From 68aa3bc6d6081c983005d0b70e7dd3f22265a0f8 Mon Sep 17 00:00:00 2001 From: Frederick Mayle Date: Tue, 7 Jun 2022 15:51:31 +0000 Subject: libbinder: Remove flexible array from RpcWireReply We are going to change the size of this struct depending on the protocol version and that gets messy when there is a flexible array member. We could remove it from RpcWireTransaction as well, but that is a bigger change and there is no motivation yet (besides consistency). This change also happens to optimize out one allocation when the reply parcel is zero bytes. Bug: 185909244 Test: TH Change-Id: I18a5712ba80e7b311b945ef54977b66ffa43e1ca --- libs/binder/RpcState.cpp | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) (limited to 'libs/binder/RpcState.cpp') diff --git a/libs/binder/RpcState.cpp b/libs/binder/RpcState.cpp index 7ec8e0738d..f16a9ab98f 100644 --- a/libs/binder/RpcState.cpp +++ b/libs/binder/RpcState.cpp @@ -563,7 +563,7 @@ status_t RpcState::transactAddress(const sp& connecti static void cleanup_reply_data(Parcel* p, const uint8_t* data, size_t dataSize, const binder_size_t* objects, size_t objectsCount) { (void)p; - delete[] const_cast(data - offsetof(RpcWireReply, data)); + delete[] const_cast(data); (void)dataSize; LOG_ALWAYS_FATAL_IF(objects != nullptr); LOG_ALWAYS_FATAL_IF(objectsCount != 0, "%zu objects remaining", objectsCount); @@ -585,25 +585,30 @@ status_t RpcState::waitForReply(const sp& connection, return status; } - CommandData data(command.bodySize); - if (!data.valid()) return NO_MEMORY; - - iovec iov{data.data(), command.bodySize}; - if (status_t status = rpcRec(connection, session, "reply body", &iov, 1); status != OK) - return status; - if (command.bodySize < sizeof(RpcWireReply)) { ALOGE("Expecting %zu but got %" PRId32 " bytes for RpcWireReply. Terminating!", sizeof(RpcWireReply), command.bodySize); (void)session->shutdownAndWait(false); return BAD_VALUE; } - RpcWireReply* rpcReply = reinterpret_cast(data.data()); - if (rpcReply->status != OK) return rpcReply->status; + RpcWireReply rpcReply; + CommandData data(command.bodySize - sizeof(RpcWireReply)); + if (!data.valid()) return NO_MEMORY; + + iovec iovs[]{ + {&rpcReply, sizeof(RpcWireReply)}, + {data.data(), data.size()}, + }; + if (status_t status = rpcRec(connection, session, "reply body", iovs, arraysize(iovs)); + status != OK) + return status; + if (rpcReply.status != OK) return rpcReply.status; + + uint8_t* parcelData = data.data(); + size_t parcelDataSize = data.size(); data.release(); - reply->rpcSetDataReference(session, rpcReply->data, - command.bodySize - offsetof(RpcWireReply, data), cleanup_reply_data); + reply->rpcSetDataReference(session, parcelData, parcelDataSize, cleanup_reply_data); return OK; } -- cgit v1.2.3-59-g8ed1b