Re: [PATCHv4 bpf-next 2/7] uprobe: Add uretprobe syscall to speed up return probe

On Fri, May 03, 2024 at 08:35:24PM +, Edgecombe, Rick P wrote: > On Fri, 2024-05-03 at 22:17 +0200, Jiri Olsa wrote: > > when uretprobe is created, kernel overwrites the return address on user > > stack to point to user space trampoline, so the setup is in kernel hands > > I mean for uprobes

Re: [PATCHv4 bpf-next 2/7] uprobe: Add uretprobe syscall to speed up return probe

On Fri, May 03, 2024 at 07:38:18PM +, Edgecombe, Rick P wrote: +Some more shadow stack folks from other archs. We are discussing how uretprobes work with shadow stack. Context: https://lore.kernel.org/lkml/ZjU4ganRF1Cbiug6@krava/ Thanks Rick. Yeah I didn't give enough attention to

Re: [PATCHv4 bpf-next 2/7] uprobe: Add uretprobe syscall to speed up return probe

On Fri, 2024-05-03 at 22:17 +0200, Jiri Olsa wrote: > when uretprobe is created, kernel overwrites the return address on user > stack to point to user space trampoline, so the setup is in kernel hands I mean for uprobes in general. I'm didn't have any specific ideas in mind, but in general when

Re: [PATCHv4 bpf-next 2/7] uprobe: Add uretprobe syscall to speed up return probe

On Fri, May 03, 2024 at 07:38:18PM +, Edgecombe, Rick P wrote: > +Some more shadow stack folks from other archs. We are discussing how > uretprobes > work with shadow stack. > > Context: > https://lore.kernel.org/lkml/ZjU4ganRF1Cbiug6@krava/ > > On Fri, 2024-05-03 at 21:18 +0200, Jiri Olsa

Re: [PATCHv4 bpf-next 2/7] uprobe: Add uretprobe syscall to speed up return probe

+Some more shadow stack folks from other archs. We are discussing how uretprobes work with shadow stack. Context: https://lore.kernel.org/lkml/ZjU4ganRF1Cbiug6@krava/ On Fri, 2024-05-03 at 21:18 +0200, Jiri Olsa wrote: > > hack below seems to fix it for the current uprobe setup, > we need

Re: [PATCHv4 bpf-next 2/7] uprobe: Add uretprobe syscall to speed up return probe

On Fri, May 03, 2024 at 03:53:15PM +, Edgecombe, Rick P wrote: > On Fri, 2024-05-03 at 15:04 +0200, Jiri Olsa wrote: > > On Fri, May 03, 2024 at 01:34:53PM +0200, Peter Zijlstra wrote: > > > On Thu, May 02, 2024 at 02:23:08PM +0200, Jiri Olsa wrote: > > > > Adding uretprobe syscall instead of

Re: [PATCHv4 bpf-next 2/7] uprobe: Add uretprobe syscall to speed up return probe

On Fri, 2024-05-03 at 15:04 +0200, Jiri Olsa wrote: > On Fri, May 03, 2024 at 01:34:53PM +0200, Peter Zijlstra wrote: > > On Thu, May 02, 2024 at 02:23:08PM +0200, Jiri Olsa wrote: > > > Adding uretprobe syscall instead of trap to speed up return probe. > > > > > > At the moment the uretprobe

Re: [PATCHv4 bpf-next 2/7] uprobe: Add uretprobe syscall to speed up return probe

On Fri, May 03, 2024 at 01:34:53PM +0200, Peter Zijlstra wrote: > On Thu, May 02, 2024 at 02:23:08PM +0200, Jiri Olsa wrote: > > Adding uretprobe syscall instead of trap to speed up return probe. > > > > At the moment the uretprobe setup/path is: > > > > - install entry uprobe > > > > -

Re: [PATCHv4 bpf-next 2/7] uprobe: Add uretprobe syscall to speed up return probe

On Thu, May 02, 2024 at 02:23:08PM +0200, Jiri Olsa wrote: > Adding uretprobe syscall instead of trap to speed up return probe. > > At the moment the uretprobe setup/path is: > > - install entry uprobe > > - when the uprobe is hit, it overwrites probed function's return address > on

[PATCHv4 bpf-next 2/7] uprobe: Add uretprobe syscall to speed up return probe

Adding uretprobe syscall instead of trap to speed up return probe. At the moment the uretprobe setup/path is: - install entry uprobe - when the uprobe is hit, it overwrites probed function's return address on stack with address of the trampoline that contains breakpoint instruction