diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/auditsc.c | 2 | ||||
| -rw-r--r-- | kernel/bpf/btf.c | 147 | ||||
| -rw-r--r-- | kernel/bpf/cgroup.c | 70 | ||||
| -rw-r--r-- | kernel/bpf/core.c | 17 | ||||
| -rw-r--r-- | kernel/bpf/helpers.c | 12 | ||||
| -rw-r--r-- | kernel/bpf/percpu_freelist.c | 20 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 7 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 49 | ||||
| -rw-r--r-- | kernel/cfi.c | 22 | ||||
| -rw-r--r-- | kernel/events/core.c | 16 | ||||
| -rw-r--r-- | kernel/irq/chip.c | 5 | ||||
| -rw-r--r-- | kernel/locking/lockdep.c | 2 | ||||
| -rw-r--r-- | kernel/panic.c | 2 | ||||
| -rw-r--r-- | kernel/printk/internal.h | 2 | ||||
| -rw-r--r-- | kernel/printk/printk.c | 8 | ||||
| -rw-r--r-- | kernel/printk/printk_safe.c | 32 | ||||
| -rw-r--r-- | kernel/reboot.c | 2 | ||||
| -rw-r--r-- | kernel/sched/core.c | 36 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 5 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 64 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 13 | ||||
| -rw-r--r-- | kernel/trace/rethook.c | 9 | ||||
| -rw-r--r-- | kernel/trace/trace_uprobe.c | 5 | ||||
| -rw-r--r-- | kernel/workqueue.c | 16 |
24 files changed, 464 insertions, 99 deletions
diff --git a/kernel/auditsc.c b/kernel/auditsc.c index f3a2abd6d1a1..3a8c9d744800 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1014,10 +1014,10 @@ static void audit_reset_context(struct audit_context *ctx) ctx->target_comm[0] = '\0'; unroll_tree_refs(ctx, NULL, 0); WARN_ON(!list_empty(&ctx->killed_trees)); - ctx->type = 0; audit_free_module(ctx); ctx->fds[0] = -1; audit_proctitle_free(ctx); + ctx->type = 0; /* reset last for audit_free_*() */ } static inline struct audit_context *audit_alloc_context(enum audit_state state) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 63d0ac7dfe2f..d003d4d8242a 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -309,6 +309,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = { [BTF_KIND_FLOAT] = "FLOAT", [BTF_KIND_DECL_TAG] = "DECL_TAG", [BTF_KIND_TYPE_TAG] = "TYPE_TAG", + [BTF_KIND_ENUM64] = "ENUM64", }; const char *btf_type_str(const struct btf_type *t) @@ -666,6 +667,7 @@ static bool btf_type_has_size(const struct btf_type *t) case BTF_KIND_ENUM: case BTF_KIND_DATASEC: case BTF_KIND_FLOAT: + case BTF_KIND_ENUM64: return true; } @@ -711,6 +713,11 @@ static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t) return (const struct btf_decl_tag *)(t + 1); } +static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t) +{ + return (const struct btf_enum64 *)(t + 1); +} + static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) { return kind_ops[BTF_INFO_KIND(t->info)]; @@ -1019,6 +1026,7 @@ static const char *btf_show_name(struct btf_show *show) parens = "{"; break; case BTF_KIND_ENUM: + case BTF_KIND_ENUM64: prefix = "enum"; break; default: @@ -1834,6 +1842,7 @@ __btf_resolve_size(const struct btf *btf, const struct btf_type *type, case BTF_KIND_UNION: case BTF_KIND_ENUM: case BTF_KIND_FLOAT: + case BTF_KIND_ENUM64: size = type->size; goto resolved; @@ -3670,6 +3679,7 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env, { const struct btf_enum *enums = btf_type_enum(t); struct btf *btf = env->btf; + const char *fmt_str; u16 i, nr_enums; u32 meta_needed; @@ -3683,11 +3693,6 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env, return -EINVAL; } - if (btf_type_kflag(t)) { - btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); - return -EINVAL; - } - if (t->size > 8 || !is_power_of_2(t->size)) { btf_verifier_log_type(env, t, "Unexpected size"); return -EINVAL; @@ -3718,7 +3723,8 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env, if (env->log.level == BPF_LOG_KERNEL) continue; - btf_verifier_log(env, "\t%s val=%d\n", + fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n"; + btf_verifier_log(env, fmt_str, __btf_name_by_offset(btf, enums[i].name_off), enums[i].val); } @@ -3759,7 +3765,10 @@ static void btf_enum_show(const struct btf *btf, const struct btf_type *t, return; } - btf_show_type_value(show, "%d", v); + if (btf_type_kflag(t)) + btf_show_type_value(show, "%d", v); + else + btf_show_type_value(show, "%u", v); btf_show_end_type(show); } @@ -3772,6 +3781,109 @@ static struct btf_kind_operations enum_ops = { .show = btf_enum_show, }; +static s32 btf_enum64_check_meta(struct btf_verifier_env *env, + const struct btf_type *t, + u32 meta_left) +{ + const struct btf_enum64 *enums = btf_type_enum64(t); + struct btf *btf = env->btf; + const char *fmt_str; + u16 i, nr_enums; + u32 meta_needed; + + nr_enums = btf_type_vlen(t); + meta_needed = nr_enums * sizeof(*enums); + + if (meta_left < meta_needed) { + btf_verifier_log_basic(env, t, + "meta_left:%u meta_needed:%u", + meta_left, meta_needed); + return -EINVAL; + } + + if (t->size > 8 || !is_power_of_2(t->size)) { + btf_verifier_log_type(env, t, "Unexpected size"); + return -EINVAL; + } + + /* enum type either no name or a valid one */ + if (t->name_off && + !btf_name_valid_identifier(env->btf, t->name_off)) { + btf_verifier_log_type(env, t, "Invalid