mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-19 17:14:40 +08:00
27bc50fc90
linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam R. Howlett. An overlapping range-based tree for vmas. It it apparently slight more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com). This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY0HaPgAKCRDdBJ7gKXxA joPjAQDZ5LlRCMWZ1oxLP2NOTp6nm63q9PWcGnmY50FjD/dNlwEAnx7OejCLWGWf bbTuk6U2+TKgJa4X7+pbbejeoqnt5QU= =xfWx -----END PGP SIGNATURE----- Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
850 lines
20 KiB
C
850 lines
20 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* Copyright (c) 2020 Facebook */
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#include <linux/init.h>
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#include <linux/namei.h>
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#include <linux/pid_namespace.h>
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#include <linux/fs.h>
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#include <linux/fdtable.h>
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#include <linux/filter.h>
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#include <linux/btf_ids.h>
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#include "mmap_unlock_work.h"
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static const char * const iter_task_type_names[] = {
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"ALL",
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"TID",
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"PID",
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};
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struct bpf_iter_seq_task_common {
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struct pid_namespace *ns;
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enum bpf_iter_task_type type;
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u32 pid;
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u32 pid_visiting;
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};
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struct bpf_iter_seq_task_info {
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/* The first field must be struct bpf_iter_seq_task_common.
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* this is assumed by {init, fini}_seq_pidns() callback functions.
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*/
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struct bpf_iter_seq_task_common common;
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u32 tid;
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};
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static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_common *common,
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u32 *tid,
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bool skip_if_dup_files)
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{
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struct task_struct *task, *next_task;
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struct pid *pid;
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u32 saved_tid;
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if (!*tid) {
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/* The first time, the iterator calls this function. */
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pid = find_pid_ns(common->pid, common->ns);
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if (!pid)
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return NULL;
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task = get_pid_task(pid, PIDTYPE_TGID);
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if (!task)
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return NULL;
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*tid = common->pid;
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common->pid_visiting = common->pid;
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return task;
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}
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/* If the control returns to user space and comes back to the
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* kernel again, *tid and common->pid_visiting should be the
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* same for task_seq_start() to pick up the correct task.
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*/
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if (*tid == common->pid_visiting) {
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pid = find_pid_ns(common->pid_visiting, common->ns);
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task = get_pid_task(pid, PIDTYPE_PID);
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return task;
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}
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pid = find_pid_ns(common->pid_visiting, common->ns);
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if (!pid)
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return NULL;
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task = get_pid_task(pid, PIDTYPE_PID);
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if (!task)
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return NULL;
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retry:
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if (!pid_alive(task)) {
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put_task_struct(task);
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return NULL;
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}
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next_task = next_thread(task);
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put_task_struct(task);
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if (!next_task)
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return NULL;
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saved_tid = *tid;
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*tid = __task_pid_nr_ns(next_task, PIDTYPE_PID, common->ns);
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if (!*tid || *tid == common->pid) {
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/* Run out of tasks of a process. The tasks of a
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* thread_group are linked as circular linked list.
