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-rw-r--r--kernel/bpf/bpf_task_storage.c4
-rw-r--r--kernel/bpf/btf.c19
-rw-r--r--kernel/bpf/mmap_unlock_work.h65
-rw-r--r--kernel/bpf/stackmap.c82
-rw-r--r--kernel/bpf/task_iter.c82
-rw-r--r--kernel/bpf/verifier.c34
6 files changed, 198 insertions, 88 deletions
diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage.c
index ebfa8bc90892..bb69aea1a777 100644
--- a/kernel/bpf/bpf_task_storage.c
+++ b/kernel/bpf/bpf_task_storage.c
@@ -323,7 +323,7 @@ const struct bpf_func_proto bpf_task_storage_get_proto = {
.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_BTF_ID,
- .arg2_btf_id = &btf_task_struct_ids[0],
+ .arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
.arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
.arg4_type = ARG_ANYTHING,
};
@@ -334,5 +334,5 @@ const struct bpf_func_proto bpf_task_storage_delete_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_BTF_ID,
- .arg2_btf_id = &btf_task_struct_ids[0],
+ .arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
};
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index dbc3ad07e21b..6b9d23be1e99 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -282,6 +282,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
[BTF_KIND_DATASEC] = "DATASEC",
[BTF_KIND_FLOAT] = "FLOAT",
[BTF_KIND_DECL_TAG] = "DECL_TAG",
+ [BTF_KIND_TYPE_TAG] = "TYPE_TAG",
};
const char *btf_type_str(const struct btf_type *t)
@@ -418,6 +419,7 @@ static bool btf_type_is_modifier(const struct btf_type *t)
case BTF_KIND_VOLATILE:
case BTF_KIND_CONST:
case BTF_KIND_RESTRICT:
+ case BTF_KIND_TYPE_TAG:
return true;
}
@@ -1737,6 +1739,7 @@ __btf_resolve_size(const struct btf *btf, const struct btf_type *type,
case BTF_KIND_VOLATILE:
case BTF_KIND_CONST:
case BTF_KIND_RESTRICT:
+ case BTF_KIND_TYPE_TAG:
id = type->type;
type = btf_type_by_id(btf, type->type);
break;
@@ -2345,6 +2348,8 @@ static int btf_ref_type_check_meta(struct btf_verifier_env *env,
const struct btf_type *t,
u32 meta_left)
{
+ const char *value;
+
if (btf_type_vlen(t)) {
btf_verifier_log_type(env, t, "vlen != 0");
return -EINVAL;
@@ -2360,7 +2365,7 @@ static int btf_ref_type_check_meta(struct btf_verifier_env *env,
return -EINVAL;
}
- /* typedef type must have a valid name, and other ref types,
+ /* typedef/type_tag type must have a valid name, and other ref types,
* volatile, const, restrict, should have a null name.
*/
if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) {
@@ -2369,6 +2374,12 @@ static int btf_ref_type_check_meta(struct btf_verifier_env *env,
btf_verifier_log_type(env, t, "Invalid name");
return -EINVAL;
}
+ } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) {
+ value = btf_name_by_offset(env->btf, t->name_off);
+ if (!value || !value[0]) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
} else {
if (t->name_off) {
btf_verifier_log_type(env, t, "Invalid name");
@@ -4059,6 +4070,7 @@ static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
[BTF_KIND_DATASEC] = &datasec_ops,
[BTF_KIND_FLOAT] = &float_ops,
[BTF_KIND_DECL_TAG] = &decl_tag_ops,
+ [BTF_KIND_TYPE_TAG] = &modifier_ops,
};
static s32 btf_check_meta(struct btf_verifier_env *env,
@@ -6342,7 +6354,10 @@ const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = {
.arg4_type = ARG_ANYTHING,
};
-BTF_ID_LIST_GLOBAL_SINGLE(btf_task_struct_ids, struct, task_struct)
+BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE)
+#define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type)
+BTF_TRACING_TYPE_xxx
+#undef BTF_TRACING_TYPE
/* BTF ID set registration API for modules */
diff --git a/kernel/bpf/mmap_unlock_work.h b/kernel/bpf/mmap_unlock_work.h
new file mode 100644
index 000000000000..5d18d7d85bef
--- /dev/null
+++ b/kernel/bpf/mmap_unlock_work.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2021 Facebook
+ */
+
+#ifndef __MMAP_UNLOCK_WORK_H__
+#define __MMAP_UNLOCK_WORK_H__
+#include <linux/irq_work.h>
+
+/* irq_work to run mmap_read_unlock() in irq_work */
+struct mmap_unlock_irq_work {
+ struct irq_work irq_work;
+ struct mm_struct *mm;
+};
+
+DECLARE_PER_CPU(struct mmap_unlock_irq_work, mmap_unlock_work);
+
+/*
+ * We cannot do mmap_read_unlock() when the irq is disabled, because of
+ * risk to deadlock with rq_lock. To look up vma when the irqs are
+ * disabled, we need to run mmap_read_unlock() in irq_work. We use a
+ * percpu variable to do the irq_work. If the irq_work is already used
+ * by another lookup, we fall over.
