From: Steven Rostedt <rostedt@goodmis.org>
To: "Yordan Karadzhov (VMware)" <y.karadz@gmail.com>
Cc: linux-trace-devel@vger.kernel.org
Subject: Re: [PATCH v2 0/7] Final fixes before KS 2.0
Date: Mon, 17 May 2021 19:28:31 -0400 [thread overview]
Message-ID: <20210517192831.15d5773c@gandalf.local.home> (raw)
In-Reply-To: <20210517192104.0272eb84@gandalf.local.home>
On Mon, 17 May 2021 19:21:04 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> On Mon, 17 May 2021 17:21:33 +0300
> "Yordan Karadzhov (VMware)" <y.karadz@gmail.com> wrote:
>
> > v2 changes:
> > - Still showing all CPU plots from the new trace file when
> > appending [PATCH kernel-shark: Preserve open graphs when
> > appending data].
> > - Setting "seq.buffer" to NULL after calling trace_seq_destroy()
> > in [PATCH kernel-shark: Fix the checking if "trace_seq" was destroyed]
> > - [PATCH kernel-shark: No slash at the end of KS_PLUGIN_INSTALL_PREFIX]
> > is new.
>
> Hi Yordan,
>
> I was playing a bit with kernelshark, and found that if I load a file and
> append one, exit, load them again, then click:
>
> File -> Sessions -> Restore Last Session
>
> It crashes.
>
> Looks to be something is freed and then reused, because when I ran it under
> gdb, it crashed in allocation of memory (asprintf). That usually means that
> something was freed twice, someplace else. Or freed and then used.
>
Running valgrind, reported this:
==6862== Invalid read of size 8
==6862== at 0x494CA89: map_collection_back_request (libkshark-collection.c:474)
static int
map_collection_back_request(const struct kshark_entry_collection *col,
struct kshark_entry_request *req)
{
size_t req_first, req_end;
ssize_t col_index;
int req_count;
col_index = map_collection_request_init(col, req, false, &req_end);
if (col_index == KS_EMPTY_BIN)
return 0;
/*
* Now loop over the intervals of the collection going backwards till
* the end of the inputted request and create a separate request for
* each of those interest.
*/
req_count = 1;
while (col_index >= 0 && req_end <= col->break_points[col_index]) {
// col_index can be zero entering this loop.
if (req_end >= col->resume_points[col_index]) {
/*
* The last entry of the original request is inside
* the "col_index" collection interval. Close the
* collection request here and return.
*/
req->n = req->first - req_end + 1;
break;
}
/*
* The last entry of the original request is outside of the
* "col_index" interval. Close the collection request at the
* end of this interval and move to the next one. Try to make
* another request there.
*/
req->n = req->first -
col->resume_points[col_index] + 1;
--col_index;
// col_index is decremented (-1)
if (req_end > col->break_points[col_index]) {
Reading a negative index in an array.
Which is where valgrind reported. But I don't think this is what caused the
crash.
-- Steve
next prev parent reply other threads:[~2021-05-17 23:28 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-17 14:21 [PATCH v2 0/7] Final fixes before KS 2.0 Yordan Karadzhov (VMware)
2021-05-17 14:21 ` [PATCH v2 1/7] kernel-shark: Preserve markers when appending data Yordan Karadzhov (VMware)
2021-05-17 14:21 ` [PATCH v2 2/7] kernel-shark: Preserve open graphs " Yordan Karadzhov (VMware)
2021-05-17 14:21 ` [PATCH v2 3/7] kernel-shark: Clear before loading new session Yordan Karadzhov (VMware)
2021-05-17 14:21 ` [PATCH v2 4/7] kernel-shark: Better handling of plugins when appending data file Yordan Karadzhov (VMware)
2021-05-17 14:21 ` [PATCH v2 5/7] kernel-shark: Do draw the combo point of the mark Yordan Karadzhov (VMware)
2021-05-17 14:21 ` [PATCH v2 6/7] kernel-shark: Fix the checking if "trace_seq" was destroyed Yordan Karadzhov (VMware)
2021-05-17 14:21 ` [PATCH v2 7/7] kernel-shark: No slash at the end of KS_PLUGIN_INSTALL_PREFIX Yordan Karadzhov (VMware)
2021-05-17 23:21 ` [PATCH v2 0/7] Final fixes before KS 2.0 Steven Rostedt
2021-05-17 23:28 ` Steven Rostedt [this message]
2021-05-18 7:30 ` Yordan Karadzhov
2021-05-18 12:46 ` Steven Rostedt
2021-05-18 12:58 ` Yordan Karadzhov
2021-05-18 13:44 ` Steven Rostedt
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=20210517192831.15d5773c@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=linux-trace-devel@vger.kernel.org \
--cc=y.karadz@gmail.com \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).