Cleanup and preparation to simplify the next changes.
- Use current->tgid instead of current->group_leader->pid
- Use get_task_pid(current, PIDTYPE_TGID) instead of
get_task_pid(current->group_leader, PIDTYPE_PID)
Link: https://lkml.kernel.org/r/aXY_wKewzV5lCa5I@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Felix Kuehling <felix.kuehling@amd.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Christan König <christian.koenig@amd.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With or without this change the checked condition can be falsely true if
proc->tsk execs, but this is fine: binder_alloc_mmap_handler() checks
vma->vm_mm == alloc->mm.
Link: https://lkml.kernel.org/r/aXY_uPYyUg4rwNOg@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Christan König <christian.koenig@amd.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "don't abuse task_struct.group_leader", v2.
This series removes the usage of ->group_leader when it is "obviously
unnecessary".
I am going to move ->group_leader from task_struct to signal_struct or at
least add the new task_group_leader() helper. So I will send more
tree-wide changes on top of this series.
This patch (of 7):
Cleanup and preparation to simplify the next changes.
- Use current->tgid instead of current->group_leader->pid
- Use the value returned by get_task_struct() to initialize proc->tsk
Link: https://lkml.kernel.org/r/aXY_h8i78n6yD9JY@redhat.com
Link: https://lkml.kernel.org/r/aXY_ryGDwdygl1Tv@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Christan König <christian.koenig@amd.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kho_reserve_scratch() iterates over all online NUMA nodes to allocate
per-node scratch memory. On systems with memoryless NUMA nodes (nodes
that have CPUs but no memory), memblock_alloc_range_nid() fails because
there is no memory available on that node. This causes KHO initialization
to fail and kho_enable to be set to false.
Some ARM64 systems have NUMA topologies where certain nodes contain only
CPUs without any associated memory. These configurations are valid and
should not prevent KHO from functioning.
Fix this by only counting nodes that have memory (N_MEMORY state) and skip
memoryless nodes in the per-node scratch allocation loop.
Link: https://lkml.kernel.org/r/20260120175913.34368-1-epetron@amazon.de
Fixes: 3dc92c3114 ("kexec: add Kexec HandOver (KHO) generation helpers").
Signed-off-by: Evangelos Petrongonas <epetron@amazon.de>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
crash_load_dm_crypt_keys() reads dm-crypt volume keys from the user
keyring. It uses user_key_payload_locked() without holding key->sem,
which makes lockdep complain when kexec_file_load() assembles the crash
image:
=============================
WARNING: suspicious RCU usage
-----------------------------
./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
no locks held by kexec/4875.
stack backtrace:
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x80
lockdep_rcu_suspicious.cold+0x4e/0x96
crash_load_dm_crypt_keys+0x314/0x390
bzImage64_load+0x116/0x9a0
? __lock_acquire+0x464/0x1ba0
__do_sys_kexec_file_load+0x26a/0x4f0
do_syscall_64+0xbd/0x430
entry_SYSCALL_64_after_hwframe+0x77/0x7f
In addition, the key returned by request_key() is never key_put()'d,
leaking a key reference on each load attempt.
Take key->sem while copying the payload and drop the key reference
afterwards.
Link: https://lkml.kernel.org/r/patch.git-2d4d76083a5c.your-ad-here.call-01769426386-ext-2560@work.hours
Fixes: 479e58549b ("crash_dump: store dm crypt keys in kdump reserved memory")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Coiby Xu <coxu@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* use dedicated labels for error handling instead of checking if a pointer
is not null to decide if it should be unmapped
* drop assignment of values to err that are only used to print a numeric
error code, there are pr_warn()s for each failure already so printing a
numeric error code in the next line does not add anything useful
Link: https://lkml.kernel.org/r/20260122121757.575987-1-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The user.* sysctls implement the ctl_table_root::permissions hook and they
override the file access mode based on the CAP_SYS_RESOURCE capability (at
most rwx if capable, at most r-- if not). The capability is being checked
unconditionally, so if an LSM denies the capability, an audit record may
be logged even when access is in fact granted.
Given the logic in the set_permissions() function in kernel/ucount.c and
the unfortunate way the permission checking is implemented, it doesn't
seem viable to avoid false positive denials by deferring the capability
check. Thus, do the same as in net_ctl_permissions() (net/sysctl_net.c) -
switch from ns_capable() to ns_capable_noaudit(), so that the check never
logs an audit record.
Link: https://lkml.kernel.org/r/20260122140745.239428-1-omosnace@redhat.com
Fixes: dbec28460a ("userns: Add per user namespace sysctls.")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Alexey Gladkov <legion@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The IPC sysctls implement the ctl_table_root::permissions hook and they
override the file access mode based on the CAP_CHECKPOINT_RESTORE
capability, which is being checked regardless of whether any access is
actually denied or not, so if an LSM denies the capability, an audit
record may be logged even when access is in fact granted.
