The percpu_counter is used for scenarios where performance is more
important than the accuracy. For percpu_counter users, who want more
accurate information in their slowpath, percpu_counter_sum is provided
which traverses all the online CPUs to accumulate the data. The reason it
only needs to traverse online CPUs is because percpu_counter does
implement CPU offline callback which syncs the local data of the offlined
CPU.
However there is a small race window between the online CPUs traversal of
percpu_counter_sum and the CPU offline callback. The offline callback has
to traverse all the percpu_counters on the system to flush the CPU local
data which can be a lot. During that time, the CPU which is going offline
has already been published as offline to all the readers. So, as the
offline callback is running, percpu_counter_sum can be called for one
counter which has some state on the CPU going offline. Since
percpu_counter_sum only traverses online CPUs, it will skip that specific
CPU and the offline callback might not have flushed the state for that
specific percpu_counter on that offlined CPU.
Normally this is not an issue because percpu_counter users can deal with
some inaccuracy for small time window. However a new user i.e. mm_struct
on the cleanup path wants to check the exact state of the percpu_counter
through check_mm(). For such users, this patch introduces
percpu_counter_sum_all() which traverses all possible CPUs and it is used
in fork.c:check_mm() to avoid the potential race.
This issue is exposed by the later patch "mm: convert mm's rss stats into
percpu_counter".
Link: https://lkml.kernel.org/r/20221109012011.881058-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If KPROBES_SANITY_TEST and ARCH_CORRECT_STACKTRACE_ON_KRETPROBE is enabled, but
STACKTRACE is not set. Build failed as below:
lib/test_kprobes.c: In function `stacktrace_return_handler':
lib/test_kprobes.c:228:8: error: implicit declaration of function `stack_trace_save'; did you mean `stacktrace_driver'? [-Werror=implicit-function-declaration]
ret = stack_trace_save(stack_buf, STACK_BUF_SIZE, 0);
^~~~~~~~~~~~~~~~
stacktrace_driver
cc1: all warnings being treated as errors
scripts/Makefile.build:250: recipe for target 'lib/test_kprobes.o' failed
make[2]: *** [lib/test_kprobes.o] Error 1
To fix this error, Select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE is enabled.
Link: https://lkml.kernel.org/r/20221121030620.63181-1-hucool.lihua@huawei.com
Fixes: 1f6d3a8f5e ("kprobes: Add a test case for stacktrace from kretprobe handler")
Signed-off-by: Li Hua <hucool.lihua@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Along the development cycle, the testing code support for module/in-kernel
compiles was removed. Restore this functionality by moving any internal
API tests to the userspace side, as well as threading tests. Fix the
lockdep issues and add a way to reduce memory usage so the tests can
complete with KASAN + memleak detection. Make the tests work on 32 bit
hosts where possible and detect 32 bit hosts in the radix test suite.
[akpm@linux-foundation.org: fix module export]
[akpm@linux-foundation.org: fix it some more]
[liam.howlett@oracle.com: fix compile warnings on 32bit build in check_find()]
Link: https://lkml.kernel.org/r/20221107203816.1260327-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20221028180415.3074673-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
clang-analyzer reported some Dead Stores in mas_anode_descend(). Upon
inspection, there were a few clean ups that would make the code cleaner:
The count variable was set from the mt_slots array and then updated but
never used again. Just use the array reference directly.
Also stop updating the type since it isn't used after the update.
Stop setting the gaps pointer to NULL at the start since it is always
set before the loop begins.
Link: https://lkml.kernel.org/r/20221026151413.4032730-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull networking fixes from Paolo Abeni:
"Including fixes from bluetooth and netfilter.
