From d7c114e9e7acd710307306090f4c4d70b48dec9c Mon Sep 17 00:00:00 2001 From: Martijn Coenen Date: Fri, 30 Sep 2016 14:05:40 +0200 Subject: [PATCH] android: binder: add extra size to allocator. The binder_buffer allocator currently only allocates space for the data and offsets buffers of a Parcel. This change allows for requesting an additional chunk of data in the buffer, which can for example be used to hold additional meta-data about the transaction (eg a security context). Change-Id: I58ab9c383a2e1a3057aae6adaa596ce867f1b157 Signed-off-by: Martijn Coenen --- drivers/android/binder.c | 41 +++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 13 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 14a42c1d25cb..4e1187df0785 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -303,6 +303,7 @@ struct binder_buffer { struct binder_node *target_node; size_t data_size; size_t offsets_size; + size_t extra_buffers_size; uint8_t data[0]; }; @@ -670,7 +671,9 @@ err_no_vma: static struct binder_buffer *binder_alloc_buf(struct binder_proc *proc, size_t data_size, - size_t offsets_size, int is_async) + size_t offsets_size, + size_t extra_buffers_size, + int is_async) { struct rb_node *n = proc->free_buffers.rb_node; struct binder_buffer *buffer; @@ -678,7 +681,7 @@ static struct binder_buffer *binder_alloc_buf(struct binder_proc *proc, struct rb_node *best_fit = NULL; void *has_page_addr; void *end_page_addr; - size_t size; + size_t size, data_offsets_size; if (proc->vma == NULL) { pr_err("%d: binder_alloc_buf, no vma\n", @@ -686,15 +689,20 @@ static struct binder_buffer *binder_alloc_buf(struct binder_proc *proc, return NULL; } - size = ALIGN(data_size, sizeof(void *)) + + data_offsets_size = ALIGN(data_size, sizeof(void *)) + ALIGN(offsets_size, sizeof(void *)); - if (size < data_size || size < offsets_size) { + if (data_offsets_size < data_size || data_offsets_size < offsets_size) { binder_user_error("%d: got transaction with invalid size %zd-%zd\n", proc->pid, data_size, offsets_size); return NULL; } - + size = data_offsets_size + ALIGN(extra_buffers_size, sizeof(void *)); + if (size < data_offsets_size || size < extra_buffers_size) { + binder_user_error("%d: got transaction with invalid extra_buffers_size %zd\n", + proc->pid, extra_buffers_size); + return NULL; + } if (is_async && proc->free_async_space < size + sizeof(struct binder_buffer)) { binder_debug(BINDER_DEBUG_BUFFER_ALLOC, @@ -763,6 +771,7 @@ static struct binder_buffer *binder_alloc_buf(struct binder_proc *proc, proc->pid, size, buffer); buffer->data_size = data_size; buffer->offsets_size = offsets_size; + buffer->extra_buffers_size = extra_buffers_size; buffer->async_transaction = is_async; if (is_async) { proc->free_async_space -= size + sizeof(struct binder_buffer); @@ -837,7 +846,8 @@ static void binder_free_buf(struct binder_proc *proc, buffer_size = binder_buffer_size(proc, buffer); size = ALIGN(buffer->data_size, sizeof(void *)) + - ALIGN(buffer->offsets_size, sizeof(void *)); + ALIGN(buffer->offsets_size, sizeof(void *)) + + ALIGN(buffer->extra_buffers_size, sizeof(void *)); binder_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: binder_free_buf %p size %zd buffer_size %zd\n", @@ -1556,7 +1566,8 @@ err_fd_not_accepted: static void binder_transaction(struct binder_proc *proc, struct binder_thread *thread, - struct binder_transaction_data *tr, int reply) + struct binder_transaction_data *tr, int reply, + binder_size_t extra_buffers_size) { int ret; struct binder_transaction *t; @@ -1700,20 +1711,22 @@ static void binder_transaction(struct binder_proc *proc, if (reply) binder_debug(BINDER_DEBUG_TRANSACTION, - "%d:%d BC_REPLY %d -> %d:%d, data %016llx-%016llx size %lld-%lld\n", + "%d:%d BC_REPLY %d -> %d:%d, data %016llx-%016llx size %lld-%lld-%lld\n", proc->pid, thread->pid, t->debug_id, target_proc->pid, target_thread->pid, (u64)tr->data.ptr.buffer, (u64)tr->data.ptr.offsets, - (u64)tr->data_size, (u64)tr->offsets_size); + (u64)tr->data_size, (u64)tr->offsets_size, + (u64)extra_buffers_size); else binder_debug(BINDER_DEBUG_TRANSACTION, - "%d:%d BC_TRANSACTION %d -> %d - node %d, data %016llx-%016llx size %lld-%lld\n", + "%d:%d BC_TRANSACTION %d -> %d - node %d, data %016llx-%016llx size %lld-%lld-%lld\n", proc->pid, thread->pid, t->debug_id, target_proc->pid, target_node->debug_id, (u64)tr->data.ptr.buffer, (u64)tr->data.ptr.offsets, - (u64)tr->data_size, (u64)tr->offsets_size); + (u64)tr->data_size, (u64)tr->offsets_size, + (u64)extra_buffers_size); if (!reply && !(tr->flags & TF_ONE_WAY)) t->from = thread; @@ -1729,7 +1742,8 @@ static void binder_transaction(struct binder_proc *proc, trace_binder_transaction(reply, t, target_node); t->buffer = binder_alloc_buf(target_proc, tr->data_size, - tr->offsets_size, !reply && (t->flags & TF_ONE_WAY)); + tr->offsets_size, extra_buffers_size, + !reply && (t->flags & TF_ONE_WAY)); if (t->buffer == NULL) { return_error = BR_FAILED_REPLY; goto err_binder_alloc_buf_failed; @@ -2079,7 +2093,8 @@ static int binder_thread_write(struct binder_proc *proc, if (copy_from_user(&tr, ptr, sizeof(tr))) return -EFAULT; ptr += sizeof(tr); - binder_transaction(proc, thread, &tr, cmd == BC_REPLY); + binder_transaction(proc, thread, &tr, + cmd == BC_REPLY, 0); break; } -- 2.34.1