Commit d11219ad ("amdgpu: disable powerpc support for the newer
display engine") disabled the DCN driver for all of powerpc due to
unresolved build failures with some compilers.

Further digging shows that the build failures only occur with compilers
that default to 64-bit long double.

Both the ppc64 and ppc64le ABIs define long double to be 128-bits, but
there are compilers in the wild that default to 64-bits. The compilers
provided by the major distros (Fedora, Ubuntu) default to 128-bits and
are not affected by the build failure.

There is a compiler flag to force 128-bit long double, which may be the
correct long term fix, but as an interim fix only allow building the DCN
driver if long double is 128-bits by default.

The bisection in commit d11219ad must have gone off the rails at
some point, the build failure occurs all the way back to the original
commit that enabled DCN support on powerpc, at least with some
toolchains.

Depends-on: d11219ad ("amdgpu: disable powerpc support for the newer display engine")
Fixes: 16a9dea1 ("amdgpu: Enable initial DCN support on POWER")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Dan Horák <dan@danny.cz>
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2100
Link: https://lore.kernel.org/r/20220725123918.1903255-1-mpe@ellerman.id.au

Scattered across the archs are 3 basic forms of tlb_{start,end}_vma().
Provide two new MMU_GATHER_knobs to enumerate them and remove the per
arch tlb_{start,end}_vma() implementations.

 - MMU_GATHER_NO_FLUSH_CACHE indicates the arch has flush_cache_range()
   but does *NOT* want to call it for each VMA.

 - MMU_GATHER_MERGE_VMAS indicates the arch wants to merge the
   invalidate across multiple VMAs if possible.

With these it is possible to capture the three forms:

  1) empty stubs;
     select MMU_GATHER_NO_FLUSH_CACHE and MMU_GATHER_MERGE_VMAS

  2) start: flush_cache_range(), end: empty;
     select MMU_GATHER_MERGE_VMAS

  3) start: flush_cache_range(), end: flush_tlb_range();
     default

Obviously, if the architecture does not have flush_cache_range() then
it also doesn't need to select MMU_GATHER_NO_FLUSH_CACHE.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When RDRAND was introduced, there was much discussion on whether it
should be trusted and how the kernel should handle that. Initially, two
mechanisms cropped up, CONFIG_ARCH_RANDOM, a compile time switch, and
"nordrand", a boot-time switch.

Later the thinking evolved. With a properly designed RNG, using RDRAND
values alone won't harm anything, even if the outputs are malicious.
Rather, the issue is whether those values are being *trusted* to be good
or not. And so a new set of options were introduced as the real
ones that people use -- CONFIG_RANDOM_TRUST_CPU and "random.trust_cpu".
With these options, RDRAND is used, but it's not always credited. So in
the worst case, it does nothing, and in the best case, maybe it helps.

Along the way, CONFIG_ARCH_RANDOM's meaning got sort of pulled into the
center and became something certain platforms force-select.

The old options don't really help with much, and it's a bit odd to have
special handling for these instructions when the kernel can deal fine
with the existence or untrusted existence or broken existence or
non-existence of that CPU capability.

Simplify the situation by removing CONFIG_ARCH_RANDOM and using the
ordinary asm-generic fallback pattern instead, keeping the two options
that are actually used. For now it leaves "nordrand" for now, as the
removal of that will take a different route.
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Context tracking is going to be used not only to track user transitions
but also idle/IRQs/NMIs. The user tracking part will then become a
separate feature. Prepare Kconfig for that.

[ frederic: Apply Max Filippov feedback. ]
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>

With commit ffa0b64e ("powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit")
the kernel now validate the addr against high_memory value. This results
in the below BUG_ON with dax pfns.

