[bpf-next,v4,00/14] Fix accessing syscall arguments

Message

Ilya Leoshkevich Feb. 8, 2022, 5:16 a.m. UTC

libbpf now has macros to access syscall arguments in an
architecture-agnostic manner, but unfortunately they have a number of
issues on non-Intel arches, which this series aims to fix.

v1: https://lore.kernel.org/bpf/[e-mail]/
v1 -> v2:
* Put orig_gpr2 in place of args[1] on s390 (Vasily).
* Fix arm64, powerpc and riscv (Heiko).

v2: https://lore.kernel.org/bpf/[e-mail]/
v2 -> v3:
* Undo args[1] change (Andrii).
* Rename PT_REGS_SYSCALL to PT_REGS_SYSCALL_REGS (Andrii).
* Split the riscv patch (Andrii).

v3: https://lore.kernel.org/bpf/[e-mail]/
v3 -> v4:
* Undo arm64's and s390's user_pt_regs changes.
* Use struct pt_regs when vmlinux.h is available (Andrii).
* Use offsetofend for accessing orig_gpr2 and orig_x0 (Andrii).
* Move libbpf's copy of offsetofend to a new header.
* Fix riscv's __PT_FP_REG.
* Use PT_REGS_SYSCALL_REGS in test_probe_user.c.
* Test bpf_syscall_macro with userspace headers.
* Use Naveen's suggestions and code in patches 5 and 6.
* Add warnings to arm64's and s390's ptrace.h (Andrii).

Tested on x86_64, s390x, arm64, ppc64el and riscv64 in QEMU.

+cc Mark.

Ilya Leoshkevich (14):
  selftests/bpf: Fix an endianness issue in bpf_syscall_macro test
  selftests/bpf: Fix a potential offsetofend redefinition in
    test_cls_redirect
  selftests/bpf: Compile bpf_syscall_macro test also with user headers
  libbpf: Fix a typo in bpf_tracing.h
  libbpf: Generalize overriding syscall parameter access macros
  libbpf: Add PT_REGS_SYSCALL_REGS macro
  selftests/bpf: Use PT_REGS_SYSCALL_REGS in bpf_syscall_macro
  libbpf: Use struct pt_regs when compiling with kernel headers
  libbpf: Fix riscv register names
  libbpf: Move data structure manipulation macros to
    bpf_common_helpers.h
  libbpf: Fix accessing the first syscall argument on s390
  s390: add a comment that warns that orig_gpr2 should not be moved
  libbpf: Fix accessing the first syscall argument on arm64
  arm64: add a comment that warns that orig_x0 should not be moved

 arch/arm64/include/asm/ptrace.h               |   4 +
 arch/s390/include/asm/ptrace.h                |   4 +
 tools/lib/bpf/Makefile                        |   2 +-
 tools/lib/bpf/bpf_common_helpers.h            |  30 +++++
 tools/lib/bpf/bpf_helpers.h                   |  15 +--
 tools/lib/bpf/bpf_tracing.h                   | 107 +++++++++++++++---
 tools/testing/selftests/bpf/bpf_util.h        |  10 +-
 ...acro.c => test_bpf_syscall_macro_common.h} |   8 +-
 .../test_bpf_syscall_macro_kernel.c           |  13 +++
 .../prog_tests/test_bpf_syscall_macro_user.c  |  13 +++
 tools/testing/selftests/bpf/progs/bpf_misc.h  |   4 -
 ...all_macro.c => bpf_syscall_macro_common.h} |  15 ++-
 .../bpf/progs/bpf_syscall_macro_kernel.c      |   4 +
 .../bpf/progs/bpf_syscall_macro_user.c        |  10 ++
 .../selftests/bpf/progs/test_cls_redirect.c   |   2 +
 .../selftests/bpf/progs/test_probe_user.c     |   8 +-
 16 files changed, 191 insertions(+), 58 deletions(-)
 create mode 100644 tools/lib/bpf/bpf_common_helpers.h
 rename tools/testing/selftests/bpf/prog_tests/{test_bpf_syscall_macro.c => test_bpf_syscall_macro_common.h} (89%)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/test_bpf_syscall_macro_kernel.c
 create mode 100644 tools/testing/selftests/bpf/prog_tests/test_bpf_syscall_macro_user.c
 rename tools/testing/selftests/bpf/progs/{bpf_syscall_macro.c => bpf_syscall_macro_common.h} (79%)
 create mode 100644 tools/testing/selftests/bpf/progs/bpf_syscall_macro_kernel.c
 create mode 100644 tools/testing/selftests/bpf/progs/bpf_syscall_macro_user.c