[PATCH v3 bpf-next 0/8] Allocate bpf trampoline on bpf_prog_pack

[Song Liu <song@kernel.org>]

This set enables allocating bpf trampoline from bpf_prog_pack on x86. The
majority of this work, however, is the refactoring of trampoline code.
This is needed because we need to handle 4 archs and 2 users (trampoline
and struct_ops).

1/8 is a dependency that is already applied to bpf tree.
2/8 through 7/8 refactors trampoline code. A few helpers are added.
8/8 finally let bpf trampoline on x86 use bpf_prog_pack.

Changes in v3:
1. Fix bug in s390. (Thanks to Ilya Leoshkevich).
2. Fix build error in riscv. (kernel test robot).

Changes in v2:
1. Add missing changes in net/bpf/bpf_dummy_struct_ops.c.
2. Reduce one dry run in arch_prepare_bpf_trampoline. (Xu Kuohai)
3. Other small fixes.

Song Liu (8):
  s390/bpf: Let arch_prepare_bpf_trampoline return program size
  bpf: Let bpf_prog_pack_free handle any pointer
  bpf: Adjust argument names of arch_prepare_bpf_trampoline()
  bpf: Add helpers for trampoline image management
  bpf, x86: Adjust arch_prepare_bpf_trampoline return value
  bpf: Add arch_bpf_trampoline_size()
  bpf: Use arch_bpf_trampoline_size
  x86, bpf: Use bpf_prog_pack for bpf trampoline

 arch/arm64/net/bpf_jit_comp.c   |  55 +++++++++-----
 arch/riscv/net/bpf_jit_comp64.c |  25 ++++---
 arch/s390/net/bpf_jit_comp.c    |  56 +++++++++------
 arch/x86/net/bpf_jit_comp.c     | 124 +++++++++++++++++++++++++-------
 include/linux/bpf.h             |  12 +++-
 include/linux/filter.h          |   2 +-
 kernel/bpf/bpf_struct_ops.c     |  19 +++--
 kernel/bpf/core.c               |  21 +++---
 kernel/bpf/dispatcher.c         |   5 +-
 kernel/bpf/trampoline.c         |  93 ++++++++++++++++++------
 net/bpf/bpf_dummy_struct_ops.c  |   7 +-
 11 files changed, 292 insertions(+), 127 deletions(-)

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2.34.1