[  635.798741][T26531] kernel BUG at mm/page_alloc.c:5521!
1:mon> e
cpu 0x1: Vector: 700 (Program Check) at [c000000007287630]
    pc: c00000000055ed48: free_pages.part.0+0x48/0x110
    lr: c00000000053ca70: tlb_finish_mmu+0x80/0xd0
    sp: c0000000072878d0
   msr: 800000000282b033
  current = 0xc00000000afabe00
  paca    = 0xc00000037ffff300   irqmask: 0x03   irq_happened: 0x05
    pid   = 26531, comm = 50-landscape-sy
kernel BUG at :5521!
Linux version 5.19.0-rc3-14659-g4ec05be7c2e1 (kvaneesh@ltc-boston8) (gcc (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #625 SMP Thu Jun 23 00:35:43 CDT 2022
1:mon> t
[link register   ] c00000000053ca70 tlb_finish_mmu+0x80/0xd0
[c0000000072878d0] c00000000053ca54 tlb_finish_mmu+0x64/0xd0 (unreliable)
[c000000007287900] c000000000539424 exit_mmap+0xe4/0x2a0
[c0000000072879e0] c00000000019fc1c mmput+0xcc/0x210
[c000000007287a20] c000000000629230 begin_new_exec+0x5e0/0xf40
[c000000007287ae0] c00000000070b3cc load_elf_binary+0x3ac/0x1e00
[c000000007287c10] c000000000627af0 bprm_execve+0x3b0/0xaf0
[c000000007287cd0] c000000000628414 do_execveat_common.isra.0+0x1e4/0x310
[c000000007287d80] c00000000062858c sys_execve+0x4c/0x60
[c000000007287db0] c00000000002c1b0 system_call_exception+0x160/0x2c0
[c000000007287e10] c00000000000c53c system_call_common+0xec/0x250

The fix is to make sure we update high_memory on memory hotplug.
This is similar to what x86 does in commit 3072e413 ("mm/memory_hotplug: introduce add_pages")

Fixes: ffa0b64e ("powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220629050925.31447-1-aneesh.kumar@linux.ibm.com

All architecture-independent users of virt_to_bus() and bus_to_virt()
have been fixed to use the dma mapping interfaces or have been
removed now.  This means the definitions on most architectures, and the
CONFIG_VIRT_TO_BUS symbol are now obsolete and can be removed.

The only exceptions to this are a few network and scsi drivers for m68k
Amiga and VME machines and ppc32 Macintosh. These drivers work correctly
with the old interfaces and are probably not worth changing.

On alpha and parisc, virt_to_bus() were still used in asm/floppy.h.
alpha can use isa_virt_to_bus() like x86 does, and parisc can just
open-code the virt_to_phys() here, as this is architecture specific
code.

I tried updating the bus-virt-phys-mapping.rst documentation, which
started as an email from Linus to explain some details of the Linux-2.0
driver interfaces. The bits about virt_to_bus() were declared obsolete
backin 2000, and the rest is not all that relevant any more, so in the
end I just decided to remove the file completely.
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

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: edbadaf0 ("powerpc/kasan: Fix stack overflow by increasing THREAD_SHIFT")
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Use MIN_THREAD_SHIFT as suggested by Christophe]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220601143114.133524-1-mpe@ellerman.id.au

The HAVE_IRQ_EXIT_ON_IRQ_STACK option tells generic code that irq_exit()
is called while still running on the hard irq stack (hardirq_ctx[] in
the powerpc code).

Selecting the option means the generic code will *not* switch to the
softirq stack before running softirqs, because the code is already
running on the (mostly empty) hard irq stack.

But since commit 1b1b6a6f ("powerpc: handle irq_enter/irq_exit in
interrupt handler wrappers"), irq_exit() is now called on the regular task
stack, not the hard irq stack.

That's because previously irq_exit() was called in __do_irq() which is
run on the hard irq stack, but now it is called in
interrupt_async_exit_prepare() which is called from do_irq() constructed
by the wrapper macro, which is after the switch back to the task stack.

So drop HAVE_IRQ_EXIT_ON_IRQ_STACK from the Kconfig. This will mean an
extra stack switch when processing some interrupts, but should
significantly reduce the likelihood of stack overflow.

