blaster4385/linux-IllusionX/kernel/sched, branch v6.12.1

Merge tag 'sched_ext-for-6.12-rc7-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

2024-11-15T17:59:51Z

Pull sched_ext fix from Tejun Heo: "One more fix for v6.12-rc7 ops.cpu_acquire() was being invoked with the wrong kfunc mask allowing the operation to call kfuncs which shouldn't be allowed. Fix it by using SCX_KF_REST instead, which is trivial and low risk" * tag 'sched_ext-for-6.12-rc7-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: ops.cpu_acquire() should be called with SCX_KF_REST

sched_ext: ops.cpu_acquire() should be called with SCX_KF_REST

2024-11-14T18:50:58Z

ops.cpu_acquire() is currently called with 0 kf_maks which is interpreted as SCX_KF_UNLOCKED which allows all unlocked kfuncs, but ops.cpu_acquire() is called from balance_one() under the rq lock and should only be allowed call kfuncs that are safe under the rq lock. Update it to use SCX_KF_REST. Signed-off-by: Tejun Heo Cc: David Vernet Cc: Zhao Mengmeng Link: http://lkml.kernel.org/r/ZzYvf2L3rlmjuKzh@slm.duckdns.org Fixes: 245254f7081d ("sched_ext: Implement sched_ext_ops.cpu_acquire/release()")

Merge tag 'sched_ext-for-6.12-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

2024-11-11T22:09:57Z

Pull sched_ext fixes from Tejun Heo: - The fair sched class currently has a bug where its balance() returns true telling the sched core that it has tasks to run but then NULL from pick_task(). This makes sched core call sched_ext's pick_task() without preceding balance() which can lead to stalls in partial mode. For now, work around by detecting the condition and forcing the CPU to go through another scheduling cycle. - Add a missing newline to an error message and fix drgn introspection tool which went out of sync. * tag 'sched_ext-for-6.12-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: Handle cases where pick_task_scx() is called without preceding balance_scx() sched_ext: Update scx_show_state.py to match scx_ops_bypass_depth's new type sched_ext: Add a missing newline at the end of an error message

sched_ext: Handle cases where pick_task_scx() is called without preceding balance_scx()

2024-11-09T20:43:55Z

sched_ext dispatches tasks from the BPF scheduler from balance_scx() and thus every pick_task_scx() call must be preceded by balance_scx(). While this usually holds, due to a bug, there are cases where the fair class's balance() returns true indicating that it has tasks to run on the CPU and thus terminating balance() calls but fails to actually find the next task to run when pick_task() is called. In such cases, pick_task_scx() can be called without preceding balance_scx(). Detect this condition using SCX_RQ_BAL_PENDING flags. If detected, keep running the previous task if possible and avoid stalling from entering idle without balancing. Signed-off-by: Tejun Heo Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/Ztj_h5c2LYsdXYbA@slm.duckdns.org

sched_ext: Add a missing newline at the end of an error message

2024-11-05T21:45:24Z

Signed-off-by: Tejun Heo

Merge tag 'sched-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-11-03T18:18:28Z

Pull scheduler fixes from Thomas Gleixner: - Plug a race between pick_next_task_fair() and try_to_wake_up() where both try to write to the same task, even though both paths hold a runqueue lock, but obviously from different runqueues. The problem is that the store to task::on_rq in __block_task() is visible to try_to_wake_up() which assumes that the task is not queued. Both sides then operate on the same task. Cure it by rearranging __block_task() so the the store to task::on_rq is the last operation on the task. - Prevent a potential NULL pointer dereference in task_numa_work() task_numa_work() iterates the VMAs of a process. A concurrent unmap of the address space can result in a NULL pointer return from vma_next() which is unchecked. Add the missing NULL pointer check to prevent this. - Operate on the correct scheduler policy in task_should_scx() task_should_scx() returns true when a task should be handled by sched EXT. It checks the tasks scheduling policy. This fails when the check is done before a policy has been set. Cure it by handing the policy into task_should_scx() so it operates on the requested value. - Add the missing handling of sched EXT in the delayed dequeue mechanism. This was simply forgotten. * tag 'sched-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/ext: Fix scx vs sched_delayed sched: Pass correct scheduling policy to __setscheduler_class sched/numa: Fix the potential null pointer dereference in task_numa_work() sched: Fix pick_next_task_fair() vs try_to_wake_up() race

sched/ext: Fix scx vs sched_delayed

2024-10-30T21:42:12Z

Commit 98442f0ccd82 ("sched: Fix delayed_dequeue vs switched_from_fair()") forgot about scx :/ Fixes: 98442f0ccd82 ("sched: Fix delayed_dequeue vs switched_from_fair()") Reported-by: Tejun Heo Signed-off-by: Peter Zijlstra (Intel) Acked-by: Tejun Heo Link: https://lkml.kernel.org/r/20241030104934.GK14555@noisy.programming.kicks-ass.net

