From: Song Liu <liu.song.a23@gmail.com>
To: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Oleg Nesterov <oleg@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
mhiramat@kernel.org, Peter Zijlstra <peterz@infradead.org>,
mingo@redhat.com, acme@kernel.org,
alexander.shishkin@linux.intel.com, jolsa@redhat.com,
namhyung@kernel.org, open list <linux-kernel@vger.kernel.org>,
ananth@linux.vnet.ibm.com,
Alexis Berlemont <alexis.berlemont@gmail.com>,
naveen.n.rao@linux.vnet.ibm.com,
linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org,
linux@armlinux.org.uk, ralf@linux-mips.org, paul.burton@mips.com
Subject: Re: [PATCH v9 2/4] Uprobes/sdt: Prevent multiple reference counter for same uprobe
Date: Tue, 21 Aug 2018 14:35:29 -0700 [thread overview]
Message-ID: <CAPhsuW5DBOuYjYsUyWRZimeRKJhmA=RNM-rpcRhsfXwWfVG6qw@mail.gmail.com> (raw)
In-Reply-To: <CAPhsuW4QbT+0wHYW-A7G8z-Xp=8M+0w1Efmc1006PbqNTfOSxg@mail.gmail.com>
On Sun, Aug 19, 2018 at 10:54 PM, Song Liu <liu.song.a23@gmail.com> wrote:
> On Sun, Aug 19, 2018 at 9:42 PM, Ravi Bangoria
> <ravi.bangoria@linux.ibm.com> wrote:
>> We assume to have only one reference counter for one uprobe.
>> Don't allow user to register multiple uprobes having same
>> inode+offset but different reference counter.
>>
>> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
>> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
>> Reviewed-by: Oleg Nesterov <oleg@redhat.com>
>
> Reviewed-by: Song Liu <songliubraving@fb.com>
Reviewed-and-tested-by: Song Liu <songliubraving@fb.com>
>
>> ---
>> kernel/events/uprobes.c | 19 +++++++++++++++++++
>> 1 file changed, 19 insertions(+)
>>
>> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
>> index 35065febcb6c..ecee371a59c7 100644
>> --- a/kernel/events/uprobes.c
>> +++ b/kernel/events/uprobes.c
>> @@ -679,6 +679,16 @@ static struct uprobe *insert_uprobe(struct uprobe *uprobe)
>> return u;
>> }
>>
>> +static void
>> +ref_ctr_mismatch_warn(struct uprobe *cur_uprobe, struct uprobe *uprobe)
>> +{
>> + pr_warn("ref_ctr_offset mismatch. inode: 0x%lx offset: 0x%llx "
>> + "ref_ctr_offset(old): 0x%llx ref_ctr_offset(new): 0x%llx\n",
>> + uprobe->inode->i_ino, (unsigned long long) uprobe->offset,
>> + (unsigned long long) cur_uprobe->ref_ctr_offset,
>> + (unsigned long long) uprobe->ref_ctr_offset);
>> +}
>> +
>> static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset,
>> loff_t ref_ctr_offset)
>> {
>> @@ -698,6 +708,12 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset,
>> cur_uprobe = insert_uprobe(uprobe);
>> /* a uprobe exists for this inode:offset combination */
>> if (cur_uprobe) {
>> + if (cur_uprobe->ref_ctr_offset != uprobe->ref_ctr_offset) {
>> + ref_ctr_mismatch_warn(cur_uprobe, uprobe);
>> + put_uprobe(cur_uprobe);
>> + kfree(uprobe);
>> + return ERR_PTR(-EINVAL);
>> + }
>> kfree(uprobe);
>> uprobe = cur_uprobe;
>> }
>> @@ -1112,6 +1128,9 @@ static int __uprobe_register(struct inode *inode, loff_t offset,
>> uprobe = alloc_uprobe(inode, offset, ref_ctr_offset);
>> if (!uprobe)
>> return -ENOMEM;
>> + if (IS_ERR(uprobe))
>> + return PTR_ERR(uprobe);
>> +
>> /*
>> * We can race with uprobe_unregister()->delete_uprobe().
>> * Check uprobe_is_active() and retry if it is false.
>> --
>> 2.14.4
>>
next prev parent reply other threads:[~2018-08-21 21:35 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-20 4:42 [PATCH v9 0/4] Uprobes: Support SDT markers having reference count (semaphore) Ravi Bangoria
2018-08-20 4:42 ` [PATCH v9 1/4] " Ravi Bangoria
2018-08-20 5:53 ` Song Liu
2018-08-21 21:35 ` Song Liu
2018-08-22 12:39 ` Srikar Dronamraju
2018-08-28 19:07 ` Song Liu
2018-08-28 19:34 ` Steven Rostedt
2018-08-20 4:42 ` [PATCH v9 2/4] Uprobes/sdt: Prevent multiple reference counter for same uprobe Ravi Bangoria
2018-08-20 5:54 ` Song Liu
2018-08-21 21:35 ` Song Liu [this message]
2018-08-20 4:42 ` [PATCH v9 3/4] trace_uprobe/sdt: " Ravi Bangoria
2018-08-21 20:46 ` Song Liu
2018-08-20 4:42 ` [PATCH v9 4/4] perf probe: Support SDT markers having reference counter (semaphore) Ravi Bangoria
2018-08-21 21:33 ` Song Liu
2018-08-30 18:45 ` Steven Rostedt
2018-08-30 18:50 ` Arnaldo Carvalho de Melo
2018-08-30 19:43 ` Steven Rostedt
2018-08-20 17:38 ` [PATCH v9 0/4] Uprobes: Support SDT markers having reference count (semaphore) Song Liu
2018-08-21 4:42 ` Ravi Bangoria
2018-08-21 4:55 ` Song Liu
2018-08-21 5:23 ` Ravi Bangoria
2018-08-21 6:20 ` Ravi Bangoria
2018-08-21 7:34 ` Naveen N. Rao
2018-08-21 11:58 ` Ravi Bangoria
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='CAPhsuW5DBOuYjYsUyWRZimeRKJhmA=RNM-rpcRhsfXwWfVG6qw@mail.gmail.com' \
--to=liu.song.a23@gmail.com \
--cc=acme@kernel.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=alexis.berlemont@gmail.com \
--cc=ananth@linux.vnet.ibm.com \
--cc=jolsa@redhat.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@linux-mips.org \
--cc=linux@armlinux.org.uk \
--cc=mhiramat@kernel.org \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=naveen.n.rao@linux.vnet.ibm.com \
--cc=oleg@redhat.com \
--cc=paul.burton@mips.com \
--cc=peterz@infradead.org \
--cc=ralf@linux-mips.org \
--cc=ravi.bangoria@linux.ibm.com \
--cc=rostedt@goodmis.org \
--cc=srikar@linux.vnet.ibm.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 NNTP newsgroup(s).