From 7557f189942571821a09879edfcdfdafefe4d67f Mon Sep 17 00:00:00 2001 From: Kriish Sharma Date: Fri, 3 Oct 2025 18:08:49 +0000 Subject: binder: Fix missing kernel-doc entries in binder.c Fix several kernel-doc warnings in `drivers/android/binder.c` caused by undocumented struct members and function parameters. In particular, add missing documentation for the `@thread` parameter in binder_free_buf_locked(). Signed-off-by: Kriish Sharma Acked-by: Carlos Llamas Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) (limited to 'drivers/android/binder.c') diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 8c99ceaa303b..3a09c54bc37b 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2418,10 +2418,10 @@ err_fd_not_accepted: /** * struct binder_ptr_fixup - data to be fixed-up in target buffer - * @offset offset in target buffer to fixup - * @skip_size bytes to skip in copy (fixup will be written later) - * @fixup_data data to write at fixup offset - * @node list node + * @offset: offset in target buffer to fixup + * @skip_size: bytes to skip in copy (fixup will be written later) + * @fixup_data: data to write at fixup offset + * @node: list node * * This is used for the pointer fixup list (pf) which is created and consumed * during binder_transaction() and is only accessed locally. No @@ -2438,10 +2438,10 @@ struct binder_ptr_fixup { /** * struct binder_sg_copy - scatter-gather data to be copied - * @offset offset in target buffer - * @sender_uaddr user address in source buffer - * @length bytes to copy - * @node list node + * @offset: offset in target buffer + * @sender_uaddr: user address in source buffer + * @length: bytes to copy + * @node: list node * * This is used for the sg copy list (sgc) which is created and consumed * during binder_transaction() and is only accessed locally. No @@ -4063,14 +4063,15 @@ binder_freeze_notification_done(struct binder_proc *proc, /** * binder_free_buf() - free the specified buffer - * @proc: binder proc that owns buffer - * @buffer: buffer to be freed - * @is_failure: failed to send transaction + * @proc: binder proc that owns buffer + * @thread: binder thread performing the buffer release + * @buffer: buffer to be freed + * @is_failure: failed to send transaction * - * If buffer for an async transaction, enqueue the next async + * If the buffer is for an async transaction, enqueue the next async * transaction from the node. * - * Cleanup buffer and free it. + * Cleanup the buffer and free it. */ static void binder_free_buf(struct binder_proc *proc, -- cgit v1.2.3 From d90eeb8ecd227c204ab6c34a17b372bd950b7aa2 Mon Sep 17 00:00:00 2001 From: Alice Ryhl Date: Wed, 15 Oct 2025 14:26:55 +0000 Subject: binder: remove "invalid inc weak" check There are no scenarios where a weak increment is invalid on binder_node. The only possible case where it could be invalid is if the kernel delivers BR_DECREFS to the process that owns the node, and then increments the weak refcount again, effectively "reviving" a dead node. However, that is not possible: when the BR_DECREFS command is delivered, the kernel removes and frees the binder_node. The fact that you were able to call binder_inc_node_nilocked() implies that the node is not yet destroyed, which implies that BR_DECREFS has not been delivered to userspace, so incrementing the weak refcount is valid. Note that it's currently possible to trigger this condition if the owner calls BINDER_THREAD_EXIT while node->has_weak_ref is true. This causes BC_INCREFS on binder_ref instances to fail when they should not. Cc: stable@vger.kernel.org Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Reported-by: Yu-Ting Tseng Signed-off-by: Alice Ryhl Link: https://patch.msgid.link/20251015-binder-weak-inc-v1-1-7914b092c371@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) (limited to 'drivers/android/binder.c') diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 3a09c54bc37b..a3a1b5c33ba3 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -851,17 +851,8 @@ static int binder_inc_node_nilocked(struct binder_node *node, int strong, } else { if (!internal) node->local_weak_refs++; - if (!node->has_weak_ref && list_empty(&node->work.entry)) { - if (target_list == NULL) { - pr_err("invalid inc weak node for %d\n", - node->debug_id); - return -EINVAL; - } - /* - * See comment above - */ + if (!node->has_weak_ref && target_list && list_empty(&node->work.entry)) binder_enqueue_work_ilocked(&node->work, target_list); - } } return 0; } -- cgit v1.2.3