From b9830d120cbe155863399f25eaef6aa8353e767f Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Fri, 26 Feb 2016 15:13:19 -0800 Subject: [PATCH] Drivers: hv: util: Pass the channel information during the init call Pass the channel information to the util drivers that need to defer reading the channel while they are processing a request. This would address the following issue reported by Vitaly: Commit 3cace4a61610 ("Drivers: hv: utils: run polling callback always in interrupt context") removed direct *_transaction.state = HVUTIL_READY assignments from *_handle_handshake() functions introducing the following race: if a userspace daemon connects before we get first non-negotiation request from the server hv_poll_channel() won't set transaction state to HVUTIL_READY as (!channel) condition will fail, we set it to non-NULL on the first real request from the server. Signed-off-by: K. Y. Srinivasan Reported-by: Vitaly Kuznetsov Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv_fcopy.c | 2 +- drivers/hv/hv_kvp.c | 2 +- drivers/hv/hv_snapshot.c | 2 +- drivers/hv/hv_util.c | 1 + include/linux/hyperv.h | 1 + 5 files changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c index c37a71e13de0..23c70799ad8a 100644 --- a/drivers/hv/hv_fcopy.c +++ b/drivers/hv/hv_fcopy.c @@ -251,7 +251,6 @@ void hv_fcopy_onchannelcallback(void *context) */ fcopy_transaction.recv_len = recvlen; - fcopy_transaction.recv_channel = channel; fcopy_transaction.recv_req_id = requestid; fcopy_transaction.fcopy_msg = fcopy_msg; @@ -317,6 +316,7 @@ static void fcopy_on_reset(void) int hv_fcopy_init(struct hv_util_service *srv) { recv_buffer = srv->recv_buffer; + fcopy_transaction.recv_channel = srv->channel; /* * When this driver loads, the user level daemon that diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c index d4ab81bcd515..9b9b370fe22a 100644 --- a/drivers/hv/hv_kvp.c +++ b/drivers/hv/hv_kvp.c @@ -639,7 +639,6 @@ void hv_kvp_onchannelcallback(void *context) */ kvp_transaction.recv_len = recvlen; - kvp_transaction.recv_channel = channel; kvp_transaction.recv_req_id = requestid; kvp_transaction.kvp_msg = kvp_msg; @@ -688,6 +687,7 @@ int hv_kvp_init(struct hv_util_service *srv) { recv_buffer = srv->recv_buffer; + kvp_transaction.recv_channel = srv->channel; /* * When this driver loads, the user level daemon that diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c index 67def4a831c8..3fba14e88f03 100644 --- a/drivers/hv/hv_snapshot.c +++ b/drivers/hv/hv_snapshot.c @@ -263,7 +263,6 @@ void hv_vss_onchannelcallback(void *context) */ vss_transaction.recv_len = recvlen; - vss_transaction.recv_channel = channel; vss_transaction.recv_req_id = requestid; vss_transaction.msg = (struct hv_vss_msg *)vss_msg; @@ -337,6 +336,7 @@ hv_vss_init(struct hv_util_service *srv) return -ENOTSUPP; } recv_buffer = srv->recv_buffer; + vss_transaction.recv_channel = srv->channel; /* * When this driver loads, the user level daemon that diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c index 7994ec2e4151..d5acaa2d8e61 100644 --- a/drivers/hv/hv_util.c +++ b/drivers/hv/hv_util.c @@ -322,6 +322,7 @@ static int util_probe(struct hv_device *dev, srv->recv_buffer = kmalloc(PAGE_SIZE * 4, GFP_KERNEL); if (!srv->recv_buffer) return -ENOMEM; + srv->channel = dev->channel; if (srv->util_init) { ret = srv->util_init(srv); if (ret) { diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index d23dab0d770b..aa0fadce9308 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1251,6 +1251,7 @@ u64 hv_do_hypercall(u64 control, void *input, void *output); struct hv_util_service { u8 *recv_buffer; + void *channel; void (*util_cb)(void *); int (*util_init)(struct hv_util_service *); void (*util_deinit)(void); -- 2.39.2