On the 32-bit parisc architecture, we always used the
-ffunction-sections compiler option to tell the compiler to put the
functions into seperate text sections. This is necessary, otherwise
"big" kernel modules like ext4 or ipv6 fail to load because some
branches won't be able to reach their stubs.
Commit 1ba9f89794 ("vmlinux.lds: Unify TEXT_MAIN, DATA_MAIN, and related
macros") broke this for parisc because all text sections will get
unconditionally merged now.
Introduce the ARCH_WANTS_MODULES_TEXT_SECTIONS config option which
avoids the text section merge for modules, and fix this issue by
enabling this option by default for 32-bit parisc.
Fixes: 1ba9f89794 ("vmlinux.lds: Unify TEXT_MAIN, DATA_MAIN, and related macros")
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: stable@vger.kernel.org # v6.19+
Suggested-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Helge Deller <deller@gmx.de>
The assembly code of ip_fast_csum() triggers unaligned access warnings
if the IP header isn't correctly aligned:
Kernel: unaligned access to 0x173d22e76 in inet_gro_receive+0xbc/0x2e8 (iir 0x0e8810b6)
Kernel: unaligned access to 0x173d22e7e in inet_gro_receive+0xc4/0x2e8 (iir 0x0e88109a)
Kernel: unaligned access to 0x173d22e82 in inet_gro_receive+0xc8/0x2e8 (iir 0x0e90109d)
Kernel: unaligned access to 0x173d22e7a in inet_gro_receive+0xd0/0x2e8 (iir 0x0e9810b8)
Kernel: unaligned access to 0x173d22e86 in inet_gro_receive+0xdc/0x2e8 (iir 0x0e8810b8)
We have the option to a) ignore the warnings, b) work around it by
adding more code to check for alignment, or c) to switch to the generic
implementation and rely on the compiler to optimize the code.
Let's go with c), because a) isn't nice, and b) would effectively lead
to an implementation which is basically equal to c).
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v7.0+
Pull parisc updates from Helge Deller:
"Minor enhancements and fixes, specifically:
- report emulation and alignment faults via perf
- add initial kernel-side support for perf_events
- small initialization fixes in the parisc firmware layer
- adjust TC* constants and avoid referencing termio structs to avoid
userspace build errors"
* tag 'parisc-for-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Fix iodc and device path return values on old machines
parisc: Firmware: Fix returned path for PDC_MODULE_FIND on older machines
parisc: Add initial kernel-side perf_event support
parisc: Report software alignment faults via perf
parisc: Report emulation faults via perf
parisc: don't reference obsolete termio struct for TC* constants
parisc: Remove spurious if statement from raw_copy_from_user()
Ftrace is tightly coupled with architecture specific code because it
requires the use of trampolines written in assembly. This means that when
a new feature or optimization is made, it must be done for all
architectures. To simplify the approach, CONFIG_HAVE_FTRACE_* configs are
added to denote which architecture has the new enhancement so that other
architectures can still function until they too have been updated.
The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the
DYNAMIC_FTRACE work, but now every architecture that implements
DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it redundant
with the HAVE_DYNAMIC_FTRACE.
Remove the HAVE_FTRACE_MCOUNT config and use DYNAMIC_FTRACE directly where
applicable.
Link: https://lore.kernel.org/all/20250703154916.48e3ada7@gandalf.local.home/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20250704104838.27a18690@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pull dma-mapping updates from Christoph Hellwig:
- support DMA zones for arm64 systems where memory starts at > 4GB
(Baruch Siach, Catalin Marinas)
- support direct calls into dma-iommu and thus obsolete dma_map_ops for
many common configurations (Leon Romanovsky)
- add DMA-API tracing (Sean Anderson)
- remove the not very useful return value from various dma_set_* APIs
(Christoph Hellwig)
- misc cleanups and minor optimizations (Chen Y, Yosry Ahmed, Christoph
Hellwig)
* tag 'dma-mapping-6.12-2024-09-19' of git://git.infradead.org/users/hch/dma-mapping:
dma-mapping: reflow dma_supported
dma-mapping: reliably inform about DMA support for IOMMU
dma-mapping: add tracing for dma-mapping API calls
dma-mapping: use IOMMU DMA calls for common alloc/free page calls
dma-direct: optimize page freeing when it is not addressable
dma-mapping: clearly mark DMA ops as an architecture feature
vdpa_sim: don't select DMA_OPS
arm64: mm: keep low RAM dma zone
dma-mapping: don't return errors from dma_set_max_seg_size
dma-mapping: don't return errors from dma_set_seg_boundary
dma-mapping: don't return errors from dma_set_min_align_mask
scsi: check that busses support the DMA API before setting dma parameters
arm64: mm: fix DMA zone when dma-ranges is missing
dma-mapping: direct calls for dma-iommu
dma-mapping: call ->unmap_page and ->unmap_sg unconditionally
arm64: support DMA zone above 4GB
dma-mapping: replace zone_dma_bits by zone_dma_limit
dma-mapping: use bit masking to check VM_DMA_COHERENT
DMA ops are a helper for architectures and not for drivers to override
the DMA implementation.
