kernel(). This, as a result, enables
   support for new hardware which can recover from a machine check
   encountered during a fast string copy and makes that the default and
   lets the older hardware which does not support that advance recovery,
   opt in to use the old, fragile, slow variant, by Dan Williams.

 - New AMD hw enablement, by Yazen Ghannam and Akshay Gupta.

 - Do not use MSR-tracing accessors in #MC context and flag any fault
   while accessing MCA architectural MSRs as an architectural violation
   with the hope that such hw/fw misdesigns are caught early during the
   hw eval phase and they don't make it into production.

 - Misc fixes, improvements and cleanups, as always.

* tag 'ras_updates_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Allow for copy_mc_fragile symbol checksum to be generated
  x86/mce: Decode a kernel instruction to determine if it is copying from user
  x86/mce: Recover from poison found while copying from user space
  x86/mce: Avoid tail copy when machine check terminated a copy from user
  x86/mce: Add _ASM_EXTABLE_CPY for copy user access
  x86/mce: Provide method to find out the type of an exception handler
  x86/mce: Pass pointer to saved pt_regs to severity calculation routines
  x86/copy_mc: Introduce copy_mc_enhanced_fast_string()
  x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()
  x86/mce: Drop AMD-specific "DEFERRED" case from Intel severity rule list
  x86/mce: Add Skylake quirk for patrol scrub reported errors
  RAS/CEC: Convert to DEFINE_SHOW_ATTRIBUTE()
  x86/mce: Annotate mce_rd/wrmsrl() with noinstr
  x86/mce/dev-mcelog: Do not update kflags on AMD systems
  x86/mce: Stop mce_reign() from re-computing severity for every CPU
  x86/mce: Make mce_rdmsrl() panic on an inaccessible MSR
  x86/mce: Increase maximum number of banks to 64
  x86/mce: Delay clearing IA32_MCG_STATUS to the end of do_machine_check()
  x86/MCE/AMD, EDAC/mce_amd: Remove struct smca_hwid.xec_bitmap
  RAS/CEC: Fix cec_init() prototype
</content>
</entry>
<entry>
<title>seccomp: Move config option SECCOMP to arch/Kconfig</title>
<updated>2020-10-08T20:17:47Z</updated>
<author>
<name>YiFei Zhu</name>
</author>
<published>2020-09-24T12:44:16Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=282a181b1a0d66de1f0894d82f395fcd478f51d1'/>
<id>urn:sha1:282a181b1a0d66de1f0894d82f395fcd478f51d1</id>
<content type='text'>
In order to make adding configurable features into seccomp easier,
it's better to have the options at one single location, considering
especially that the bulk of seccomp code is arch-independent. An quick
look also show that many SECCOMP descriptions are outdated; they talk
about /proc rather than prctl.

As a result of moving the config option and keeping it default on,
architectures arm, arm64, csky, riscv, sh, and xtensa did not have SECCOMP
on by default prior to this and SECCOMP will be default in this change.

Architectures microblaze, mips, powerpc, s390, sh, and sparc have an
outdated depend on PROC_FS and this dependency is removed in this change.

Suggested-by: Jann Horn &lt;jannh@google.com&gt;
Link: https://lore.kernel.org/lkml/CAG48ez1YWz9cnp08UZgeieYRhHdqh-ch7aNwc4JRBnGyrmgfMg@mail.gmail.com/
Signed-off-by: YiFei Zhu &lt;yifeifz2@illinois.edu&gt;
[kees: added HAVE_ARCH_SECCOMP help text, tweaked wording]
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/9ede6ef35c847e58d61e476c6a39540520066613.1600951211.git.yifeifz2@illinois.edu
</content>
</entry>
<entry>
<title>powerpc/rtas: Restrict RTAS requests from userspace</title>
<updated>2020-10-06T12:22:27Z</updated>
<author>
<name>Andrew Donnellan</name>
</author>
<published>2020-08-20T04:45:12Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=bd59380c5ba4147dcbaad3e582b55ccfd120b764'/>
<id>urn:sha1:bd59380c5ba4147dcbaad3e582b55ccfd120b764</id>
<content type='text'>
A number of userspace utilities depend on making calls to RTAS to retrieve
information and update various things.

The existing API through which we expose RTAS to userspace exposes more
RTAS functionality than we actually need, through the sys_rtas syscall,
which allows root (or anyone with CAP_SYS_ADMIN) to make any RTAS call they
want with arbitrary arguments.

Many RTAS calls take the address of a buffer as an argument, and it's up to
the caller to specify the physical address of the buffer as an argument. We
allocate a buffer (the "RMO buffer") in the Real Memory Area that RTAS can
access, and then expose the physical address and size of this buffer in
/proc/powerpc/rtas/rmo_buffer. Userspace is expected to read this address,
poke at the buffer using /dev/mem, and pass an address in the RMO buffer to
the RTAS call.

However, there's nothing stopping the caller from specifying whatever
address they want in the RTAS call, and it's easy to construct a series of
RTAS calls that can overwrite arbitrary bytes (even without /dev/mem
access).

Additionally, there are some RTAS calls that do potentially dangerous
things and for which there are no legitimate userspace use cases.

In the past, this would not have been a particularly big deal as it was
assumed that root could modify all system state freely, but with Secure
Boot and lockdown we need to care about this.

We can't fundamentally change the ABI at this point, however we can address
this by implementing a filter that checks RTAS calls against a list
of permitted calls and forces the caller to use addresses within the RMO
buffer.

The list is based off the list of calls that are used by the librtas
userspace library, and has been tested with a number of existing userspace
RTAS utilities. For compatibility with any applications we are not aware of
that require other calls, the filter can be turned off at build time.

Cc: stable@vger.kernel.org
Reported-by: Daniel Axtens &lt;dja@axtens.net&gt;
Signed-off-by: Andrew Donnellan &lt;ajd@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200820044512.7543-1-ajd@linux.ibm.com
</content>
</entry>
</feed>
