mbox series

[PATCHv8,bpf-next,0/9] uprobe: uretprobe speed up

Message ID 20240611112158.40795-1-jolsa@kernel.org (mailing list archive)
Headers show
Series uprobe: uretprobe speed up | expand

Message

Jiri Olsa June 11, 2024, 11:21 a.m. UTC
hi,
as part of the effort on speeding up the uprobes [0] coming with
return uprobe optimization by using syscall instead of the trap
on the uretprobe trampoline.

The speed up depends on instruction type that uprobe is installed
and depends on specific HW type, please check patch 1 for details.

Patches 1-8 are based on bpf-next/master, but patch 2 and 3 are
apply-able on linux-trace.git tree probes/for-next branch.
Patch 9 is based on man-pages master.

v8 changes:
- rebased (another new syscall got merged)
- added acks

Also available at:
  https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
  uretprobe_syscall

thanks,
jirka


Notes to check list items in Documentation/process/adding-syscalls.rst:

- System Call Alternatives
  New syscall seems like the best way in here, because we need
  just to quickly enter kernel with no extra arguments processing,
  which we'd need to do if we decided to use another syscall.

- Designing the API: Planning for Extension
  The uretprobe syscall is very specific and most likely won't be
  extended in the future.

  At the moment it does not take any arguments and even if it does
  in future, it's allowed to be called only from trampoline prepared
  by kernel, so there'll be no broken user.

- Designing the API: Other Considerations
  N/A because uretprobe syscall does not return reference to kernel
  object.

- Proposing the API
  Wiring up of the uretprobe system call is in separate change,
  selftests and man page changes are part of the patchset.

- Generic System Call Implementation
  There's no CONFIG option for the new functionality because it
  keeps the same behaviour from the user POV.

- x86 System Call Implementation
  It's 64-bit syscall only.

- Compatibility System Calls (Generic)
  N/A uretprobe syscall has no arguments and is not supported
  for compat processes.

- Compatibility System Calls (x86)
  N/A uretprobe syscall is not supported for compat processes.

- System Calls Returning Elsewhere
  N/A.

- Other Details
  N/A.

- Testing
  Adding new bpf selftests and ran ltp on top of this change.

- Man Page
  Attached.

- Do not call System Calls in the Kernel
  N/A.


[0] https://lore.kernel.org/bpf/ZeCXHKJ--iYYbmLj@krava/
---
Jiri Olsa (8):
      x86/shstk: Make return uprobe work with shadow stack
      uprobe: Wire up uretprobe system call
      uprobe: Add uretprobe syscall to speed up return probe
      selftests/x86: Add return uprobe shadow stack test
      selftests/bpf: Add uretprobe syscall test for regs integrity
      selftests/bpf: Add uretprobe syscall test for regs changes
      selftests/bpf: Add uretprobe syscall call from user space test
      selftests/bpf: Add uretprobe shadow stack test

 arch/x86/entry/syscalls/syscall_64.tbl                      |   1 +
 arch/x86/include/asm/shstk.h                                |   4 +
 arch/x86/kernel/shstk.c                                     |  16 ++++
 arch/x86/kernel/uprobes.c                                   | 124 ++++++++++++++++++++++++++++-
 include/linux/syscalls.h                                    |   2 +
 include/linux/uprobes.h                                     |   3 +
 include/uapi/asm-generic/unistd.h                           |   5 +-
 kernel/events/uprobes.c                                     |  24 ++++--
 kernel/sys_ni.c                                             |   2 +
 tools/include/linux/compiler.h                              |   4 +
 tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c       | 123 ++++++++++++++++++++++++++++-
 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c     | 385 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 tools/testing/selftests/bpf/progs/uprobe_syscall.c          |  15 ++++
 tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c |  17 ++++
 tools/testing/selftests/x86/test_shadow_stack.c             | 145 ++++++++++++++++++++++++++++++++++
 15 files changed, 860 insertions(+), 10 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
 create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall.c
 create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c

Jiri Olsa (1):
      man2: Add uretprobe syscall page

 man/man2/uretprobe.2 | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 man/man2/uretprobe.2

Comments

Masami Hiramatsu (Google) June 11, 2024, 2:52 p.m. UTC | #1
On Tue, 11 Jun 2024 13:21:49 +0200
Jiri Olsa <jolsa@kernel.org> wrote:

> hi,
> as part of the effort on speeding up the uprobes [0] coming with
> return uprobe optimization by using syscall instead of the trap
> on the uretprobe trampoline.
> 
> The speed up depends on instruction type that uprobe is installed
> and depends on specific HW type, please check patch 1 for details.
> 
> Patches 1-8 are based on bpf-next/master, but patch 2 and 3 are
> apply-able on linux-trace.git tree probes/for-next branch.
> Patch 9 is based on man-pages master.
> 
> v8 changes:
> - rebased (another new syscall got merged)
> - added acks
> 
> Also available at:
>   https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
>   uretprobe_syscall

Applied patch [1/9] - [8/9] on probes/for-next in 
 git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git

Thank you!