Current release - regressions:
- net: several zerocopy flags fixes
- netfilter: fix possible memory leak in nf_nat_init()
- openvswitch: add missing .resv_start_op
Previous releases - regressions:
- neigh: fix null-ptr-deref in neigh_table_clear()
- sched: fix use after free in red_enqueue()
- dsa: fall back to default tagger if we can't load the one from DT
- bluetooth: fix use-after-free in l2cap_conn_del()
Previous releases - always broken:
- netfilter: netlink notifier might race to release objects
- nfc: fix potential memory leak of skb
- bluetooth: fix use-after-free caused by l2cap_reassemble_sdu
- bluetooth: use skb_put to set length
- eth: tun: fix bugs for oversize packet when napi frags enabled
- eth: lan966x: fixes for when MTU is changed
- eth: dwmac-loongson: fix invalid mdio_node"
* tag 'net-6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (53 commits)
vsock: fix possible infinite sleep in vsock_connectible_wait_data()
vsock: remove the unused 'wait' in vsock_connectible_recvmsg()
ipv6: fix WARNING in ip6_route_net_exit_late()
bridge: Fix flushing of dynamic FDB entries
net, neigh: Fix null-ptr-deref in neigh_table_clear()
net/smc: Fix possible leaked pernet namespace in smc_init()
stmmac: dwmac-loongson: fix invalid mdio_node
ibmvnic: Free rwi on reset success
net: mdio: fix undefined behavior in bit shift for __mdiobus_register
Bluetooth: L2CAP: Fix attempting to access uninitialized memory
Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm
Bluetooth: L2CAP: Fix accepting connection request for invalid SPSM
Bluetooth: hci_conn: Fix not restoring ISO buffer count on disconnect
Bluetooth: L2CAP: Fix memory leak in vhci_write
Bluetooth: L2CAP: fix use-after-free in l2cap_conn_del()
Bluetooth: virtio_bt: Use skb_put to set length
Bluetooth: hci_conn: Fix CIS connection dst_type handling
Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu
netfilter: ipset: enforce documented limit to prevent allocating huge memory
isdn: mISDN: netjet: fix wrong check of device registration
...
Jakub reported that the addition of the "network_byte_order"
member in struct nla_policy increases size of 32bit platforms.
Instead of scraping the bit from elsewhere Johannes suggested
to add explicit NLA_BE types instead, so do this here.
NLA_POLICY_MAX_BE() macro is removed again, there is no need
for it: NLA_POLICY_MAX(NLA_BE.., ..) will do the right thing.
NLA_BE64 can be added later.
Fixes: 08724ef699 ("netlink: introduce NLA_POLICY_MAX_BE")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Suggested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20221031123407.9158-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull misc hotfixes from Andrew Morton:
"Eight fix pre-6.0 bugs and the remainder address issues which were
introduced in the 6.1-rc merge cycle, or address issues which aren't
considered sufficiently serious to warrant a -stable backport"
* tag 'mm-hotfixes-stable-2022-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (23 commits)
mm: multi-gen LRU: move lru_gen_add_mm() out of IRQ-off region
lib: maple_tree: remove unneeded initialization in mtree_range_walk()
mmap: fix remap_file_pages() regression
mm/shmem: ensure proper fallback if page faults
mm/userfaultfd: replace kmap/kmap_atomic() with kmap_local_page()
x86: fortify: kmsan: fix KMSAN fortify builds
x86: asm: make sure __put_user_size() evaluates pointer once
Kconfig.debug: disable CONFIG_FRAME_WARN for KMSAN by default
x86/purgatory: disable KMSAN instrumentation
mm: kmsan: export kmsan_copy_page_meta()
mm: migrate: fix return value if all subpages of THPs are migrated successfully
mm/uffd: fix vma check on userfault for wp
mm: prep_compound_tail() clear page->private
mm,madvise,hugetlb: fix unexpected data loss with MADV_DONTNEED on hugetlbfs
mm/page_isolation: fix clang deadcode warning
fs/ext4/super.c: remove unused `deprecated_msg'
ipc/msg.c: fix percpu_counter use after free
memory tier, sysfs: rename attribute "nodes" to "nodelist"
MAINTAINERS: git://github.com -> https://github.com for nilfs2
mm/kmemleak: prevent soft lockup in kmemleak_scan()'s object iteration loops
...
Before the do-while loop in mtree_range_walk(), the variables next, min,
max need to be initialized. The variables last, prev_min and prev_max are
set within the loop body before they are eventually used after exiting the
loop body.
As it is a do-while loop, the loop body is executed at least once, so the
variables last, prev_min and prev_max do not need to be initialized before
the loop body.
Remove unneeded initialization of last and prev_min.
The needless initialization was reported by clang-analyzer as Dead Stores.