name"); + return -EINVAL; + } + + btf_verifier_log_type(env, t, NULL); + + for (i = 0; i < nr_enums; i++) { + if (!btf_name_offset_valid(btf, enums[i].name_off)) { + btf_verifier_log(env, "\tInvalid name_offset:%u", + enums[i].name_off); + return -EINVAL; + } + + /* enum member must have a valid name */ + if (!enums[i].name_off || + !btf_name_valid_identifier(btf, enums[i].name_off)) { + btf_verifier_log_type(env, t, "Invalid name"); + return -EINVAL; + } + + if (env->log.level == BPF_LOG_KERNEL) + continue; + + fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n"; + btf_verifier_log(env, fmt_str, + __btf_name_by_offset(btf, enums[i].name_off), + btf_enum64_value(enums + i)); + } + + return meta_needed; +} + +static void btf_enum64_show(const struct btf *btf, const struct btf_type *t, + u32 type_id, void *data, u8 bits_offset, + struct btf_show *show) +{ + const struct btf_enum64 *enums = btf_type_enum64(t); + u32 i, nr_enums = btf_type_vlen(t); + void *safe_data; + s64 v; + + safe_data = btf_show_start_type(show, t, type_id, data); + if (!safe_data) + return; + + v = *(u64 *)safe_data; + + for (i = 0; i < nr_enums; i++) { + if (v != btf_enum64_value(enums + i)) + continue; + + btf_show_type_value(show, "%s", + __btf_name_by_offset(btf, + enums[i].name_off)); + + btf_show_end_type(show); + return; + } + + if (btf_type_kflag(t)) + btf_show_type_value(show, "%lld", v); + else + btf_show_type_value(show, "%llu", v); + btf_show_end_type(show); +} + +static struct btf_kind_operations enum64_ops = { + .check_meta = btf_enum64_check_meta, + .resolve = btf_df_resolve, + .check_member = btf_enum_check_member, + .check_kflag_member = btf_enum_check_kflag_member, + .log_details = btf_enum_log, + .show = btf_enum64_show, +}; + static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) @@ -4438,6 +4550,7 @@ static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { [BTF_KIND_FLOAT] = &float_ops, [BTF_KIND_DECL_TAG] = &decl_tag_ops, [BTF_KIND_TYPE_TAG] = &modifier_ops, + [BTF_KIND_ENUM64] = &enum64_ops, }; static s32 btf_check_meta(struct btf_verifier_env *env, @@ -4815,6 +4928,7 @@ static int btf_check_type_tags(struct btf_verifier_env *env, n = btf_nr_types(btf); for (i = start_id; i < n; i++) { const struct btf_type *t; + int chain_limit = 32; u32 cur_id = i; t = btf_type_by_id(btf, i); @@ -4827,6 +4941,10 @@ static int btf_check_type_tags(struct btf_verifier_env *env, in_tags = btf_type_is_type_tag(t); while (btf_type_is_modifier(t)) { + if (!chain_limit--) { + btf_verifier_log(env, "Max chain length or cycle detected"); + return -ELOOP; + } if (btf_type_is_type_tag(t)) { if (!in_tags) { btf_verifier_log(env, "Type tags don't precede modifiers"); @@ -5299,7 +5417,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type, /* skip modifiers */ while (btf_type_is_modifier(t)) t = btf_type_by_id(btf, t->type); - if (btf_type_is_small_int(t) || btf_type_is_enum(t)) + if (btf_type_is_small_int(t) || btf_is_any_enum(t)) /* accessing a scalar */ return true; if (!btf_type_is_ptr(t)) { @@ -5763,7 +5881,7 @@ static int __get_type_size(struct btf *btf, u32 btf_id, if (btf_type_is_ptr(t)) /* kernel size of pointer. Not BPF's size of pointer*/ return sizeof(void *); - if (btf_type_is_int(t) || btf_type_is_enum(t)) + if (btf_type_is_int(t) || btf_is_any_enum(t)) return t->size; *bad_type = t; return -EINVAL; @@ -5911,7 +6029,7 @@ static int btf_check_func_type_match(struct bpf_verifier_log *log, * to context only. And only global functions can be replaced. * Hence type check only those types. */ - if (btf_type_is_int(t1) || btf_type_is_enum(t1)) + if (btf_type_is_int(t1) || btf_is_any_enum(t1)) continue; if (!btf_type_is_ptr(t1)) { bpf_log(log, @@ -6409,7 +6527,7 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, t = btf_type_by_id(btf, t->type); while (btf_type_is_modifier(t)) t = btf_type_by_id(btf, t->type); - if (!btf_type_is_int(t) && !btf_type_is_enum(t)) { + if (!btf_type_is_int(t) && !btf_is_any_enum(t)) { bpf_log(log, "Global function %s() doesn't return scalar. Only those are supported.\n", tname); @@ -6424,7 +6542,7 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, t = btf_type_by_id(btf, args[i].type); while (btf_type_is_modifier(t)) t = btf_type_by_id(btf, t->type); - if (btf_type_is_int(t) || btf_type_is_enum(t)) { + if (btf_type_is_int(t) || btf_is_any_enum(t)) { reg->type = SCALAR_VALUE; continue; } @@ -7336,6 +7454,7 @@ recur: case BTF_KIND_UNION: case BTF_KIND_ENUM: case BTF_KIND_FWD: + case BTF_KIND_ENUM64: return 1; case BTF_KIND_INT: /* just reject deprecated bitfield-like integers; all other @@ -7388,10 +7507,10 @@ recur: * field-based relocations. This function assumes that root types were already * checked for name match. Beyond that initial root-level name check, names * are completely ignored. Compatibility rules are as follows: - * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs are considered compatible, but + * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs/ENUM64s are considered compatible, but * kind should match for local and target types (i.e., STRUCT is not * compatible with UNION); - * - for ENUMs, the size is ignored; + * - for ENUMs/ENUM64s, the size is ignored; * - for INT, size and signedness are ignored; * - for ARRAY, dimensionality is ignored, element types are checked for * compatibility recursively; diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index afb414b26d01..7a394f7c205c 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -721,6 +721,60 @@ static struct bpf_prog_list *find_detach_entry(struct list_head *progs, } /** + * purge_effective_progs() - After compute_effective_progs fails to alloc new + * cgrp->bpf.inactive table we can recover by + * recomputing the array in place. + * + * @cgrp: The cgroup which descendants to travers + * @prog: A program to detach or NULL + * @link: A link to detach or NULL + * @atype: Type of detach operation + */ +static void purge_effective_progs(struct cgroup *cgrp, struct bpf_prog *prog, + struct bpf_cgroup_link *link, + enum cgroup_bpf_attach_type atype) +{ + struct cgroup_subsys_state *css; + struct bpf_prog_array *progs; + struct bpf_prog_list *pl; + struct list_head *head; + struct cgroup *cg; + int pos; + + /* recompute effective prog array in place */ + css_for_each_descendant_pre(css, &cgrp->self) { + struct cgroup *desc = container_of(css, struct cgroup, self); + + if (percpu_ref_is_zero(&desc->bpf.refcnt)) + continue; + + /* find position of link or prog in effective progs array */ + for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) { + if (pos && !(cg->bpf.flags[atype] & BPF_F_ALLOW_MULTI)) + continue; + + head = &cg->bpf.progs[atype]; + list_for_each_entry(pl, head, node) { + if (!prog_list_prog(pl)) + continue; + if (pl->prog == prog && pl->link == link) + goto found; + pos++; + } + } +found: + BUG_ON(!cg); + progs = rcu_dereference_protected( + desc->bpf.effective[atype], + lockdep_is_held(&cgroup_mutex)); + + /* Remove the program from the array */ + WARN_ONCE(bpf_prog_array_delete_safe_at(progs, pos), + "Failed to purge a prog from array at index %d", pos); + } +} + +/** * __cgroup_bpf_detach() - Detach the program or link from a cgroup, and * propagate the change to descendants * @cgrp: The cgroup which descendants to traverse @@ -739,7 +793,6 @@ static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, struct bpf_prog_list *pl; struct list_head *progs; u32 flags; - int err; atype = to_cgroup_bpf_attach_type(type); if (atype < 0) @@ -761,9 +814,12 @@ static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, pl->prog = NULL; pl->link = NULL; - err = update_effective_progs(cgrp, atype); - if (err) - goto cleanup; + if (update_effective_progs(cgrp, atype)) { + /* if update effective array failed replace the prog with a dummy prog*/ + pl->prog = old_prog; + pl->link = link; + purge_effective_progs(cgrp, old_prog, link, atype); + } /* now can actually delete it from this cgroup list */ list_del(&pl->node); @@ -775,12 +831,6 @@ static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, bpf_prog_put(old_prog); static_branch_dec(&cgroup_bpf_enabled_key[atype]); return 0; - -cleanup: - /* restore back prog or link */ - pl->prog = old_prog; - pl->link = link; - return err; } static int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 5f6f3f829b36..b5ffebcce6cc 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -176,7 +176,7 @@ void bpf_prog_jit_attempt_done(struct bpf_prog *prog) * here is relative to the prog itself instead of the main prog. * This array has one entry for each xlated bpf insn. * - * jited_off is the byte off to the last byte of the jited insn. + * jited_off is the byte off to the end of the jited insn. * * Hence, with * insn_start: @@ -2279,6 +2279,21 @@ void bpf_prog_array_free(struct bpf_prog_array *progs) kfree_rcu(progs, rcu); } +static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu) +{ + struct bpf_prog_array *progs; + + progs = container_of(rcu, struct bpf_prog_array, rcu); + kfree_rcu(progs, rcu); +} + +void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs) +{ + if (!progs || progs == &bpf_empty_prog_array.hdr) + return; + call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb); +} + int bpf_prog_array_length(struct bpf_prog_array *array) { struct bpf_prog_array_item *item; diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 225806a02efb..a1c84d256f83 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -584,7 +584,7 @@ BPF_CALL_3(bpf_strncmp, const char *, s1, u32, s1_sz, const char *, s2) return strncmp(s1, s2, s1_sz); } -const struct bpf_func_proto bpf_strncmp_proto = { +static const struct bpf_func_proto bpf_strncmp_proto = { .func = bpf_strncmp, .gpl_only = false, .ret_type = RET_INTEGER, @@ -1402,7 +1402,7 @@ BPF_CALL_2(bpf_kptr_xchg, void *, map_value, void *, ptr) */ #define BPF_PTR_POISON ((void *)((0xeB9FUL << 2) + POISON_POINTER_DELTA)) -const struct bpf_func_proto bpf_kptr_xchg_proto = { +static const struct bpf_func_proto bpf_kptr_xchg_proto = { .func = bpf_kptr_xchg, .gpl_only = false, .ret_type = RET_PTR_TO_BTF_ID_OR_NULL, @@ -1487,7 +1487,7 @@ error: return err; } -const struct bpf_func_proto bpf_dynptr_from_mem_proto = { +static const struct bpf_func_proto bpf_dynptr_from_mem_proto = { .func = bpf_dynptr_from_mem, .gpl_only = false, .ret_type = RET_INTEGER, @@ -1513,7 +1513,7 @@ BPF_CALL_4(bpf_dynptr_read, void *, dst, u32, len, struct bpf_dynptr_kern *, src return 0; } -const struct bpf_func_proto bpf_dynptr_read_proto = { +static const struct bpf_func_proto bpf_dynptr_read_proto = { .func = bpf_dynptr_read, .gpl_only = false, .ret_type = RET_INTEGER, @@ -1539,7 +1539,7 @@ BPF_CALL_4(bpf_dynptr_write, struct bpf_dynptr_kern *, dst, u32, offset, void *, return 0; } -const struct bpf_func_proto bpf_dynptr_write_proto = { +static const struct bpf_func_proto bpf_dynptr_write_proto = { .func = bpf_dynptr_write, .gpl_only = false, .ret_type = RET_INTEGER, @@ -1566,7 +1566,7 @@ BPF_CALL_3(bpf_dynptr_data, struct bpf_dynptr_kern *, ptr, u32, offset, u32, len return (unsigned long)(ptr->data + ptr->offset + offset); } -const struct bpf_func_proto bpf_dynptr_data_proto = { +static const struct bpf_func_proto bpf_dynptr_data_proto = { .func = bpf_dynptr_data, .gpl_only = false, .ret_type = RET_PTR_TO_DYNPTR_MEM_OR_NULL, diff --git a/kernel/bpf/percpu_freelist.c b/kernel/bpf/percpu_freelist.c index 3d897de89061..00b874c8e889 100644 --- a/kernel/bpf/percpu_freelist.c +++ b/kernel/bpf/percpu_freelist.c @@ -31,7 +31,7 @@ static inline void pcpu_freelist_push_node(struct pcpu_freelist_head *head, struct pcpu_freelist_node *node) { node->next = head->first; - head->first = node; + WRITE_ONCE(head->first, node); } static inline void ___pcpu_freelist_push(struct pcpu_freelist_head *head, @@ -130,14 +130,17 @@ static struct pcpu_freelist_node *___pcpu_freelist_pop(struct pcpu_freelist *s) orig_cpu = cpu = raw_smp_processor_id(); while (1) { head = per_cpu_ptr(s->freelist, cpu); + if (!READ_ONCE(head->first)) + goto next_cpu; raw_spin_lock(&head->lock); node = head->first; if (node) { - head->first = node->next; + WRITE_ONCE(head->first, node->next); raw_spin_unlock(&head->lock); return node; } raw_spin_unlock(&head->lock); +next_cpu: cpu = cpumask_next(cpu, cpu_possible_mask); if (cpu >= nr_cpu_ids) cpu = 0; @@ -146,10 +149,12 @@ static struct pcpu_freelist_node *___pcpu_freelist_pop(struct pcpu_freelist *s) } /* per cpu lists are all empty, try extralist */ + if (!READ_ONCE(s->extralist.first)) + return NULL; raw_spin_lock(&s->extralist.lock); node = s->extralist.first; if (node) - s->extralist.first = node->next; + WRITE_ONCE(s->extralist.first, node->next); raw_spin_unlock(&s->extralist.lock); return node; } @@ -164,15 +169,18 @@ ___pcpu_freelist_pop_nmi(struct pcpu_freelist *s) orig_cpu = cpu = raw_smp_processor_id(); while (1) { head = per_cpu_ptr(s->freelist, cpu); + if (!READ_ONCE(head->first)) + goto next_cpu; if (raw_spin_trylock(&head->lock)) { node = head->first; if (node) { - head->first = node->next; + WRITE_ONCE(head->first, node->next); raw_spin_unlock(&head->lock); return node; } raw_spin_unlock(&head->lock); } +next_cpu: cpu = cpumask_next(cpu, cpu_possible_mask); if (cpu >= nr_cpu_ids) cpu = 0; @@ -181,11 +189,11 @@ ___pcpu_freelist_pop_nmi(struct pcpu_freelist *s) } /* cannot pop from per cpu lists, try extralist */ - if (!raw_spin_trylock(&s->extralist.lock)) + if (!READ_ONCE(s->extralist.first) || !raw_spin_trylock(&s->extralist.lock)) return NULL; node = s->extralist.first; if (node) - s->extralist.first = node->next; + WRITE_ONCE(s->extralist.first, node->next); raw_spin_unlock(&s->extralist.lock); return node; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 2b69306d3c6e..7d5af5b99f0d 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -4090,14 +4090,15 @@ static int bpf_prog_get_info_by_fd(struct file *file, info.nr_jited_line_info = 0; if (info.nr_jited_line_info && ulen) { if (bpf_dump_raw_ok(file->f_cred)) { + unsigned long line_addr; __u64 __user *user_linfo; u32 i; user_linfo = u64_to_user_ptr(info.jited_line_info); ulen = min_t(u32, info.nr_jited_line_info, ulen); for (i = 0; i < ulen; i++) { - if (put_user((__u64)(long)prog->aux->jited_linfo[i], - &user_linfo[i])) + line_addr = (unsigned long)prog->aux->jited_linfo[i]; + if (put_user((__u64)line_addr, &user_linfo[i])) return -EFAULT; } } else { @@ -5130,7 +5131,7 @@ BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flag return *res ? 