Unfortunately driver authors keep ignoring this. Make the fact more
clear by renaming the symbol to ARCH_HAS_DMA_OPS and having the two drivers
overriding their dma_ops depend on that. These drivers should probably be
marked broken, but we can give them a bit of a grace period for that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> # for IPU6
Acked-by: Robin Murphy <robin.murphy@arm.com>
ARCH_DMA_MINALIGN was defined as 16 - this is too small - it may be
possible that two unrelated 16-byte allocations share a cache line. If
one of these allocations is written using DMA and the other is written
using cached write, the value that was written with DMA may be
corrupted.
This commit changes ARCH_DMA_MINALIGN to be 128 on PA20 and 32 on PA1.1 -
that's the largest possible cache line size.
As different parisc microarchitectures have different cache line size, we
define arch_slab_minalign(), cache_line_size() and
dma_get_cache_alignment() so that the kernel may tune slab cache
parameters dynamically, based on the detected cache line size.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Pull parisc updates from Helge Deller:
"The gettimeofday() and clock_gettime() syscalls are now available as
vDSO functions, and Dave added a patch which allows to use NVMe cards
in the PCI slots as fast and easy alternative to SCSI discs.
Summary:
- add gettimeofday() and clock_gettime() vDSO functions
- enable PCI_MSI_ARCH_FALLBACKS to allow PCI to PCIe bridge adaptor
with PCIe NVME card to function in parisc machines
- allow users to reduce kernel unaligned runtime warnings
- minor code cleanups"
* tag 'parisc-for-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Add support for CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
parisc: Use max() to calculate parisc_tlb_flush_threshold
parisc: Fix warning at drivers/pci/msi/msi.h:121
parisc: Add 64-bit gettimeofday() and clock_gettime() vDSO functions
parisc: Add 32-bit gettimeofday() and clock_gettime() vDSO functions
parisc: Clean up unistd.h file
Allow users to disable kernel warnings for unaligned memory
accesses from kernel via the /proc/sys/kernel/ignore-unaligned-usertrap
procfs entry.
That way users can disable those warnings in case they happen too
often.
Signed-off-by: Helge Deller <deller@gmx.de>
Fix warning at drivers/pci/msi/msi.h:121.
Recently, I added a PCI to PCIe bridge adaptor and a PCIe NVME card
to my rp3440. Then, I noticed this warning at boot:
WARNING: CPU: 0 PID: 10 at drivers/pci/msi/msi.h:121 pci_msi_setup_msi_irqs+0x68/0x90
CPU: 0 PID: 10 Comm: kworker/u32:0 Not tainted 6.9.7-parisc64 #1 Debian 6.9.7-1
Hardware name: 9000/800/rp3440
Workqueue: async async_run_entry_fn
We need to select PCI_MSI_ARCH_FALLBACKS when PCI_MSI is selected.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v6.0+
Signed-off-by: Helge Deller <deller@gmx.de>
The sys_fanotify_mark() syscall on parisc uses the reverse word order
for the two halves of the 64-bit argument compared to all syscalls on
all 32-bit architectures. As far as I can tell, the problem is that
the function arguments on parisc are sorted backwards (26, 25, 24, 23,
...) compared to everyone else, so the calling conventions of using an
even/odd register pair in native word order result in the lower word
coming first in function arguments, matching the expected behavior
on little-endian architectures. The system call conventions however
ended up matching what the other 32-bit architectures do.