Merge tag 'sched_ext-for-6.12-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

2024-10-30T02:35:40Z

Pull sched_ext fixes from Tejun Heo: - Instances of scx_ops_bypass() could race each other leading to misbehavior. Fix by protecting the operation with a spinlock. - selftest and userspace header fixes * tag 'sched_ext-for-6.12-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: Fix enq_last_no_enq_fails selftest sched_ext: Make cast_mask() inline scx: Fix raciness in scx_ops_bypass() scx: Fix exit selftest to use custom DSQ sched_ext: Fix function pointer type mismatches in BPF selftests selftests/sched_ext: add order-only dependency of runner.o on BPFOBJ

sched: Pass correct scheduling policy to __setscheduler_class

2024-10-29T12:57:51Z

Commit 98442f0ccd82 ("sched: Fix delayed_dequeue vs switched_from_fair()") overlooked that __setscheduler_prio(), now __setscheduler_class() relies on p->policy for task_should_scx(), and moved the call before __setscheduler_params() updates it, causing it to be using the old p->policy value. Resolve this by changing task_should_scx() to take the policy itself instead of a task pointer, such that __sched_setscheduler() can pass in the updated policy. Fixes: 98442f0ccd82 ("sched: Fix delayed_dequeue vs switched_from_fair()") Signed-off-by: Aboorva Devarajan Signed-off-by: Peter Zijlstra (Intel) Acked-by: Tejun Heo

sched/numa: Fix the potential null pointer dereference in task_numa_work()

2024-10-26T07:28:37Z

When running stress-ng-vm-segv test, we found a null pointer dereference error in task_numa_work(). Here is the backtrace: [323676.066985] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 ...... [323676.067108] CPU: 35 PID: 2694524 Comm: stress-ng-vm-se ...... [323676.067113] pstate: 23401009 (nzCv daif +PAN -UAO +TCO +DIT +SSBS BTYPE=--) [323676.067115] pc : vma_migratable+0x1c/0xd0 [323676.067122] lr : task_numa_work+0x1ec/0x4e0 [323676.067127] sp : ffff8000ada73d20 [323676.067128] x29: ffff8000ada73d20 x28: 0000000000000000 x27: 000000003e89f010 [323676.067130] x26: 0000000000080000 x25: ffff800081b5c0d8 x24: ffff800081b27000 [323676.067133] x23: 0000000000010000 x22: 0000000104d18cc0 x21: ffff0009f7158000 [323676.067135] x20: 0000000000000000 x19: 0000000000000000 x18: ffff8000ada73db8 [323676.067138] x17: 0001400000000000 x16: ffff800080df40b0 x15: 0000000000000035 [323676.067140] x14: ffff8000ada73cc8 x13: 1fffe0017cc72001 x12: ffff8000ada73cc8 [323676.067142] x11: ffff80008001160c x10: ffff000be639000c x9 : ffff8000800f4ba4 [323676.067145] x8 : ffff000810375000 x7 : ffff8000ada73974 x6 : 0000000000000001 [323676.067147] x5 : 0068000b33e26707 x4 : 0000000000000001 x3 : ffff0009f7158000 [323676.067149] x2 : 0000000000000041 x1 : 0000000000004400 x0 : 0000000000000000 [323676.067152] Call trace: [323676.067153] vma_migratable+0x1c/0xd0 [323676.067155] task_numa_work+0x1ec/0x4e0 [323676.067157] task_work_run+0x78/0xd8 [323676.067161] do_notify_resume+0x1ec/0x290 [323676.067163] el0_svc+0x150/0x160 [323676.067167] el0t_64_sync_handler+0xf8/0x128 [323676.067170] el0t_64_sync+0x17c/0x180 [323676.067173] Code: d2888001 910003fd f9000bf3 aa0003f3 (f9401000) [323676.067177] SMP: stopping secondary CPUs [323676.070184] Starting crashdump kernel... stress-ng-vm-segv in stress-ng is used to stress test the SIGSEGV error handling function of the system, which tries to cause a SIGSEGV error on return from unmapping the whole address space of the child process. Normally this program will not cause kernel crashes. But before the munmap system call returns to user mode, a potential task_numa_work() for numa balancing could be added and executed. In this scenario, since the child process has no vma after munmap, the vma_next() in task_numa_work() will return a null pointer even if the vma iterator restarts from 0. Recheck the vma pointer before dereferencing it in task_numa_work(). Fixes: 214dbc428137 ("sched: convert to vma iterator") Signed-off-by: Shawn Wang Signed-off-by: Peter Zijlstra (Intel) Cc: stable@vger.kernel.org # v6.2+ Link: https://lkml.kernel.org/r/20241025022208.125527-1-shawnwang@linux.alibaba.com