> 
> thanks,
> jirka
> 
> 
> Notes to check list items in Documentation/process/adding-syscalls.rst:
> 
> - System Call Alternatives
>   New syscall seems like the best way in here, because we need
>   just to quickly enter kernel with no extra arguments processing,
>   which we'd need to do if we decided to use another syscall.
> 
> - Designing the API: Planning for Extension
>   The uretprobe syscall is very specific and most likely won't be
>   extended in the future.
> 
>   At the moment it does not take any arguments and even if it does
>   in future, it's allowed to be called only from trampoline prepared
>   by kernel, so there'll be no broken user.
> 
> - Designing the API: Other Considerations
>   N/A because uretprobe syscall does not return reference to kernel
>   object.
> 
> - Proposing the API
>   Wiring up of the uretprobe system call is in separate change,
>   selftests and man page changes are part of the patchset.
> 
> - Generic System Call Implementation
>   There's no CONFIG option for the new functionality because it
>   keeps the same behaviour from the user POV.
> 
> - x86 System Call Implementation
>   It's 64-bit syscall only.
> 
> - Compatibility System Calls (Generic)
>   N/A uretprobe syscall has no arguments and is not supported
>   for compat processes.
> 
> - Compatibility System Calls (x86)
>   N/A uretprobe syscall is not supported for compat processes.
> 
> - System Calls Returning Elsewhere
>   N/A.
> 
> - Other Details
>   N/A.
> 
> - Testing
>   Adding new bpf selftests and ran ltp on top of this change.
> 
> - Man Page
>   Attached.
> 
> - Do not call System Calls in the Kernel
>   N/A.
> 
> 
> [0] https://lore.kernel.org/bpf/ZeCXHKJ--iYYbmLj@krava/
> ---
> Jiri Olsa (8):
>       x86/shstk: Make return uprobe work with shadow stack
>       uprobe: Wire up uretprobe system call
>       uprobe: Add uretprobe syscall to speed up return probe
>       selftests/x86: Add return uprobe shadow stack test
>       selftests/bpf: Add uretprobe syscall test for regs integrity
>       selftests/bpf: Add uretprobe syscall test for regs changes
>       selftests/bpf: Add uretprobe syscall call from user space test
>       selftests/bpf: Add uretprobe shadow stack test
> 
>  arch/x86/entry/syscalls/syscall_64.tbl                      |   1 +
>  arch/x86/include/asm/shstk.h                                |   4 +
>  arch/x86/kernel/shstk.c                                     |  16 ++++
>  arch/x86/kernel/uprobes.c                                   | 124 ++++++++++++++++++++++++++++-
>  include/linux/syscalls.h                                    |   2 +
>  include/linux/uprobes.h                                     |   3 +
>  include/uapi/asm-generic/unistd.h                           |   5 +-
>  kernel/events/uprobes.c                                     |  24 ++++--
>  kernel/sys_ni.c                                             |   2 +
>  tools/include/linux/compiler.h                              |   4 +
>  tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c       | 123 ++++++++++++++++++++++++++++-
>  tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c     | 385 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  tools/testing/selftests/bpf/progs/uprobe_syscall.c          |  15 ++++
>  tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c |  17 ++++
>  tools/testing/selftests/x86/test_shadow_stack.c             | 145 ++++++++++++++++++++++++++++++++++
>  15 files changed, 860 insertions(+), 10 deletions(-)
>  create mode 100644 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
>  create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall.c
>  create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c
> 
> Jiri Olsa (1):
>       man2: Add uretprobe syscall page
> 
>  man/man2/uretprobe.2 | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 56 insertions(+)
>  create mode 100644 man/man2/uretprobe.2
Andrii Nakryiko June 12, 2024, 7:02 a.m. UTC | #2
On Tue, Jun 11, 2024 at 3:52 PM Masami Hiramatsu <mhiramat@kernel.org> wrote:
>
> On Tue, 11 Jun 2024 13:21:49 +0200
> Jiri Olsa <jolsa@kernel.org> wrote:
>
> > hi,
> > as part of the effort on speeding up the uprobes [0] coming with
> > return uprobe optimization by using syscall instead of the trap
> > on the uretprobe trampoline.
> >
> > The speed up depends on instruction type that uprobe is installed
> > and depends on specific HW type, please check patch 1 for details.
> >
> > Patches 1-8 are based on bpf-next/master, but patch 2 and 3 are
> > apply-able on linux-trace.git tree probes/for-next branch.
> > Patch 9 is based on man-pages master.
> >
> > v8 changes:
> > - rebased (another new syscall got merged)
> > - added acks
> >
> > Also available at:
> >   https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
> >   uretprobe_syscall
>
> Applied patch [1/9] - [8/9] on probes/for-next in
>  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
>

Thanks, Masami, looks good! I also confirmed that probes/for-next and
bpf-next/master can be merged with no conflicts (hopefully it stays
this way till the next merge window).