It also means the softirq stack will be used for running softirqs from
other interrupts that don't use the hard irq stack, eg. timer interrupts.

Fixes: 1b1b6a6f ("powerpc: handle irq_enter/irq_exit in interrupt handler wrappers")
Cc: stable@vger.kernel.org # v5.12+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220525032639.1947280-1-mpe@ellerman.id.au

include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.

Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.

It is time to get rid of this complexity.

Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.

Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.

Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.

No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.

Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)

Implement a limited form of KASAN for Book3S 64-bit machines running under
the Radix MMU, supporting only outline mode.

 - Enable the compiler instrumentation to check addresses and maintain the
   shadow region. (This is the guts of KASAN which we can easily reuse.)

 - Require kasan-vmalloc support to handle modules and anything else in
   vmalloc space.

 - KASAN needs to be able to validate all pointer accesses, but we can't
   instrument all kernel addresses - only linear map and vmalloc. On boot,
   set up a single page of read-only shadow that marks all iomap and
   vmemmap accesses as valid.

 - Document KASAN in powerpc docs.

Background
----------

KASAN support on Book3S is a bit tricky to get right:

 - It would be good to support inline instrumentation so as to be able to
   catch stack issues that cannot be caught with outline mode.

 - Inline instrumentation requires a fixed offset.

 - Book3S runs code with translations off ("real mode") during boot,
   including a lot of generic device-tree parsing code which is used to
   determine MMU features.

    [ppc64 mm note: The kernel installs a linear mapping at effective
    address c000...-c008.... This is a one-to-one mapping with physical
    memory from 0000... onward. Because of how memory accesses work on
    powerpc 64-bit Book3S, a kernel pointer in the linear map accesses the
    same memory both with translations on (accessing as an 'effective
    address'), and with translations off (accessing as a 'real
    address'). This works in both guests and the hypervisor. For more
    details, see s5.7 of Book III of version 3 of the ISA, in particular
    the Storage Control Overview, s5.7.3, and s5.7.5 - noting that this
    KASAN implementation currently only supports Radix.]

 - Some code - most notably a lot of KVM code - also runs with translations
   off after boot.

 - Therefore any offset has to point to memory that is valid with
   translations on or off.

One approach is just to give up on inline instrumentation. This way
boot-time checks can be delayed until after the MMU is set is up, and we
can just not instrument any code that runs with translations off after
booting. Take this approach for now and require outline instrumentation.

Previous attempts allowed inline instrumentation. However, they came with
some unfortunate restrictions: only physically contiguous memory could be
used and it had to be specified at compile time. Maybe we can do better in
the future.

[paulus@ozlabs.org - Rebased onto 5.17.  Note that a kernel with
 CONFIG_KASAN=y will crash during boot on a machine using HPT
 translation because not all the entry points to the generic
 KASAN code are protected with a call to kasan_arch_is_ready().]

Originally-by: Balbir Singh <bsingharora@gmail.com> # ppc64 out-of-line radix version
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
[mpe: Update copyright year and comment formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YoTE69OQwiG7z+Gu@cleo

Other arches (sh, mips, hexagon) use standard names for PAGE_SIZE
related config symbols.

Add matching symbols for powerpc, which are enabled by default but
depend on our architecture specific PAGE_SIZE symbols.

This allows generic/driver code to express dependencies on the PAGE_SIZE
without needing to refer to architecture specific config symbols.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220505125123.2088143-1-mpe@ellerman.id.au

Now that we have CONFIG_PPC64_ELF_ABI_V1 and CONFIG_PPC64_ELF_ABI_V2,
get rid of all indirect detection of ABI version.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/709d9d69523c14c8a9fba4486395dca0f2d675b1.1652074503.git.christophe.leroy@csgroup.eu

Select CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT and
remove arch/powerpc/mm/mmap.c

This change reuses the generic framework added by
commit 67f3977f ("arm64, mm: move generic mmap layout
functions to mm") without any functional change.

