Correct issue with not checking kmalloc return value.
This fix now only uses one receive buffer for all hv_utils
channels, and will do only one kmalloc on init and will return
with a -ENOMEM if kmalloc fails on initialize.
Thanks to Evgeniy Polyakov <zbr@xxxxxxxxxxx> for pointing this out.
And thanks to Jesper Juhl <jj@xxxxxxxxxxxxx> and Ky Srinivasan
<ksrinivasan@xxxxxxxxxx> for suggesting a better implementation of
my original patch.
Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Signed-off-by: Hank Janssen <hjanssen@xxxxxxxxxxxxx>
Cc:Evgeniy Polyakov <zbr@xxxxxxxxxxx>
Cc:Jesper Juhl <jj@xxxxxxxxxxxxx>
Cc:Ky Srinivasan <ksrinivasan@xxxxxxxxxx>
---
drivers/staging/hv/hv_utils.c | 68 +++++++++++++++++++---------------------
1 files changed, 32 insertions(+), 36 deletions(-)
diff --git a/drivers/staging/hv/hv_utils.c b/drivers/staging/hv/hv_utils.c
index 53e1e29..4ed4ab8 100644
--- a/drivers/staging/hv/hv_utils.c
+++ b/drivers/staging/hv/hv_utils.c
@@ -38,12 +38,15 @@
#include "vmbus_api.h"
#include "utils.h"
+/*
+ * Buffer used to receive packets from Hyper-V
+ */
+static u8 *chan_buf;
static void shutdown_onchannelcallback(void *context)
{
struct vmbus_channel *channel = context;
- u8 *buf;
- u32 buflen, recvlen;
+ u32 recvlen;
u64 requestid;
u8 execute_shutdown = false;
@@ -52,22 +55,19 @@ static void shutdown_onchannelcallback(void *context)
struct icmsg_hdr *icmsghdrp;
struct icmsg_negotiate *negop = NULL;
- buflen = PAGE_SIZE;
- buf = kmalloc(buflen, GFP_ATOMIC);
-
- vmbus_recvpacket(channel, buf, buflen, &recvlen, &requestid);
+ vmbus_recvpacket(channel, chan_buf, PAGE_SIZE, &recvlen, &requestid);
if (recvlen > 0) {
DPRINT_DBG(VMBUS, "shutdown packet: len=%d, requestid=%lld",
recvlen, requestid);
- icmsghdrp = (struct icmsg_hdr *)&buf[
+ icmsghdrp = (struct icmsg_hdr *)&chan_buf[
sizeof(struct vmbuspipe_hdr)];
if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
- prep_negotiate_resp(icmsghdrp, negop, buf);
+ prep_negotiate_resp(icmsghdrp, negop, chan_buf);
} else {
- shutdown_msg = (struct shutdown_msg_data *)&buf[
+ shutdown_msg = (struct shutdown_msg_data *)&chan_buf[
sizeof(struct vmbuspipe_hdr) +
sizeof(struct icmsg_hdr)];
@@ -93,13 +93,11 @@ static void shutdown_onchannelcallback(void *context)
icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE;
- vmbus_sendpacket(channel, buf,
+ vmbus_sendpacket(channel, chan_buf,
recvlen, requestid,
VmbusPacketTypeDataInBand, 0);
}
- kfree(buf);
-
if (execute_shutdown == true)
orderly_poweroff(false);
}
@@ -150,28 +148,24 @@ static inline void adj_guesttime(u64 hosttime, u8 flags)
static void timesync_onchannelcallback(void *context)
{
struct vmbus_channel *channel = context;
- u8 *buf;
- u32 buflen, recvlen;
+ u32 recvlen;
u64 requestid;
struct icmsg_hdr *icmsghdrp;
struct ictimesync_data *timedatap;
- buflen = PAGE_SIZE;
- buf = kmalloc(buflen, GFP_ATOMIC);
-
- vmbus_recvpacket(channel, buf, buflen, &recvlen, &requestid);
+ vmbus_recvpacket(channel, chan_buf, PAGE_SIZE, &recvlen, &requestid);
