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-rw-r--r--kernel/bpf/task_iter.c39
-rw-r--r--kernel/bpf/trampoline.c4
-rw-r--r--kernel/bpf/verifier.c12
-rw-r--r--tools/testing/selftests/bpf/prog_tests/bpf_iter.c73
-rw-r--r--tools/testing/selftests/bpf/prog_tests/btf_dump.c2
5 files changed, 112 insertions, 18 deletions
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
index c2a2182ce570..c4ab9d6cdbe9 100644
--- a/kernel/bpf/task_iter.c
+++ b/kernel/bpf/task_iter.c
@@ -438,6 +438,7 @@ struct bpf_iter_seq_task_vma_info {
*/
struct bpf_iter_seq_task_common common;
struct task_struct *task;
+ struct mm_struct *mm;
struct vm_area_struct *vma;
u32 tid;
unsigned long prev_vm_start;
@@ -456,16 +457,19 @@ 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;
+ struct mm_struct *curr_mm;
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.
+ * the task_struct, holds a refcount on mm->mm_users, 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;
+ curr_mm = info->mm;
/* In case of lock contention, drop mmap_lock to unblock
* the writer.
*
@@ -504,13 +508,15 @@ task_vma_seq_get_next(struct bpf_iter_seq_task_vma_info *info)
* 4.2) VMA2 and VMA2' covers different ranges, process
* VMA2'.
*/
- if (mmap_lock_is_contended(curr_task->mm)) {
+ if (mmap_lock_is_contended(curr_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))
+ mmap_read_unlock(curr_mm);
+ if (mmap_read_lock_killable(curr_mm)) {
+ mmput(curr_mm);
goto finish;
+ }
} else {
op = task_vma_iter_next_vma;
}
@@ -535,42 +541,47 @@ again:
op = task_vma_iter_find_vma;
}
- if (!curr_task->mm)
+ curr_mm = get_task_mm(curr_task);
+ if (!curr_mm)
goto next_task;
- if (mmap_read_lock_killable(curr_task->mm))
+ if (mmap_read_lock_killable(curr_mm)) {
+ mmput(curr_mm);
goto finish;
+ }
}
switch (op) {
case task_vma_iter_first_vma:
- curr_vma = find_vma(curr_task->mm, 0);
+ curr_vma = find_vma(curr_mm, 0);
break;
case task_vma_iter_next_vma:
- curr_vma = find_vma(curr_task->mm, curr_vma->vm_end);
+ curr_vma = find_vma(curr_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);
+ curr_vma = find_vma(curr_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);
+ curr_vma = find_vma(curr_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);
+ mmap_read_unlock(curr_mm);
+ mmput(curr_mm);
goto next_task;
}
info->task = curr_task;
info->vma = curr_vma;
+ info->mm = curr_mm;
return curr_vma;
next_task:
@@ -579,6 +590,7 @@ next_task:
put_task_struct(curr_task);
info->task = NULL;
+ info->mm = NULL;
info->tid++;
goto again;
@@ -587,6 +599,7 @@ finish:
put_task_struct(curr_task);
info->task = NULL;
info->vma = NULL;
+ info->mm = NULL;
return NULL;
}
@@ -658,7 +671,9 @@ static void task_vma_seq_stop(struct seq_file *seq, void *v)
*/
info->prev_vm_start = ~0UL;
info->prev_vm_end = info->vma->vm_end;
- mmap_read_unlock(info->task->mm);
+ mmap_read_unlock(info->mm);
+ mmput(info->mm);
+ info->mm = NULL;
put_task_struct(info->task);
info->task = NULL;
}
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 11f5ec0b8016..d0ed7d6f5eec 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -488,6 +488,10 @@ again:
/* reset fops->func and fops->trampoline for re-register */
tr->fops->func = NULL;
tr->fops->trampoline = 0;
+
+ /* reset im->image memory attr for arch_prepare_bpf_trampoline */
+ set_memory_nx((long)im->image, 1);
+ set_memory_rw((long)im->image, 1);
goto again;
}
#endif
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 243d06ce6842..85f96c1e9f62 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1054,6 +1054,8 @@ static void print_insn_state(struct bpf_verifier_env *env,
