mbox series

[v4,0/3] Fix the incorrect register read for syscalls on x86_64

Message ID 20220119131209.36092-1-Kenta.Tada@sony.com (mailing list archive)
Headers show
Series Fix the incorrect register read for syscalls on x86_64 | expand

Message

Kenta Tada Jan. 19, 2022, 1:12 p.m. UTC 
Currently, rcx is read as the fourth parameter of syscall on x86_64.
But x86_64 Linux System Call convention uses r10 actually.
This commit adds the wrapper for users who want to access to
syscall params to analyze the user space.

Changelog:
----------
v1 -> v2:
- Rebase to current bpf-next
https://lore.kernel.org/bpf/20211222213924.1869758-1-andrii@kernel.org/

v2 -> v3:
- Modify the definition of SYSCALL macros for only targeted archs.
- Define __BPF_TARGET_MISSING variants for completeness.
- Remove CORE variants. These macros will not be used.
- Add a selftest.

v3 -> v4:
- Modify a selftest not to use serial tests.
- Modify a selftest to use ASSERT_EQ().
- Extract syscall wrapper for all the other tests.
- Add CORE variants.

Kenta Tada (3):
  libbpf: Extract syscall wrapper
  libbpf: Fix the incorrect register read for syscalls on x86_64
  libbpf: Add a test to confirm PT_REGS_PARM4_SYSCALL

 tools/lib/bpf/bpf_tracing.h                   | 34 +++++++++++++
 .../bpf/prog_tests/test_bpf_syscall_macro.c   | 49 ++++++++++++++++++
 tools/testing/selftests/bpf/progs/bpf_misc.h  | 19 +++++++
 .../selftests/bpf/progs/bpf_syscall_macro.c   | 51 +++++++++++++++++++
 .../selftests/bpf/progs/test_probe_user.c     | 15 +-----
 5 files changed, 154 insertions(+), 14 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/test_bpf_syscall_macro.c
 create mode 100644 tools/testing/selftests/bpf/progs/bpf_misc.h
 create mode 100644 tools/testing/selftests/bpf/progs/bpf_syscall_macro.c