diff options
| author | Juntong Deng <juntong.deng@outlook.com> | 2024-10-14 11:21:08 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-10-16 18:21:18 +0200 |
| commit | 675c3596ff32c040d1dd2e28dd57e83e634b9f60 (patch) | |
| tree | 7e6e15f1c82074493a04863cde253fb509fdb71c /kernel/bpf/helpers.c | |
| parent | Merge branch 'bpf-add-kmem_cache-iterator-and-kfunc' (diff) | |
| download | linux-675c3596ff32c040d1dd2e28dd57e83e634b9f60.tar.xz linux-675c3596ff32c040d1dd2e28dd57e83e634b9f60.zip | |
bpf: Add bpf_task_from_vpid() kfunc
bpf_task_from_pid() that currently exists looks up the
struct task_struct corresponding to the pid in the root pid
namespace (init_pid_ns).
This patch adds bpf_task_from_vpid() which looks up the
struct task_struct corresponding to vpid in the pid namespace
of the current process.
This is useful for getting information about other processes
in the same pid namespace.
Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Link: https://lore.kernel.org/r/AM6PR03MB5848E50DA58F79CDE65433C399442@AM6PR03MB5848.eurprd03.prod.outlook.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/helpers.c')
| -rw-r--r-- | kernel/bpf/helpers.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index aaaefefdf692..073e6f04f4d7 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2522,6 +2522,25 @@ __bpf_kfunc struct task_struct *bpf_task_from_pid(s32 pid) } /** + * bpf_task_from_vpid - Find a struct task_struct from its vpid by looking it up + * in the pid namespace of the current task. If a task is returned, it must + * either be stored in a map, or released with bpf_task_release(). + * @vpid: The vpid of the task being looked up. + */ +__bpf_kfunc struct task_struct *bpf_task_from_vpid(s32 vpid) +{ + struct task_struct *p; + + rcu_read_lock(); + p = find_task_by_vpid(vpid); + if (p) + p = bpf_task_acquire(p); + rcu_read_unlock(); + + return p; +} + +/** * bpf_dynptr_slice() - Obtain a read-only pointer to the dynptr data. * @p: The dynptr whose data slice to retrieve * @offset: Offset into the dynptr @@ -3034,6 +3053,7 @@ BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU) BTF_ID_FLAGS(func, bpf_task_get_cgroup1, KF_ACQUIRE | KF_RCU | KF_RET_NULL) #endif BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_task_from_vpid, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_throw) BTF_KFUNCS_END(generic_btf_ids) |