0 : -ENOENT; } -const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { +static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { .func = bpf_kallsyms_lookup_name, .gpl_only = false, .ret_type = RET_INTEGER, diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index aedac2ac02b9..2859901ffbe3 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5848,6 +5848,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; enum bpf_arg_type arg_type = fn->arg_type[arg]; enum bpf_reg_type type = reg->type; + u32 *arg_btf_id = NULL; int err = 0; if (arg_type == ARG_DONTCARE) @@ -5884,7 +5885,11 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, */ goto skip_type_check; - err = check_reg_type(env, regno, arg_type, fn->arg_btf_id[arg], meta); + /* arg_btf_id and arg_size are in a union. */ + if (base_type(arg_type) == ARG_PTR_TO_BTF_ID) + arg_btf_id = fn->arg_btf_id[arg]; + + err = check_reg_type(env, regno, arg_type, arg_btf_id, meta); if (err) return err; @@ -6011,6 +6016,11 @@ skip_type_check: * next is_mem_size argument below. */ meta->raw_mode = arg_type & MEM_UNINIT; + if (arg_type & MEM_FIXED_SIZE) { + err = check_helper_mem_access(env, regno, + fn->arg_size[arg], false, + meta); + } } else if (arg_type_is_mem_size(arg_type)) { bool zero_size_allowed = (arg_type == ARG_CONST_SIZE_OR_ZERO); @@ -6400,11 +6410,19 @@ static bool check_raw_mode_ok(const struct bpf_func_proto *fn) return count <= 1; } -static bool check_args_pair_invalid(enum bpf_arg_type arg_curr, - enum bpf_arg_type arg_next) +static bool check_args_pair_invalid(const struct bpf_func_proto *fn, int arg) { - return (base_type(arg_curr) == ARG_PTR_TO_MEM) != - arg_type_is_mem_size(arg_next); + bool is_fixed = fn->arg_type[arg] & MEM_FIXED_SIZE; + bool has_size = fn->arg_size[arg] != 0; + bool is_next_size = false; + + if (arg + 1 < ARRAY_SIZE(fn->arg_type)) + is_next_size = arg_type_is_mem_size(fn->arg_type[arg + 1]); + + if (base_type(fn->arg_type[arg]) != ARG_PTR_TO_MEM) + return is_next_size; + + return has_size == is_next_size || is_next_size == is_fixed; } static bool check_arg_pair_ok(const struct bpf_func_proto *fn) @@ -6415,11 +6433,11 @@ static bool check_arg_pair_ok(const struct bpf_func_proto *fn) * helper function specification. */ if (arg_type_is_mem_size(fn->arg1_type) || - base_type(fn->arg5_type) == ARG_PTR_TO_MEM || - check_args_pair_invalid(fn->arg1_type, fn->arg2_type) || - check_args_pair_invalid(fn->arg2_type, fn->arg3_type) || - check_args_pair_invalid(fn->arg3_type, fn->arg4_type) || - check_args_pair_invalid(fn->arg4_type, fn->arg5_type)) + check_args_pair_invalid(fn, 0) || + check_args_pair_invalid(fn, 1) || + check_args_pair_invalid(fn, 2) || + check_args_pair_invalid(fn, 3) || + check_args_pair_invalid(fn, 4)) return false; return true; @@ -6460,7 +6478,10 @@ static bool check_btf_id_ok(const struct bpf_func_proto *fn) if (base_type(fn->arg_type[i]) == ARG_PTR_TO_BTF_ID && !fn->arg_btf_id[i]) return false; - if (base_type(fn->arg_type[i]) != ARG_PTR_TO_BTF_ID && fn->arg_btf_id[i]) + if (base_type(fn->arg_type[i]) != ARG_PTR_TO_BTF_ID && fn->arg_btf_id[i] && + /* arg_btf_id and arg_size are in a union. */ + (base_type(fn->arg_type[i]) != ARG_PTR_TO_MEM || + !(fn->arg_type[i] & MEM_FIXED_SIZE))) return false; } @@ -10901,7 +10922,7 @@ static int check_btf_func(struct bpf_verifier_env *env, goto err_free; ret_type = btf_type_skip_modifiers(btf, func_proto->type, NULL); scalar_return = - btf_type_is_small_int(ret_type) || btf_type_is_enum(ret_type); + btf_type_is_small_int(ret_type) || btf_is_any_enum(ret_type); if (i && !scalar_return && env->subprog_info[i].has_ld_abs) { verbose(env, "LD_ABS is only allowed in functions that return 'int'.\n"); goto err_free; @@ -14829,8 +14850,8 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) } if (prog->aux->sleepable && prog->type != BPF_PROG_TYPE_TRACING && - prog->type != BPF_PROG_TYPE_LSM) { - verbose(env, "Only fentry/fexit/fmod_ret and lsm programs can be sleepable\n"); + prog->type != BPF_PROG_TYPE_LSM && prog->type != BPF_PROG_TYPE_KPROBE) { + verbose(env, "Only fentry/fexit/fmod_ret, lsm, and kprobe/uprobe programs can be sleepable\n"); return -EINVAL; } diff --git a/kernel/cfi.c b/kernel/cfi.c index 9594cfd1cf2c..08102d19ec15 100644 --- a/kernel/cfi.c +++ b/kernel/cfi.c @@ -281,6 +281,8 @@ static inline cfi_check_fn find_module_check_fn(unsigned long ptr) static inline cfi_check_fn find_check_fn(unsigned long ptr) { cfi_check_fn fn = NULL; + unsigned long flags; + bool rcu_idle; if (is_kernel_text(ptr)) return __cfi_check; @@ -290,13 +292,21 @@ static inline cfi_check_fn find_check_fn(unsigned long ptr) * the shadow and __module_address use RCU, so we need to wake it * up if necessary. */ - RCU_NONIDLE({ - if (IS_ENABLED(CONFIG_CFI_CLANG_SHADOW)) - fn = find_shadow_check_fn(ptr); + rcu_idle = !rcu_is_watching(); + if (rcu_idle) { + local_irq_save(flags); + rcu_irq_enter(); + } + + if (IS_ENABLED(CONFIG_CFI_CLANG_SHADOW)) + fn = find_shadow_check_fn(ptr); + if (!fn) + fn = find_module_check_fn(ptr); - if (!fn) - fn = find_module_check_fn(ptr); - }); + if (rcu_idle) { + rcu_irq_exit(); + local_irq_restore(flags); + } return fn; } diff --git a/kernel/events/core.c b/kernel/events/core.c index 80782cddb1da..48bae58d240e 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10068,26 +10068,30 @@ static inline bool perf_event_is_tracing(struct perf_event *event) int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie) { - bool is_kprobe, is_tracepoint, is_syscall_tp; + bool is_kprobe, is_uprobe, is_tracepoint, is_syscall_tp; if (!perf_event_is_tracing(event)) return perf_event_set_bpf_handler(event, prog, bpf_cookie); - is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE; + is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_KPROBE; + is_uprobe = event->tp_event->flags & TRACE_EVENT_FL_UPROBE; is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT; is_syscall_tp = is_syscall_trace_event(event->tp_event); - if (!is_kprobe && !is_tracepoint && !is_syscall_tp) + if (!is_kprobe && !is_uprobe && !is_tracepoint && !is_syscall_tp) /* bpf programs can only be attached to u/kprobe or tracepoint */ return -EINVAL; - if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) || + if (((is_kprobe || is_uprobe) && prog->type != BPF_PROG_TYPE_KPROBE) || (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) || (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) return -EINVAL; + if (prog->type == BPF_PROG_TYPE_KPROBE && prog->aux->sleepable && !is_uprobe) + /* only uprobe programs are allowed to be sleepable */ + return -EINVAL; + /* Kprobe override only works for kprobes, not uprobes. */ - if (prog->kprobe_override && - !(event->tp_event->flags & TRACE_EVENT_FL_KPROBE)) + if (prog->kprobe_override && !is_kprobe) return -EINVAL; if (is_tracepoint || is_syscall_tp) { diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index e6b8e564b37f..886789dcee43 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -1006,8 +1006,10 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle, if (desc->irq_data.chip != &no_irq_chip) mask_ack_irq(desc); irq_state_set_disabled(desc); - if (is_chained) + if (is_chained) { desc->action = NULL; + WARN_ON(irq_chip_pm_put(irq_desc_get_irq_data(desc))); + } desc->depth = 1; } desc->handle_irq = handle; @@ -1033,6 +1035,7 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle, irq_settings_set_norequest(desc); irq_settings_set_nothread(desc); desc->action = &chained_action; + WARN_ON(irq_chip_pm_get(irq_desc_get_irq_data(desc))); irq_activate_and_startup(desc, IRQ_RESEND); } } diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 81e87280513e..f06b91ca6482 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -5432,7 +5432,7 @@ static struct pin_cookie __lock_pin_lock(struct lockdep_map *lock) * be guessable and still allows some pin nesting in * our u32 pin_count. */ - cookie.val = 1 + (prandom_u32() >> 16); + cookie.val = 1 + (sched_clock() & 0xffff); hlock->pin_count += cookie.val; return cookie; } diff --git a/kernel/panic.c b/kernel/panic.c index a3c758dba15a..4cf13c37bd08 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -297,6 +297,7 @@ void panic(const char *fmt, ...) * unfortunately means it may not be hardened to work in a * panic situation. */ + try_block_console_kthreads(10000); smp_send_stop(); } else { /* @@ -304,6 +305,7 @@ void panic(const char *fmt, ...) * kmsg_dump, we will need architecture dependent extra * works in addition to stopping other CPUs. */ + try_block_console_kthreads(10000); crash_smp_send_stop(); } diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index d947ca6c84f9..e7d8578860ad 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -20,6 +20,8 @@ enum printk_info_flags { LOG_CONT = 8, /* text is a fragment of a continuation line */ }; +extern bool block_console_kthreads; + __printf(4, 0) int vprintk_store(int facility, int level, const struct dev_printk_info *dev_info, diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index ea3dd55709e7..b095fb5f5f61 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -250,6 +250,9 @@ static atomic_t console_kthreads_active = ATOMIC_INIT(0); #define console_kthread_printing_exit() \ atomic_dec(&console_kthreads_active) +/* Block console kthreads to avoid processing new messages. */ +bool block_console_kthreads; + /* * Helper macros to handle lockdep when locking/unlocking console_sem. We use * macros instead of functions so that _RET_IP_ contains useful information. @@ -3729,7 +3732,10 @@ static bool printer_should_wake(struct console *con, u64 seq) return true; if (con->blocked || - console_kthreads_atomically_blocked()) { + console_kthreads_atomically_blocked() || + block_console_kthreads || + system_state > SYSTEM_RUNNING || + oops_in_progress) { return false; } diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c index ef0f9a2044da..caac4de1ea59 100644 --- a/kernel/printk/printk_safe.c +++ b/kernel/printk/printk_safe.c @@ -8,7 +8,9 @@ #include <linux/smp.h> #include <linux/cpumask.h> #include <linux/printk.h> +#include <linux/console.h> #include <linux/kprobes.h> +#include <linux/delay.h> #include "internal.h" @@ -50,3 +52,33 @@ asmlinkage int vprintk(const char *fmt, va_list args) return vprintk_default(fmt, args); } EXPORT_SYMBOL(vprintk); + +/** + * try_block_console_kthreads() - Try to block console kthreads and + * make the global console_lock() avaialble + * + * @timeout_ms: The maximum time (in ms) to wait. + * + * Prevent console kthreads from starting processing new messages. Wait + * until the global console_lock() become available. + * + * Context: Can be called in any context. + */ +void try_block_console_kthreads(int timeout_ms) +{ + block_console_kthreads = true; + + /* Do not wait when the console lock could not be safely taken. */ + if (this_cpu_read(printk_context) || in_nmi()) + return; + + while (timeout_ms > 0) { + if (console_trylock()) { + console_unlock(); + return; + } + + udelay(1000); + timeout_ms -= 1; + } +} diff --git a/kernel/reboot.c b/kernel/reboot.c index b5a71d1ff603..80564ffafabf 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -82,6 +82,7 @@ void kernel_restart_prepare(char *cmd) { blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); system_state = SYSTEM_RESTART; + try_block_console_kthreads(10000); usermodehelper_disable(); device_shutdown(); } @@ -270,6 +271,7 @@ static void kernel_shutdown_prepare(enum system_states state) blocking_notifier_call_chain(&reboot_notifier_list, (state == SYSTEM_HALT) ? SYS_HALT : SYS_POWER_OFF, NULL); system_state = state; + try_block_console_kthreads(10000); usermodehelper_disable(); device_shutdown(); } diff --git a/kernel/sched/core.c b/kernel/sched/core.c index bfa7452ca92e..da0bf6fe9ecd 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4798,25 +4798,55 @@ static void do_balance_callbacks(struct rq *rq, struct callback_head *head) static void balance_push(struct rq *rq); +/* + * balance_push_callback is a right abuse of the callback interface and plays + * by significantly different rules. + * + * Where the normal balance_callback's purpose is to be ran in the same context + * that queued it (only later, when it's safe to drop rq->lock again), + * balance_push_callback is specifically targeted at __schedule(). + * + * This abuse is tolerated because it places all the unlikely/odd cases behind + * a single test, namely: rq->balance_callback == NULL. + */ struct callback_head balance_push_callback = { .next = NULL, .func = (void (*)(struct callback_head *))balance_push, }; -static inline struct callback_head *splice_balance_callbacks(struct rq *rq) +static inline struct callback_head * +__splice_balance_callbacks(struct rq *rq, bool split) { struct callback_head *head = rq->balance_callback; + if (likely(!head)) + return NULL; + lockdep_assert_rq_held(rq); - if (head) + /* + * Must not take balance_push_callback off the list when + * splice_balance_callbacks() and balance_callbacks() are not + * in the same rq->lock section. + * + * In that case it would be possible for __schedule() to interleave + * and observe the list empty. + */ + if (split && head == &balance_push_callback) + head = NULL; + else rq->balance_callback = NULL; return head; } +static inline struct callback_head *splice_balance_callbacks(struct rq *rq) +{ + return __splice_balance_callbacks(rq, true); +} + static void __balance_callbacks(struct rq *rq) { - do_balance_callbacks(rq, splice_balance_callbacks(rq)); + do_balance_callbacks(rq, __splice_balance_callbacks(rq, false)); } static inline void balance_callbacks(struct rq *rq, struct callback_head *head) diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 01259611beb9..47b89a0fc6e5 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1693,6 +1693,11 @@ queue_balance_callback(struct rq *rq, { lockdep_assert_rq_held(rq); + /* + * Don't (re)queue an already queued item; nor queue anything when + * balance_push() is active, see the comment with + * balance_push_callback. + */ if (unlikely(head->next || rq->balance_callback == &balance_push_callback)) return; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 7a13e6ac6327..68e5cdd24cef 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1936,7 +1936,7 @@ int perf_event_attach_bpf_prog(struct perf_event *event, event->prog = prog; event->bpf_cookie = bpf_cookie; rcu_assign_pointer(event->tp_event->prog_array, new_array); - bpf_prog_array_free(old_array); + bpf_prog_array_free_sleepable(old_array); unlock: mutex_unlock(&bpf_event_mutex); @@ -1962,7 +1962,7 @@ void perf_event_detach_bpf_prog(struct perf_event *event) bpf_prog_array_delete_safe(old_array, event->prog); } else { rcu_assign_pointer(event->tp_event->prog_array, new_array); - bpf_prog_array_free(old_array); + bpf_prog_array_free_sleepable(old_array); } bpf_prog_put(event->prog); @@ -2423,7 +2423,7 @@ kprobe_multi_link_handler(struct fprobe *fp, unsigned long entry_ip, kprobe_multi_link_prog_run(link, entry_ip, regs); } -static int symbols_cmp(const void *a, const void *b) +static int symbols_cmp_r(const void *a, const void *b, const void *priv) { const char **str_a = (const char **) a; const char **str_b = (const char **) b; @@ -2431,6 +2431,28 @@ static int symbols_cmp(const void *a, const void *b) return strcmp(*str_a, *str_b); } +struct multi_symbols_sort { + const char **funcs; + u64 *cookies; +}; + +static void symbols_swap_r(void *a, void *b, int size, const void *priv) +{ + const struct multi_symbols_sort *data = priv; + const char **name_a = a, **name_b = b; + + swap(*name_a, *name_b); + + /* If defined, swap also related cookies. */ + if (data->cookies) { + u64 *cookie_a, *cookie_b; + + cookie_a = data->cookies + (name_a - data->funcs); + cookie_b = data->cookies + (name_b - data->funcs); + swap(*cookie_a, *cookie_b); + } +} + int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { struct