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*/
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*tid = saved_tid;
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return NULL;
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}
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get_task_struct(next_task);
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common->pid_visiting = *tid;
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if (skip_if_dup_files && task->files == task->group_leader->files) {
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task = next_task;
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goto retry;
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}
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return next_task;
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}
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static struct task_struct *task_seq_get_next(struct bpf_iter_seq_task_common *common,
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u32 *tid,
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bool skip_if_dup_files)
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{
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struct task_struct *task = NULL;
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struct pid *pid;
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if (common->type == BPF_TASK_ITER_TID) {
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if (*tid && *tid != common->pid)
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return NULL;
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rcu_read_lock();
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pid = find_pid_ns(common->pid, common->ns);
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if (pid) {
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task = get_pid_task(pid, PIDTYPE_TGID);
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*tid = common->pid;
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}
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rcu_read_unlock();
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return task;
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}
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if (common->type == BPF_TASK_ITER_TGID) {
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rcu_read_lock();
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task = task_group_seq_get_next(common, tid, skip_if_dup_files);
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rcu_read_unlock();
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return task;
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}
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rcu_read_lock();
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retry:
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pid = find_ge_pid(*tid, common->ns);
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if (pid) {
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*tid = pid_nr_ns(pid, common->ns);
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task = get_pid_task(pid, PIDTYPE_PID);
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if (!task) {
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++*tid;
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goto retry;
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} else if (skip_if_dup_files && !thread_group_leader(task) &&
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task->files == task->group_leader->files) {
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put_task_struct(task);
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task = NULL;
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++*tid;
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goto retry;
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}
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}
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rcu_read_unlock();
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return task;
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}
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static void *task_seq_start(struct seq_file *seq, loff_t *pos)
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{
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struct bpf_iter_seq_task_info *info = seq->private;
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struct task_struct *task;
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task = task_seq_get_next(&info->common, &info->tid, false);
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if (!task)
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return NULL;
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if (*pos == 0)
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++*pos;
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return task;
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}
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static void *task_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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{
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struct bpf_iter_seq_task_info *info = seq->private;
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struct task_struct *task;
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++*pos;
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++info->tid;
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put_task_struct((struct task_struct *)v);
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task = task_seq_get_next(&info->common, &info->tid, false);
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if (!task)
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return NULL;
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return task;
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}
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struct bpf_iter__task {
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__bpf_md_ptr(struct bpf_iter_meta *, meta);
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__bpf_md_ptr(struct task_struct *, task);
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};
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DEFINE_BPF_ITER_FUNC(task, struct bpf_iter_meta *meta, struct task_struct *task)
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static int __task_seq_show(struct seq_file *seq, struct task_struct *task,
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bool in_stop)
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{
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struct bpf_iter_meta meta;
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struct bpf_iter__task ctx;
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struct bpf_prog *prog;
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meta.seq = seq;
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prog = bpf_iter_get_info(&meta, in_stop);
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if (!prog)
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return 0;
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ctx.meta = &meta;
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ctx.task = task;
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return bpf_iter_run_prog(prog, &ctx);
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}
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static int task_seq_show(struct seq_file *seq, void *v)
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{
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return __task_seq_show(seq, v, false);
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}
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static void task_seq_stop(struct seq_file *seq, void *v)
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{
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if (!v)
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(void)__task_seq_show(seq, v, true);
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else
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put_task_struct((struct task_struct *)v);
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}
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static int bpf_iter_attach_task(struct bpf_prog *prog,
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union bpf_iter_link_info *linfo,
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struct bpf_iter_aux_info *aux)
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{
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unsigned int flags;
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struct pid *pid;
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pid_t tgid;
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if ((!!linfo->task.tid + !!linfo->task.pid + !!linfo->task.pid_fd) > 1)
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return -EINVAL;
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aux->task.type = BPF_TASK_ITER_ALL;
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if (linfo->task.tid != 0) {
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aux->task.type = BPF_TASK_ITER_TID;
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aux->task.pid = linfo->task.tid;
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}
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if (linfo->task.pid != 0) {
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aux->task.type = BPF_TASK_ITER_TGID;
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aux->task.pid = linfo->task.pid;
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}
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if (linfo->task.pid_fd != 0) {
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aux->task.type = BPF_TASK_ITER_TGID;
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pid = pidfd_get_pid(linfo->task.pid_fd, &flags);
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if (IS_ERR(pid))
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return PTR_ERR(pid);
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tgid = pid_nr_ns(pid, task_active_pid_ns(current));
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aux->task.pid = tgid;
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put_pid(pid);
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}
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return 0;
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}
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static const struct seq_operations task_seq_ops = {
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.start = task_seq_start,
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.next = task_seq_next,
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.stop = task_seq_stop,
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.show = task_seq_show,
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};
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struct bpf_iter_seq_task_file_info {
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/* The first field must be struct bpf_iter_seq_task_common.
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* this is assumed by {init, fini}_seq_pidns() callback functions.
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*/
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struct bpf_iter_seq_task_common common;
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struct task_struct *task;
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u32 tid;
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u32 fd;
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};
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static struct file *
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task_file_seq_get_next(struct bpf_iter_seq_task_file_info *info)
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{
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u32 saved_tid = info->tid;
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struct task_struct *curr_task;
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unsigned int curr_fd = info->fd;
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/* If this function returns a non-NULL file object,
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* it held a reference to the task/file.
