linux.git/tools/testing/selftests/resctrl, branch v6.12.80

selftests/resctrl: Protect against array overflow when reading strings

2024-12-14T19:03:41+00:00

[ Upstream commit 46058430fc5d39c114f7e1b9c6ff14c9f41bd531 ]

resctrl selftests discover system properties via a variety of sysfs files.
The MBM and MBA tests need to discover the event and umask with which to
configure the performance event used to measure read memory bandwidth.
This is done by parsing the contents of
/sys/bus/event_source/devices/uncore_imc_/events/cas_count_read
Similarly, the resctrl selftests discover the cache size via
/sys/bus/cpu/devices/cpu/cache/index/size.

Take care to do bounds checking when using fscanf() to read the
contents of files into a string buffer because by default fscanf() assumes
arbitrarily long strings. If the file contains more bytes than the array
can accommodate then an overflow will occur.

Provide a maximum field width to the conversion specifier to protect
against array overflow. The maximum is one less than the array size because
string input stores a terminating null byte that is not covered by the
maximum field width.

Signed-off-by: Reinette Chatre 
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin

selftests/resctrl: Protect against array overrun during iMC config parsing

2024-12-05T13:01:33+00:00

[ Upstream commit 48ed4e799e8fbebae838dca404a8527763d41191 ]

The MBM and MBA tests need to discover the event and umask with which to
configure the performance event used to measure read memory bandwidth.
This is done by parsing the
/sys/bus/event_source/devices/uncore_imc_/events/cas_count_read
file for each iMC instance that contains the formatted
output: "event=,umask="

Parsing of cas_count_read contents is done by initializing an array of
MAX_TOKENS elements with tokens (deliminated by "=,") from this file.
Remove the unnecessary append of a delimiter to the string needing to be
parsed. Per the strtok() man page: "delimiter bytes at the start or end of
the string are ignored". This has no impact on the token placement within
the array.

After initialization, the actual event and umask is determined by
parsing the tokens directly following the "event" and "umask" tokens
respectively.

Iterating through the array up to index "i < MAX_TOKENS" but then
accessing index "i + 1" risks array overrun during the final iteration.
Avoid array overrun by ensuring that the index used within for
loop will always be valid.

Fixes: 1d3f08687d76 ("selftests/resctrl: Read memory bandwidth from perf IMC counter and from resctrl file system")
Signed-off-by: Reinette Chatre 
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin

selftests/resctrl: Fix memory overflow due to unhandled wraparound

2024-12-05T13:01:33+00:00

[ Upstream commit caf02626b2bf164a02c808240f19dbf97aced664 ]

alloc_buffer() allocates and initializes (with random data) a
buffer of requested size. The initialization starts from the beginning
of the allocated buffer and incrementally assigns sizeof(uint64_t) random
data to each cache line. The initialization uses the size of the
buffer to control the initialization flow, decrementing the amount of
buffer needing to be initialized after each iteration.

The size of the buffer is stored in an unsigned (size_t) variable s64
and the test "s64 > 0" is used to decide if initialization is complete.
The problem is that decrementing the buffer size may wrap around
if the buffer size is not divisible by "CL_SIZE / sizeof(uint64_t)"
resulting in the "s64 > 0" test being true and memory beyond the buffer
"initialized".

Use a signed value for the buffer size to support all buffer sizes.

Fixes: a2561b12fe39 ("selftests/resctrl: Add built in benchmark")
Signed-off-by: Reinette Chatre 
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin

selftests/resctrl: Print accurate buffer size as part of MBM results

2024-12-05T13:01:33+00:00

[ Upstream commit 1b4840395f08e9723a15fea42c2d31090e8375f3 ]

By default the MBM test uses the "fill_buf" benchmark to keep reading
from a buffer with size DEFAULT_SPAN while measuring memory bandwidth.
User space can provide an alternate benchmark or amend the size of
the buffer "fill_buf" should use.

Analysis of the MBM measurements do not require that a buffer be used
and thus do not require knowing the size of the buffer if it was used
during testing. Even so, the buffer size is printed as informational
as part of the MBM test results. What is printed as buffer size is
hardcoded as DEFAULT_SPAN, even if the test relied on another benchmark
(that may or may not use a buffer) or if user space amended the buffer
size.