As the compiler already identifies these assignments as unneeded, it
optimizes the assignments away. Hence:
No functional change. No change in object code.
Link: https://lkml.kernel.org/r/20221026120029.12555-2-lukas.bulwahn@gmail.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull networking fixes from Jakub Kicinski:
"Including fixes from 802.15.4 (Zigbee et al).
Current release - regressions:
- ipa: fix bugs in the register conversion for IPA v3.1 and v3.5.1
Current release - new code bugs:
- mptcp: fix abba deadlock on fastopen
- eth: stmmac: rk3588: allow multiple gmac controllers in one system
Previous releases - regressions:
- ip: rework the fix for dflt addr selection for connected nexthop
- net: couple more fixes for misinterpreting bits in struct page
after the signature was added
Previous releases - always broken:
- ipv6: ensure sane device mtu in tunnels
- openvswitch: switch from WARN to pr_warn on a user-triggerable path
- ethtool: eeprom: fix null-deref on genl_info in dump
- ieee802154: more return code fixes for corner cases in
dgram_sendmsg
- mac802154: fix link-quality-indicator recording
- eth: mlx5: fixes for IPsec, PTP timestamps, OvS and conntrack
offload
- eth: fec: limit register access on i.MX6UL
- eth: bcm4908_enet: update TX stats after actual transmission
- can: rcar_canfd: improve IRQ handling for RZ/G2L
Misc:
- genetlink: piggy back on the newly added resv_op_start to enforce
more sanity checks on new commands"
* tag 'net-6.1-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (57 commits)
net: enetc: survive memory pressure without crashing
kcm: do not sense pfmemalloc status in kcm_sendpage()
net: do not sense pfmemalloc status in skb_append_pagefrags()
net/mlx5e: Fix macsec sci endianness at rx sa update
net/mlx5e: Fix wrong bitwise comparison usage in macsec_fs_rx_add_rule function
net/mlx5e: Fix macsec rx security association (SA) update/delete
net/mlx5e: Fix macsec coverity issue at rx sa update
net/mlx5: Fix crash during sync firmware reset
net/mlx5: Update fw fatal reporter state on PCI handlers successful recover
net/mlx5e: TC, Fix cloned flow attr instance dests are not zeroed
net/mlx5e: TC, Reject forwarding from internal port to internal port
net/mlx5: Fix possible use-after-free in async command interface
net/mlx5: ASO, Create the ASO SQ with the correct timestamp format
net/mlx5e: Update restore chain id for slow path packets
net/mlx5e: Extend SKB room check to include PTP-SQ
net/mlx5: DR, Fix matcher disconnect error flow
net/mlx5: Wait for firmware to enable CRS before pci_restore_state
net/mlx5e: Do not increment ESN when updating IPsec ESN state
netdevsim: remove dir in nsim_dev_debugfs_init() when creating ports dir failed
netdevsim: fix memory leak in nsim_drv_probe() when nsim_dev_resources_register() failed
...
The "random rhlist add/delete operations" actually wasn't very random, as all
cases tested the same bit. Since the later parts of this loop depend on the
first case execute this unconditionally, and then test on different bits for the
remaining tests. While at it only request as much random bits as are actually
used.
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert test exclusion into test skipping. This brings the logic for
why a test is being skipped into the test itself, instead of having to
spread ifdefs around the code. This will make cleanup easier as minimum
tests get raised. Drop __maybe_unused so missed tests will be noticed
again and clean up whitespace.