It wouldn't be viable to restructure the sysctl permission logic to only
check the capability when the access would be actually denied if it's not
granted. Thus, do the same as in net_ctl_permissions() (net/sysctl_net.c)
- switch from ns_capable() to ns_capable_noaudit(), so that the check
never emits an audit record.
Link: https://lkml.kernel.org/r/20260122141303.241133-1-omosnace@redhat.com
Fixes: 0889f44e28 ("ipc: Check permissions for checkpoint_restart sysctls at open time")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Alexey Gladkov <legion@kernel.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Paul Moore <paul@paul-moore.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kexec_load_purgatory() derives image->start by locating e_entry inside an
SHF_EXECINSTR section. If the purgatory object contains multiple
executable sections with overlapping sh_addr, the entrypoint check can
match more than once and trigger a WARN.
Derive the entry section from the purgatory_start symbol when present and
compute image->start from its final placement. Keep the existing e_entry
fallback for purgatories that do not expose the symbol.
WARNING: kernel/kexec_file.c:1009 at kexec_load_purgatory+0x395/0x3c0, CPU#10: kexec/1784
Call Trace:
<TASK>
bzImage64_load+0x133/0xa00
__do_sys_kexec_file_load+0x2b3/0x5c0
do_syscall_64+0x81/0x610
entry_SYSCALL_64_after_hwframe+0x76/0x7e
[me@linux.beauty: move helper to avoid forward declaration, per Baoquan]
Link: https://lkml.kernel.org/r/20260128043511.316860-1-me@linux.beauty
Link: https://lkml.kernel.org/r/20260120124005.148381-1-me@linux.beauty
Fixes: 8652d44f46 ("kexec: support purgatories with .text.hot sections")
Signed-off-by: Li Chen <me@linux.beauty>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Li Chen <me@linux.beauty>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: Ricardo Ribalda Delgado <ribalda@chromium.org>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
commit c06c303832 ("ocfs2: fix xattr array entry __counted_by error")
doesn't handle all cases and the cleanup job for preserved xattr entries
still has bug:
- the 'last' pointer should be shifted by one unit after cleanup
an array entry.
- current code logic doesn't cleanup the first entry when xh_count is 1.
Note, commit c06c303832 is also a bug fix for 0fe9b66c65.
Link: https://lkml.kernel.org/r/20251210015725.8409-2-heming.zhao@suse.com
Fixes: 0fe9b66c65 ("ocfs2: Add preserve to reflink.")
Signed-off-by: Heming Zhao <heming.zhao@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When idtab allocation fails, net is not registered with rio_add_net() yet,
so kfree(net) is sufficient to release the memory. Set mport->net to NULL
to avoid dangling pointer.
Link: https://lkml.kernel.org/r/20260121013508.195836-1-lihaoxiang@isrc.iscas.ac.cn
Fixes: e6b585ca6e ("rapidio: move net allocation into core code")
Signed-off-by: Haoxiang Li <lihaoxiang@isrc.iscas.ac.cn>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Problem
=======
Commit 658eb5ab91 ("delayacct: add delay max to record delay peak")
introduced the delay max for getdelays, which records abnormal latency
peaks and helps us understand the magnitude of such delays. However, the
peak latency value alone is insufficient for effective root cause
analysis. Without the precise timestamp of when the peak occurred, we
still lack the critical context needed to correlate it with other system
events.
Solution
========
To address this, we need to additionally record a precise timestamp when
the maximum latency occurs. By correlating this timestamp with system
logs and monitoring metrics, we can identify processes with abnormal
resource usage at the same moment, which can help us to pinpoint root
causes.
Use Case
========
bash-4.4# ./getdelays -d -t 227
print delayacct stats ON
TGID 227
CPU count real total virtual total delay total delay average delay max delay min delay max timestamp
46 188000000 192348334 4098012 0.089ms 0.429260ms 0.051205ms 2026-01-15T15:06:58
IO count delay total delay average delay max delay min delay max timestamp
0 0 0.000ms 0.000000ms 0.000000ms N/A
SWAP count delay total delay average delay max delay min delay max timestamp
0 0 0.000ms 0.000000ms 0.000000ms N/A
RECLAIM count delay total delay average delay max delay min delay max timestamp
0 0 0.000ms 0.000000ms 0.000000ms N/A
THRAS HING count delay total delay average delay max delay min delay max timestamp
0 0 0.000ms 0.000000ms 0.000000ms N/A
COMPACT count delay total delay average delay max delay min delay max timestamp
0 0 0.000ms 0.000000ms 0.000000ms N/A
WPCOPY count delay total delay average delay max delay min delay max timestamp
182 19413338 0.107ms 0.547353ms 0.022462ms 2026-01-15T15:05:24
IRQ count delay total delay average delay max delay min delay max timestamp
0 0 0.000ms 0.000000ms 0.000000ms N/A
Link: https://lkml.kernel.org/r/20260119100241520gWubW8-5QfhSf9gjqcc_E@zte.com.cn
Signed-off-by: Wang Yaxin <wang.yaxin@zte.com.cn>
Cc: Fan Yu <fan.yu9@zte.com.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__noinstr_text_start is adding noise to the script, ignore it.
