SUNRPC: Fix a NULL pointer deref in trace_svc_stats_latency()

Some paths through svc_process() leave rqst->rq_procinfo set to
NULL, which triggers a crash if tracing happens to be enabled.

Fixes: 89ff87494c ("SUNRPC: Display RPC procedure names instead of proc numbers")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Chuck Lever 2021-08-05 15:11:24 -04:00
parent ea49dc7900
commit 5c11720767
3 changed files with 20 additions and 4 deletions

View file

@ -527,6 +527,7 @@ void svc_wake_up(struct svc_serv *);
void svc_reserve(struct svc_rqst *rqstp, int space);
struct svc_pool * svc_pool_for_cpu(struct svc_serv *serv, int cpu);
char * svc_print_addr(struct svc_rqst *, char *, size_t);
const char * svc_proc_name(const struct svc_rqst *rqstp);
int svc_encode_result_payload(struct svc_rqst *rqstp,
unsigned int offset,
unsigned int length);

View file

@ -1642,7 +1642,7 @@ TRACE_EVENT(svc_process,
__field(u32, vers)
__field(u32, proc)
__string(service, name)
__string(procedure, rqst->rq_procinfo->pc_name)
__string(procedure, svc_proc_name(rqst))
__string(addr, rqst->rq_xprt ?
rqst->rq_xprt->xpt_remotebuf : "(null)")
),
@ -1652,7 +1652,7 @@ TRACE_EVENT(svc_process,
__entry->vers = rqst->rq_vers;
__entry->proc = rqst->rq_proc;
__assign_str(service, name);
__assign_str(procedure, rqst->rq_procinfo->pc_name);
__assign_str(procedure, svc_proc_name(rqst));
__assign_str(addr, rqst->rq_xprt ?
rqst->rq_xprt->xpt_remotebuf : "(null)");
),
@ -1918,7 +1918,7 @@ TRACE_EVENT(svc_stats_latency,
TP_STRUCT__entry(
__field(u32, xid)
__field(unsigned long, execute)
__string(procedure, rqst->rq_procinfo->pc_name)
__string(procedure, svc_proc_name(rqst))
__string(addr, rqst->rq_xprt->xpt_remotebuf)
),
@ -1926,7 +1926,7 @@ TRACE_EVENT(svc_stats_latency,
__entry->xid = be32_to_cpu(rqst->rq_xid);
__entry->execute = ktime_to_us(ktime_sub(ktime_get(),
rqst->rq_stime));
__assign_str(procedure, rqst->rq_procinfo->pc_name);
__assign_str(procedure, svc_proc_name(rqst));
__assign_str(addr, rqst->rq_xprt->xpt_remotebuf);
),

View file

@ -1650,6 +1650,21 @@ u32 svc_max_payload(const struct svc_rqst *rqstp)
}
EXPORT_SYMBOL_GPL(svc_max_payload);
/**
* svc_proc_name - Return RPC procedure name in string form
* @rqstp: svc_rqst to operate on
*
* Return value:
* Pointer to a NUL-terminated string
*/
const char *svc_proc_name(const struct svc_rqst *rqstp)
{
if (rqstp && rqstp->rq_procinfo)
return rqstp->rq_procinfo->pc_name;
return "unknown";
}
/**
* svc_encode_result_payload - mark a range of bytes as a result payload
* @rqstp: svc_rqst to operate on