summaryrefslogtreecommitdiff
path: root/include/trace
diff options
context:
space:
mode:
authorChuck Lever <chuck.lever@oracle.com>2022-04-06 20:51:32 +0300
committerChuck Lever <chuck.lever@oracle.com>2022-04-07 17:22:51 +0300
commit4d5004451ab2218eab94a30e1841462c9316ba19 (patch)
treeebc22ea61cad0ed0384e6ee9d818f47754d89e6a /include/trace
parent773f91b2cf3f52df0d7508fdbf60f37567cdaee4 (diff)
downloadlinux-4d5004451ab2218eab94a30e1841462c9316ba19.tar.xz
SUNRPC: Fix the svc_deferred_event trace class
Fix a NULL deref crash that occurs when an svc_rqst is deferred while the sunrpc tracing subsystem is enabled. svc_revisit() sets dr->xprt to NULL, so it can't be relied upon in the tracepoint to provide the remote's address. Unfortunately we can't revert the "svc_deferred_class" hunk in commit ece200ddd54b ("sunrpc: Save remote presentation address in svc_xprt for trace events") because there is now a specific check of event format specifiers for unsafe dereferences. The warning that check emits is: event svc_defer_recv has unsafe dereference of argument 1 A "%pISpc" format specifier with a "struct sockaddr *" is indeed flagged by this check. Instead, take the brute-force approach used by the svcrdma_qp_error tracepoint. Convert the dr::addr field into a presentation address in the TP_fast_assign() arm of the trace event, and store that as a string. This fix can be backported to -stable kernels. In the meantime, commit c6ced22997ad ("tracing: Update print fmt check to handle new __get_sockaddr() macro") is now in v5.18, so this wonky fix can be replaced with __sockaddr() and friends properly during the v5.19 merge window. Fixes: ece200ddd54b ("sunrpc: Save remote presentation address in svc_xprt for trace events") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'include/trace')
-rw-r--r--include/trace/events/sunrpc.h7
1 files changed, 4 insertions, 3 deletions
diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index ab8ae1f6ba84..4eb706fa5825 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -2017,17 +2017,18 @@ DECLARE_EVENT_CLASS(svc_deferred_event,
TP_STRUCT__entry(
__field(const void *, dr)
__field(u32, xid)
- __string(addr, dr->xprt->xpt_remotebuf)
+ __array(__u8, addr, INET6_ADDRSTRLEN + 10)
),
TP_fast_assign(
__entry->dr = dr;
__entry->xid = be32_to_cpu(*(__be32 *)(dr->args +
(dr->xprt_hlen>>2)));
- __assign_str(addr, dr->xprt->xpt_remotebuf);
+ snprintf(__entry->addr, sizeof(__entry->addr) - 1,
+ "%pISpc", (struct sockaddr *)&dr->addr);
),
- TP_printk("addr=%s dr=%p xid=0x%08x", __get_str(addr), __entry->dr,
+ TP_printk("addr=%s dr=%p xid=0x%08x", __entry->addr, __entry->dr,
__entry->xid)
);