Comparison between powerpc implementation and the generic one:
- mmap_is_legacy() is identical.
- arch_mmap_rnd() does exactly the same allthough it's written
slightly differently.
- MIN_GAP and MAX_GAP are identical.
- mmap_base() does the same but uses STACK_RND_MASK which provides
the same values as stack_maxrandom_size().
- arch_pick_mmap_layout() is identical.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/518f9def87d3c889d5958103e7463cf45a2f673d.1649523076.git.christophe.leroy@csgroup.eu

This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT.  While here, this also localizes
arch_vm_get_page_prot() as __vm_get_page_prot() and moves it near
vm_get_page_prot().

Link: https://lkml.kernel.org/r/20220414062125.609297-3-anshuman.khandual@arm.comSigned-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The existing per-arch definitions are pretty much historic cruft.
Move SYSVIPC_COMPAT into init/Kconfig.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Helge Deller <deller@gmx.de>  # parisc
Link: https://lore.kernel.org/r/20220405071314.3225832-5-guoren@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

book3s/32 and 8xx have a separate area for allocating modules,
defined by MODULES_VADDR / MODULES_END.

On book3s/32, it is not possible to protect against execution
on a page basis. A full 256M segment is either Exec or NoExec.
The module area is in an Exec segment while vmalloc area is
in a NoExec segment.

In order to protect module data against execution, select
ARCH_WANTS_MODULES_DATA_IN_VMALLOC.

For the 8xx (and possibly other 32 bits platform in the future),
there is no such constraint on Exec/NoExec protection, however
there is a critical distance between kernel functions and callers
that needs to remain below 32Mbytes in order to avoid costly
trampolines. By allocating data outside of module area, we
increase the chance for module text to remain within acceptable
distance from kernel core text.

So select ARCH_WANTS_MODULES_DATA_IN_VMALLOC for 8xx as well.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

This reverts commit 02752bd9.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Add rethook powerpc64 implementation. Most of the code has been copied from
kretprobes on powerpc64.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/164735288495.1084943.539630613772422267.stgit@devnote2

One of the things that CONFIG_HARDENED_USERCOPY sanity-checks is whether
an object that is about to be copied to/from userspace is overlapping
the stack at all. If it is, it performs a number of inexpensive
bounds checks. One of the finer-grained checks is whether an object
crosses stack frames within the stack region. Doing this on x86 with
CONFIG_FRAME_POINTER was cheap/easy. Doing it with ORC was deemed too
heavy, and was left out (a while ago), leaving the courser whole-stack
check.

The LKDTM tests USERCOPY_STACK_FRAME_TO and USERCOPY_STACK_FRAME_FROM
try to exercise these cross-frame cases to validate the defense is
working. They have been failing ever since ORC was added (which was
expected). While Muhammad was investigating various LKDTM failures[1],
he asked me for additional details on them, and I realized that when
exact stack frame boundary checking is not available (i.e. everything
except x86 with FRAME_POINTER), it could check if a stack object is at
least "current depth valid", in the sense that any object within the
stack region but not between start-of-stack and current_stack_pointer
should be considered unavailable (i.e. its lifetime is from a call no
longer present on the stack).

Introduce ARCH_HAS_CURRENT_STACK_POINTER to track which architectures
have actually implemented the common global register alias.

Additionally report usercopy bounds checking failures with an offset
from current_stack_pointer, which may assist with diagnosing failures.

The LKDTM USERCOPY_STACK_FRAME_TO and USERCOPY_STACK_FRAME_FROM tests
(once slightly adjusted in a separate patch) pass again with this fixed.

[1] https://github.com/kernelci/kernelci-project/issues/84

Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
v1: https://lore.kernel.org/lkml/20220216201449.2087956-1-keescook@chromium.org
v2: https://lore.kernel.org/lkml/20220224060342.1855457-1-keescook@chromium.org
v3: https://lore.kernel.org/lkml/20220225173345.3358109-1-keescook@chromium.org
v4: - improve commit log (akpm)

Replace HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR by a config option
named CONFIG_HAVE_FUNCTION_DESCRIPTORS and use it instead of
'dereference_function_descriptor' macro to know whether an
arch has function descriptors.