Ensure that accurate buffer size is printed when using "fill_buf"
benchmark and omit the buffer size information if another benchmark
is used.

Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Signed-off-by: Reinette Chatre 
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin

selftests:resctrl: Fix build failure on archs without __cpuid_count()

2024-09-06T16:46:03+00:00

When resctrl is built on architectures without __cpuid_count()
support, build fails. resctrl uses __cpuid_count() defined in
kselftest.h.

Even though the problem is seen while building resctrl on aarch64,
this error can be seen on any platform that doesn't support CPUID.

CPUID is a x86/x86-64 feature and code paths with CPUID asm commands
will fail to build on all other architectures.

All others tests call __cpuid_count() do so from x86/x86_64 code paths
when _i386__ or __x86_64__ are defined. resctrl is an exception.

Fix the problem by defining __cpuid_count() only when __i386__ or
__x86_64__ are defined in kselftest.h and changing resctrl to call
__cpuid_count() only when __i386__ or __x86_64__ are defined.

In file included from resctrl.h:24,
                 from cat_test.c:11:
In function ‘arch_supports_noncont_cat’,
    inlined from ‘noncont_cat_run_test’ at cat_test.c:326:6:
../kselftest.h:74:9: error: impossible constraint in ‘asm’
   74 |         __asm__ __volatile__ ("cpuid\n\t"                               \
      |         ^~~~~~~
cat_test.c:304:17: note: in expansion of macro ‘__cpuid_count’
  304 |                 __cpuid_count(0x10, 1, eax, ebx, ecx, edx);
      |                 ^~~~~~~~~~~~~
../kselftest.h:74:9: error: impossible constraint in ‘asm’
   74 |         __asm__ __volatile__ ("cpuid\n\t"                               \
      |         ^~~~~~~
cat_test.c:306:17: note: in expansion of macro ‘__cpuid_count’
  306 |                 __cpuid_count(0x10, 2, eax, ebx, ecx, edx);

Fixes: ae638551ab64 ("selftests/resctrl: Add non-contiguous CBMs CAT test")
Reported-by: Muhammad Usama Anjum 
Closes: https://lore.kernel.org/lkml/20240809071059.265914-1-usama.anjum@collabora.com/
Reported-by: Ilpo Järvinen 
Signed-off-by: Shuah Khan 
Acked-by: Reinette Chatre 
Reviewed-by: Muhammad Usama Anjum 
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Shuah Khan

Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-07-22T00:15:46+00:00

Pull MM updates from Andrew Morton:

- In the series "mm: Avoid possible overflows in dirty throttling" Jan
Kara addresses a couple of issues in the writeback throttling code.
These fixes are also targetted at -stable kernels.

- Ryusuke Konishi's series "nilfs2: fix potential issues related to
reserved inodes" does that. This should actually be in the
mm-nonmm-stable tree, along with the many other nilfs2 patches. My
bad.

- More folio conversions from Kefeng Wang in the series "mm: convert to
folio_alloc_mpol()"

- Kemeng Shi has sent some cleanups to the writeback code in the series
"Add helper functions to remove repeated code and improve readability
of cgroup writeback"

- Kairui Song has made the swap code a little smaller and a little
faster in the series "mm/swap: clean up and optimize swap cache
index".

- In the series "mm/memory: cleanly support zeropage in
vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
Hildenbrand has reworked the rather sketchy handling of the use of
the zeropage in MAP_SHARED mappings. I don't see any runtime effects
here - more a cleanup/understandability/maintainablity thing.

- Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
of higher addresses, for aarch64. The (poorly named) series is
"Restructure va_high_addr_switch".

- The core TLB handling code gets some cleanups and possible slight
optimizations in Bang Li's series "Add update_mmu_tlb_range() to
simplify code".

- Jane Chu has improved the handling of our
fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
the series "Enhance soft hwpoison handling and injection".

- Jeff Johnson has sent a billion patches everywhere to add
MODULE_DESCRIPTION() to everything. Some landed in this pull.

- In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
has simplified migration's use of hardware-offload memory copying.

- Yosry Ahmed performs more folio API conversions in his series "mm:
zswap: trivial folio conversions".