+ */
+static inline bool bpf_mmap_unlock_get_irq_work(struct mmap_unlock_irq_work **work_ptr)
+{
+ struct mmap_unlock_irq_work *work = NULL;
+ bool irq_work_busy = false;
+
+ if (irqs_disabled()) {
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+ work = this_cpu_ptr(&mmap_unlock_work);
+ if (irq_work_is_busy(&work->irq_work)) {
+ /* cannot queue more up_read, fallback */
+ irq_work_busy = true;
+ }
+ } else {
+ /*
+ * PREEMPT_RT does not allow to trylock mmap sem in
+ * interrupt disabled context. Force the fallback code.
+ */
+ irq_work_busy = true;
+ }
+ }
+
+ *work_ptr = work;
+ return irq_work_busy;
+}
+
+static inline void bpf_mmap_unlock_mm(struct mmap_unlock_irq_work *work, struct mm_struct *mm)
+{
+ if (!work) {
+ mmap_read_unlock(mm);
+ } else {
+ work->mm = mm;
+
+ /* The lock will be released once we're out of interrupt
+ * context. Tell lockdep that we've released it now so
+ * it doesn't complain that we forgot to release it.
+ */
+ rwsem_release(&mm->mmap_lock.dep_map, _RET_IP_);
+ irq_work_queue(&work->irq_work);
+ }
+}
+
+#endif /* __MMAP_UNLOCK_WORK_H__ */
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index 6e75bbee39f0..49e567209c6b 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -7,10 +7,10 @@
#include <linux/kernel.h>
#include <linux/stacktrace.h>
#include <linux/perf_event.h>
-#include <linux/irq_work.h>
#include <linux/btf_ids.h>
#include <linux/buildid.h>
#include "percpu_freelist.h"
+#include "mmap_unlock_work.h"
#define STACK_CREATE_FLAG_MASK \
(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY | \
@@ -31,25 +31,6 @@ struct bpf_stack_map {
struct stack_map_bucket *buckets[];
};
-/* irq_work to run up_read() for build_id lookup in nmi context */
-struct stack_map_irq_work {
- struct irq_work irq_work;
- struct mm_struct *mm;
-};
-
-static void do_up_read(struct irq_work *entry)
-{
- struct stack_map_irq_work *work;
-
- if (WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_RT)))
- return;
-
- work = container_of(entry, struct stack_map_irq_work, irq_work);
- mmap_read_unlock_non_owner(work->mm);
-}
-
-static DEFINE_PER_CPU(struct stack_map_irq_work, up_read_work);
-
static inline bool stack_map_use_build_id(struct bpf_map *map)
{
return (map->map_flags & BPF_F_STACK_BUILD_ID);
@@ -149,35 +130,13 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
u64 *ips, u32 trace_nr, bool user)
{
int i;
+ struct mmap_unlock_irq_work *work = NULL;
+ bool irq_work_busy = bpf_mmap_unlock_get_irq_work(&work);
struct vm_area_struct *vma;
- bool irq_work_busy = false;
- struct stack_map_irq_work *work = NULL;
-
- if (irqs_disabled()) {
- if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
- work = this_cpu_ptr(&up_read_work);
- if (irq_work_is_busy(&work->irq_work)) {
- /* cannot queue more up_read, fallback */
- irq_work_busy = true;
- }
- } else {
- /*
- * PREEMPT_RT does not allow to trylock mmap sem in
- * interrupt disabled context. Force the fallback code.
- */
- irq_work_busy = true;
- }
- }
- /*
- * We cannot do up_read() when the irq is disabled, because of
- * risk to deadlock with rq_lock. To do build_id lookup when the
- * irqs are disabled, we need to run up_read() in irq_work. We use
- * a percpu variable to do the irq_work. If the irq_work is
- * already used by another lookup, we fall back to report ips.
- *
- * Same fallback is used for kernel stack (!user) on a stackmap
- * with build_id.
+ /* If the irq_work is in use, fall back to report ips. Same
+ * fallback is used for kernel stack (!user) on a stackmap with
+ * build_id.