To limit churn in one of the following patches, use
an #ifdef/#else construct with empty first part
instead of an #ifndef in asm-generic/sections.h

On powerpc, make sure the config option matches the ABI used
by the compiler with a BUILD_BUG_ON() and add missing _CALL_ELF=2
when calling 'sparse' so that sparse sees the same piece of
code as GCC.

And include a helper to check whether an arch has function
descriptors or not : have_function_descriptors()
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4a0f11fb0ea74a3197bc44dd7ba25e53a24fd03d.1644928018.git.christophe.leroy@csgroup.eu

The book3s/32 MMU doesn't support per page execution protection and
doesn't support RO protection for kernel pages.

However, on the 603 which implements software loaded TLBs, execution
protection is honored by the TLB Miss handler which doesn't load
Instruction TLB for non executable pages. And RO protection is
honored by clearing the C bit for RO pages, leading to DSI.

So on the 603, STRICT_MODULE_RWX is possible without much effort.
Don't disable STRICT_MODULE_RWX on book3s/32 and print a warning
in case STRICT_MODULE_RWX has been selected and the platform has
a Hardware HASH MMU.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1e6162f334167e75f1140082932e3a354b16daba.1642413973.git.christophe.leroy@csgroup.eu

Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS. It accelerates the call
of livepatching.

Also note that powerpc being the last one to convert to
CONFIG_DYNAMIC_FTRACE_WITH_ARGS, it will now be possible to remove
klp_arch_set_pc() on all architectures.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5831f711a778fcd6eb51eb5898f1faae4378b35b.1640017960.git.christophe.leroy@csgroup.eu

PPC64 needs some special logic to properly set up the TOC.
See commit 85baa095 ("powerpc/livepatch: Add live patching support
on ppc64le") for details.

PPC32 doesn't have TOC so it doesn't need that logic, so adding
LIVEPATCH support is straight forward.

Add CONFIG_LIVEPATCH_64 and move livepatch stack logic into that item.

Livepatch sample modules all work.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/63cb094125b6a6038c65eeac2abaabbabe63addd.1640017960.git.christophe.leroy@csgroup.eu

Patch series "mm: percpu: Cleanup percpu first chunk function".

When supporting page mapping percpu first chunk allocator on arm64, we
found there are lots of duplicated codes in percpu embed/page first chunk
allocator.  This patchset is aimed to cleanup them and should no function
change.

The currently supported status about 'embed' and 'page' in Archs shows
below,

	embed: NEED_PER_CPU_PAGE_FIRST_CHUNK
	page:  NEED_PER_CPU_EMBED_FIRST_CHUNK

		embed	page
	------------------------
	arm64	  Y	 Y
	mips	  Y	 N
	powerpc	  Y	 Y
	riscv	  Y	 N
	sparc	  Y	 Y
	x86	  Y	 Y
	------------------------

There are two interfaces about percpu first chunk allocator,

 extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
                                size_t atom_size,
                                pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
-                               pcpu_fc_alloc_fn_t alloc_fn,
-                               pcpu_fc_free_fn_t free_fn);
+                               pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);

 extern int __init pcpu_page_first_chunk(size_t reserved_size,
-                               pcpu_fc_alloc_fn_t alloc_fn,
-                               pcpu_fc_free_fn_t free_fn,
-                               pcpu_fc_populate_pte_fn_t populate_pte_fn);
+                               pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);

The pcpu_fc_alloc_fn_t/pcpu_fc_free_fn_t is killed, we provide generic
pcpu_fc_alloc() and pcpu_fc_free() function, which are called in the
pcpu_embed/page_first_chunk().

1) For pcpu_embed_first_chunk(), pcpu_fc_cpu_to_node_fn_t is needed to be
   provided when archs supported NUMA.