For instance using __always_inline on __skb_incr_checksum_unnecessary and
CC=clang build.
Before this patch, __noinstr_text_start can show up and confuse us.
$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/2 grow/shrink: 3/0 up/down: 212/-206 (6)
Function old new delta
tcp6_gro_complete 208 283 +75
tcp4_gro_complete 376 449 +73
__noinstr_text_start 3536 3600 +64
__pfx___skb_incr_checksum_unnecessary 32 - -32
__skb_incr_checksum_unnecessary 174 - -174
Total: Before=25509464, After=25509470, chg +0.00%
After this patch we have a more precise result.
$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/2 grow/shrink: 2/0 up/down: 148/-206 (-58)
Function old new delta
tcp6_gro_complete 208 283 +75
tcp4_gro_complete 376 449 +73
__pfx___skb_incr_checksum_unnecessary 32 - -32
__skb_incr_checksum_unnecessary 174 - -174
Total: Before=25505928, After=25505870, chg -0.00%
Link: https://lkml.kernel.org/r/20260117083448.3877418-1-edumazet@google.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tracing is a half of the kernel.h in terms of LOCs, although it's a
self-consistent part. It is intended for quick debugging purposes and
isn't used by the normal tracing utilities.
Move it to a separate header. If someone needs to just throw a
trace_printk() in their driver, they will not have to pull all the heavy
tracing machinery.
This is a pure move.
Link: https://lkml.kernel.org/r/20260116042510.241009-7-ynorov@nvidia.com
Signed-off-by: Yury Norov <ynorov@nvidia.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The __trace_puts() function takes a string pointer and the size of the
string itself. All users currently simply pass in the strlen() of the
string it is also passing in. There's no reason to pass in the size.
Instead have the __trace_puts() function do the strlen() within the
function itself.
This fixes a header recursion issue where using strlen() in the macro
calling __trace_puts() requires adding #include <linux/string.h> in order
to use strlen(). Removing the use of strlen() from the header fixes the
recursion issue.
Link: https://lore.kernel.org/all/aUN8Hm377C5A0ILX@yury/
Link: https://lkml.kernel.org/r/20260116042510.241009-6-ynorov@nvidia.com
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Yury Norov <ynorov@nvidia.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The macro is related to sysfs, but is defined in kernel.h. Move it to the
proper header, and unload the generic kernel.h.
Now that the macro is removed from kernel.h, linux/moduleparam.h is
decoupled, and kernel.h inclusion can be removed.
Link: https://lkml.kernel.org/r/20260116042510.241009-4-ynorov@nvidia.com
Signed-off-by: Yury Norov <ynorov@nvidia.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The following patch drops moduleparam.h dependency on kernel.h. In
preparation to it, list all the required headers explicitly.
Link: https://lkml.kernel.org/r/20260116042510.241009-3-ynorov@nvidia.com
Signed-off-by: Yury Norov <ynorov@nvidia.com>
Suggested-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Unload linux/kernel.h", v5.
kernel.h hosts declarations that can be placed better. This series
decouples kernel.h with some explicit and implicit dependencies; also,
moves tracing functionality to a new independent header.
This patch (of 6):
The macro was introduced in 1994, v1.0.4, for stacks protection. Since
that, people found better ways to protect stacks, and now the macro is
only used by i915 selftests. Move it to a local header and drop from the
kernel.h.
Link: https://lkml.kernel.org/r/20260116042510.241009-1-ynorov@nvidia.com
Link: https://lkml.kernel.org/r/20260116042510.241009-2-ynorov@nvidia.com
Signed-off-by: Yury Norov <ynorov@nvidia.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Aaron Tomlin <atomlin@atomlin.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When building the kernel using a version of LLVM between llvmorg-19-init
(the first commit of the LLVM 19 development cycle) and the change in
LLVM that actually added __typeof_unqual__ for all C modes [1], which
might happen during a bisect of LLVM, there is a build failure:
In file included from arch/x86/kernel/asm-offsets.c:9:
In file included from include/linux/crypto.h:15:
In file included from include/linux/completion.h:12:
In file included from include/linux/swait.h:7:
In file included from include/linux/spinlock.h:56:
In file included from include/linux/preempt.h:79:
arch/x86/include/asm/preempt.h:61:2: error: call to undeclared function '__typeof_unqual__'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
61 | raw_cpu_and_4(__preempt_count, ~PREEMPT_NEED_RESCHED);
| ^
arch/x86/include/asm/percpu.h:478:36: note: expanded from macro 'raw_cpu_and_4'
478 | #define raw_cpu_and_4(pcp, val) percpu_binary_op(4, , "and", (pcp), val)
| ^
arch/x86/include/asm/percpu.h:210:3: note: expanded from macro 'percpu_binary_op'
210 | TYPEOF_UNQUAL(_var) pto_tmp__; \
| ^
include/linux/compiler.h:248:29: note: expanded from macro 'TYPEOF_UNQUAL'
248 | # define TYPEOF_UNQUAL(exp) __typeof_unqual__(exp)
| ^
The current logic of CC_HAS_TYPEOF_UNQUAL just checks for a major
version of 19 but half of the 19 development cycle did not have support
for __typeof_unqual__.