bpf_kprobe_multi_link *link = NULL; @@ -2468,38 +2490,46 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr if (!addrs) return -ENOMEM; + ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); + if (ucookies) { + cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); + if (!cookies) { + err = -ENOMEM; + goto error; + } + if (copy_from_user(cookies, ucookies, size)) { + err = -EFAULT; + goto error; + } + } + if (uaddrs) { if (copy_from_user(addrs, uaddrs, size)) { err = -EFAULT; goto error; } } else { + struct multi_symbols_sort data = { + .cookies = cookies, + }; struct user_syms us; err = copy_user_syms(&us, usyms, cnt); if (err) goto error; - sort(us.syms, cnt, sizeof(*us.syms), symbols_cmp, NULL); + if (cookies) + data.funcs = us.syms; + + sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, + symbols_swap_r, &data); + err = ftrace_lookup_symbols(us.syms, cnt, addrs); free_user_syms(&us); if (err) goto error; } - ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); - if (ucookies) { - cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); - if (!cookies) { - err = -ENOMEM; - goto error; - } - if (copy_from_user(cookies, ucookies, size)) { - err = -EFAULT; - goto error; - } - } - link = kzalloc(sizeof(*link), GFP_KERNEL); if (!link) { err = -ENOMEM; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index e750fe141a60..601ccf1b2f09 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -8029,15 +8029,23 @@ static int kallsyms_callback(void *data, const char *name, struct module *mod, unsigned long addr) { struct kallsyms_data *args = data; + const char **sym; + int idx; - if (!bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp)) + sym = bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp); + if (!sym) + return 0; + + idx = sym - args->syms; + if (args->addrs[idx]) return 0; addr = ftrace_location(addr); if (!addr) return 0; - args->addrs[args->found++] = addr; + args->addrs[idx] = addr; + args->found++; return args->found == args->cnt ? 1 : 0; } @@ -8062,6 +8070,7 @@ int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *a struct kallsyms_data args; int err; + memset(addrs, 0, sizeof(*addrs) * cnt); args.addrs = addrs; args.syms = sorted_syms; args.cnt = cnt; diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c index b56833700d23..c69d82273ce7 100644 --- a/kernel/trace/rethook.c +++ b/kernel/trace/rethook.c @@ -154,6 +154,15 @@ struct rethook_node *rethook_try_get(struct rethook *rh) if (unlikely(!handler)) return NULL; + /* + * This expects the caller will set up a rethook on a function entry. + * When the function returns, the rethook will eventually be reclaimed + * or released in the rethook_recycle() with call_rcu(). + * This means the caller must be run in the RCU-availabe context. + */ + if (unlikely(!rcu_is_watching())) + return NULL; + fn = freelist_try_get(&rh->pool); if (!fn) return NULL; diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 9711589273cd..0282c119b1b2 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -16,6 +16,7 @@ #include <linux/namei.h> #include <linux/string.h> #include <linux/rculist.h> +#include <linux/filter.h> #include "trace_dynevent.h" #include "trace_probe.h" @@ -1346,9 +1347,7 @@ static void __uprobe_perf_func(struct trace_uprobe *tu, if (bpf_prog_array_valid(call)) { u32 ret; - preempt_disable(); - ret = trace_call_bpf(call, regs); - preempt_enable(); + ret = bpf_prog_run_array_sleepable(call->prog_array, regs, bpf_prog_run); if (!ret) return; } diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 4056f2a3f9d5..1ea50f6be843 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2788,13 +2788,13 @@ static bool flush_workqueue_prep_pwqs(struct workqueue_struct *wq, } /** - * flush_workqueue - ensure that any scheduled work has run to completion. + * __flush_workqueue - ensure that any scheduled work has run to completion. * @wq: workqueue to flush * * This function sleeps until all work items which were queued on entry * have finished execution, but it is not livelocked by new incoming ones. */ -void flush_workqueue(struct workqueue_struct *wq) +void __flush_workqueue(struct workqueue_struct *wq) { struct wq_flusher this_flusher = { .list = LIST_HEAD_INIT(this_flusher.list), @@ -2943,7 +2943,7 @@ void flush_workqueue(struct workqueue_struct *wq) out_unlock: mutex_unlock(&wq->mutex); } -EXPORT_SYMBOL(flush_workqueue); +EXPORT_SYMBOL(__flush_workqueue); /** * drain_workqueue - drain a workqueue @@ -2971,7 +2971,7 @@ void drain_workqueue(struct workqueue_struct *wq) wq->flags |= __WQ_DRAINING; mutex_unlock(&wq->mutex); reflush: - flush_workqueue(wq); + __flush_workqueue(wq); mutex_lock(&wq->mutex); @@ -6111,3 +6111,11 @@ void __init workqueue_init(void) wq_online = true; wq_watchdog_init(); } + +/* + * Despite the naming, this is a no-op function which is here only for avoiding + * link error. Since compile-time warning may fail to catch, we will need to + * emit run-time warning from __flush_workqueue(). + */ +void __warn_flushing_systemwide_wq(void) { } +EXPORT_SYMBOL(__warn_flushing_systemwide_wq); |