2) For pcpu_page_first_chunk(), the pcpu_fc_populate_pte_fn_t is killed too,
   a generic pcpu_populate_pte() which marked '__weak' is provided, if you
   need a different function to populate pte on the arch(like x86), please
   provide its own implementation.

[1] https://github.com/kevin78/linux.git percpu-cleanup

This patch (of 4):

The HAVE_SETUP_PER_CPU_AREA/NEED_PER_CPU_EMBED_FIRST_CHUNK/
NEED_PER_CPU_PAGE_FIRST_CHUNK/USE_PERCPU_NUMA_NODE_ID configs, which have
duplicate definitions on platforms that subscribe it.

Move them into mm, drop these redundant definitions and instead just
select it on applicable platforms.

Link: https://lkml.kernel.org/r/20211216112359.103822-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20211216112359.103822-2-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves
128kB kernel image size (90kB text) on powernv_defconfig minus KVM,
350kB on pseries_defconfig minus KVM, 40kB on a tiny config.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup defined(ARCH_HAS_MEMREMAP_COMPAT_ALIGN), which needs CONFIG.
      Fix radix_enabled() use in setup_initial_memory_limit(). Add some
      stubs to reduce number of ifdefs.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211201144153.2456614-18-npiggin@gmail.com

This adds Kconfig selection which allows 64s hash MMU support to be
disabled. It can be disabled if radix support is enabled, the minimum
supported CPU type is POWER9 (or higher), and KVM is not selected.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211201144153.2456614-17-npiggin@gmail.com

memremap_compat_align is only relevant when ZONE_DEVICE is selected.
ZONE_DEVICE depends on ARCH_HAS_PTE_DEVMAP, which is only selected
by PPC_BOOK3S_64.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211201144153.2456614-13-npiggin@gmail.com

Unlike PPC64, PPC32 doesn't require any special compiler option
to get _mcount() call not clobbering registers.

Provide ftrace_regs_caller() and ftrace_regs_call() and activate
HAVE_DYNAMIC_FTRACE_WITH_REGS.

That's heavily copied from ftrace_64_mprofile.S

For the time being leave livepatching aside, it will come with
following patch.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1862dc7719855cc2a4eec80920d94c955877557e.1635423081.git.christophe.leroy@csgroup.eu

Some core kernel code starts to go beyond the 2048 byte stack size
warning at NR_CPUS=8192, so select CPUMASK_OFFSTACK in that case.
x86 does similarly for very large NR_CPUS.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105035042.1398309-2-npiggin@gmail.com

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

This reverts commit 566af8cd.

This caused some conflicts vs the audit tree, and the audit maintainers
would prefer we postpone this to the next merge window so we have more
time for testing.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

CONFIG_STRICT_KERNEL_RWX should be set by default on every
architectures (See https://github.com/KSPP/linux/issues/4)

On PPC32 we have to find a compromise between performance and/or
memory wasting and selection of strict_kernel_rwx, because it implies
either smaller memory chunks or larger alignment between RO memory
and RW memory.

For instance the 8xx maps memory with 8M pages. So either the limit
between RO and RW must be 8M aligned or it falls back or 512k pages
which implies more pressure on the TLB.

book3s/32 maps memory with BATs as much as possible. BATS can have
any power-of-two size between 128k and 256M but we have only 4 to 8
BATs so the alignment must be good enough to allow efficient use of
the BATs and avoid falling back on standard page mapping which would
kill performance.

So let's go one step forward and make it the default but still allow
users to unset it when wanted.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/057c40164084bfc7d77c0b2ff78d95dbf6a2a21b.1632503622.git.christophe.leroy@csgroup.eu

Add support for out-of-line static calls on PPC32. This change
improve performance of calls to global function pointers by
using direct calls instead of indirect calls.

The trampoline is initialy populated with a 'blr' or branch to target,
followed by an unreachable long jump sequence.

