kernel/linux.git/include/linux/sched/task_stack.h, branch v6.19.11

sched/task_stack: Add missing const qualifier to end_of_stack()

2025-07-26T21:28:35+00:00

Add missing const qualifier to the non-CONFIG_THREAD_INFO_IN_TASK version of end_of_stack() to match the CONFIG_THREAD_INFO_IN_TASK version. Fixes a warning with CONFIG_KSTACK_ERASE=y on archs that don't select THREAD_INFO_IN_TASK (such as LoongArch): error: passing 'const struct task_struct *' to parameter of type 'struct task_struct *' discards qualifiers The stackleak_task_low_bound() function correctly uses a const task parameter, but the legacy end_of_stack() prototype didn't like that. Build tested on loongarch (with CONFIG_KSTACK_ERASE=y) and m68k (with CONFIG_DEBUG_STACK_USAGE=y). Fixes: a45728fd4120 ("LoongArch: Enable HAVE_ARCH_STACKLEAK") Reported-by: Nathan Chancellor Closes: https://lore.kernel.org/all/20250726004313.GA3650901@ax162 Cc: Youling Tang Cc: Huacai Chen Tested-by: Nathan Chancellor Signed-off-by: Kees Cook

task_stack.h: remove obsolete __HAVE_ARCH_KSTACK_END check

2025-05-12T00:54:04+00:00

Remove __HAVE_ARCH_KSTACK_END as it has been obsolete since removal of metag architecture in v4.17. Link: https://lkml.kernel.org/r/20250403-kstack-end-v1-1-7798e71f34d1@linaro.org Signed-off-by: Pasha Tatashin Link: https://lore.kernel.org/20240311164638.2015063-2-pasha.tatashin@soleen.com Signed-off-by: Linus Walleij Signed-off-by: Andrew Morton

Merge tag 'sched-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-11-19T22:16:06+00:00

Pull scheduler updates from Ingo Molnar: "Core facilities: - Add the "Lazy preemption" model (CONFIG_PREEMPT_LAZY=y), which optimizes fair-class preemption by delaying preemption requests to the tick boundary, while working as full preemption for RR/FIFO/DEADLINE classes. (Peter Zijlstra) - x86: Enable Lazy preemption (Peter Zijlstra) - riscv: Enable Lazy preemption (Jisheng Zhang) - Initialize idle tasks only once (Thomas Gleixner) - sched/ext: Remove sched_fork() hack (Thomas Gleixner) Fair scheduler: - Optimize the PLACE_LAG when se->vlag is zero (Huang Shijie) Idle loop: - Optimize the generic idle loop by removing unnecessary memory barrier (Zhongqiu Han) RSEQ: - Improve cache locality of RSEQ concurrency IDs for intermittent workloads (Mathieu Desnoyers) Waitqueues: - Make wake_up_{bit,var} less fragile (Neil Brown) PSI: - Pass enqueue/dequeue flags to psi callbacks directly (Johannes Weiner) Preparatory patches for proxy execution: - Add move_queued_task_locked helper (Connor O'Brien) - Consolidate pick_*_task to task_is_pushable helper (Connor O'Brien) - Split out __schedule() deactivate task logic into a helper (John Stultz) - Split scheduler and execution contexts (Peter Zijlstra) - Make mutex::wait_lock irq safe (Juri Lelli) - Expose __mutex_owner() (Juri Lelli) - Remove wakeups from under mutex::wait_lock (Peter Zijlstra) Misc fixes and cleanups: - Remove unused __HAVE_THREAD_FUNCTIONS hook support (David Disseldorp) - Update the comment for TIF_NEED_RESCHED_LAZY (Sebastian Andrzej Siewior) - Remove unused bit_wait_io_timeout (Dr. David Alan Gilbert) - remove the DOUBLE_TICK feature (Huang Shijie) - fix the comment for PREEMPT_SHORT (Huang Shijie) - Fix unnused variable warning (Christian Loehle) - No PREEMPT_RT=y for all{yes,mod}config" * tag 'sched-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) sched, x86: Update the comment for TIF_NEED_RESCHED_LAZY. sched: No PREEMPT_RT=y for all{yes,mod}config riscv: add PREEMPT_LAZY support sched, x86: Enable Lazy preemption sched: Enable PREEMPT_DYNAMIC for PREEMPT_RT sched: Add Lazy preemption model sched: Add TIF_NEED_RESCHED_LAZY infrastructure sched/ext: Remove sched_fork() hack sched: Initialize idle tasks only once sched: psi: pass enqueue/dequeue flags to psi callbacks directly sched/uclamp: Fix unnused variable warning sched: Split scheduler and execution contexts sched: Split out __schedule() deactivate task logic into a helper sched: Consolidate pick_*_task to task_is_pushable helper sched: Add move_queued_task_locked helper locking/mutex: Expose __mutex_owner() locking/mutex: Make mutex::wait_lock irq safe locking/mutex: Remove wakeups from under mutex::wait_lock sched: Improve cache locality of RSEQ concurrency IDs for intermittent workloads sched: idle: Optimize the generic idle loop by removing needless memory barrier ...