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* Otherwise, it does not hold any reference.
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*/
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again:
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if (info->task) {
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curr_task = info->task;
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curr_fd = info->fd;
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} else {
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curr_task = task_seq_get_next(&info->common, &info->tid, true);
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if (!curr_task) {
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info->task = NULL;
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return NULL;
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}
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/* set info->task */
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info->task = curr_task;
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if (saved_tid == info->tid)
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curr_fd = info->fd;
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else
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curr_fd = 0;
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}
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rcu_read_lock();
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for (;; curr_fd++) {
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struct file *f;
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f = task_lookup_next_fd_rcu(curr_task, &curr_fd);
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if (!f)
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break;
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if (!get_file_rcu(f))
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continue;
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/* set info->fd */
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info->fd = curr_fd;
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rcu_read_unlock();
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return f;
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}
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/* the current task is done, go to the next task */
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rcu_read_unlock();
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put_task_struct(curr_task);
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if (info->common.type == BPF_TASK_ITER_TID) {
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info->task = NULL;
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return NULL;
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}
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info->task = NULL;
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info->fd = 0;
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saved_tid = ++(info->tid);
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goto again;
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}
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static void *task_file_seq_start(struct seq_file *seq, loff_t *pos)
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{
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struct bpf_iter_seq_task_file_info *info = seq->private;
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struct file *file;
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info->task = NULL;
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file = task_file_seq_get_next(info);
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if (file && *pos == 0)
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++*pos;
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return file;
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}
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static void *task_file_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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{
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struct bpf_iter_seq_task_file_info *info = seq->private;
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++*pos;
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++info->fd;
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fput((struct file *)v);
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return task_file_seq_get_next(info);
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}
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struct bpf_iter__task_file {
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__bpf_md_ptr(struct bpf_iter_meta *, meta);
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__bpf_md_ptr(struct task_struct *, task);
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u32 fd __aligned(8);
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__bpf_md_ptr(struct file *, file);
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};
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DEFINE_BPF_ITER_FUNC(task_file, struct bpf_iter_meta *meta,
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struct task_struct *task, u32 fd,
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struct file *file)
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static int __task_file_seq_show(struct seq_file *seq, struct file *file,
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bool in_stop)
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{
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struct bpf_iter_seq_task_file_info *info = seq->private;
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struct bpf_iter__task_file ctx;
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struct bpf_iter_meta meta;
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struct bpf_prog *prog;
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meta.seq = seq;
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prog = bpf_iter_get_info(&meta, in_stop);
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if (!prog)
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return 0;
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ctx.meta = &meta;
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ctx.task = info->task;
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ctx.fd = info->fd;
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ctx.file = file;
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return bpf_iter_run_prog(prog, &ctx);
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}
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static int task_file_seq_show(struct seq_file *seq, void *v)
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{
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return __task_file_seq_show(seq, v, false);
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}
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static void task_file_seq_stop(struct seq_file *seq, void *v)
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{
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struct bpf_iter_seq_task_file_info *info = seq->private;
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if (!v) {
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(void)__task_file_seq_show(seq, v, true);
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} else {
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fput((struct file *)v);
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put_task_struct(info->task);
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info->task = NULL;
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}
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}
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static int init_seq_pidns(void *priv_data, struct bpf_iter_aux_info *aux)
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{
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struct bpf_iter_seq_task_common *common = priv_data;
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common->ns = get_pid_ns(task_active_pid_ns(current));
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common->type = aux->task.type;
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common->pid = aux->task.pid;
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|
|
|
return 0;
|
|
}
|
|
|
|
static void fini_seq_pidns(void *priv_data)
|
|
{
|
|
struct bpf_iter_seq_task_common *common = priv_data;
|
|
|
|
put_pid_ns(common->ns);
|
|
}
|
|
|
|
static const struct seq_operations task_file_seq_ops = {
|
|
.start = task_file_seq_start,
|
|
.next = task_file_seq_next,
|
|
.stop = task_file_seq_stop,
|
|
.show = task_file_seq_show,
|
|
};
|
|
|
|
struct bpf_iter_seq_task_vma_info {
|
|
/* The first field must be struct bpf_iter_seq_task_common.
|
|
* this is assumed by {init, fini}_seq_pidns() callback functions.