- In the series "large folios swap-in: handle refault cases first",
Chuanhua Han inches us forward in the handling of large pages in the
swap code. This is a cleanup and optimization, working toward the end
objective of full support of large folio swapin/out.

- In the series "mm,swap: cleanup VMA based swap readahead window
calculation", Huang Ying has contributed some cleanups and a possible
fixlet to his VMA based swap readahead code.

- In the series "add mTHP support for anonymous shmem" Baolin Wang has
taught anonymous shmem mappings to use multisize THP. By default this
is a no-op - users must opt in vis sysfs controls. Dramatic
improvements in pagefault latency are realized.

- David Hildenbrand has some cleanups to our remaining use of
page_mapcount() in the series "fs/proc: move page_mapcount() to
fs/proc/internal.h".

- David also has some highmem accounting cleanups in the series
"mm/highmem: don't track highmem pages manually".

- Build-time fixes and cleanups from John Hubbard in the series
"cleanups, fixes, and progress towards avoiding "make headers"".

- Cleanups and consolidation of the core pagemap handling from Barry
Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
and utilize them".

- Lance Yang's series "Reclaim lazyfree THP without splitting" has
reduced the latency of the reclaim of pmd-mapped THPs under fairly
common circumstances. A 10x speedup is seen in a microbenchmark.

It does this by punting to aother CPU but I guess that's a win unless
all CPUs are pegged.

- hugetlb_cgroup cleanups from Xiu Jianfeng in the series
"mm/hugetlb_cgroup: rework on cftypes".

- Miaohe Lin's series "Some cleanups for memory-failure" does just that
thing.

- Someone other than SeongJae has developed a DAMON feature in Honggyu
Kim's series "DAMON based tiered memory management for CXL memory".
This adds DAMON features which may be used to help determine the
efficiency of our placement of CXL/PCIe attached DRAM.

- DAMON user API centralization and simplificatio work in SeongJae
Park's series "mm/damon: introduce DAMON parameters online commit
function".

- In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
David Hildenbrand does some maintenance work on zsmalloc - partially
modernizing its use of pageframe fields.

- Kefeng Wang provides more folio conversions in the series "mm: remove
page_maybe_dma_pinned() and page_mkclean()".

- More cleanup from David Hildenbrand, this time in the series
"mm/memory_hotplug: use PageOffline() instead of PageReserved() for
!ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
pages" and permits the removal of some virtio-mem hacks.

- Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
__folio_add_anon_rmap()" is a cleanup to the anon folio handling in
preparation for mTHP (multisize THP) swapin.

- Kefeng Wang's series "mm: improve clear and copy user folio"
implements more folio conversions, this time in the area of large
folio userspace copying.

- The series "Docs/mm/damon/maintaier-profile: document a mailing tool
and community meetup series" tells people how to get better involved
with other DAMON developers. From SeongJae Park.

- A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
that.

- David Hildenbrand sends along more cleanups, this time against the
migration code. The series is "mm/migrate: move NUMA hinting fault
folio isolation + checks under PTL".

- Jan Kara has found quite a lot of strangenesses and minor errors in
the readahead code. He addresses this in the series "mm: Fix various
readahead quirks".

- SeongJae Park's series "selftests/damon: test DAMOS tried regions and
{min,max}_nr_regions" adds features and addresses errors in DAMON's
self testing code.

- Gavin Shan has found a userspace-triggerable WARN in the pagecache
code. The series "mm/filemap: Limit page cache size to that supported
by xarray" addresses this. The series is marked cc:stable.

- Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
and cleanup" cleans up and slightly optimizes KSM.

- Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
code motion. The series (which also makes the memcg-v1 code
Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
under config option" and "mm: memcg: put cgroup v1-specific memcg
data under CONFIG_MEMCG_V1"

- Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
adds an additional feature to this cgroup-v2 control file.

- The series "Userspace controls soft-offline pages" from Jiaqi Yan
permits userspace to stop the kernel's automatic treatment of
excessive correctable memory errors. In order to permit userspace to
monitor and handle this situation.

- Kefeng Wang's series "mm: migrate: support poison recover from
migrate folio" teaches the kernel to appropriately handle migration
from poisoned source folios rather than simply panicing.

