On Thu, Jul 23, 2020 at 01:13:21AM +0200, Michael Karcher wrote:
> Port sh to use the new SECCOMP_FILTER code.
>
> Signed-off-by: Michael Karcher <ker...@mkarcher.dialup.fu-berlin.de>
> ---
> arch/sh/Kconfig | 1 +
> arch/sh/kernel/entry-common.S | 2 ++
> arch/sh/kernel/ptrace_32.c | 5 +++--
> tools/testing/selftests/seccomp/seccomp_bpf.c | 8 +++++++-
> 4 files changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
> index 32d959849df9..10b510c16841 100644
> --- a/arch/sh/Kconfig
> +++ b/arch/sh/Kconfig
> @@ -27,6 +27,7 @@ config SUPERH
> select GENERIC_SMP_IDLE_THREAD
> select GUP_GET_PTE_LOW_HIGH if X2TLB
> select HAVE_ARCH_AUDITSYSCALL
> + select HAVE_ARCH_SECCOMP_FILTER
> select HAVE_ARCH_KGDB
> select HAVE_ARCH_TRACEHOOK
> select HAVE_DEBUG_BUGVERBOSE
> diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S
> index c4d88d61890d..ad963104d22d 100644
> --- a/arch/sh/kernel/entry-common.S
> +++ b/arch/sh/kernel/entry-common.S
> @@ -368,6 +368,8 @@ syscall_trace_entry:
> mov.l 7f, r11 ! Call do_syscall_trace_enter which notifies
> jsr @r11 ! superior (will chomp R[0-7])
> nop
> + cmp/eq #-1, r0
> + bt syscall_exit
> mov.l r0, @(OFF_R0,r15) ! Save return value
> ! Reload R0-R4 from kernel stack, where the
> ! parent may have modified them using
> diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c
> index 64bfb714943e..25ccfbd02bfa 100644
> --- a/arch/sh/kernel/ptrace_32.c
> +++ b/arch/sh/kernel/ptrace_32.c
> @@ -485,8 +485,6 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs
> *regs)
> {
> long ret = 0;
>
> - secure_computing_strict(regs->regs[0]);
> -
> if (test_thread_flag(TIF_SYSCALL_TRACE) &&
> tracehook_report_syscall_entry(regs))
> /*
> @@ -496,6 +494,9 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs
> *regs)
> */
> ret = -1L;
>
> + if (secure_computing() == -1)
> + return -1;
> +
> if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
> trace_sys_enter(regs, regs->regs[0]);
>
This patch broke strace - it spews out bogus syscalls and gets the
tracee hung. I suspect the last hunk is wrong and breaks all
non-seccomp tracing. I'll follow up with further analysis and possibly
a fix if you don't find one sooner.
Rich