A glibc cleanup in 2020 changed the userspace behavior in a way that
handles all architectures consistently, but this inadvertently broke
parisc32 by changing to the same method as everyone else.
The change made it into glibc-2.35 and subsequently into debian 12
(bookworm), which is the latest stable release. This means we
need to choose between reverting the glibc change or changing the
kernel to match it again, but either hange will leave some systems
broken.
Pick the option that is more likely to help current and future
users and change the kernel to match current glibc. This also
means the behavior is now consistent across architectures, but
it breaks running new kernels with old glibc builds before 2.35.
Link: https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=d150181d73d9
Link: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/arch/parisc/kernel/sys_parisc.c?h=57b1dfbd5b4a39d
Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Tested-by: Helge Deller <deller@gmx.de>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
I found this through code inspection, please double-check to make
sure I got the bug and the fix right.
The alternative is to fix this by reverting glibc back to the
unusual behavior.
Pull Kbuild updates from Masahiro Yamada:
- Generate a list of built DTB files (arch/*/boot/dts/dtbs-list)
- Use more threads when building Debian packages in parallel
- Fix warnings shown during the RPM kernel package uninstallation
- Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to
Makefile
- Support GCC's -fmin-function-alignment flag
- Fix a null pointer dereference bug in modpost
- Add the DTB support to the RPM package
- Various fixes and cleanups in Kconfig
* tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (67 commits)
kconfig: tests: test dependency after shuffling choices
kconfig: tests: add a test for randconfig with dependent choices
kconfig: tests: support KCONFIG_SEED for the randconfig runner
kbuild: rpm-pkg: add dtb files in kernel rpm
kconfig: remove unneeded menu_is_visible() call in conf_write_defconfig()
kconfig: check prompt for choice while parsing
kconfig: lxdialog: remove unused dialog colors
kconfig: lxdialog: fix button color for blackbg theme
modpost: fix null pointer dereference
kbuild: remove GCC's default -Wpacked-bitfield-compat flag
kbuild: unexport abs_srctree and abs_objtree
kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1
kconfig: remove named choice support
kconfig: use linked list in get_symbol_str() to iterate over menus
kconfig: link menus to a symbol
kbuild: fix inconsistent indentation in top Makefile
kbuild: Use -fmin-function-alignment when available
alpha: merge two entries for CONFIG_ALPHA_GAMMA
alpha: merge two entries for CONFIG_ALPHA_EV4
kbuild: change DTC_FLAGS_<basetarget>.o to take the path relative to $(obj)
...
Pull MM updates from Andrew Morton:
- Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory. Series
"implement "memmap on memory" feature on s390".
- More folio conversions from Matthew Wilcox in the series
"Convert memcontrol charge moving to use folios"
"mm: convert mm counter to take a folio"
- Chengming Zhou has optimized zswap's rbtree locking, providing
significant reductions in system time and modest but measurable
reductions in overall runtimes. The series is "mm/zswap: optimize the
scalability of zswap rb-tree".
- Chengming Zhou has also provided the series "mm/zswap: optimize zswap
lru list" which provides measurable runtime benefits in some
swap-intensive situations.
- And Chengming Zhou further optimizes zswap in the series "mm/zswap:
optimize for dynamic zswap_pools". Measured improvements are modest.
- zswap cleanups and simplifications from Yosry Ahmed in the series
"mm: zswap: simplify zswap_swapoff()".
- In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
contributed several DAX cleanups as well as adding a sysfs tunable to
control the memmap_on_memory setting when the dax device is
hotplugged as system memory.
- Johannes Weiner has added the large series "mm: zswap: cleanups",
which does that.
- More DAMON work from SeongJae Park in the series
"mm/damon: make DAMON debugfs interface deprecation unignorable"
"selftests/damon: add more tests for core functionalities and corner cases"
"Docs/mm/damon: misc readability improvements"
"mm/damon: let DAMOS feeds and tame/auto-tune itself"
- In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
extension" Rakie Kim has developed a new mempolicy interleaving
policy wherein we allocate memory across nodes in a weighted fashion
rather than uniformly. This is beneficial in heterogeneous memory
environments appearing with CXL.
- Christophe Leroy has contributed some cleanup and consolidation work
against the ARM pagetable dumping code in the series "mm: ptdump:
Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
- Luis Chamberlain has added some additional xarray selftesting in the
series "test_xarray: advanced API multi-index tests".