Harden the logic of CC_HAS_TYPEOF_UNQUAL to avoid this error by only
using __typeof_unqual__ with a released version of LLVM 19, which is
greater than or equal to 19.1.0 with LLVM's versioning scheme that
matches GCC's [2].
Link: cc308f60d4 [1]
Link: 4532617ae4 [2]
Link: https://lkml.kernel.org/r/20260116-require-llvm-19-1-for-typeof_unqual-v1-1-3b9a4a4b212b@kernel.org
Fixes: ac053946f5 ("compiler.h: introduce TYPEOF_UNQUAL() macro")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When restoring a page (from kho_restore_pages()) or folio (from
kho_restore_folio()), KHO must initialize the struct page. The
initialization differs slightly depending on if a folio is requested or a
set of 0-order pages is requested.
Conceptually, it is quite simple to understand. When restoring 0-order
pages, each page gets a refcount of 1 and that's it. When restoring a
folio, head page gets a refcount of 1 and tail pages get 0.
kho_restore_page() tries to combine the two separate initialization flow
into one piece of code. While it works fine, it is more complicated to
read than it needs to be. Make the code simpler by splitting the two
initalization paths into two separate functions. This improves
readability by clearly showing how each type must be initialized.
Link: https://lkml.kernel.org/r/20260116112217.915803-3-pratyush@kernel.org
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "kho: clean up page initialization logic", v2.
This series simplifies the page initialization logic in
kho_restore_page(). It was originally only a single patch [0], but on
Pasha's suggestion, I added another patch to use unsigned long for
nr_pages.
Technically speaking, the patches aren't related and can be applied
independently, but bundling them together since patch 2 relies on 1 and it
is easier to manage them this way.
This patch (of 2):
With 4k pages, a 32-bit nr_pages can span up to 16 TiB. While it is a
lot, there exist systems with terabytes of RAM. gup is also moving to
using long for nr_pages. Use unsigned long and make KHO future-proof.
Link: https://lkml.kernel.org/r/20260116112217.915803-1-pratyush@kernel.org
Link: https://lkml.kernel.org/r/20260116112217.915803-2-pratyush@kernel.org
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Suggested-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Some versions of tools that apply patches incorrectly allow lines that
start with 3 dashes and have additional content on the same line.
Checkpatch will now emit an ERROR on these lines and optionally convert
those lines from dashes to equals with --fix.
Link: https://lkml.kernel.org/r/6ec1ed08328340db42655287afd5fa4067316b11.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Ian Rogers <irogers@google.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Stehen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When scratch area fails to reserve, KHO prints a message indicating that.
But it doesn't say which scratch failed to allocate. This can be useful
information for debugging. Even more so when the failure is hard to
reproduce.
Along with the current message, also print which exact scratch area failed
to be reserved.
Link: https://lkml.kernel.org/r/20260116165416.1262531-1-pratyush@kernel.org
Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: David Matlack <dmatlack@google.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Pratyush Yadav <pratyush@kernel.org>
Cc: Samiullah Khawaja <skhawaja@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Check all loaded modules and report any that have their 'taint'
flags set. The tainted module output format is:
* <module_name> (<taint_flags>)
Example output:
Kernel is "tainted" for the following reasons:
* externally-built ('out-of-tree') module was loaded (#12)
* unsigned module was loaded (#13)
Raw taint value as int/string: 12288/'G OE '
Tainted modules:
* dump_test (OE)
Link: https://lkml.kernel.org/r/20260115064756.531592-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Thorsten Leemhuis <linux@leemhuis.info>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As CPU core counts increase, the number of NVMe IRQs may be smaller than
the total number of CPUs. This forces multiple CPUs to share the same
IRQ. If the IRQ affinity and the CPU's cluster do not align, a
performance penalty can be observed on some platforms.
This patch improves IRQ affinity by grouping CPUs by cluster within each
NUMA domain, ensuring better locality between CPUs and their assigned NVMe
IRQs.
Details:
Intel Xeon E platform packs 4 CPU cores as 1 module (cluster) and share
the L2 cache. Let's say, if there are 40 CPUs in 1 NUMA domain and 11
IRQs to dispatch. The existing algorithm will map first 7 IRQs each with
4 CPUs and remained 4 IRQs each with 3 CPUs. The last 4 IRQs may have
cross cluster issue. For example, the 9th IRQ which pinned to CPU32, then
for CPU31, it will have cross L2 memory access.