sched/task_stack: fix object_is_on_stack() for KASAN tagged pointers

2024-11-15T06:43:48+00:00

When CONFIG_KASAN_SW_TAGS and CONFIG_KASAN_STACK are enabled, the object_is_on_stack() function may produce incorrect results due to the presence of tags in the obj pointer, while the stack pointer does not have tags. This discrepancy can lead to incorrect stack object detection and subsequently trigger warnings if CONFIG_DEBUG_OBJECTS is also enabled. Example of the warning: ODEBUG: object 3eff800082ea7bb0 is NOT on stack ffff800082ea0000, but annotated. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at lib/debugobjects.c:557 __debug_object_init+0x330/0x364 Modules linked in: CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc5 #4 Hardware name: linux,dummy-virt (DT) pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __debug_object_init+0x330/0x364 lr : __debug_object_init+0x330/0x364 sp : ffff800082ea7b40 x29: ffff800082ea7b40 x28: 98ff0000c0164518 x27: 98ff0000c0164534 x26: ffff800082d93ec8 x25: 0000000000000001 x24: 1cff0000c00172a0 x23: 0000000000000000 x22: ffff800082d93ed0 x21: ffff800081a24418 x20: 3eff800082ea7bb0 x19: efff800000000000 x18: 0000000000000000 x17: 00000000000000ff x16: 0000000000000047 x15: 206b63617473206e x14: 0000000000000018 x13: ffff800082ea7780 x12: 0ffff800082ea78e x11: 0ffff800082ea790 x10: 0ffff800082ea79d x9 : 34d77febe173e800 x8 : 34d77febe173e800 x7 : 0000000000000001 x6 : 0000000000000001 x5 : feff800082ea74b8 x4 : ffff800082870a90 x3 : ffff80008018d3c4 x2 : 0000000000000001 x1 : ffff800082858810 x0 : 0000000000000050 Call trace: __debug_object_init+0x330/0x364 debug_object_init_on_stack+0x30/0x3c schedule_hrtimeout_range_clock+0xac/0x26c schedule_hrtimeout+0x1c/0x30 wait_task_inactive+0x1d4/0x25c kthread_bind_mask+0x28/0x98 init_rescuer+0x1e8/0x280 workqueue_init+0x1a0/0x3cc kernel_init_freeable+0x118/0x200 kernel_init+0x28/0x1f0 ret_from_fork+0x10/0x20 ---[ end trace 0000000000000000 ]--- ODEBUG: object 3eff800082ea7bb0 is NOT on stack ffff800082ea0000, but annotated. ------------[ cut here ]------------ Link: https://lkml.kernel.org/r/20241113042544.19095-1-qun-wei.lin@mediatek.com Signed-off-by: Qun-Wei Lin Cc: Andrew Yang Cc: AngeloGioacchino Del Regno Cc: Casper Li Cc: Catalin Marinas Cc: Chinwen Chang Cc: Kent Overstreet Cc: Matthias Brugger Cc: Pasha Tatashin Cc: Shakeel Butt Cc: Signed-off-by: Andrew Morton

sched: remove unused __HAVE_THREAD_FUNCTIONS hook support

2024-10-07T07:28:40+00:00

__HAVE_THREAD_FUNCTIONS could be defined by architectures wishing to provide their own task_thread_info(), task_stack_page(), setup_thread_stack() and end_of_stack() hooks. Commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture") removed the last upstream consumer of __HAVE_THREAD_FUNCTIONS, so change the remaining !CONFIG_THREAD_INFO_IN_TASK && !__HAVE_THREAD_FUNCTIONS conditionals to only check for the former case. Signed-off-by: David Disseldorp Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Ard Biesheuvel Link: https://lkml.kernel.org/r/20240930050945.30304-2-ddiss@suse.de

task_stack: uninline stack_not_used

2024-09-02T03:25:49+00:00

Given that stack_not_used() is not performance critical function uninline it. Link: https://lkml.kernel.org/r/20240730150158.832783-4-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20240724203322.2765486-4-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Acked-by: Shakeel Butt Cc: Domenico Cerasuolo Cc: Kent Overstreet Cc: Li Zhijian Cc: Matthew Wilcox Cc: Nhat Pham Cc: Peter Zijlstra Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Zi Yan Signed-off-by: Andrew Morton

task_stack.h: add missing include

2023-12-21T00:26:30+00:00

Signed-off-by: Kent Overstreet

sched: Fix KCSAN noinstr violation

2023-04-14T14:08:26+00:00

With KCSAN enabled, end_of_stack() can get out-of-lined. Force it inline. Fixes the following warnings: vmlinux.o: warning: objtool: check_stackleak_irqoff+0x2b: call to end_of_stack() leaves .noinstr.text section Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/cc1b4d73d3a428a00d206242a68fdf99a934ca7b.1681320026.git.jpoimboe@kernel.org

task_stack, x86/cea: Force-inline stack helpers

2022-04-04T08:13:07+00:00

Force-inline two stack helpers to fix the following objtool warnings: vmlinux.o: warning: objtool: in_task_stack()+0xc: call to task_stack_page() leaves .noinstr.text section vmlinux.o: warning: objtool: in_entry_stack()+0x10: call to cpu_entry_stack() leaves .noinstr.text section Signed-off-by: Borislav Petkov Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220324183607.31717-2-bp@alien8.de

fork: Move task stack accounting to do_exit()

2022-02-22T21:25:02+00:00

There is no need to perform the stack accounting of the outgoing task in its final schedule() invocation which happens with preemption disabled. The task is leaving, the resources will be freed and the accounting can happen in do_exit() before the actual schedule invocation which frees the stack memory. Move the accounting of the stack memory from release_task_stack() to exit_task_stack_account() which then can be invoked from do_exit(). Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Acked-by: Andy Lutomirski Link: https://lore.kernel.org/r/20220217102406.3697941-7-bigeasy@linutronix.de