|
Re: Invalid filename/mode in openat tracepoint data
I ran the same test with strace. One of the file data points that doesn't show up is this:
bpftrace:
sys_enter_openat mode:0 filename: (93911401193582)
strace:
openat(AT_FDCWD,
I ran the same test with strace. One of the file data points that doesn't show up is this:
bpftrace:
sys_enter_openat mode:0 filename: (93911401193582)
strace:
openat(AT_FDCWD,
|
By
Tristan Mayfield
·
#1879
·
|
|
Re: Invalid filename/mode in openat tracepoint data
Hello Tristan,
thanks for spending the time to check this out!
One thing I forgot to mention is that I can verify with strace that the filename parameter is always present.
I initially suspected
Hello Tristan,
thanks for spending the time to check this out!
One thing I forgot to mention is that I can verify with strace that the filename parameter is always present.
I initially suspected
|
By
alessandro.gario@...
·
#1878
·
|
|
Re: Invalid filename/mode in openat tracepoint data
I don't have an answer, but I verified this with the following
bpftrace script and using the action of switching to zsh/oh-my-zsh
from
I don't have an answer, but I verified this with the following
bpftrace script and using the action of switching to zsh/oh-my-zsh
from
|
By
Tristan Mayfield
·
#1877
·
|
|
Invalid filename/mode in openat tracepoint data
Hello everyone,
I'll start with some backstory first: I wrote my own BPF library to trace functions/syscalls and yesterday I noticed that I am sometimes receiving broken openat() tracepoint data.
Hello everyone,
I'll start with some backstory first: I wrote my own BPF library to trace functions/syscalls and yesterday I noticed that I am sometimes receiving broken openat() tracepoint data.
|
By
alessandro.gario@...
·
#1876
·
|
|
Port mirroring using bpf_clone_redirect
Hello,
I am trying a port mirroring use case that basically mirrors traffic from host1 to host2. On host 1 I have two interfaces eth0 and eth1 and have configured vxlan interface on eth1. I have used
Hello,
I am trying a port mirroring use case that basically mirrors traffic from host1 to host2. On host 1 I have two interfaces eth0 and eth1 and have configured vxlan interface on eth1. I have used
|
By
Kanthi P
·
#1875
·
|
|
bpf batch support for queue/stack
Hi,
Lately, I've been working on in-kernel traffic analysis with eBPF and
the newest features released in the latest kernel versions
(queue/stack, batch operations,...).
For some reason, I couldn't
Hi,
Lately, I've been working on in-kernel traffic analysis with eBPF and
the newest features released in the latest kernel versions
(queue/stack, batch operations,...).
For some reason, I couldn't
|
By
Simone Magnani
·
#1874
·
|
|
Re: BPF Concurrency
Thanks, fetch_and_add would be more appropriate to my use-case
Thanks, fetch_and_add would be more appropriate to my use-case
|
By
Kanthi P
·
#1873
·
|
|
Re: BPF Concurrency
You cannot use the return value. A recent llvm should return an error
if you try to use it.
There is some preliminary work to have more atomic operations in the
BPF ISA.
You cannot use the return value. A recent llvm should return an error
if you try to use it.
There is some preliminary work to have more atomic operations in the
BPF ISA.
|
By
Yonghong Song
·
#1872
·
|
|
Re: BPF Concurrency
Hi Jesper and Quentin,
Nice, I checked that logic. If I understand it right, that implementation would also need few operations to be atomic, for example the window movements(whenever R and B are
Hi Jesper and Quentin,
Nice, I checked that logic. If I understand it right, that implementation would also need few operations to be atomic, for example the window movements(whenever R and B are
|
By
Kanthi P
·
#1871
·
|
|
Re: BPF Concurrency
Thanks Andrii. __sync_fetch_and_add doesn't seem to work as expected, it is adding the increment, but it is returning the wrong value.
I am actually hitting the same issue mentioned here:
Thanks Andrii. __sync_fetch_and_add doesn't seem to work as expected, it is adding the increment, but it is returning the wrong value.
I am actually hitting the same issue mentioned here:
|
By
Kanthi P
·
#1870
·
|
|
Re: BPF Concurrency
2020-06-16 14:18 UTC+0200 ~ Jesper Dangaard Brouer <brouer@...>
Hi Jesper, Kanthi,
This token bucket implementation was realised in the context of a
research project (BEBA), for which the OPP
2020-06-16 14:18 UTC+0200 ~ Jesper Dangaard Brouer <brouer@...>
Hi Jesper, Kanthi,
This token bucket implementation was realised in the context of a
research project (BEBA), for which the OPP
|
By
Quentin Monnet
·
#1869
·
|
|
Re: BPF Concurrency
Hi Kanthi and Quentin,
You mention token counter as the use-case, for somehow ratelimiting
(TCP connections in your case?).