> Thank you!
>
> >
> > thanks,
> > jirka
> >
> >
> > Notes to check list items in Documentation/process/adding-syscalls.rst:
> >
> > - System Call Alternatives
> >   New syscall seems like the best way in here, because we need
> >   just to quickly enter kernel with no extra arguments processing,
> >   which we'd need to do if we decided to use another syscall.
> >
> > - Designing the API: Planning for Extension
> >   The uretprobe syscall is very specific and most likely won't be
> >   extended in the future.
> >
> >   At the moment it does not take any arguments and even if it does
> >   in future, it's allowed to be called only from trampoline prepared
> >   by kernel, so there'll be no broken user.
> >
> > - Designing the API: Other Considerations
> >   N/A because uretprobe syscall does not return reference to kernel
> >   object.
> >
> > - Proposing the API
> >   Wiring up of the uretprobe system call is in separate change,
> >   selftests and man page changes are part of the patchset.
> >
> > - Generic System Call Implementation
> >   There's no CONFIG option for the new functionality because it
> >   keeps the same behaviour from the user POV.
> >
> > - x86 System Call Implementation
> >   It's 64-bit syscall only.
> >
> > - Compatibility System Calls (Generic)
> >   N/A uretprobe syscall has no arguments and is not supported
> >   for compat processes.
> >
> > - Compatibility System Calls (x86)
> >   N/A uretprobe syscall is not supported for compat processes.
> >
> > - System Calls Returning Elsewhere
> >   N/A.
> >
> > - Other Details
> >   N/A.
> >
> > - Testing
> >   Adding new bpf selftests and ran ltp on top of this change.
> >
> > - Man Page
> >   Attached.
> >
> > - Do not call System Calls in the Kernel
> >   N/A.
> >
> >
> > [0] https://lore.kernel.org/bpf/ZeCXHKJ--iYYbmLj@krava/
> > ---
> > Jiri Olsa (8):
> >       x86/shstk: Make return uprobe work with shadow stack
> >       uprobe: Wire up uretprobe system call
> >       uprobe: Add uretprobe syscall to speed up return probe
> >       selftests/x86: Add return uprobe shadow stack test
> >       selftests/bpf: Add uretprobe syscall test for regs integrity
> >       selftests/bpf: Add uretprobe syscall test for regs changes
> >       selftests/bpf: Add uretprobe syscall call from user space test
> >       selftests/bpf: Add uretprobe shadow stack test
> >
> >  arch/x86/entry/syscalls/syscall_64.tbl                      |   1 +
> >  arch/x86/include/asm/shstk.h                                |   4 +
> >  arch/x86/kernel/shstk.c                                     |  16 ++++
> >  arch/x86/kernel/uprobes.c                                   | 124 ++++++++++++++++++++++++++++-
> >  include/linux/syscalls.h                                    |   2 +
> >  include/linux/uprobes.h                                     |   3 +
> >  include/uapi/asm-generic/unistd.h                           |   5 +-
> >  kernel/events/uprobes.c                                     |  24 ++++--
> >  kernel/sys_ni.c                                             |   2 +
> >  tools/include/linux/compiler.h                              |   4 +
> >  tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c       | 123 ++++++++++++++++++++++++++++-
> >  tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c     | 385 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  tools/testing/selftests/bpf/progs/uprobe_syscall.c          |  15 ++++
> >  tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c |  17 ++++
> >  tools/testing/selftests/x86/test_shadow_stack.c             | 145 ++++++++++++++++++++++++++++++++++
> >  15 files changed, 860 insertions(+), 10 deletions(-)
> >  create mode 100644 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> >  create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall.c
> >  create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c
> >
> > Jiri Olsa (1):
> >       man2: Add uretprobe syscall page
> >
> >  man/man2/uretprobe.2 | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 56 insertions(+)
> >  create mode 100644 man/man2/uretprobe.2
>
>
> --
> Masami Hiramatsu (Google) <mhiramat@kernel.org>