2024-04-10 16:35:42

by Steven Rostedt

[permalink] [raw]
Subject: [PATCH] SUNRPC: Fix rpcgss_context trace event acceptor field

From: "Steven Rostedt (Google)" <[email protected]>

The rpcgss_context trace event acceptor field is a dynamically sized
string that records the "data" parameter. But this parameter is also
dependent on the "len" field to determine the size of the data.

It needs to use __string_len() helper macro where the length can be passed
in. It also incorrectly uses strncpy() to save it instead of
__assign_str(). As these macros can change, it is not wise to open code
them in trace events.

As of commit c759e609030c ("tracing: Remove __assign_str_len()"),
__assign_str() can be used for both __string() and __string_len() fields.
Before that commit, __assign_str_len() is required to be used. This needs
to be noted for backporting. (In actuality, commit c1fa617caeb0 ("tracing:
Rework __assign_str() and __string() to not duplicate getting the string")
is the commit that makes __string_str_len() obsolete).

Cc: [email protected]
Fixes: 0c77668ddb4e7 ("SUNRPC: Introduce trace points in rpc_auth_gss.ko")
Signed-off-by: Steven Rostedt (Google) <[email protected]>
---
include/trace/events/rpcgss.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/trace/events/rpcgss.h b/include/trace/events/rpcgss.h
index ba2d96a1bc2f..f50fcafc69de 100644
--- a/include/trace/events/rpcgss.h
+++ b/include/trace/events/rpcgss.h
@@ -609,7 +609,7 @@ TRACE_EVENT(rpcgss_context,
__field(unsigned int, timeout)
__field(u32, window_size)
__field(int, len)
- __string(acceptor, data)
+ __string_len(acceptor, data, len)
),

TP_fast_assign(
@@ -618,7 +618,7 @@ TRACE_EVENT(rpcgss_context,
__entry->timeout = timeout;
__entry->window_size = window_size;
__entry->len = len;
- strncpy(__get_str(acceptor), data, len);
+ __assign_str(acceptor, data);
),

TP_printk("win_size=%u expiry=%lu now=%lu timeout=%u acceptor=%.*s",
--
2.43.0



2024-04-10 16:39:19

by Chuck Lever

[permalink] [raw]
Subject: Re: [PATCH] SUNRPC: Fix rpcgss_context trace event acceptor field

On Wed, Apr 10, 2024 at 12:38:13PM -0400, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <[email protected]>
>
> The rpcgss_context trace event acceptor field is a dynamically sized
> string that records the "data" parameter. But this parameter is also
> dependent on the "len" field to determine the size of the data.
>
> It needs to use __string_len() helper macro where the length can be passed
> in. It also incorrectly uses strncpy() to save it instead of
> __assign_str(). As these macros can change, it is not wise to open code
> them in trace events.
>
> As of commit c759e609030c ("tracing: Remove __assign_str_len()"),
> __assign_str() can be used for both __string() and __string_len() fields.
> Before that commit, __assign_str_len() is required to be used. This needs
> to be noted for backporting. (In actuality, commit c1fa617caeb0 ("tracing:
> Rework __assign_str() and __string() to not duplicate getting the string")
> is the commit that makes __string_str_len() obsolete).
>
> Cc: [email protected]
> Fixes: 0c77668ddb4e7 ("SUNRPC: Introduce trace points in rpc_auth_gss.ko")
> Signed-off-by: Steven Rostedt (Google) <[email protected]>

Acked-by: Chuck Lever <[email protected]>


> ---
> include/trace/events/rpcgss.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/trace/events/rpcgss.h b/include/trace/events/rpcgss.h
> index ba2d96a1bc2f..f50fcafc69de 100644
> --- a/include/trace/events/rpcgss.h
> +++ b/include/trace/events/rpcgss.h
> @@ -609,7 +609,7 @@ TRACE_EVENT(rpcgss_context,
> __field(unsigned int, timeout)
> __field(u32, window_size)
> __field(int, len)
> - __string(acceptor, data)
> + __string_len(acceptor, data, len)
> ),
>
> TP_fast_assign(
> @@ -618,7 +618,7 @@ TRACE_EVENT(rpcgss_context,
> __entry->timeout = timeout;
> __entry->window_size = window_size;
> __entry->len = len;
> - strncpy(__get_str(acceptor), data, len);
> + __assign_str(acceptor, data);
> ),
>
> TP_printk("win_size=%u expiry=%lu now=%lu timeout=%u acceptor=%.*s",
> --
> 2.43.0
>

--
Chuck Lever

2024-04-10 18:04:24

by Steven Rostedt

[permalink] [raw]
Subject: Re: [PATCH] SUNRPC: Fix rpcgss_context trace event acceptor field

On Wed, 10 Apr 2024 13:07:20 -0400
Chuck Lever <[email protected]> wrote:

> Well I guess I could test it for you. I'll take it for nfsd v6.9-rc.

Thanks!

-- Steve