|
|
*/
|
|
struct bpf_iter_seq_task_common common;
|
|
struct task_struct *task;
|
|
struct vm_area_struct *vma;
|
|
u32 tid;
|
|
unsigned long prev_vm_start;
|
|
unsigned long prev_vm_end;
|
|
};
|
|
|
|
enum bpf_task_vma_iter_find_op {
|
|
task_vma_iter_first_vma, /* use find_vma() with addr 0 */
|
|
task_vma_iter_next_vma, /* use vma_next() with curr_vma */
|
|
task_vma_iter_find_vma, /* use find_vma() to find next vma */
|
|
};
|
|
|
|
static struct vm_area_struct *
|
|
task_vma_seq_get_next(struct bpf_iter_seq_task_vma_info *info)
|
|
{
|
|
enum bpf_task_vma_iter_find_op op;
|
|
struct vm_area_struct *curr_vma;
|
|
struct task_struct *curr_task;
|
|
u32 saved_tid = info->tid;
|
|
|
|
/* If this function returns a non-NULL vma, it holds a reference to
|
|
* the task_struct, and holds read lock on vma->mm->mmap_lock.
|
|
* If this function returns NULL, it does not hold any reference or
|
|
* lock.
|
|
*/
|
|
if (info->task) {
|
|
curr_task = info->task;
|
|
curr_vma = info->vma;
|
|
/* In case of lock contention, drop mmap_lock to unblock
|
|
* the writer.
|
|
*
|
|
* After relock, call find(mm, prev_vm_end - 1) to find
|
|
* new vma to process.
|
|
*
|
|
* +------+------+-----------+
|
|
* | VMA1 | VMA2 | VMA3 |
|
|
* +------+------+-----------+
|
|
* | | | |
|
|
* 4k 8k 16k 400k
|
|
*
|
|
* For example, curr_vma == VMA2. Before unlock, we set
|
|
*
|
|
* prev_vm_start = 8k
|
|
* prev_vm_end = 16k
|
|
*
|
|
* There are a few cases:
|
|
*
|
|
* 1) VMA2 is freed, but VMA3 exists.
|
|
*
|
|
* find_vma() will return VMA3, just process VMA3.
|
|
*
|
|
* 2) VMA2 still exists.
|
|
*
|
|
* find_vma() will return VMA2, process VMA2->next.
|
|
*
|
|
* 3) no more vma in this mm.
|
|
*
|
|
* Process the next task.
|
|
*
|
|
* 4) find_vma() returns a different vma, VMA2'.
|
|
*
|
|
* 4.1) If VMA2 covers same range as VMA2', skip VMA2',
|
|
* because we already covered the range;
|
|
* 4.2) VMA2 and VMA2' covers different ranges, process
|
|
* VMA2'.
|
|
*/
|
|
if (mmap_lock_is_contended(curr_task->mm)) {
|
|
info->prev_vm_start = curr_vma->vm_start;
|
|
info->prev_vm_end = curr_vma->vm_end;
|
|
op = task_vma_iter_find_vma;
|
|
mmap_read_unlock(curr_task->mm);
|
|
if (mmap_read_lock_killable(curr_task->mm))
|
|
goto finish;
|
|
} else {
|
|
op = task_vma_iter_next_vma;
|
|
}
|
|
} else {
|
|
again:
|
|
curr_task = task_seq_get_next(&info->common, &info->tid, true);
|
|
if (!curr_task) {
|
|
info->tid++;
|
|
goto finish;
|
|
}
|
|
|
|
if (saved_tid != info->tid) {
|
|
/* new task, process the first vma */
|
|
op = task_vma_iter_first_vma;
|
|
} else {
|
|
/* Found the same tid, which means the user space
|
|
* finished data in previous buffer and read more.
|
|
* We dropped mmap_lock before returning to user
|
|
* space, so it is necessary to use find_vma() to
|
|
* find the next vma to process.