In order to cater with parallele execution, the trampoline needs to
be updated in a way that ensures it remains consistent at all time.
This means we can't use the traditional lis/addi to load r12 with
the target address, otherwise there would be a window during which
the first instruction contains the upper part of the new target
address while the second instruction still contains the lower part of
the old target address. To avoid that the target address is stored
just after the 'bctr' and loaded from there with a single instruction.

Then, depending on the target distance, arch_static_call_transform()
will either replace the first instruction by a direct 'bl <target>' or
'nop' in order to have the trampoline fall through the long jump
sequence.

For the special case of __static_call_return0(), to avoid the risk of
a far branch, a version of it is inlined at the end of the trampoline.

Performancewise the long jump sequence is probably not better than
the indirect calls set by GCC when we don't use static calls, but
such calls are unlikely to be required on powerpc32: With most
configurations the kernel size is far below 32 Mbytes so only
modules may happen to be too far. And even modules are likely to
be close enough as they are allocated below the kernel core and
as close as possible of the kernel text.

static_call selftest is running successfully with this change.

With this patch, __do_irq() has the following sequence to trace
irq entries:

	c0004a00 <__SCT__tp_func_irq_entry>:
	c0004a00:	48 00 00 e0 	b       c0004ae0 <__traceiter_irq_entry>
	c0004a04:	3d 80 c0 00 	lis     r12,-16384
	c0004a08:	81 8c 4a 1c 	lwz     r12,18972(r12)
	c0004a0c:	7d 89 03 a6 	mtctr   r12
	c0004a10:	4e 80 04 20 	bctr
	c0004a14:	38 60 00 00 	li      r3,0
	c0004a18:	4e 80 00 20 	blr
	c0004a1c:	00 00 00 00 	.long 0x0
...
	c0005654 <__do_irq>:
...
	c0005664:	7c 7f 1b 78 	mr      r31,r3
...
	c00056a0:	81 22 00 00 	lwz     r9,0(r2)
	c00056a4:	39 29 00 01 	addi    r9,r9,1
	c00056a8:	91 22 00 00 	stw     r9,0(r2)
	c00056ac:	3d 20 c0 af 	lis     r9,-16209
	c00056b0:	81 29 74 cc 	lwz     r9,29900(r9)
	c00056b4:	2c 09 00 00 	cmpwi   r9,0
	c00056b8:	41 82 00 10 	beq     c00056c8 <__do_irq+0x74>
	c00056bc:	80 69 00 04 	lwz     r3,4(r9)
	c00056c0:	7f e4 fb 78 	mr      r4,r31
	c00056c4:	4b ff f3 3d 	bl      c0004a00 <__SCT__tp_func_irq_entry>

Before this patch, __do_irq() was doing the following to trace irq
entries:

	c0005700 <__do_irq>:
...
	c0005710:	7c 7e 1b 78 	mr      r30,r3
...
	c000574c:	93 e1 00 0c 	stw     r31,12(r1)
	c0005750:	81 22 00 00 	lwz     r9,0(r2)
	c0005754:	39 29 00 01 	addi    r9,r9,1
	c0005758:	91 22 00 00 	stw     r9,0(r2)
	c000575c:	3d 20 c0 af 	lis     r9,-16209
	c0005760:	83 e9 f4 cc 	lwz     r31,-2868(r9)
	c0005764:	2c 1f 00 00 	cmpwi   r31,0
	c0005768:	41 82 00 24 	beq     c000578c <__do_irq+0x8c>
	c000576c:	81 3f 00 00 	lwz     r9,0(r31)
	c0005770:	80 7f 00 04 	lwz     r3,4(r31)
	c0005774:	7d 29 03 a6 	mtctr   r9
	c0005778:	7f c4 f3 78 	mr      r4,r30
	c000577c:	4e 80 04 21 	bctrl
	c0005780:	85 3f 00 0c 	lwzu    r9,12(r31)
	c0005784:	2c 09 00 00 	cmpwi   r9,0
	c0005788:	40 82 ff e4 	bne     c000576c <__do_irq+0x6c>

Behind the fact of now using a direct 'bl' instead of a
'load/mtctr/bctr' sequence, we can also see that we get one less
register on the stack.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6ec2a7865ed6a5ec54ab46d026785bafe1d837ea.1630484892.git.christophe.leroy@csgroup.eu

Commit e65e1fc2 ("[PATCH] syscall class hookup for all normal
targets") added generic support for AUDIT but that didn't include
support for bi-arch like powerpc.

