Re: Broken kretprobe stack traces

2021-03-04 Thread Daniel Xu
On Wed, Mar 3, 2021, at 6:18 PM, Daniel Xu wrote: > On Wed, Mar 03, 2021 at 03:37:40PM -0500, Steven Rostedt wrote: > > On Wed, 03 Mar 2021 12:13:08 -0800 > > "Daniel Xu" wrote: > > > > > On Wed, Mar 3, 2021, at 11:58 AM, Daniel Xu wrote: > > > > On Wed, Mar 03, 2021 at 09:26:04AM -0500, Steven

Re: Broken kretprobe stack traces

2021-03-04 Thread Masami Hiramatsu
On Wed, 3 Mar 2021 09:26:04 -0500 Steven Rostedt wrote: > On Wed, 3 Mar 2021 13:48:28 +0900 > Masami Hiramatsu wrote: > > > > > > > > > I think (can't prove) this used to work: > > Would be good to find out if it did. > > > > > I'm not sure the bpftrace had correctly handled it or not.

Re: Broken kretprobe stack traces

2021-03-03 Thread Daniel Xu
On Wed, Mar 03, 2021 at 03:37:40PM -0500, Steven Rostedt wrote: > On Wed, 03 Mar 2021 12:13:08 -0800 > "Daniel Xu" wrote: > > > On Wed, Mar 3, 2021, at 11:58 AM, Daniel Xu wrote: > > > On Wed, Mar 03, 2021 at 09:26:04AM -0500, Steven Rostedt wrote: > > > > On Wed, 3 Mar 2021 13:48:28 +0900 > >

Re: Broken kretprobe stack traces

2021-03-03 Thread Steven Rostedt
On Wed, 03 Mar 2021 12:13:08 -0800 "Daniel Xu" wrote: > On Wed, Mar 3, 2021, at 11:58 AM, Daniel Xu wrote: > > On Wed, Mar 03, 2021 at 09:26:04AM -0500, Steven Rostedt wrote: > > > On Wed, 3 Mar 2021 13:48:28 +0900 > > > Masami Hiramatsu wrote: > > > > > > > > > > > > > > > > > I think

Re: Broken kretprobe stack traces

2021-03-03 Thread Daniel Xu
On Wed, Mar 03, 2021 at 01:48:28PM +0900, Masami Hiramatsu wrote: > Hi Daniel, > > On Tue, 02 Mar 2021 17:15:13 -0800 > "Daniel Xu" wrote: > > > Hi Masami, > > > > Jakub reported a bug with kretprobe stack traces -- wondering if you've > > gotten > > any bug reports related to stack traces

Re: Broken kretprobe stack traces

2021-03-03 Thread Daniel Xu
On Wed, Mar 03, 2021 at 09:26:04AM -0500, Steven Rostedt wrote: > On Wed, 3 Mar 2021 13:48:28 +0900 > Masami Hiramatsu wrote: > > > > > > > > > I think (can't prove) this used to work: > > Would be good to find out if it did. I'm installing some older kernels now to check. Will report

Re: Broken kretprobe stack traces

2021-03-03 Thread Daniel Xu
On Wed, Mar 3, 2021, at 11:58 AM, Daniel Xu wrote: > On Wed, Mar 03, 2021 at 09:26:04AM -0500, Steven Rostedt wrote: > > On Wed, 3 Mar 2021 13:48:28 +0900 > > Masami Hiramatsu wrote: > > > > > > > > > > > > > I think (can't prove) this used to work: > > > > Would be good to find out if it

Re: Broken kretprobe stack traces

2021-03-03 Thread Steven Rostedt
On Wed, 3 Mar 2021 13:48:28 +0900 Masami Hiramatsu wrote: > > > > > I think (can't prove) this used to work: Would be good to find out if it did. > > I'm not sure the bpftrace had correctly handled it or not. > > > > > # bpftrace -e 'kretprobe:__tcp_retransmit_skb { @[kstack()] =

Re: Broken kretprobe stack traces

2021-03-03 Thread Masami Hiramatsu
Hi Daniel, On Tue, 02 Mar 2021 17:15:13 -0800 "Daniel Xu" wrote: > Hi Masami, > > Jakub reported a bug with kretprobe stack traces -- wondering if you've gotten > any bug reports related to stack traces being broken for kretprobes. Yeah, stack dumper must check the stack entry is kretprobe'd

Broken kretprobe stack traces

2021-03-03 Thread Daniel Xu
Hi Masami, Jakub reported a bug with kretprobe stack traces -- wondering if you've gotten any bug reports related to stack traces being broken for kretprobes. I think (can't prove) this used to work: # bpftrace -e 'kretprobe:__tcp_retransmit_skb { @[kstack()] = count() }' Attaching 1