*/
static void *copy_array(void *dst, const void *src, size_t n, size_t size, gfp_t flags)
{
+ size_t alloc_bytes;
+ void *orig = dst;
size_t bytes;
if (ZERO_OR_NULL_PTR(src))
@@ -1062,11 +1064,11 @@ static void *copy_array(void *dst, const void *src, size_t n, size_t size, gfp_t
if (unlikely(check_mul_overflow(n, size, &bytes)))
return NULL;
- if (ksize(dst) < ksize(src)) {
- kfree(dst);
- dst = kmalloc_track_caller(kmalloc_size_roundup(bytes), flags);
- if (!dst)
- return NULL;
+ alloc_bytes = max(ksize(orig), kmalloc_size_roundup(bytes));
+ dst = krealloc(orig, alloc_bytes, flags);
+ if (!dst) {
+ kfree(orig);
+ return NULL;
}
memcpy(dst, src, bytes);
diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
index 6f8ed61fc4b4..3af6450763e9 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
@@ -1465,6 +1465,77 @@ out:
bpf_iter_task_vma__destroy(skel);
}
+static void test_task_vma_dead_task(void)
+{
+ struct bpf_iter_task_vma *skel;
+ int wstatus, child_pid = -1;
+ time_t start_tm, cur_tm;
+ int err, iter_fd = -1;
+ int wait_sec = 3;
+
+ skel = bpf_iter_task_vma__open();
+ if (!ASSERT_OK_PTR(skel, "bpf_iter_task_vma__open"))
+ return;
+
+ skel->bss->pid = getpid();
+
+ err = bpf_iter_task_vma__load(skel);
+ if (!ASSERT_OK(err, "bpf_iter_task_vma__load"))
+ goto out;
+
+ skel->links.proc_maps = bpf_program__attach_iter(
+ skel->progs.proc_maps, NULL);
+
+ if (!ASSERT_OK_PTR(skel->links.proc_maps, "bpf_program__attach_iter")) {
+ skel->links.proc_maps = NULL;
+ goto out;
+ }
+
+ start_tm = time(NULL);
+ cur_tm = start_tm;
+
+ child_pid = fork();
+ if (child_pid == 0) {
+ /* Fork short-lived processes in the background. */
+ while (cur_tm < start_tm + wait_sec) {
+ system("echo > /dev/null");
+ cur_tm = time(NULL);
+ }
+ exit(0);
+ }
+
+ if (!ASSERT_GE(child_pid, 0, "fork_child"))
+ goto out;
+
+ while (cur_tm < start_tm + wait_sec) {
+ iter_fd = bpf_iter_create(bpf_link__fd(skel->links.proc_maps));
+ if (!ASSERT_GE(iter_fd, 0, "create_iter"))
+ goto out;
+
+ /* Drain all data from iter_fd. */
+ while (cur_tm < start_tm + wait_sec) {
+ err = read_fd_into_buffer(iter_fd, task_vma_output, CMP_BUFFER_SIZE);
+ if (!ASSERT_GE(err, 0, "read_iter_fd"))
+ goto out;
+
+ cur_tm = time(NULL);
+
+ if (err == 0)
+ break;
+ }
+
+ close(iter_fd);
+ iter_fd = -1;
+ }
+
+ check_bpf_link_info(skel->progs.proc_maps);
+
+out:
+ waitpid(child_pid, &wstatus, 0);
+ close(iter_fd);
+ bpf_iter_task_vma__destroy(skel);
+}
+
void test_bpf_sockmap_map_iter_fd(void)
{
struct bpf_iter_sockmap *skel;
@@ -1586,6 +1657,8 @@ void test_bpf_iter(void)
test_task_file();
if (test__start_subtest("task_vma"))
test_task_vma();
+ if (test__start_subtest("task_vma_dead_task"))
+ test_task_vma_dead_task();
if (test__start_subtest("task_btf"))
test_task_btf();
if (test__start_subtest("tcp4"))
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dump.c b/tools/testing/selftests/bpf/prog_tests/btf_dump.c
index 0ba2e8b9c6ac..e9ea38aa8248 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf_dump.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_dump.c
@@ -801,7 +801,7 @@ static void test_btf_dump_struct_data(struct btf *btf, struct btf_dump *d,
static void test_btf_dump_var_data(struct btf *btf, struct btf_dump *d,
char *str)
{
-#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
+#if 0
TEST_BTF_DUMP_VAR(btf, d, NULL, str, "cpu_number", int, BTF_F_COMPACT,
"int cpu_number = (int)100", 100);
#endif
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-29 08:50:55 +0300