linux-stable.git/arch/sparc/include/asm, branch linux-5.4.y

sparc/module: Add R_SPARC_UA64 relocation handling

2025-12-03T11:45:13+00:00

[ Upstream commit 05457d96175d25c976ab6241c332ae2eb5e07833 ]

This is needed so that the kernel can handle R_SPARC_UA64 relocations,
which is emitted by LLVM's IAS.

Signed-off-by: Koakuma 
Reviewed-by: Andreas Larsson 
Signed-off-by: Andreas Larsson 
Signed-off-by: Sasha Levin

sparc64: Fix incorrect function signature and add prototype for prom_cif_init

2024-08-19T03:33:32+00:00

[ Upstream commit a6c3ea1ec96307dbfbb2f16d96c674c5cc80f445 ]

Remove the unused cif_stack argument and add a protype in oplib_64.h
Commit ef3e035c3a9b ("sparc64: Fix register corruption in top-most
kernel stack frame during boot.") removed the cif_stack argument to
prom_cif init in the declaration at the caller site and the usage of it
within prom_cif_init, but not in the function signature of the function
itself.

This also fixes the following warning:
arch/sparc/prom/p1275.c:52:6: warning: no previous prototype for ‘prom_cif_init’

Fixes: ef3e035c3a9b ("sparc64: Fix register corruption in top-most kernel stack frame during boot.")
Link: https://lore.kernel.org/r/20240710094155.458731-3-andreas@gaisler.com
Signed-off-by: Andreas Larsson 
Signed-off-by: Sasha Levin

sparc64: Fix number of online CPUs

2024-06-16T11:28:51+00:00

commit 98937707fea8375e8acea0aaa0b68a956dd52719 upstream.

Nick Bowler reported:
    When using newer kernels on my Ultra 60 with dual 450MHz UltraSPARC-II
    CPUs, I noticed that only CPU 0 comes up, while older kernels (including
    4.7) are working fine with both CPUs.

      I bisected the failure to this commit:

      9b2f753ec23710aa32c0d837d2499db92fe9115b is the first bad commit
      commit 9b2f753ec23710aa32c0d837d2499db92fe9115b
      Author: Atish Patra 
      Date:   Thu Sep 15 14:54:40 2016 -0600

      sparc64: Fix cpu_possible_mask if nr_cpus is set

    This is a small change that reverts very easily on top of 5.18: there is
    just one trivial conflict.  Once reverted, both CPUs work again.

    Maybe this is related to the fact that the CPUs on this system are
    numbered CPU0 and CPU2 (there is no CPU1)?

The current code that adjust cpu_possible based on nr_cpu_ids do not
take into account that CPU's may not come one after each other.
Move the chech to the function that setup the cpu_possible mask
so there is no need to adjust it later.

Signed-off-by: Sam Ravnborg 
Fixes: 9b2f753ec237 ("sparc64: Fix cpu_possible_mask if nr_cpus is set")
Reported-by: Nick Bowler 
Tested-by: Nick Bowler 
Link: https://lore.kernel.org/sparclinux/20201009161924.c8f031c079dd852941307870@gmx.de/
Link: https://lore.kernel.org/all/CADyTPEwt=ZNams+1bpMB1F9w_vUdPsGCt92DBQxxq_VtaLoTdw@mail.gmail.com/
Cc: stable@vger.kernel.org # v4.8+
Cc: Andreas Larsson 
Cc: David S. Miller 
Cc: Atish Patra 
Cc: Bob Picco 
Cc: Vijay Kumar 
Cc: David S. Miller 
Reviewed-by: Andreas Larsson 
Acked-by: Arnd Bergmann 
Link: https://lore.kernel.org/r/20240330-sparc64-warnings-v1-9-37201023ee2f@ravnborg.org
Signed-off-by: Andreas Larsson 
Signed-off-by: Greg Kroah-Hartman

sparc/cpu: Switch to arch_cpu_finalize_init()

2023-08-08T17:56:34+00:00

commit 44ade508e3bfac45ae97864587de29eb1a881ec0 upstream

check_bugs() is about to be phased out. Switch over to the new
arch_cpu_finalize_init() implementation.

No functional change.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Sam Ravnborg 
Link: https://lore.kernel.org/r/20230613224545.431995857@linutronix.de
Signed-off-by: Daniel Sneddon 
Signed-off-by: Greg Kroah-Hartman

sparc: use fallback for random_get_entropy() instead of zero

2022-06-22T12:11:15+00:00

commit ac9756c79797bb98972736b13cfb239fd2cffb79 upstream.