CPU |28 29 30 31|32 33 34 35|36 ...
-------- -------- --------
IRQ 8 9 10
If this patch applied, then first 2 IRQs each mapped with 2 CPUs and rest
9 IRQs each mapped with 4 CPUs, which avoids the cross cluster memory
access.
CPU |00 01 02 03|04 05 06 07|08 09 10 11| ...
----- ----- ----------- -----------
IRQ 1 2 3 4
As a result, 15%+ performance difference is observed in FIO
libaio/randread/bs=8k.
Changes since V1:
- Add more performance details in commit messages.
- Fix endless loop when topology_cluster_cpumask return invalid mask.
History:
v1: https://lore.kernel.org/all/20251024023038.872616-1-wangyang.guo@intel.com/
v1 [RESEND]: https://lore.kernel.org/all/20251111020608.1501543-1-wangyang.guo@intel.com/
Link: https://lkml.kernel.org/r/20260113022958.3379650-1-wangyang.guo@intel.com
Signed-off-by: Wangyang Guo <wangyang.guo@intel.com>
Reviewed-by: Tianyou Li <tianyou.li@intel.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Tested-by: Dan Liang <dan.liang@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@fb.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Radu Rendec <rrendec@redhat.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a new Kconfig symbol to make CONFIG_DEBUG_ATOMIC more useful on those
architectures which do not align dynamic allocations to 8-byte boundaries.
Without this, CONFIG_DEBUG_ATOMIC produces excessive WARN splats.
Link: https://lkml.kernel.org/r/6d25a12934fe9199332f4d65d17c17de450139a8.1768281748.git.fthain@linux-m68k.org
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Daniel Borkman <daniel@iogearbox.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Hao Luo <haoluo@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Sasha Levin (Microsoft) <sashal@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Some recent commits incorrectly assumed 4-byte alignment of locks. That
assumption fails on Linux/m68k (and, interestingly, would have failed on
Linux/cris also). The jump label implementation makes a similar alignment
assumption.
The expectation that atomic_t and atomic64_t variables will be naturally
aligned seems reasonable, as indeed they are on 64-bit architectures. But
atomic64_t isn't naturally aligned on csky, m68k, microblaze, nios2,
openrisc and sh. Neither atomic_t nor atomic64_t are naturally aligned on
m68k.
This patch brings a little uniformity by specifying natural alignment for
atomic types. One benefit is that atomic64_t variables do not get split
across a page boundary. The cost is that some structs grow which leads to
cache misses and wasted memory.
See also, commit bbf2a330d9 ("x86: atomic64: The atomic64_t data type
should be 8 bytes aligned on 32-bit too").
Link: https://lkml.kernel.org/r/a76bc24a4e7c1d8112d7d5fa8d14e4b694a0e90c.1768281748.git.fthain@linux-m68k.org
Link: https://lore.kernel.org/lkml/CAFr9PX=MYUDGJS2kAvPMkkfvH+0-SwQB_kxE4ea0J_wZ_pk=7w@mail.gmail.com
Link: https://lore.kernel.org/lkml/CAMuHMdW7Ab13DdGs2acMQcix5ObJK0O2dG_Fxzr8_g58Rc1_0g@mail.gmail.com/
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Acked-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Guo Ren <guoren@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Daniel Borkman <daniel@iogearbox.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Hao Luo <haoluo@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin (Microsoft) <sashal@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Align atomic storage", v7.
This series adds the __aligned attribute to atomic_t and atomic64_t
definitions in include/linux and include/asm-generic (respectively) to get
natural alignment of both types on csky, m68k, microblaze, nios2, openrisc
and sh.
This series also adds Kconfig options to enable a new run-time warning to
help reveal misaligned atomic accesses on platforms which don't trap that.
The performance impact is expected to vary across platforms and workloads.
The measurements I made on m68k show that some workloads run faster and
others slower.
This patch (of 4):
Align bpf_res_spin_lock to avoid a BUILD_BUG_ON() when the alignment
changes, as it will do on m68k when, in a subsequent patch, the minimum
alignment of the atomic_t member of struct rqspinlock gets increased from
2 to 4. Drop the BUILD_BUG_ON() as it becomes redundant.
Link: https://lkml.kernel.org/r/cover.1768281748.git.fthain@linux-m68k.org
Link: https://lkml.kernel.org/r/8a83876b07d1feacc024521e44059ae89abbb1ea.1768281748.git.fthain@linux-m68k.org
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Daniel Borkman <daniel@iogearbox.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Guo Ren <guoren@kernel.org>
Cc: Hao Luo <haoluo@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Sasha Levin (Microsoft) <sashal@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
get_boot_config_from_initrd() scans up to 3 bytes before initrd_end to
handle GRUB 4-byte alignment. As a result, the bootconfig header
immediately preceding the magic may be unaligned.