|
|
*/
|
|
op = task_vma_iter_find_vma;
|
|
}
|
|
|
|
if (!curr_task->mm)
|
|
goto next_task;
|
|
|
|
if (mmap_read_lock_killable(curr_task->mm))
|
|
goto finish;
|
|
}
|
|
|
|
switch (op) {
|
|
case task_vma_iter_first_vma:
|
|
curr_vma = find_vma(curr_task->mm, 0);
|
|
break;
|
|
case task_vma_iter_next_vma:
|
|
curr_vma = find_vma(curr_task->mm, curr_vma->vm_end);
|
|
break;
|
|
case task_vma_iter_find_vma:
|
|
/* We dropped mmap_lock so it is necessary to use find_vma
|
|
* to find the next vma. This is similar to the mechanism
|
|
* in show_smaps_rollup().
|
|
*/
|
|
curr_vma = find_vma(curr_task->mm, info->prev_vm_end - 1);
|
|
/* case 1) and 4.2) above just use curr_vma */
|
|
|
|
/* check for case 2) or case 4.1) above */
|
|
if (curr_vma &&
|
|
curr_vma->vm_start == info->prev_vm_start &&
|
|
curr_vma->vm_end == info->prev_vm_end)
|
|
curr_vma = find_vma(curr_task->mm, curr_vma->vm_end);
|
|
break;
|
|
}
|
|
if (!curr_vma) {
|
|
/* case 3) above, or case 2) 4.1) with vma->next == NULL */
|
|
mmap_read_unlock(curr_task->mm);
|
|
goto next_task;
|
|
}
|
|
info->task = curr_task;
|
|
info->vma = curr_vma;
|
|
return curr_vma;
|
|
|
|
next_task:
|
|
if (info->common.type == BPF_TASK_ITER_TID)
|
|
goto finish;
|
|
|
|
put_task_struct(curr_task);
|
|
info->task = NULL;
|
|
info->tid++;
|
|
goto again;
|
|
|
|
finish:
|
|
if (curr_task)
|
|
put_task_struct(curr_task);
|
|
info->task = NULL;
|
|
info->vma = NULL;
|
|
return NULL;
|
|
}
|
|
|
|
static void *task_vma_seq_start(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
struct bpf_iter_seq_task_vma_info *info = seq->private;
|
|
struct vm_area_struct *vma;
|
|
|
|
vma = task_vma_seq_get_next(info);
|
|
if (vma && *pos == 0)
|
|
++*pos;
|
|
|
|
return vma;
|
|
}
|
|
|
|
static void *task_vma_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
struct bpf_iter_seq_task_vma_info *info = seq->private;
|
|
|
|
++*pos;
|
|
return task_vma_seq_get_next(info);
|
|
}
|
|
|
|
struct bpf_iter__task_vma {
|
|
__bpf_md_ptr(struct bpf_iter_meta *, meta);
|
|
__bpf_md_ptr(struct task_struct *, task);
|
|
__bpf_md_ptr(struct vm_area_struct *, vma);
|
|
};
|
|
|
|
DEFINE_BPF_ITER_FUNC(task_vma, struct bpf_iter_meta *meta,
|
|
struct task_struct *task, struct vm_area_struct *vma)
|
|
|
|
static int __task_vma_seq_show(struct seq_file *seq, bool in_stop)
|
|
{
|
|
struct bpf_iter_seq_task_vma_info *info = seq->private;
|
|
struct bpf_iter__task_vma ctx;
|
|
struct bpf_iter_meta meta;
|
|
struct bpf_prog *prog;
|
|
|
|
meta.seq = seq;
|
|
prog = bpf_iter_get_info(&meta, in_stop);
|
|
if (!prog)
|
|
return 0;
|
|
|
|
ctx.meta = &meta;
|
|
ctx.task = info->task;
|
|
ctx.vma = info->vma;
|
|
return bpf_iter_run_prog(prog, &ctx);
|
|
}
|
|
|
|
static int task_vma_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
return __task_vma_seq_show(seq, false);
|
|
}
|
|
|
|
static void task_vma_seq_stop(struct seq_file *seq, void *v)
|
|
{
|
|
struct bpf_iter_seq_task_vma_info *info = seq->private;
|
|
|
|
if (!v) {
|
|
(void)__task_vma_seq_show(seq, true);
|
|
} else {
|
|
/* info->vma has not been seen by the BPF program. If the
|
|
* user space reads more, task_vma_seq_get_next should
|
|
* return this vma again. Set prev_vm_start to ~0UL,
|
|
* so that we don't skip the vma returned by the next
|
|
* find_vma() (case task_vma_iter_find_vma in
|
|
* task_vma_seq_get_next()).