- Muhammad Usama Anjum has reworked the selftest code to make its
human-readable output conform to the TAP ("Test Anything Protocol")
format. Amongst other things, this opens up the use of third-party
tools to parse and process out selftesting results.
- Ryan Roberts has added fork()-time PTE batching of THP ptes in the
series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
targeted at arm64, this significantly speeds up fork() when the
process has a large number of pte-mapped folios.
- David Hildenbrand also gets in on the THP pte batching game in his
series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
implements batching during munmap() and other pte teardown
situations. The microbenchmark improvements are nice.
- And in the series "Transparent Contiguous PTEs for User Mappings"
Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
mappings"). Kernel build times on arm64 improved nicely. Ryan's
series "Address some contpte nits" provides some followup work.
- In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
fixed an obscure hugetlb race which was causing unnecessary page
faults. He has also added a reproducer under the selftest code.
- In the series "selftests/mm: Output cleanups for the compaction
test", Mark Brown did what the title claims.
- Kinsey Ho has added the series "mm/mglru: code cleanup and
refactoring".
- Even more zswap material from Nhat Pham. The series "fix and extend
zswap kselftests" does as claimed.
- In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
in our handling of DAX on archiecctures which have virtually aliasing
data caches. The arm architecture is the main beneficiary.
- Lokesh Gidra's series "per-vma locks in userfaultfd" provides
dramatic improvements in worst-case mmap_lock hold times during
certain userfaultfd operations.
- Some page_owner enhancements and maintenance work from Oscar Salvador
in his series
"page_owner: print stacks and their outstanding allocations"
"page_owner: Fixup and cleanup"
- Uladzislau Rezki has contributed some vmalloc scalability
improvements in his series "Mitigate a vmap lock contention". It
realizes a 12x improvement for a certain microbenchmark.
- Some kexec/crash cleanup work from Baoquan He in the series "Split
crash out from kexec and clean up related config items".
- Some zsmalloc maintenance work from Chengming Zhou in the series
"mm/zsmalloc: fix and optimize objects/page migration"
"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
- Zi Yan has taught the MM to perform compaction on folios larger than
order=0. This a step along the path to implementaton of the merging
of large anonymous folios. The series is named "Enable >0 order folio
memory compaction".
- Christoph Hellwig has done quite a lot of cleanup work in the
pagecache writeback code in his series "convert write_cache_pages()
to an iterator".
- Some modest hugetlb cleanups and speedups in Vishal Moola's series
"Handle hugetlb faults under the VMA lock".
- Zi Yan has changed the page splitting code so we can split huge pages
into sizes other than order-0 to better utilize large folios. The
series is named "Split a folio to any lower order folios".
- David Hildenbrand has contributed the series "mm: remove
total_mapcount()", a cleanup.
- Matthew Wilcox has sought to improve the performance of bulk memory
freeing in his series "Rearrange batched folio freeing".
- Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
provides large improvements in bootup times on large machines which
are configured to use large numbers of hugetlb pages.
- Matthew Wilcox's series "PageFlags cleanups" does that.
- Qi Zheng's series "minor fixes and supplement for ptdesc" does that
also. S390 is affected.
- Cleanups to our pagemap utility functions from Peter Xu in his series
"mm/treewide: Replace pXd_large() with pXd_leaf()".
- Nico Pache has fixed a few things with our hugepage selftests in his
series "selftests/mm: Improve Hugepage Test Handling in MM
Selftests".
- Also, of course, many singleton patches to many things. Please see
the individual changelogs for details.
* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
mm/zswap: remove the memcpy if acomp is not sleepable
crypto: introduce: acomp_is_async to expose if comp drivers might sleep
memtest: use {READ,WRITE}_ONCE in memory scanning
mm: prohibit the last subpage from reusing the entire large folio
mm: recover pud_leaf() definitions in nopmd case
selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
selftests/mm: skip uffd hugetlb tests with insufficient hugepages
selftests/mm: dont fail testsuite due to a lack of hugepages
mm/huge_memory: skip invalid debugfs new_order input for folio split
mm/huge_memory: check new folio order when split a folio
mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
mm: fix list corruption in put_pages_list
mm: remove folio from deferred split list before uncharging it
filemap: avoid unnecessary major faults in filemap_fault()
mm,page_owner: drop unnecessary check
mm,page_owner: check for null stack_record before bumping its refcount
mm: swap: fix race between free_swap_and_cache() and swapoff()
mm/treewide: align up pXd_leaf() retval across archs
mm/treewide: drop pXd_large()
...