Read the size and checksum fields with get_unaligned_le32() instead of
casting to u32 * and using le32_to_cpu(), avoiding potential unaligned
access and silencing sparse "cast to restricted __le32" warnings.
Sparse warnings (gcc + C=1):
init/main.c:292:16: warning: cast to restricted __le32
init/main.c:293:16: warning: cast to restricted __le32
No functional change intended.
Link: https://lkml.kernel.org/r/20260113101532.1630770-1-sun.jian.kdev@gmail.com
Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The rdinit parameter is set by default, and attempted during boot even if
not specified in the command line. Only print the warning about rdinit
being inaccessible if the rdinit value was found in command line; it's
just noise otherwise.
[akpm@linux-foundation.org: move ramdisk_execute_command_set into __initdata]
Link: https://lkml.kernel.org/r/20260111125635.53682-1-lillian@star-ark.net
Signed-off-by: Lillian Berry <lillian@star-ark.net>
Cc: Ahmad Fatoum <a.fatoum@pengutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Francesco Valla <francesco@valla.it>
Cc: Guo Weikang <guoweikang.kernel@gmail.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Huan Yang <link@vivo.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Follow an observation that (n ^ (n - 1)) will only ever retain the most
significant bit set in the word operated on if that is the only bit set in
the first place, and use it to determine whether a number is a whole power
of 2, avoiding the need for an explicit check for nonzero.
This reduces the sequence produced to 3 instructions only across Alpha,
MIPS, and RISC-V targets, down from 4, 5, and 4 respectively, removing a
branch in the two latter cases. And it's 5 instructions on POWER and
x86-64 vs 8 and 9 respectively. There are no branches now emitted here
for targets that have a suitable conditional set operation, although an
inline expansion will often end with one, depending on what code a call to
this function is used in.
Credit goes to GCC authors for coming up with this optimisation used as
the fallback for (__builtin_popcountl(n) == 1), equivalent to this code,
for targets where the hardware population count operation is considered
expensive.
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.2601111836250.30566@angie.orcam.me.uk
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: John Garry <john.g.garry@oracle.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Su Hui <suhui@nfschina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This patch is a preparation step for HPCC, for the OOM killer
improvements. I suspect that this patch is useful on its own, because it
really makes no sense to sum up accounting statistics of use_mm within
kernel threads which are only temporarily using those mm.
When we hit acct_account_cputime within a irq handler over a kthread that
happens to use a userspace mm, we end up summing up the mm's RSS into the
tsk acct_rss_mem1, which eventually decays.
I don't see a good rationale behind tracking the mm's rss in that way when
a kthread use a userspace mm temporarily through use_mm.
It causes issues with init_mm and efi_mm which only partially initialize
their mm_struct when introducing the new hierarchical percpu counters to
replace RSS counters, which requires a pointer dereference when reading
the approximate counter sum. The current percpu counters simply load a
zeroed atomic counter, which happen to work.
Skip all kernel threads in acct_account_cputime(), not just those that
happen to have a NULL mm.
This is a preparation step before introducing the hierarchical percpu
counters.
Link: https://lkml.kernel.org/r/20251224173810.648699-2-mathieu.desnoyers@efficios.com
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Liam R . Howlett" <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Martin Liu <liumartin@google.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pointless overhead to use a work queue to reset the static key for a
DO_ONCE_SLEEPABLE() invocation.
Note that the previous code path included a BUG_ON() if the static key
was already disabled. Dropped that as part of this change because:
1) Use of BUG_ON() is highly discouraged.
2) There is a WARN_ON() in the static_branch_disable() code path
that would provide adequate breadcrumbs to debug any issue.
Link: https://lkml.kernel.org/r/aWU4tfTju1l3oZCu@agluck-desk3
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Corrupted FAT images can leave a directory inode with an incorrect
i_nlink (e.g. 2 even though subdirectories exist). rmdir then
unconditionally calls drop_nlink(dir) and can drive i_nlink to 0,
triggering the WARN_ON in drop_nlink().
Add a sanity check in vfat_rmdir() and msdos_rmdir(): only drop the
parent link count when it is at least 3, otherwise report a filesystem
error.
Link: https://lkml.kernel.org/r/20260101111148.1437-1-zhiyuzhang999@gmail.com
Fixes: 9a53c3a783 ("[PATCH] r/o bind mounts: unlink: monitor i_nlink")
Signed-off-by: Zhiyu Zhang <zhiyuzhang999@gmail.com>
Reported-by: Zhiyu Zhang <zhiyuzhang999@gmail.com>
Closes: https://lore.kernel.org/linux-fsdevel/aVN06OKsKxZe6-Kv@casper.infradead.org/T/#t
Tested-by: Zhiyu Zhang <zhiyuzhang999@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kexec_handover_internal.h is included twice in kexec_handover.c. Remove
the redundant first inclusion to eliminate the duplication.
