From: Petr Mladek <pmladek@suse.cz>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Jiri Kosina <jkosina@suse.cz>, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [RFC][PATCH 04/12 v3] tracing: Convert seq_buf_path() to be like seq_path()
Date: Wed, 5 Nov 2014 15:45:53 +0100 [thread overview]
Message-ID: <20141105144553.GE4570@pathway.suse.cz> (raw)
In-Reply-To: <20141104160222.048795666@goodmis.org>
On Tue 2014-11-04 10:52:41, Steven Rostedt wrote:
> From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
>
> Rewrite seq_buf_path() like it is done in seq_path() and allow
> it to accept any escape character instead of just "\n".
>
> Making seq_buf_path() like seq_path() will help prevent problems
> when converting seq_file to use the seq_buf logic.
>
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
> ---
> include/linux/seq_buf.h | 2 +-
> kernel/trace/seq_buf.c | 30 ++++++++++++++++--------------
> kernel/trace/trace_seq.c | 2 +-
> 3 files changed, 18 insertions(+), 16 deletions(-)
>
> diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h
> index 97872154d51c..6d1c57d6073f 100644
> --- a/include/linux/seq_buf.h
> +++ b/include/linux/seq_buf.h
> @@ -64,7 +64,7 @@ extern int seq_buf_putc(struct seq_buf *s, unsigned char c);
> extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len);
> extern int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
> unsigned int len);
> -extern int seq_buf_path(struct seq_buf *s, const struct path *path);
> +extern int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc);
>
> extern int seq_buf_bitmask(struct seq_buf *s, const unsigned long *maskp,
> int nmaskbits);
> diff --git a/kernel/trace/seq_buf.c b/kernel/trace/seq_buf.c
> index 2bf582753902..243123b12d16 100644
> --- a/kernel/trace/seq_buf.c
> +++ b/kernel/trace/seq_buf.c
> @@ -272,28 +272,30 @@ int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
> * seq_buf_path - copy a path into the sequence buffer
> * @s: seq_buf descriptor
> * @path: path to write into the sequence buffer.
> + * @esc: set of characters to escape in the output
> *
> * Write a path name into the sequence buffer.
> *
> * Returns zero on success, -1 on overflow
>
> */
> -int seq_buf_path(struct seq_buf *s, const struct path *path)
> +int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc)
> {
> - unsigned int len = SEQ_BUF_LEFT(s);
> - unsigned char *p;
> -
> - WARN_ON(s->size == 0);
I would keep this check.
> - p = d_path(path, s->buffer + s->len, len);
> - if (!IS_ERR(p)) {
> - p = mangle_path(s->buffer + s->len, p, "\n");
> - if (p) {
> - s->len = p - s->buffer;
> - return 0;
> + char *buf = s->buffer + s->len;
> + size_t size = SEQ_BUF_LEFT(s);
I would use the variable name "len" to make it consistent with
the other fucntions in seq_buf.c.
> + int res = -1;
> +
> + if (size) {
> + char *p = d_path(path, buf, size);
> + if (!IS_ERR(p)) {
> + char *end = mangle_path(buf, p, esc);
> + if (end)
> + res = end - buf;
> }
> }
> - seq_buf_set_overflow(s);
We still should set overflow on failure.
> - return -1;
> + if (res > 0)
> + s->len += res;
> +
> + return res;
It returns -1 on failure and the number of written characters on
success. This is incompatible with the other seq_buf functions
and with the comment above this function. Also it changes the
return value from trace_seq_path().
I do not mind about the used scheme but I think that we should
make it consistent.
