From mboxrd@z Thu Jan 1 00:00:00 1970 From: takahiro.akashi@linaro.org (AKASHI Takahiro) Date: Fri, 08 Aug 2014 16:35:42 +0900 Subject: [PATCH v5 3/3] arm64: Add seccomp support In-Reply-To: References: <1406020499-5537-1-git-send-email-takahiro.akashi@linaro.org> <1406020499-5537-4-git-send-email-takahiro.akashi@linaro.org> <53D082E9.8090303@amacapital.net> <53D09C4F.9010104@linaro.org> <53D2255C.9050006@linaro.org> Message-ID: <53E47DCE.4080902@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 08/06/2014 12:08 AM, Kees Cook wrote: > On Fri, Jul 25, 2014 at 2:37 AM, AKASHI Takahiro > wrote: >> I found a bug in my current patch (v5). When 32-bit tracer skips a system call, >> we should not update syscallno from x8 since syscallno is re-written directly >> via ptrace(PTRACE_SET_SYSCALL). > > Ah, yes. Will aarch64 have a PTRACE_SET_SYSCALL option, or is this > strictly a 32-bit vs 64-bit issue? As discussed in a few weeks ago, aarch64 won't support PTRACE_SET_SYSCALL. >> I'm sure that my next version should work with 32/64-bit tracers on 64-bit >> kernel. > > Do you have a git tree uploaded anywhere? I'd love to follow this more > closely. When do you expect a v6? I'd like to submit v6 as soon as possible, but (1) how we should handle syscall(-1) is annoying me. Without ptracer, we will normally return -ENOSYS but, for example, what if some seccomp filter is installed and it does allow (or doesn't have any rule against) '-1' syscall? Since the kernel doesn't know tracer's intention, we should just let syscall(-1) return a bogus value. Thus we will see inconsistent results of syscall(-1). (2) I'm investigating some failures in Kees' test suite. * 'TRACE.handler' case on compat task: Now I found a bug in arm64's compat_siginfo_t and fixed it. * 'TSYNC.two_siblings_*' cases on 32/64-bit task: I rebased my patch on pre-v3.17-rc1, but those cases still fail. I have no clues at this moment. So please be patient for a while. -Takahiro AKASHI > Thanks! > > -Kees >