Link: https://lkml.kernel.org/r/20251216114400.2677311-1-longwei27@huawei.com
Signed-off-by: Long Wei <longwei27@huawei.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: hewenliang <hewenliang4@huawei.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
During the initialization phase, the test_kho module invokes the
kho_preserve_folio function, which internally configures bitmaps within
kho_mem_track and establishes chunk linked lists in KHO. Upon unloading
the test_kho module, it is necessary to clean up these states.
Link: https://lkml.kernel.org/r/20260107022427.4114424-1-longwei27@huawei.com
Signed-off-by: Long Wei <longwei27@huawei.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: hewenliang <hewenliang4@huawei.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This patch converts the existing glob selftest (lib/globtest.c) to use the
KUnit framework (lib/tests/glob_kunit.c).
The new test:
- Migrates all 64 test cases from the original test to the KUnit suite.
- Removes the custom 'verbose' module parameter as KUnit handles logging.
- Updates Kconfig.debug and Makefile to support the new KUnit test.
- Updates Kconfig and Makefile to remove the original selftest.
- Updates GLOB_SELFTEST to GLOB_KUNIT_TEST for arch/m68k/configs.
This commit is verified by `./tools/testing/kunit/kunit.py run'
with the .kunit/.kunitconfig:
CONFIG_KUNIT=y
CONFIG_GLOB_KUNIT_TEST=y
Link: https://lkml.kernel.org/r/20260108120753.27339-1-note351@hotmail.com
Signed-off-by: Kir Chou <note351@hotmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: <kirchou@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The Task::group_leader() method currently allows you to access the
group_leader() of any task, for example one you hold a refcount to. But
this is not safe in general since the group leader could change when a
task exits. See for example commit a15f37a401 ("kernel/sys.c: fix the
racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths").
All existing users of Task::group_leader() call this method on current,
which is guaranteed running, so there's not an actual issue in Rust code
today. But to prevent code in the future from making this mistake,
restrict Task::group_leader() so that it can only be called on current.
There are some other cases where accessing task->group_leader is okay.
For example it can be safe if you hold tasklist_lock or rcu_read_lock().
However, only supporting current->group_leader is sufficient for all
in-tree Rust users of group_leader right now. Safe Rust functionality for
accessing it under rcu or while holding tasklist_lock may be added in the
future if required by any future Rust module.
This patch is a bugfix in that it prevents users of this API from writing
incorrect code. It doesn't change behavior of correct code.
Link: https://lkml.kernel.org/r/20260107-task-group-leader-v2-1-8fbf816f2a2f@google.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Fixes: 313c4281bc ("rust: add basic `Task`")
Reported-by: Oleg Nesterov <oleg@redhat.com>
Closes: https://lore.kernel.org/all/aTLnV-5jlgfk1aRK@redhat.com/
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Benno Lossin <lossin@kernel.org>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: FUJITA Tomonori <fujita.tomonori@gmail.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Panagiotis Foliadis <pfoliadis@posteo.net>
Cc: Shankari Anand <shankari.ak0208@gmail.com>
Cc: Trevor Gross <tmgross@umich.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The comment for get_task_mm() in kernel/fork.c incorrectly references the
deprecated function `use_mm()`, which has been renamed to
`kthread_use_mm()` in kernel/kthread.c.
This patch updates the documentation to reflect the current function
names, ensuring accuracy when developers refer to the kernel thread memory
context API.
No functional changes were introduced.
Link: https://lkml.kernel.org/r/KUZPR04MB8965F954108B4DD7E8FFDB2B8F84A@KUZPR04MB8965.apcprd04.prod.outlook.com
Signed-off-by: mingzhu.wang <mingzhu.wang@transsion.com>
Cc: Ben Segall <bsegall@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiazi Li <jqqlijiazi@gmail.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Kees Cook <kees@kernel.org>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a check to verify the group descriptor has enough free bits before
attempting allocation in ocfs2_move_extent(). This prevents a kernel
BUG_ON crash in ocfs2_block_group_set_bits() when the move_extents ioctl
is called on a crafted or corrupted filesystem.
The existing validation in ocfs2_validate_gd_self() only checks static
metadata consistency (bg_free_bits_count <= bg_bits) when the descriptor
is first read from disk. However, during move_extents operations,
multiple allocations can exhaust the free bits count below the requested
allocation size, triggering BUG_ON(le16_to_cpu(bg->bg_free_bits_count) <
num_bits).
The debug trace shows the issue clearly:
- Block group 32 validated with bg_free_bits_count=427
- Repeated allocations decreased count: 427 -> 171 -> 43 -> ... -> 1
- Final request for 2 bits with only 1 available triggers BUG_ON
By adding an early check in ocfs2_move_extent() right after
ocfs2_find_victim_alloc_group(), we return -ENOSPC gracefully instead of
crashing the kernel. This also avoids unnecessary work in
ocfs2_probe_alloc_group() and __ocfs2_move_extent() when the allocation
will fail.