|
|
*/
|
|
info->prev_vm_start = ~0UL;
|
|
info->prev_vm_end = info->vma->vm_end;
|
|
mmap_read_unlock(info->task->mm);
|
|
put_task_struct(info->task);
|
|
info->task = NULL;
|
|
}
|
|
}
|
|
|
|
static const struct seq_operations task_vma_seq_ops = {
|
|
.start = task_vma_seq_start,
|
|
.next = task_vma_seq_next,
|
|
.stop = task_vma_seq_stop,
|
|
.show = task_vma_seq_show,
|
|
};
|
|
|
|
static const struct bpf_iter_seq_info task_seq_info = {
|
|
.seq_ops = &task_seq_ops,
|
|
.init_seq_private = init_seq_pidns,
|
|
.fini_seq_private = fini_seq_pidns,
|
|
.seq_priv_size = sizeof(struct bpf_iter_seq_task_info),
|
|
};
|
|
|
|
static int bpf_iter_fill_link_info(const struct bpf_iter_aux_info *aux, struct bpf_link_info *info)
|
|
{
|
|
switch (aux->task.type) {
|
|
case BPF_TASK_ITER_TID:
|
|
info->iter.task.tid = aux->task.pid;
|
|
break;
|
|
case BPF_TASK_ITER_TGID:
|
|
info->iter.task.pid = aux->task.pid;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void bpf_iter_task_show_fdinfo(const struct bpf_iter_aux_info *aux, struct seq_file *seq)
|
|
{
|
|
seq_printf(seq, "task_type:\t%s\n", iter_task_type_names[aux->task.type]);
|
|
if (aux->task.type == BPF_TASK_ITER_TID)
|
|
seq_printf(seq, "tid:\t%u\n", aux->task.pid);
|
|
else if (aux->task.type == BPF_TASK_ITER_TGID)
|
|
seq_printf(seq, "pid:\t%u\n", aux->task.pid);
|
|
}
|
|
|
|
static struct bpf_iter_reg task_reg_info = {
|
|
.target = "task",
|
|
.attach_target = bpf_iter_attach_task,
|
|
.feature = BPF_ITER_RESCHED,
|
|
.ctx_arg_info_size = 1,
|
|
.ctx_arg_info = {
|
|
{ offsetof(struct bpf_iter__task, task),
|
|
PTR_TO_BTF_ID_OR_NULL },
|
|
},
|
|
.seq_info = &task_seq_info,
|
|
.fill_link_info = bpf_iter_fill_link_info,
|
|
.show_fdinfo = bpf_iter_task_show_fdinfo,
|
|
};
|
|
|
|
static const struct bpf_iter_seq_info task_file_seq_info = {
|
|
.seq_ops = &task_file_seq_ops,
|
|
.init_seq_private = init_seq_pidns,
|
|
.fini_seq_private = fini_seq_pidns,
|
|
.seq_priv_size = sizeof(struct bpf_iter_seq_task_file_info),
|
|
};
|
|
|
|
static struct bpf_iter_reg task_file_reg_info = {
|
|
.target = "task_file",
|
|
.attach_target = bpf_iter_attach_task,
|
|
.feature = BPF_ITER_RESCHED,
|
|
.ctx_arg_info_size = 2,
|
|
.ctx_arg_info = {
|
|
{ offsetof(struct bpf_iter__task_file, task),
|
|
PTR_TO_BTF_ID_OR_NULL },
|
|
{ offsetof(struct bpf_iter__task_file, file),
|
|
PTR_TO_BTF_ID_OR_NULL },
|
|
},
|
|
.seq_info = &task_file_seq_info,
|
|
.fill_link_info = bpf_iter_fill_link_info,
|
|
.show_fdinfo = bpf_iter_task_show_fdinfo,
|
|
};
|
|
|
|
static const struct bpf_iter_seq_info task_vma_seq_info = {
|
|
.seq_ops = &task_vma_seq_ops,
|
|
.init_seq_private = init_seq_pidns,
|
|
.fini_seq_private = fini_seq_pidns,
|
|
.seq_priv_size = sizeof(struct bpf_iter_seq_task_vma_info),
|
|
};
|
|
|
|
static struct bpf_iter_reg task_vma_reg_info = {
|
|
.target = "task_vma",
|
|
.attach_target = bpf_iter_attach_task,
|