That reminds me that Quentin implemented[1] a two-color
Hi Kanthi and Quentin,
You mention token counter as the use-case, for somehow ratelimiting
(TCP connections in your case?).
That reminds me that Quentin implemented[1] a two-color
|
By
Jesper Dangaard Brouer
·
#1868
·
|
|
Re: BPF Concurrency
You should use __sync_fetch_and_add() for both cases, and then yes,
you won't lose any update. You probably would want
__sync_add_and_fetch() to get the counter after update, but that's not
supported
You should use __sync_fetch_and_add() for both cases, and then yes,
you won't lose any update. You probably would want
__sync_add_and_fetch() to get the counter after update, but that's not
supported
|
By
Andrii Nakryiko
·
#1867
·
|
|
Re: BPF Concurrency
Thanks Song and Andrii for the response.
Use-case is global rate-limiting for incoming TCP connections. And we want to implement the token bucket algorithm using XDP for this purpose.
So we are
Thanks Song and Andrii for the response.
Use-case is global rate-limiting for incoming TCP connections. And we want to implement the token bucket algorithm using XDP for this purpose.
So we are
|
By
Kanthi P
·
#1866
·
Edited
|
|
Re: Tracing malloc/free calls in a Kubernetes Pod
Replying here again for the record since you posted the same question on the k8s slack.
Kubectl trace replaces $container_pid so you can access the pid folder in the host proc. it’s not specific
Replying here again for the record since you posted the same question on the k8s slack.
Kubectl trace replaces $container_pid so you can access the pid folder in the host proc. it’s not specific
|
By
Lorenzo Fontana
·
#1865
·
|
|
Re: Error loading xdp program that worked with bpf_load
Ok, that I can help with, then.
What's the kernel version? Where I can find repro? Steps, etc.
Basically, a bit more context would help, as I wasn't part of initial
discussion.
Ok, that I can help with, then.
What's the kernel version? Where I can find repro? Steps, etc.
Basically, a bit more context would help, as I wasn't part of initial
discussion.
|
By
Andrii Nakryiko
·
#1862
·
|
|
Re: Error loading xdp program that worked with bpf_load
<andrii.nakryiko@...> wrote:
just running ./test_xdp_veth.sh on the latest bpf-next with the latest
clang I see:
BTF debug data section '.BTF' rejected: Invalid argument (22)!
- Length:
<andrii.nakryiko@...> wrote:
just running ./test_xdp_veth.sh on the latest bpf-next with the latest
clang I see:
BTF debug data section '.BTF' rejected: Invalid argument (22)!
- Length:
|
By
Alexei Starovoitov
·
#1861
·
|
|
Re: Error loading xdp program that worked with bpf_load
<brouer@...> wrote:
This is newer Clang recording that function is global, not static.
libbpf is sanitizing BTF to remove this flag, if kernel doesn't
support this. But given this is
<brouer@...> wrote:
This is newer Clang recording that function is global, not static.
libbpf is sanitizing BTF to remove this flag, if kernel doesn't
support this. But given this is
|
By
Andrii Nakryiko
·
#1860
·
|
|
Re: Error loading xdp program that worked with bpf_load
(Cross-posting to iovisor-dev)
Seeking input from BPF-llvm developers. How come Clang/LLVM 10+ is
generating incompatible BTF-info in ELF file, and downgrading to LLVM-9
fixes the issue ?
--
Best
(Cross-posting to iovisor-dev)
Seeking input from BPF-llvm developers. How come Clang/LLVM 10+ is
generating incompatible BTF-info in ELF file, and downgrading to LLVM-9
fixes the issue ?
--
Best
|
By
Jesper Dangaard Brouer
·
#1859
·
|
|
LPM Trie methods not available in user space program (python)
Hello all,
I am trying to retrieve the keys of an LPM Trie in my user space program (similar to https://github.com/iovisor/bcc/blob/master/examples/networking/xdp/xdp_macswap_count.py) however, I am
Hello all,
I am trying to retrieve the keys of an LPM Trie in my user space program (similar to https://github.com/iovisor/bcc/blob/master/examples/networking/xdp/xdp_macswap_count.py) however, I am
|
By
mdimolianis@...
·
#1858
·
|