Messages in this thread | | | Date | Mon, 6 Jul 2015 14:44:55 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH v3 RESEND] x86/asm/entry/32, selftests: Add test_syscall_vdso test |
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* Denys Vlasenko <dvlasenk@redhat.com> 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 <dvlasenk@redhat.com> > CC: Linus Torvalds <torvalds@linux-foundation.org> > CC: Steven Rostedt <rostedt@goodmis.org> > CC: Ingo Molnar <mingo@kernel.org> > CC: Borislav Petkov <bp@alien8.de> > CC: "H. Peter Anvin" <hpa@zytor.com> > CC: Andy Lutomirski <luto@amacapital.net> > CC: Oleg Nesterov <oleg@redhat.com> > CC: Frederic Weisbecker <fweisbec@gmail.com> > CC: Alexei Starovoitov <ast@plumgrid.com> > CC: Will Drewry <wad@chromium.org> > CC: Kees Cook <keescook@chromium.org> > CC: x86@kernel.org > CC: linux-kernel@vger.kernel.org > --- > > 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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