Pull hardening updates from Kees Cook:
"As is pretty normal for this tree, there are changes all over the
place, especially for small fixes, selftest improvements, and improved
macro usability.
Some header changes ended up landing via this tree as they depended on
the string header cleanups. Also, a notable set of changes is the work
for the reintroduction of the UBSAN signed integer overflow sanitizer
so that we can continue to make improvements on the compiler side to
make this sanitizer a more viable future security hardening option.
Summary:
- string.h and related header cleanups (Tanzir Hasan, Andy
Shevchenko)
- VMCI memcpy() usage and struct_size() cleanups (Vasiliy Kovalev,
Harshit Mogalapalli)
- selftests/powerpc: Fix load_unaligned_zeropad build failure
(Michael Ellerman)
- hardened Kconfig fragment updates (Marco Elver, Lukas Bulwahn)
- Handle tail call optimization better in LKDTM (Douglas Anderson)
- Use long form types in overflow.h (Andy Shevchenko)
- Add flags param to string_get_size() (Andy Shevchenko)
- Add Coccinelle script for potential struct_size() use (Jacob
Keller)
- Fix objtool corner case under KCFI (Josh Poimboeuf)
- Drop 13 year old backward compat CAP_SYS_ADMIN check (Jingzi Meng)
- Add str_plural() helper (Michal Wajdeczko, Kees Cook)
- Ignore relocations in .notes section
- Add comments to explain how __is_constexpr() works
- Fix m68k stack alignment expectations in stackinit Kunit test
- Convert string selftests to KUnit
- Add KUnit tests for fortified string functions
- Improve reporting during fortified string warnings
- Allow non-type arg to type_max() and type_min()
- Allow strscpy() to be called with only 2 arguments
- Add binary mode to leaking_addresses scanner
- Various small cleanups to leaking_addresses scanner
- Adding wrapping_*() arithmetic helper
- Annotate initial signed integer wrap-around in refcount_t
- Add explicit UBSAN section to MAINTAINERS
- Fix UBSAN self-test warnings
- Simplify UBSAN build via removal of CONFIG_UBSAN_SANITIZE_ALL
- Reintroduce UBSAN's signed overflow sanitizer"
* tag 'hardening-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (51 commits)
selftests/powerpc: Fix load_unaligned_zeropad build failure
string: Convert helpers selftest to KUnit
string: Convert selftest to KUnit
sh: Fix build with CONFIG_UBSAN=y
compiler.h: Explain how __is_constexpr() works
overflow: Allow non-type arg to type_max() and type_min()
VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler()
lib/string_helpers: Add flags param to string_get_size()
x86, relocs: Ignore relocations in .notes section
objtool: Fix UNWIND_HINT_{SAVE,RESTORE} across basic blocks
overflow: Use POD in check_shl_overflow()
lib: stackinit: Adjust target string to 8 bytes for m68k
sparc: vdso: Disable UBSAN instrumentation
kernel.h: Move lib/cmdline.c prototypes to string.h
leaking_addresses: Provide mechanism to scan binary files
leaking_addresses: Ignore input device status lines
leaking_addresses: Use File::Temp for /tmp files
MAINTAINERS: Update LEAKING_ADDRESSES details
fortify: Improve buffer overflow reporting
fortify: Add KUnit tests for runtime overflows
...
arc, arm64, parisc and powerpc all have their own Kconfig symbols
in place of the common CONFIG_PAGE_SIZE_4KB symbols. Change these
so the common symbols are the ones that are actually used, while
leaving the arhcitecture specific ones as the user visible
place for configuring it, to avoid breaking user configs.
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> (powerpc32)
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Introduce a generic way to query whether the data cache is virtually
aliased on all architectures. Its purpose is to ensure that subsystems
which are incompatible with virtually aliased data caches (e.g. FS_DAX)
can reliably query this.