Best Regards,
Petr
next prev parent reply other threads:[~2014-11-05 14:46 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-04 15:52 [RFC][PATCH 00/12 v3] seq-buf/x86/printk: Print all stacks from NMI safely Steven Rostedt
2014-11-04 15:52 ` [RFC][PATCH 01/12 v3] x86/kvm/tracing: Use helper function trace_seq_buffer_ptr() Steven Rostedt
2014-11-04 16:27 ` Paolo Bonzini
2014-11-04 17:17 ` Rustad, Mark D
2014-11-04 19:09 ` Steven Rostedt
2014-11-04 19:35 ` Steven Rostedt
2014-11-04 20:09 ` Rustad, Mark D
2014-11-05 10:28 ` Petr Mladek
2014-11-04 15:52 ` [RFC][PATCH 02/12 v3] RAS/tracing: Use trace_seq_buffer_ptr() helper instead of open coded Steven Rostedt
2014-11-04 19:59 ` Borislav Petkov
2014-11-05 10:29 ` Petr Mladek
2014-11-04 15:52 ` [RFC][PATCH 03/12 v3] tracing: Create seq_buf layer in trace_seq Steven Rostedt
2014-11-05 14:22 ` Petr Mladek
2014-11-05 18:41 ` Steven Rostedt
2014-11-05 20:00 ` Steven Rostedt
2014-11-05 21:17 ` Steven Rostedt
2014-11-05 21:21 ` Steven Rostedt
2014-11-06 16:33 ` Petr Mladek
2014-11-07 18:30 ` Steven Rostedt
2014-11-07 18:59 ` Joe Perches
2014-11-07 19:10 ` Steven Rostedt
2014-11-10 13:53 ` Petr Mladek
2014-11-10 17:37 ` Steven Rostedt
2014-11-10 19:02 ` Petr Mladek
2014-11-06 16:13 ` Petr Mladek
2014-11-05 14:26 ` Petr Mladek
2014-11-05 18:42 ` Steven Rostedt
2014-11-04 15:52 ` [RFC][PATCH 04/12 v3] tracing: Convert seq_buf_path() to be like seq_path() Steven Rostedt
2014-11-05 14:45 ` Petr Mladek [this message]
2014-11-05 20:10 ` Steven Rostedt
2014-11-06 14:18 ` Petr Mladek
2014-11-06 21:09 ` Steven Rostedt
2014-11-06 15:01 ` Petr Mladek
2014-11-07 18:34 ` Steven Rostedt
2014-11-10 14:03 ` Petr Mladek
2014-11-10 17:38 ` Steven Rostedt
2014-11-04 15:52 ` [RFC][PATCH 05/12 v3] tracing: Convert seq_buf fields to be like seq_file fields Steven Rostedt
2014-11-05 15:57 ` Petr Mladek
2014-11-05 20:14 ` Steven Rostedt
2014-11-06 14:24 ` Petr Mladek
2014-11-04 15:52 ` [RFC][PATCH 06/12 v3] tracing: Add a seq_buf_clear() helper and clear len and readpos in init Steven Rostedt
2014-11-05 16:00 ` Petr Mladek
2014-11-04 15:52 ` [RFC][PATCH 07/12 v3] tracing: Have seq_buf use full buffer Steven Rostedt
2014-11-05 16:31 ` Petr Mladek
2014-11-05 20:21 ` Steven Rostedt
2014-11-05 21:06 ` Steven Rostedt
2014-11-06 15:31 ` Petr Mladek
2014-11-06 19:24 ` Steven Rostedt
2014-11-07 9:11 ` Petr Mladek
2014-11-07 18:37 ` Steven Rostedt
2014-11-10 18:11 ` Petr Mladek
2014-11-06 15:13 ` Petr Mladek
2014-11-04 15:52 ` [RFC][PATCH 08/12 v3] tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions Steven Rostedt
2014-11-05 16:51 ` Petr Mladek
2014-11-05 20:26 ` Steven Rostedt
2014-11-07 18:39 ` Steven Rostedt
2014-11-10 18:33 ` Petr Mladek
2014-11-10 19:23 ` Steven Rostedt
2014-11-04 15:52 ` [RFC][PATCH 09/12 v3] seq_buf: Move the seq_buf code to lib/ Steven Rostedt
2014-11-05 16:57 ` Petr Mladek
2014-11-05 20:32 ` Steven Rostedt
2014-11-04 15:52 ` [RFC][PATCH 10/12 v3] seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTF Steven Rostedt
2014-11-05 17:06 ` Petr Mladek
2014-11-05 20:33 ` Steven Rostedt
2014-11-05 20:42 ` Steven Rostedt
2014-11-06 14:39 ` Petr Mladek
2014-11-07 20:36 ` Junio C Hamano
2014-11-07 21:49 ` Steven Rostedt
2014-11-10 18:43 ` Petr Mladek
2014-11-04 15:52 ` [RFC][PATCH 11/12 v3] printk: Add per_cpu printk func to allow printk to be diverted Steven Rostedt
2014-11-06 16:56 ` Petr Mladek
2014-11-04 15:52 ` [RFC][PATCH 12/12 v3] x86/nmi: Perform a safe NMI stack trace on all CPUs Steven Rostedt
2014-11-04 23:05 ` Jiri Kosina
2014-11-04 23:41 ` Steven Rostedt
2014-11-06 18:41 ` Petr Mladek
2014-11-07 18:56 ` Steven Rostedt
2014-11-10 18:58 ` Petr Mladek
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20141105144553.GE4570@pathway.suse.cz \
--to=pmladek@suse.cz \
--cc=akpm@linux-foundation.org \
--cc=hpa@zytor.com \
--cc=jkosina@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).