if (recvlen > 0) {
DPRINT_DBG(VMBUS, "timesync packet: recvlen=%d, requestid=%lld",
recvlen, requestid);
- icmsghdrp = (struct icmsg_hdr *)&buf[
+ icmsghdrp = (struct icmsg_hdr *)&chan_buf[
sizeof(struct vmbuspipe_hdr)];
if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
- prep_negotiate_resp(icmsghdrp, NULL, buf);
+ prep_negotiate_resp(icmsghdrp, NULL, chan_buf);
} else {
- timedatap = (struct ictimesync_data *)&buf[
+ timedatap = (struct ictimesync_data *)&chan_buf[
sizeof(struct vmbuspipe_hdr) +
sizeof(struct icmsg_hdr)];
adj_guesttime(timedatap->parenttime, timedatap->flags);
@@ -180,12 +174,10 @@ static void timesync_onchannelcallback(void *context)
icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE;
- vmbus_sendpacket(channel, buf,
+ vmbus_sendpacket(channel, chan_buf,
recvlen, requestid,
VmbusPacketTypeDataInBand, 0);
}
-
- kfree(buf);
}
/*
@@ -196,28 +188,24 @@ static void timesync_onchannelcallback(void *context)
static void heartbeat_onchannelcallback(void *context)
{
struct vmbus_channel *channel = context;
- u8 *buf;
- u32 buflen, recvlen;
+ u32 recvlen;
u64 requestid;
struct icmsg_hdr *icmsghdrp;
struct heartbeat_msg_data *heartbeat_msg;
- buflen = PAGE_SIZE;
- buf = kmalloc(buflen, GFP_ATOMIC);
-
- vmbus_recvpacket(channel, buf, buflen, &recvlen, &requestid);
+ vmbus_recvpacket(channel, chan_buf, PAGE_SIZE, &recvlen, &requestid);
if (recvlen > 0) {
DPRINT_DBG(VMBUS, "heartbeat packet: len=%d, requestid=%lld",
recvlen, requestid);
- icmsghdrp = (struct icmsg_hdr *)&buf[
+ icmsghdrp = (struct icmsg_hdr *)&chan_buf[
sizeof(struct vmbuspipe_hdr)];
if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
- prep_negotiate_resp(icmsghdrp, NULL, buf);
+ prep_negotiate_resp(icmsghdrp, NULL, chan_buf);
} else {
- heartbeat_msg = (struct heartbeat_msg_data *)&buf[
+ heartbeat_msg = (struct heartbeat_msg_data *)&chan_buf[
sizeof(struct vmbuspipe_hdr) +
sizeof(struct icmsg_hdr)];
@@ -230,12 +218,10 @@ static void heartbeat_onchannelcallback(void *context)
icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE;
- vmbus_sendpacket(channel, buf,
+ vmbus_sendpacket(channel, chan_buf,
recvlen, requestid,
VmbusPacketTypeDataInBand, 0);
}
-
- kfree(buf);
}
static const struct pci_device_id __initconst
@@ -268,6 +254,14 @@ static int __init init_hyperv_utils(void)
if (!dmi_check_system(hv_utils_dmi_table))
return -ENODEV;
+ chan_buf = kmalloc(PAGE_SIZE, GFP_ATOMIC);
+
+ if (!chan_buf) {
+ printk(KERN_INFO
+ "Unable to allocate memory for receive buffer\n");
+ return -ENOMEM;
+ }
+
hv_cb_utils[HV_SHUTDOWN_MSG].channel->onchannel_callback =
&shutdown_onchannelcallback;
hv_cb_utils[HV_SHUTDOWN_MSG].callback = &shutdown_onchannelcallback;
@@ -298,6 +292,8 @@ static void exit_hyperv_utils(void)
hv_cb_utils[HV_HEARTBEAT_MSG].channel->onchannel_callback =
&chn_cb_negotiate;
hv_cb_utils[HV_HEARTBEAT_MSG].callback = &chn_cb_negotiate;
+
+ kfree(chan_buf);
}
module_init(init_hyperv_utils);
--
1.6.0.2
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