For data cache aliasing, there are three scenarios dependending on the
architecture. Here is a breakdown based on my understanding:
A) The data cache is always aliasing:
* arc
* csky
* m68k (note: shared memory mappings are incoherent ? SHMLBA is missing there.)
* sh
* parisc
B) The data cache aliasing is statically known or depends on querying CPU
state at runtime:
* arm (cache_is_vivt() || cache_is_vipt_aliasing())
* mips (cpu_has_dc_aliases)
* nios2 (NIOS2_DCACHE_SIZE > PAGE_SIZE)
* sparc32 (vac_cache_size > PAGE_SIZE)
* sparc64 (L1DCACHE_SIZE > PAGE_SIZE)
* xtensa (DCACHE_WAY_SIZE > PAGE_SIZE)
C) The data cache is never aliasing:
* alpha
* arm64 (aarch64)
* hexagon
* loongarch (but with incoherent write buffers, which are disabled since
commit d23b7795 ("LoongArch: Change SHMLBA from SZ_64K to PAGE_SIZE"))
* microblaze
* openrisc
* powerpc
* riscv
* s390
* um
* x86
Require architectures in A) and B) to select ARCH_HAS_CPU_CACHE_ALIASING and
implement "cpu_dcache_is_aliasing()".
Architectures in C) don't select ARCH_HAS_CPU_CACHE_ALIASING, and thus
cpu_dcache_is_aliasing() simply evaluates to "false".
Note that this leaves "cpu_icache_is_aliasing()" to be implemented as future
work. This would be useful to gate features like XIP on architectures
which have aliasing CPU dcache-icache but not CPU dcache-dcache.
Use "cpu_dcache" and "cpu_cache" rather than just "dcache" and "cache"
to clarify that we really mean "CPU data cache" and "CPU cache" to
eliminate any possible confusion with VFS "dentry cache" and "page
cache".
Link: https://lore.kernel.org/lkml/20030910210416.GA24258@mail.jlokier.co.uk/
Link: https://lkml.kernel.org/r/20240215144633.96437-9-mathieu.desnoyers@efficios.com
Fixes: d92576f116 ("dax: does not work correctly with virtual aliasing caches")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Michael Sclafani <dm-devel@lists.linux.dev>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
'def_bool X' is a shorthand for 'bool' plus 'default X'.
'def_bool' is redundant where 'bool' is already present, so 'def_bool X'
can be replaced with 'default X', or removed if X is 'n'.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
For simplicity in splitting out UBSan options into separate rules,
remove CONFIG_UBSAN_SANITIZE_ALL, effectively defaulting to "y", which
is how it is generally used anyway. (There are no ":= y" cases beyond
where a specific file is enabled when a top-level ":= n" is in effect.)
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
The current exception handler implementation, which assists when accessing
user space memory, may exhibit random data corruption if the compiler decides
to use a different register than the specified register %r29 (defined in
ASM_EXCEPTIONTABLE_REG) for the error code. If the compiler choose another
register, the fault handler will nevertheless store -EFAULT into %r29 and thus
trash whatever this register is used for.
Looking at the assembly I found that this happens sometimes in emulate_ldd().
To solve the issue, the easiest solution would be if it somehow is
possible to tell the fault handler which register is used to hold the error
code. Using %0 or %1 in the inline assembly is not posssible as it will show
up as e.g. %r29 (with the "%r" prefix), which the GNU assembler can not
convert to an integer.
This patch takes another, better and more flexible approach:
We extend the __ex_table (which is out of the execution path) by one 32-word.
In this word we tell the compiler to insert the assembler instruction
"or %r0,%r0,%reg", where %reg references the register which the compiler
choosed for the error return code.
In case of an access failure, the fault handler finds the __ex_table entry and
can examine the opcode. The used register is encoded in the lowest 5 bits, and
the fault handler can then store -EFAULT into this register.
Since we extend the __ex_table to 3 words we can't use the BUILDTIME_TABLE_SORT
config option any longer.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v6.0+
Helge Deller
Qi ZhengandAndrew Morton
Linus Torvalds
Peter Zijlstra
Steven Rostedt
Helge DellerandHelge Deller
Christoph Hellwig
Mikulas PatockaandHelge Deller
John David AnglinandHelge Deller
Arnd Bergmann
Mathieu DesnoyersandAndrew Morton
Masahiro Yamada
Kees Cook