Commit 4b588411 ("audit: Add generic compat syscall support")
added generic support for bi-arch.

Convert powerpc to that bi-arch generic audit support.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a4b3951d1191d4183d92a07a6097566bde60d00a.1629812058.git.christophe.leroy@csgroup.eu

Enable STRICT_KERNEL_RWX on fsl_booke.

For that, we need additional TLBCAMs dedicated to linear mapping,
based on the alignment of _sinittext.

By default, up to 768 Mbytes of memory are mapped.
It uses 3 TLBCAMs of size 256 Mbytes.

With a data alignment of 16, we need up to 9 TLBCAMs:
  16/16/16/16/64/64/64/256/256

With a data alignment of 4, we need up to 12 TLBCAMs:
  4/4/4/4/16/16/16/64/64/64/256/256

With a data alignment of 1, we need up to 15 TLBCAMs:
  1/1/1/1/4/4/4/16/16/16/64/64/64/256/256

By default, set a 16 Mbytes alignment as a compromise between memory
usage and number of TLBCAMs. This can be adjusted manually when needed.

For the time being, it doens't work when the base is randomised.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/29f9e5d2bbbc83ae9ca879265426a6278bf4d5bb.1634292136.git.christophe.leroy@csgroup.eu

fsl_booke and 44x are not able to map kernel linear memory with
pages, so they can't support DEBUG_PAGEALLOC and KFENCE, and
STRICT_KERNEL_RWX is also a problem for now.

Enable those only on book3s (both 32 and 64 except KFENCE), 8xx and 40x.

Fixes: 88df6e90 ("[POWERPC] DEBUG_PAGEALLOC for 32-bit")
Fixes: 95902e6c ("powerpc/mm: Implement STRICT_KERNEL_RWX on PPC32")
Fixes: 90cbac0e ("powerpc: Enable KFENCE for PPC32")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d1ad9fdd9b27da3fdfa16510bb542ed51fa6e134.1634292136.git.christophe.leroy@csgroup.eu

This patch converts powerpc to the generic PTDUMP implementation.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/03166d569526be70214fe9370a7bad219d2f41c8.1625762907.git.christophe.leroy@csgroup.eu

Make architectures select TRACE_IRQFLAGS_SUPPORT instead of
having many defines.

Link: https://lkml.kernel.org/r/20210731052233.4703-2-masahiroy@kernel.orgAcked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>   #arch/arc
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

The arch-specific Kconfig files use HAVE_IDE to indicate if IDE is
supported.

As IDE support and the HAVE_IDE config vanishes with commit b7fb14d3
("ide: remove the legacy ide driver"), there is no need to mention
HAVE_IDE in all those arch-specific Kconfig files.

The issue was identified with ./scripts/checkkconfigsymbols.py.

Fixes: b7fb14d3 ("ide: remove the legacy ide driver")
Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210728182115.4401-1-lukas.bulwahn@gmail.comReviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Most architectures do not need a custom implementation, and in most
cases the generic implementation is preferred, so change the polariy
on these Kconfig symbols to require architectures to select them when
they provide their own version.

The new name is CONFIG_ARCH_HAS_{STRNCPY_FROM,STRNLEN}_USER.

The remaining architectures at the moment are: ia64, mips, parisc,
um and xtensa. We should probably convert these as well, but
I was not sure how far to take this series. Thomas Bogendoerfer
had some concerns about converting mips but may still do some
more detailed measurements to see which version is better.

Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>