|
.feature = BPF_ITER_RESCHED,
|
|
.ctx_arg_info_size = 2,
|
|
.ctx_arg_info = {
|
|
{ offsetof(struct bpf_iter__task_vma, task),
|
|
PTR_TO_BTF_ID_OR_NULL },
|
|
{ offsetof(struct bpf_iter__task_vma, vma),
|
|
PTR_TO_BTF_ID_OR_NULL },
|
|
},
|
|
.seq_info = &task_vma_seq_info,
|
|
.fill_link_info = bpf_iter_fill_link_info,
|
|
.show_fdinfo = bpf_iter_task_show_fdinfo,
|
|
};
|
|
|
|
BPF_CALL_5(bpf_find_vma, struct task_struct *, task, u64, start,
|
|
bpf_callback_t, callback_fn, void *, callback_ctx, u64, flags)
|
|
{
|
|
struct mmap_unlock_irq_work *work = NULL;
|
|
struct vm_area_struct *vma;
|
|
bool irq_work_busy = false;
|
|
struct mm_struct *mm;
|
|
int ret = -ENOENT;
|
|
|
|
if (flags)
|
|
return -EINVAL;
|
|
|
|
if (!task)
|
|
return -ENOENT;
|
|
|
|
mm = task->mm;
|
|
if (!mm)
|
|
return -ENOENT;
|
|
|
|
irq_work_busy = bpf_mmap_unlock_get_irq_work(&work);
|
|
|
|
if (irq_work_busy || !mmap_read_trylock(mm))
|
|
return -EBUSY;
|
|
|
|
vma = find_vma(mm, start);
|
|
|
|
if (vma && vma->vm_start <= start && vma->vm_end > start) {
|
|
callback_fn((u64)(long)task, (u64)(long)vma,
|
|
(u64)(long)callback_ctx, 0, 0);
|
|
ret = 0;
|
|
}
|
|
bpf_mmap_unlock_mm(work, mm);
|
|
return ret;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_find_vma_proto = {
|
|
.func = bpf_find_vma,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
|
|
.arg2_type = ARG_ANYTHING,
|
|
.arg3_type = ARG_PTR_TO_FUNC,
|
|
.arg4_type = ARG_PTR_TO_STACK_OR_NULL,
|
|
.arg5_type = ARG_ANYTHING,
|
|
};
|
|
|
|
DEFINE_PER_CPU(struct mmap_unlock_irq_work, mmap_unlock_work);
|
|
|
|
static void do_mmap_read_unlock(struct irq_work *entry)
|
|
{
|
|
struct mmap_unlock_irq_work *work;
|
|
|
|
if (WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_RT)))
|
|
return;
|
|
|
|
work = container_of(entry, struct mmap_unlock_irq_work, irq_work);
|
|
mmap_read_unlock_non_owner(work->mm);
|
|
}
|
|
|
|
static int __init task_iter_init(void)
|
|
{
|
|
struct mmap_unlock_irq_work *work;
|
|
int ret, cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
work = per_cpu_ptr(&mmap_unlock_work, cpu);
|
|
init_irq_work(&work->irq_work, do_mmap_read_unlock);
|
|
}
|
|
|
|
task_reg_info.ctx_arg_info[0].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_TASK];
|
|
ret = bpf_iter_reg_target(&task_reg_info);
|
|
if (ret)
|
|
return ret;
|
|
|
|
task_file_reg_info.ctx_arg_info[0].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_TASK];
|
|
task_file_reg_info.ctx_arg_info[1].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_FILE];
|
|
ret = bpf_iter_reg_target(&task_file_reg_info);
|
|
if (ret)
|
|
return ret;
|
|
|
|
task_vma_reg_info.ctx_arg_info[0].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_TASK];
|
|
task_vma_reg_info.ctx_arg_info[1].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_VMA];
|
|
return bpf_iter_reg_target(&task_vma_reg_info);
|
|
}
|
|
late_initcall(task_iter_init);
|