- SeongJae Park's series "Docs/damon: minor fixups and improvements"
does those things.

- In the series "mm/zsmalloc: change back to per-size_class lock"
Chengming Zhou improves zsmalloc's scalability and memory
utilization.

- Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
pinning memfd folios" makes the GUP code use FOLL_PIN rather than
bare refcount increments. So these paes can first be moved aside if
they reside in the movable zone or a CMA block.

- Andrii Nakryiko has added a binary ioctl()-based API to
/proc/pid/maps for much faster reading of vma information. The series
is "query VMAs from /proc//maps".

- In the series "mm: introduce per-order mTHP split counters" Lance
Yang improves the kernel's presentation of developer information
related to multisize THP splitting.

- Michael Ellerman has developed the series "Reimplement huge pages
without hugepd on powerpc (8xx, e500, book3s/64)". This permits
userspace to use all available huge page sizes.

- In the series "revert unconditional slab and page allocator fault
injection calls" Vlastimil Babka removes a performance-affecting and
not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
mm/mglru: fix ineffective protection calculation
mm/zswap: fix a white space issue
mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
mm/hugetlb: fix possible recursive locking detected warning
mm/gup: clear the LRU flag of a page before adding to LRU batch
mm/numa_balancing: teach mpol_to_str about the balancing mode
mm: memcg1: convert charge move flags to unsigned long long
alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
lib: reuse page_ext_data() to obtain codetag_ref
lib: add missing newline character in the warning message
mm/mglru: fix overshooting shrinker memory
mm/mglru: fix div-by-zero in vmpressure_calc_level()
mm/kmemleak: replace strncpy() with strscpy()
mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
mm: ignore data-race in __swap_writepage
hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
mm: shmem: rename mTHP shmem counters
mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
mm/migrate: putback split folios when numa hint migration fails
...

selftests/resctrl: Remove test name comparing from write_bm_pid_to_resctrl()

2024-07-11T17:23:54+00:00

write_bm_pid_to_resctrl() uses resctrl_val to check test name which is
not a good interface generic resctrl FS functions should provide.

Tests define mongrp when needed. Remove the test name check in
write_bm_pid_to_resctrl() to only rely on the mongrp parameter being
non-NULL.

Remove write_bm_pid_to_resctrl() resctrl_val parameter and resctrl_val
member from the struct resctrl_val_param that are not used anymore.
Similarly, remove the test name constants that are no longer used.

Signed-off-by: Ilpo Järvinen 
Tested-by: Babu Moger 
Reviewed-by: Reinette Chatre 
Signed-off-by: Shuah Khan

selftests/resctrl: Remove mongrp from CMT test

2024-07-11T17:23:54+00:00

The CMT selftest instantiates a monitor group to read LLC occupancy.
Since the test also creates a control group, it is unnecessary to
create another one for monitoring because control groups already
provide monitoring too.

Remove the unnecessary monitor group from the CMT selftest.

Suggested-by: Reinette Chatre 
Signed-off-by: Ilpo Järvinen 
Tested-by: Babu Moger 
Reviewed-by: Reinette Chatre 
Signed-off-by: Shuah Khan

selftests/resctrl: Remove mongrp from MBA test

2024-07-11T17:23:54+00:00

Nothing during MBA test uses mongrp even if it has been defined ever
since the introduction of the MBA test in the commit 01fee6b4d1f9
("selftests/resctrl: Add MBA test").

Remove the mongrp from MBA test.

Signed-off-by: Ilpo Järvinen 
Tested-by: Babu Moger 
Reviewed-by: Reinette Chatre 
Signed-off-by: Shuah Khan

selftests/resctrl: Convert ctrlgrp & mongrp to pointers

2024-07-11T17:23:54+00:00

The struct resctrl_val_param has control and monitor groups as char
arrays but they are not supposed to be mutated within resctrl_val().

Convert the ctrlgrp and mongrp char array within resctrl_val_param to
plain const char pointers and adjust the strlen() based checks to
check NULL instead.

Signed-off-by: Ilpo Järvinen 
Tested-by: Babu Moger 
Reviewed-by: Reinette Chatre 
Signed-off-by: Shuah Khan