Link: https://lkml.kernel.org/r/20260104133504.14810-1-kartikey406@gmail.com
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Reported-by: syzbot+7960178e777909060224@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7960178e777909060224
Link: https://lore.kernel.org/all/20251231115801.293726-1-kartikey406@gmail.com/T/ [v1]
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The comment for CONFIG_BOOTPARAM_HUNG_TASK_PANIC says:
Say N if unsure.
but since commit 9544f9e694 ("hung_task: panic when there are more than
N hung tasks at the same time"), N is not a valid value for the option,
leading to a warning at build time:
.config:11736:warning: symbol value 'n' invalid for BOOTPARAM_HUNG_TASK_PANIC
as well as an error when given to menuconfig.
Fix the comment to say '0' instead of 'N'.
Link: https://lkml.kernel.org/r/20260106140140.136446-1-tglozar@redhat.com
Fixes: 9544f9e694 ("hung_task: panic when there are more than N hung tasks at the same time")
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Reported-by: Johnny Mnemonic <jm@machine-hall.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Cc: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce KHO ABI header describing preservation ABI for memblock's
reserve_mem regions and link the relevant documentation to KHO docs.
[lukas.bulwahn@redhat.com: MAINTAINERS: adjust file entry in MEMBLOCK AND MEMORY MANAGEMENT INITIALIZATION]
Link: https://lkml.kernel.org/r/20260107090438.22901-1-lukas.bulwahn@redhat.com
[rppt@kernel.org: update reserved_mem node description, per Pratyush]
Link: https://lkml.kernel.org/r/aW_M-HYZzx5SkbnZ@kernel.org
Link: https://lkml.kernel.org/r/20260105165839.285270-7-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Jason Miu <jasonmiu@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The `struct kho_vmalloc` defines the in-memory layout for preserving
vmalloc regions across kexec. This layout is a contract between kernels
and part of the KHO ABI.
To reflect this relationship, the related structs and helper macros are
relocated to the ABI header, `include/linux/kho/abi/kexec_handover.h`.
This move places the structure's definition under the protection of the
KHO_FDT_COMPATIBLE version string.
The structure and its components are now also documented within the ABI
header to describe the contract and prevent ABI breaks.
[rppt@kernel.org: update comment, per Pratyush]
Link: https://lkml.kernel.org/r/aW_Mqp6HcqLwQImS@kernel.org
Link: https://lkml.kernel.org/r/20260105165839.285270-6-rppt@kernel.org
Signed-off-by: Jason Miu <jasonmiu@google.com>
Co-developed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce the `include/linux/kho/abi/kexec_handover.h` header file, which
defines the stable ABI for the KHO mechanism. This header specifies how
preserved data is passed between kernels using an FDT.
The ABI contract includes the FDT structure, node properties, and the
"kho-v1" compatible string. By centralizing these definitions, this
header serves as the foundational agreement for inter-kernel communication
of preserved states, ensuring forward compatibility and preventing
misinterpretation of data across kexec transitions.
Since the ABI definitions are now centralized in the header files, the
YAML files that previously described the FDT interfaces are redundant.
These redundant files have therefore been removed.
Link: https://lkml.kernel.org/r/20260105165839.285270-5-rppt@kernel.org
Signed-off-by: Jason Miu <jasonmiu@google.com>
Co-developed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently index.rst in KHO documentation looks empty and sad as it only
contains links to "Kexec Handover Concepts" and "KHO FDT" chapters.
Inline contents of these chapters into index.rst to provide a single
coherent chapter describing KHO.
While on it, drop parts of the KHO FDT description that will be superseded
by addition of KHO ABI documentation.
[rppt@kernel.org: fix Documentation/core-api/kho/index.rst]
Link: https://lkml.kernel.org/r/aV4bnHlBXGpT_FMc@kernel.org
Link: https://lkml.kernel.org/r/20260105165839.285270-4-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Jason Miu <jasonmiu@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
memfd preservation ABI description starts with "This header defines" which
is fine in the header but reads weird in the generated html documentation.
Update it to make the generated documentation coherent.
Link: https://lkml.kernel.org/r/20260105165839.285270-3-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Jason Miu <jasonmiu@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "kho: ABI headers and Documentation updates".
LUO started adding KHO ABI headers to include/linux/kho/abi, but the core
parts of KHO and memblock are still using the old way for descriptions on
their ABIs.
Let's consolidate all things KHO in include/linux/kho/abi.
And while on that, make some documentation updates to have more coherent
KHO docs.
This patch (of 6):
LUO ABI description starts with "This header defines" which is fine in the
header but reads weird in the generated html documentation.
Update it to make the generated documentation coherent.
Link: https://lkml.kernel.org/r/20260105165839.285270-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20260105165839.285270-2-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Jason Miu <jasonmiu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