For example, clang-11 on i386:
[15:52:32] ================== overflow (18 subtests) ==================
[15:52:32] [PASSED] u8_u8__u8_overflow_test
[15:52:32] [PASSED] s8_s8__s8_overflow_test
[15:52:32] [PASSED] u16_u16__u16_overflow_test
[15:52:32] [PASSED] s16_s16__s16_overflow_test
[15:52:32] [PASSED] u32_u32__u32_overflow_test
[15:52:32] [PASSED] s32_s32__s32_overflow_test
[15:52:32] [SKIPPED] u64_u64__u64_overflow_test
[15:52:32] [SKIPPED] s64_s64__s64_overflow_test
[15:52:32] [SKIPPED] u32_u32__int_overflow_test
[15:52:32] [PASSED] u32_u32__u8_overflow_test
[15:52:32] [PASSED] u8_u8__int_overflow_test
[15:52:32] [PASSED] int_int__u8_overflow_test
[15:52:32] [PASSED] shift_sane_test
[15:52:32] [PASSED] shift_overflow_test
[15:52:32] [PASSED] shift_truncate_test
[15:52:32] [PASSED] shift_nonsense_test
[15:52:32] [PASSED] overflow_allocation_test
[15:52:32] [PASSED] overflow_size_helpers_test
[15:52:32] ==================== [PASSED] overflow =====================
[15:52:32] ============================================================
[15:52:32] Testing complete. Ran 18 tests: passed: 15, skipped: 3
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: llvm@lists.linux.dev
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20221006230017.1833458-1-keescook@chromium.org
Building the overflow kunit tests with clang-11 fails with:
$ ./tools/testing/kunit/kunit.py run --arch=arm --make_options LLVM=1 \
overflow
...
ld.lld: error: undefined symbol: __mulodi4
...
Clang 11 and earlier generate unwanted libcalls for signed output,
unsigned input.
Disable these tests for now, but should these become used in the kernel
we might consider that as justification for dropping clang-11 support.
Keep the clang-11 build alive a little bit longer.
Avoid -Wunused-function warnings via __maybe_unused. To test W=1:
$ make LLVM=1 -j128 defconfig
$ ./scripts/config -e KUNIT -e KUNIT_ALL
$ make LLVM=1 -j128 olddefconfig lib/overflow_kunit.o W=1
Link: https://github.com/ClangBuiltLinux/linux/issues/1711
Link: 3203143f13
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221006171751.3444575-1-ndesaulniers@google.com
The alloc_string_stream() functions were changed from returning NULL on
error to returning error pointers so these caller needs to be updated
as well.
Fixes: 78b1c6584f ("kunit: string-stream: Simplify resource use")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Pull more random number generator updates from Jason Donenfeld:
"This time with some large scale treewide cleanups.
The intent of this pull is to clean up the way callers fetch random
integers. The current rules for doing this right are:
- If you want a secure or an insecure random u64, use get_random_u64()
- If you want a secure or an insecure random u32, use get_random_u32()
The old function prandom_u32() has been deprecated for a while
now and is just a wrapper around get_random_u32(). Same for
get_random_int().
- If you want a secure or an insecure random u16, use get_random_u16()
- If you want a secure or an insecure random u8, use get_random_u8()
- If you want secure or insecure random bytes, use get_random_bytes().
The old function prandom_bytes() has been deprecated for a while
now and has long been a wrapper around get_random_bytes()
- If you want a non-uniform random u32, u16, or u8 bounded by a
certain open interval maximum, use prandom_u32_max()
I say "non-uniform", because it doesn't do any rejection sampling
or divisions. Hence, it stays within the prandom_*() namespace, not
the get_random_*() namespace.
I'm currently investigating a "uniform" function for 6.2. We'll see
what comes of that.
By applying these rules uniformly, we get several benefits:
- By using prandom_u32_max() with an upper-bound that the compiler
can prove at compile-time is ≤65536 or ≤256, internally
get_random_u16() or get_random_u8() is used, which wastes fewer
batched random bytes, and hence has higher throughput.
- By using prandom_u32_max() instead of %, when the upper-bound is
not a constant, division is still avoided, because
prandom_u32_max() uses a faster multiplication-based trick instead.
- By using get_random_u16() or get_random_u8() in cases where the
return value is intended to indeed be a u16 or a u8, we waste fewer
batched random bytes, and hence have higher throughput.
This series was originally done by hand while I was on an airplane
without Internet. Later, Kees and I worked on retroactively figuring
out what could be done with Coccinelle and what had to be done
manually, and then we split things up based on that.
So while this touches a lot of files, the actual amount of code that's
hand fiddled is comfortably small"
* tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
prandom: remove unused functions
treewide: use get_random_bytes() when possible
treewide: use get_random_u32() when possible
treewide: use get_random_{u8,u16}() when possible, part 2
treewide: use get_random_{u8,u16}() when possible, part 1
treewide: use prandom_u32_max() when possible, part 2
treewide: use prandom_u32_max() when possible, part 1