*/
if (!user || !current || !current->mm || irq_work_busy ||
!mmap_read_trylock(current->mm)) {
@@ -203,19 +162,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
- vma->vm_start;
id_offs[i].status = BPF_STACK_BUILD_ID_VALID;
}
-
- if (!work) {
- mmap_read_unlock(current->mm);
- } else {
- work->mm = current->mm;
-
- /* The lock will be released once we're out of interrupt
- * context. Tell lockdep that we've released it now so
- * it doesn't complain that we forgot to release it.
- */
- rwsem_release(&current->mm->mmap_lock.dep_map, _RET_IP_);
- irq_work_queue(&work->irq_work);
- }
+ bpf_mmap_unlock_mm(work, current->mm);
}
static struct perf_callchain_entry *
@@ -542,7 +489,7 @@ const struct bpf_func_proto bpf_get_task_stack_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
- .arg1_btf_id = &btf_task_struct_ids[0],
+ .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
.arg2_type = ARG_PTR_TO_UNINIT_MEM,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
.arg4_type = ARG_ANYTHING,
@@ -719,16 +666,3 @@ const struct bpf_map_ops stack_trace_map_ops = {
.map_btf_name = "bpf_stack_map",
.map_btf_id = &stack_trace_map_btf_id,
};
-
-static int __init stack_map_init(void)
-{
- int cpu;
- struct stack_map_irq_work *work;
-
- for_each_possible_cpu(cpu) {
- work = per_cpu_ptr(&up_read_work, cpu);
- init_irq_work(&work->irq_work, do_up_read);
- }
- return 0;
-}
-subsys_initcall(stack_map_init);
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
index b48750bfba5a..d94696198ef8 100644
--- a/kernel/bpf/task_iter.c
+++ b/kernel/bpf/task_iter.c
@@ -8,6 +8,7 @@
#include <linux/fdtable.h>
#include <linux/filter.h>
#include <linux/btf_ids.h>
+#include "mmap_unlock_work.h"
struct bpf_iter_seq_task_common {
struct pid_namespace *ns;
@@ -524,10 +525,6 @@ static const struct seq_operations task_vma_seq_ops = {
.show = task_vma_seq_show,
};
-BTF_ID_LIST(btf_task_file_ids)
-BTF_ID(struct, file)
-BTF_ID(struct, vm_area_struct)
-
static const struct bpf_iter_seq_info task_seq_info = {
.seq_ops = &task_seq_ops,
.init_seq_private = init_seq_pidns,
@@ -586,23 +583,88 @@ static struct bpf_iter_reg task_vma_reg_info = {
.seq_info = &task_vma_seq_info,
};
+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)
{
- int ret;
+ 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_task_struct_ids[0];
+ 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_task_struct_ids[0];
- task_file_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[0];
+ 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_task_struct_ids[0];
- task_vma_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[1];
+ 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);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 890b3ec375a3..0763cca139a7 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6114,6 +6114,33 @@ static int set_timer_callback_state(struct bpf_verifier_env *env,
return 0;
}
+static int set_find_vma_callback_state(struct bpf_verifier_env *env,
+ struct bpf_func_state *caller,
+ struct bpf_func_state *callee,
+ int insn_idx)
+{
+ /* bpf_find_vma(struct task_struct *task, u64 addr,
+ * void *callback_fn, void *callback_ctx, u64 flags)
+ * (callback_fn)(struct task_struct *task,
+ * struct vm_area_struct *vma, void *callback_ctx);
+ */
+ callee->regs[BPF_REG_1] = caller->regs[BPF_REG_1];
+
+ callee->regs[BPF_REG_2].type = PTR_TO_BTF_ID;
+ __mark_reg_known_zero(&callee->regs[BPF_REG_2]);
+ callee->regs[BPF_REG_2].btf = btf_vmlinux;
+ callee->regs[BPF_REG_2].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_VMA],
+
+ /* pointer to stack or null */
+ callee->regs[BPF_REG_3] = caller->regs[BPF_REG_4];
+
+ /* unused */
+ __mark_reg_not_init(env, &callee->regs[BPF_REG_4]);
+ __mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
+ callee->in_callback_fn = true;
+ return 0;
+}
+
static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
{
struct bpf_verifier_state *state = env->cur_state;
@@ -6471,6 +6498,13 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
return -EINVAL;
}
+ if (func_id == BPF_FUNC_find_vma) {
+ err = __check_func_call(env, insn, insn_idx_p, meta.subprogno,
+ set_find_vma_callback_state);
+ if (err < 0)
+ return -EINVAL;
+ }
+
if (func_id == BPF_FUNC_snprintf) {
err = check_bpf_snprintf_call(env, regs);
if (err < 0)
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-10 16:30:44 +0000