From: Ingo Molnar <mingo@kernel.org>
To: Alexei Starovoitov <ast@plumgrid.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Namhyung Kim <namhyung@kernel.org>,
Arnaldo Carvalho de Melo <acme@infradead.org>,
Jiri Olsa <jolsa@redhat.com>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
"David S. Miller" <davem@davemloft.net>,
Daniel Borkmann <daniel@iogearbox.net>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
linux-api@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v9 tip 6/9] samples: bpf: simple non-portable kprobe filter example
Date: Mon, 23 Mar 2015 08:35:07 +0100 [thread overview]
Message-ID: <20150323073506.GC25184@gmail.com> (raw)
In-Reply-To: <1426894210-27441-7-git-send-email-ast@plumgrid.com>
* Alexei Starovoitov <ast@plumgrid.com> wrote:
> +void read_trace_pipe(void)
> +{
> + int trace_fd;
> +
> + trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0);
> + if (trace_fd < 0)
> + return;
> +
> + while (1) {
> + static char buf[4096];
> + ssize_t sz;
> +
> + sz = read(trace_fd, buf, sizeof(buf));
read() will return -1 on failure ...
> + if (sz) {
... this test passes ...
> + buf[sz] = 0;
... and here we smash the stack?
> + puts(buf);
> + }
> + }
Thanks,
Ingo
next prev parent reply other threads:[~2015-03-23 7:35 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-20 23:30 [PATCH v9 tip 0/9] tracing: attach eBPF programs to kprobes Alexei Starovoitov
2015-03-20 23:30 ` [PATCH v9 tip 1/9] bpf: make internal bpf API independent of CONFIG_BPF_SYSCALL ifdefs Alexei Starovoitov
2015-03-21 12:16 ` Masami Hiramatsu
2015-03-20 23:30 ` [PATCH v9 tip 2/9] tracing: add kprobe flag Alexei Starovoitov
[not found] ` <1426894210-27441-3-git-send-email-ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
2015-03-21 12:16 ` Masami Hiramatsu
2015-03-20 23:30 ` [PATCH v9 tip 3/9] tracing: attach BPF programs to kprobes Alexei Starovoitov
[not found] ` <1426894210-27441-4-git-send-email-ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
2015-03-21 12:14 ` Masami Hiramatsu
2015-03-21 16:02 ` Alexei Starovoitov
[not found] ` <550D962E.7010400-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
2015-03-22 10:06 ` Masami Hiramatsu
2015-03-22 18:03 ` Alexei Starovoitov
[not found] ` <550F0402.80900-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
2015-03-23 2:17 ` Masami Hiramatsu
2015-03-23 4:57 ` bpf+tracing next steps. Was: " Alexei Starovoitov
[not found] ` <550F9D20.7070006-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
2015-03-23 9:27 ` Masami Hiramatsu
2015-03-25 0:40 ` Alexei Starovoitov
[not found] ` <5512040B.3020605-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
2015-03-25 12:07 ` Masami Hiramatsu
[not found] ` <1426894210-27441-1-git-send-email-ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
2015-03-20 23:30 ` [PATCH v9 tip 4/9] tracing: allow BPF programs to call bpf_ktime_get_ns() Alexei Starovoitov
2015-03-20 23:30 ` [PATCH v9 tip 5/9] tracing: allow BPF programs to call bpf_trace_printk() Alexei Starovoitov
[not found] ` <1426894210-27441-6-git-send-email-ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
2015-03-22 11:10 ` Ingo Molnar
[not found] ` <20150322111040.GA18695-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-03-22 18:05 ` Alexei Starovoitov
2015-03-20 23:30 ` [PATCH v9 tip 9/9] samples: bpf: kmem_alloc/free tracker Alexei Starovoitov
2015-03-20 23:30 ` [PATCH v9 tip 6/9] samples: bpf: simple non-portable kprobe filter example Alexei Starovoitov
[not found] ` <1426894210-27441-7-git-send-email-ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
2015-03-23 7:29 ` Ingo Molnar
[not found] ` <20150323072929.GB25184-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-03-23 17:23 ` Alexei Starovoitov
2015-03-23 7:35 ` Ingo Molnar [this message]
[not found] ` <20150323073506.GC25184-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-03-23 17:32 ` Alexei Starovoitov
2015-03-20 23:30 ` [PATCH v9 tip 7/9] samples: bpf: counting example for kfree_skb and write syscall Alexei Starovoitov
2015-03-20 23:30 ` [PATCH v9 tip 8/9] samples: bpf: IO latency analysis (iosnoop/heatmap) Alexei Starovoitov
2015-03-23 7:40 ` Ingo Molnar
2015-03-23 17:41 ` Alexei Starovoitov
2015-03-21 4:08 ` [PATCH v9 tip 0/9] tracing: attach eBPF programs to kprobes Steven Rostedt
[not found] ` <20150321000812.606ef8cb-2kNGR76GQU9OHLTnHDQRgA@public.gmane.org>
2015-03-23 7:36 ` Ingo Molnar
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