Re: [Qemu-devel] [PATCH v2 3/3] ipmi: Add the platform event message command

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

Hi Corey,

On 08/20/2017 06:46 PM, minyard@acm.org wrote:
> From: Corey Minyard <cminyard@mvista.com>
> 
> This lets an event be added to the SEL as if a sensor had generated
> it.  The OpenIPMI driver uses it for storing panic event information.
> 
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
> ---
>   hw/ipmi/ipmi_bmc_sim.c | 24 ++++++++++++++++++++++++
>   1 file changed, 24 insertions(+)
> 
> diff --git a/hw/ipmi/ipmi_bmc_sim.c b/hw/ipmi/ipmi_bmc_sim.c
> index a0bbfd5..e84d710 100644
> --- a/hw/ipmi/ipmi_bmc_sim.c
> +++ b/hw/ipmi/ipmi_bmc_sim.c
> @@ -38,6 +38,7 @@
>   
>   #define IPMI_NETFN_SENSOR_EVENT       0x04
>   
> +#define IPMI_CMD_PLATFORM_EVENT_MSG       0x02
>   #define IPMI_CMD_SET_SENSOR_EVT_ENABLE    0x28
>   #define IPMI_CMD_GET_SENSOR_EVT_ENABLE    0x29
>   #define IPMI_CMD_REARM_SENSOR_EVTS        0x2a
> @@ -1581,6 +1582,28 @@ static void set_sel_time(IPMIBmcSim *ibs,
>       ibs->sel.time_offset = now.tv_sec - ((long) val);
>   }
>   
> +static void platform_event_msg(IPMIBmcSim *ibs,
> +                               uint8_t *cmd, unsigned int cmd_len,
> +                               RspBuffer *rsp)
> +{
> +    uint8_t event[16];

Watch out, here you are using uninitialized stack,

> +
> +    event[2] = 2; /* System event record */
> +    event[7] = cmd[2]; /* Generator ID */
> +    event[8] = 0;
> +    event[9] = cmd[3]; /* EvMRev */
> +    event[10] = cmd[4]; /* Sensor type */
> +    event[11] = cmd[5]; /* Sensor number */
> +    event[12] = cmd[6]; /* Event dir / Event type */
> +    event[13] = cmd[7]; /* Event data 1 */
> +    event[14] = cmd[8]; /* Event data 2 */
> +    event[15] = cmd[9]; /* Event data 3 */
> +
> +    if (sel_add_event(ibs, event)) {

So here you have event[0,1,3-6] as crap/random.

Also it'd be more efficient to use

	memcpy(&event[9], &cmd[3], sizeof(event) - 9);

> +        rsp_buffer_set_error(rsp, IPMI_CC_OUT_OF_SPACE);
> +    }
> +}
> +
>   static void set_sensor_evt_enable(IPMIBmcSim *ibs,
>                                     uint8_t *cmd, unsigned int cmd_len,
>                                     RspBuffer *rsp)
> @@ -1757,6 +1780,7 @@ static const IPMINetfn chassis_netfn = {
>   };
>   
>   static const IPMICmdHandler sensor_event_cmds[] = {
> +    [IPMI_CMD_PLATFORM_EVENT_MSG] = { platform_event_msg, 10 },
>       [IPMI_CMD_SET_SENSOR_EVT_ENABLE] = { set_sensor_evt_enable, 4 },
>       [IPMI_CMD_GET_SENSOR_EVT_ENABLE] = { get_sensor_evt_enable, 3 },
>       [IPMI_CMD_REARM_SENSOR_EVTS] = { rearm_sensor_evts, 4 },
>