In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.

This is accomplished by just including the asm-generic code like on
other architectures, which means we can get rid of the empty stub
function here.

Cc: Thomas Gleixner 
Cc: Arnd Bergmann 
Cc: David S. Miller 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

sparc64: Use arch_validate_flags() to validate ADI flag

2021-03-17T16:03:43+00:00

[ Upstream commit 147d8622f2a26ef34beacc60e1ed8b66c2fa457f ]

When userspace calls mprotect() to enable ADI on an address range,
do_mprotect_pkey() calls arch_validate_prot() to validate new
protection flags. arch_validate_prot() for sparc looks at the first
VMA associated with address range to verify if ADI can indeed be
enabled on this address range. This has two issues - (1) Address
range might cover multiple VMAs while arch_validate_prot() looks at
only the first VMA, (2) arch_validate_prot() peeks at VMA without
holding mmap lock which can result in race condition.

arch_validate_flags() from commit c462ac288f2c ("mm: Introduce
arch_validate_flags()") allows for VMA flags to be validated for all
VMAs that cover the address range given by user while holding mmap
lock. This patch updates sparc code to move the VMA check from
arch_validate_prot() to arch_validate_flags() to fix above two
issues.

Suggested-by: Jann Horn 
Suggested-by: Christoph Hellwig 
Suggested-by: Catalin Marinas 
Signed-off-by: Khalid Aziz 
Reviewed-by: Catalin Marinas 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

mm/mmu_gather: invalidate TLB correctly on batch allocation failure and flush

2020-02-11T12:35:42+00:00

commit 0ed1325967ab5f7a4549a2641c6ebe115f76e228 upstream.

Architectures for which we have hardware walkers of Linux page table
should flush TLB on mmu gather batch allocation failures and batch flush.
Some architectures like POWER supports multiple translation modes (hash
and radix) and in the case of POWER only radix translation mode needs the
above TLBI.  This is because for hash translation mode kernel wants to
avoid this extra flush since there are no hardware walkers of linux page
table.  With radix translation, the hardware also walks linux page table
and with that, kernel needs to make sure to TLB invalidate page walk cache
before page table pages are freed.

More details in commit d86564a2f085 ("mm/tlb, x86/mm: Support invalidating
TLB caches for RCU_TABLE_FREE")

The changes to sparc are to make sure we keep the old behavior since we
are now removing HAVE_RCU_TABLE_NO_INVALIDATE.  The default value for
tlb_needs_table_invalidate is to always force an invalidate and sparc can
avoid the table invalidate.  Hence we define tlb_needs_table_invalidate to
false for sparc architecture.

Link: http://lkml.kernel.org/r/20200116064531.483522-3-aneesh.kumar@linux.ibm.com
Fixes: a46cc7a90fd8 ("powerpc/mm/radix: Improve TLB/PWC flushes")
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Michael Ellerman 	[powerpc]
Cc: 	[4.14+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

sparc64: implement ioremap_uc

2019-12-13T07:42:17+00:00

commit 38e45d81d14e5f78cd67922596b1c37b4c22ec74 upstream.

On sparc64, the whole physical IO address space is accessible using
physically addressed loads and stores. *_uc does nothing like the
others.

Cc:  # v4.19+
Reported-by: kbuild test robot 
Signed-off-by: Tuowen Zhao 
Acked-by: David S. Miller 
Signed-off-by: Lee Jones 
Signed-off-by: Greg Kroah-Hartman

arch/sparc/include/asm/pgtable_64.h: fix build

2019-09-26T17:27:06+00:00

A last-minute fixlet which I'd failed to merge at the appropriate time
had the predictable effect.

Fixes: f672e2c217e2d4b2 ("lib: untag user pointers in strn*_user")
Cc: Andrey Konovalov 
Cc: David Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib: untag user pointers in strn*_user

2019-09-26T00:51:41+00:00

Patch series "arm64: untag user pointers passed to the kernel", v19.

=== Overview

arm64 has a feature called Top Byte Ignore, which allows to embed pointer
tags into the top byte of each pointer.  Userspace programs (such as
HWASan, a memory debugging tool [1]) might use this feature and pass
tagged user pointers to the kernel through syscalls or other interfaces.

