* Denys Vlasenko <[email protected]> wrote:
> The test checks that all registers are preserved across
> 32-bit syscalls. It tests syscalls through VDSO
> (if available) and through INT 0x80, normally
> and under ptrace.
>
> If kernel is a 64-bit one, high registers (r8..r15) are poisoned
> before call and checked afterwards. They must be either preserved,
> or cleared to zero (but r11 is special); r12..15 must be preserved
> for INT 0x80.
>
> EFLAGS is checked for changes too, but change there is not considered
> to be a bug (paravirt kernels do not preserve arithmetic flags).
>
> Run-tested on 64-bit kernel:
>
> $ ./test_syscall_vdso_32
> [RUN] Executing 6-argument 32-bit syscall via VDSO
> [OK] Arguments are preserved across syscall
> [NOTE] R11 has changed:0000000000200ed7 - assuming clobbered by SYSRET
> insn
> [OK] R8..R15 did not leak kernel data
> [RUN] Executing 6-argument 32-bit syscall via INT 80
> [OK] Arguments are preserved across syscall
> [OK] R8..R15 did not leak kernel data
> [RUN] Running tests under ptrace
> [RUN] Executing 6-argument 32-bit syscall via VDSO
> [OK] Arguments are preserved across syscall
> [OK] R8..R15 did not leak kernel data
> [RUN] Executing 6-argument 32-bit syscall via INT 80
> [OK] Arguments are preserved across syscall
> [OK] R8..R15 did not leak kernel data
>
> On 32-bit paravirt kernel:
>
> $ ./test_syscall_vdso_32
> [NOTE] Not a 64-bit kernel, won't test R8..R15 leaks
> [RUN] Executing 6-argument 32-bit syscall via VDSO
> [WARN] Flags before=0000000000200ed7 id 0 00 o d i s z 0 a 0 p 1 c
> [WARN] Flags after=0000000000200246 id 0 00 i z 0 0 p 1
> [WARN] Flags change=0000000000000c91 0 00 o d s 0 a 0 0 c
> [OK] Arguments are preserved across syscall
> [RUN] Executing 6-argument 32-bit syscall via INT 80
> [OK] Arguments are preserved across syscall
> [RUN] Running tests under ptrace
> [RUN] Executing 6-argument 32-bit syscall via VDSO
> [OK] Arguments are preserved across syscall
> [RUN] Executing 6-argument 32-bit syscall via INT 80
> [OK] Arguments are preserved across syscall
>
> Signed-off-by: Denys Vlasenko <[email protected]>
> CC: Linus Torvalds <[email protected]>
> CC: Steven Rostedt <[email protected]>
> CC: Ingo Molnar <[email protected]>
> CC: Borislav Petkov <[email protected]>
> CC: "H. Peter Anvin" <[email protected]>
> CC: Andy Lutomirski <[email protected]>
> CC: Oleg Nesterov <[email protected]>
> CC: Frederic Weisbecker <[email protected]>
> CC: Alexei Starovoitov <[email protected]>
> CC: Will Drewry <[email protected]>
> CC: Kees Cook <[email protected]>
> CC: [email protected]
> CC: [email protected]
> ---
>
> Changes in v2:
> does not fail if VDSO can't be found;
> tests INT 80 syscall method;
> tests syscalls under ptrace;
> switched to /* */ comments
>
> Changes in v3:
> added checking for r8..r15 info leaks
>
> tools/testing/selftests/x86/test_syscall_vdso.c | 401
> ++++++++++++++++++++++++
> tools/testing/selftests/x86/thunks_32.S | 55 ++++
> 2 files changed, 456 insertions(+)
> create mode 100644 tools/testing/selftests/x86/test_syscall_vdso.c
> create mode 100644 tools/testing/selftests/x86/thunks_32.S
Hm, what I don't see is any Makefile integration. How am I supposed to build
this
test, and how will automated tests pick this testcase up?
Thanks,
Ingo
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