| Message ID | 20190911010122.28462-1-cascardo@canonical.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
| Series | powerpc/ptrace: Do not return ENOSYS if invalid syscall | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch next (c317052c95bef1f977b023158e5aa929215f443d) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 8 lines checked |
On Tue, Sep 10, 2019 at 10:01:22PM -0300, Thadeu Lima de Souza Cascardo wrote: > If a tracer sets the syscall number to an invalid one, allow the return > value set by the tracer to be returned the tracee. > > The test for NR_syscalls is already at entry_64.S, and it's at > do_syscall_trace_enter only to skip audit and trace. > > After this, seccomp_bpf selftests complete just fine, as the failing test > was using ptrace to change the syscall to return an error or a fake value, > but were failing as it was always returning -ENOSYS. > > Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> > --- > arch/powerpc/kernel/ptrace.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c > index 8c92febf5f44..87315335f66a 100644 > --- a/arch/powerpc/kernel/ptrace.c > +++ b/arch/powerpc/kernel/ptrace.c > @@ -3316,7 +3316,7 @@ long do_syscall_trace_enter(struct pt_regs *regs) > > /* Avoid trace and audit when syscall is invalid. */ > if (regs->gpr[0] >= NR_syscalls) > - goto skip; > + return regs->gpr[0]; > > if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) > trace_sys_enter(regs, regs->gpr[0]); Ping? Any comments on this? Thanks. Cascardo.
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 8c92febf5f44..87315335f66a 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -3316,7 +3316,7 @@ long do_syscall_trace_enter(struct pt_regs *regs) /* Avoid trace and audit when syscall is invalid. */ if (regs->gpr[0] >= NR_syscalls) - goto skip; + return regs->gpr[0]; if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_sys_enter(regs, regs->gpr[0]);
If a tracer sets the syscall number to an invalid one, allow the return value set by the tracer to be returned the tracee. The test for NR_syscalls is already at entry_64.S, and it's at do_syscall_trace_enter only to skip audit and trace. After this, seccomp_bpf selftests complete just fine, as the failing test was using ptrace to change the syscall to return an error or a fake value, but were failing as it was always returning -ENOSYS. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> --- arch/powerpc/kernel/ptrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)