Messages in this thread | | | Date | Mon, 27 Feb 2012 18:54:07 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH v11 10/12] ptrace,seccomp: Add PTRACE_SECCOMP support |
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On 02/24, Will Drewry wrote: > > arch/Kconfig | 1 + > include/linux/ptrace.h | 7 +++++-- > include/linux/seccomp.h | 4 +++- > include/linux/tracehook.h | 6 ++++++ > kernel/ptrace.c | 4 ++++ > kernel/seccomp.c | 18 ++++++++++++++++++
FYI, this conflicts with the changes -mm tree.
The changes in ptrace.* confict with Denys's "ptrace: simplify PTRACE_foo constants and PTRACE_SETOPTIONS code"
The change in tracehook.h conflicts with "ptrace: the killed tracee should not enter the syscall"
> --- a/kernel/seccomp.c > +++ b/kernel/seccomp.c > @@ -354,6 +354,24 @@ int __secure_computing_int(int this_syscall) > seccomp_send_sigsys(this_syscall, reason_code); > return -1; > } > + case SECCOMP_RET_TRACE: { > + int ret; > + struct pt_regs *regs = task_pt_regs(current); > + if (!(test_tsk_thread_flag(current, TIF_SYSCALL_TRACE)) || > + !(current->ptrace & PT_TRACE_SECCOMP)) > + return -1; > + /* > + * PT_TRACE_SECCOMP and seccomp.trace indicate whether > + * tracehook_report_syscall_entry needs to signal the > + * tracer. This avoids race conditions in hand off and > + * the requirement for TIF_SYSCALL_TRACE ensures that > + * we are in the syscall slow path. > + */ > + current->seccomp.trace = 1; > + ret = tracehook_report_syscall_entry(regs); > + current->seccomp.trace = 0; > + return ret;
To be honest, this interface looks a bit strange to me...
Once again, sorry if this was already discussed. But perhaps it would be better to introduce PTRACE_EVENT_SECCOMP/PTRACE_O_SECCOMP instead?
SECCOMP_RET_TRACE: could simply do ptrace_event(PTRACE_EVENT_SECCOMP) unconditionaly. The tracer can set the option and do PTRACE_CONT if it doesn't want the system call notifications.
This is also much simpler, no need to change ptrace/tracehook files.
Oleg.
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