Right now the kernel is already able to handle user faults with tagged
pointers, due to these patches:

1. 81cddd65 ("arm64: traps: fix userspace cache maintenance emulation on a
             tagged pointer")
2. 7dcd9dd8 ("arm64: hw_breakpoint: fix watchpoint matching for tagged
	      pointers")
3. 276e9327 ("arm64: entry: improve data abort handling of tagged
	      pointers")

This patchset extends tagged pointer support to syscall arguments.

As per the proposed ABI change [3], tagged pointers are only allowed to be
passed to syscalls when they point to memory ranges obtained by anonymous
mmap() or sbrk() (see the patchset [3] for more details).

For non-memory syscalls this is done by untaging user pointers when the
kernel performs pointer checking to find out whether the pointer comes
from userspace (most notably in access_ok).  The untagging is done only
when the pointer is being checked, the tag is preserved as the pointer
makes its way through the kernel and stays tagged when the kernel
dereferences the pointer when perfoming user memory accesses.

The mmap and mremap (only new_addr) syscalls do not currently accept
tagged addresses.  Architectures may interpret the tag as a background
colour for the corresponding vma.

Other memory syscalls (mprotect, etc.) don't do user memory accesses but
rather deal with memory ranges, and untagged pointers are better suited to
describe memory ranges internally.  Thus for memory syscalls we untag
pointers completely when they enter the kernel.

=== Other approaches

One of the alternative approaches to untagging that was considered is to
completely strip the pointer tag as the pointer enters the kernel with
some kind of a syscall wrapper, but that won't work with the countless
number of different ioctl calls.  With this approach we would need a
custom wrapper for each ioctl variation, which doesn't seem practical.

An alternative approach to untagging pointers in memory syscalls prologues
is to inspead allow tagged pointers to be passed to find_vma() (and other
vma related functions) and untag them there.  Unfortunately, a lot of
find_vma() callers then compare or subtract the returned vma start and end
fields against the pointer that was being searched.  Thus this approach
would still require changing all find_vma() callers.

=== Testing

The following testing approaches has been taken to find potential issues
with user pointer untagging:

1. Static testing (with sparse [2] and separately with a custom static
   analyzer based on Clang) to track casts of __user pointers to integer
   types to find places where untagging needs to be done.

2. Static testing with grep to find parts of the kernel that call
   find_vma() (and other similar functions) or directly compare against
   vm_start/vm_end fields of vma.

3. Static testing with grep to find parts of the kernel that compare
   user pointers with TASK_SIZE or other similar consts and macros.

4. Dynamic testing: adding BUG_ON(has_tag(addr)) to find_vma() and running
   a modified syzkaller version that passes tagged pointers to the kernel.

Based on the results of the testing the requried patches have been added
to the patchset.

=== Notes

This patchset is meant to be merged together with "arm64 relaxed ABI" [3].

This patchset is a prerequisite for ARM's memory tagging hardware feature
support [4].

This patchset has been merged into the Pixel 2 & 3 kernel trees and is
now being used to enable testing of Pixel phones with HWASan.

Thanks!

[1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html

[2] https://github.com/lucvoo/sparse-dev/commit/5f960cb10f56ec2017c128ef9d16060e0145f292

[3] https://lkml.org/lkml/2019/6/12/745

[4] https://community.arm.com/processors/b/blog/posts/arm-a-profile-architecture-2018-developments-armv85a

This patch (of 11)

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

strncpy_from_user and strnlen_user accept user addresses as arguments, and
do not go through the same path as copy_from_user and others, so here we
need to handle the case of tagged user addresses separately.

Untag user pointers passed to these functions.

Note, that this patch only temporarily untags the pointers to perform
validity checks, but then uses them as is to perform user memory accesses.

[andreyknvl@google.com: fix sparc4 build]
 Link: http://lkml.kernel.org/r/CAAeHK+yx4a-P0sDrXTUxMvO2H0CJZUFPffBrg_cU7oJOZyC7ew@mail.gmail.com
Link: http://lkml.kernel.org/r/c5a78bcad3e94d6cda71fcaa60a423231ae71e4c.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov 
Reviewed-by: Vincenzo Frascino 
Reviewed-by: Khalid Aziz 
Acked-by: Kees Cook 
Reviewed-by: Catalin Marinas 
Cc: Al Viro 
Cc: Dave Hansen 
Cc: Eric Auger 
Cc: Felix Kuehling 
Cc: Jens Wiklander 
Cc: Mauro Carvalho Chehab 
Cc: Mike Rapoport 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds