On 03/13/2018 04:56 PM, Andy Lutomirski wrote: > On Tue, Mar 13, 2018 at 11:16 PM, Howard McLauchlan <hmclauch...@fb.com> > wrote: >> Error injection is a useful mechanism to fail arbitrary kernel >> functions. However, it is often hard to guarantee an error propagates >> appropriately to user space programs. By injecting into syscalls, we can >> return arbitrary values to user space directly; this increases >> flexibility and robustness in testing, allowing us to test user space >> error paths effectively. > > Temporary NAK IMO. Specifically: > >> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h >> index a78186d826d7..e8c6d63ace78 100644 >> --- a/include/linux/syscalls.h >> +++ b/include/linux/syscalls.h >> @@ -191,6 +191,8 @@ static inline int is_syscall_trace_event(struct >> trace_event_call *tp_event) >> >> #define SYSCALL_DEFINE0(sname) \ >> SYSCALL_METADATA(_##sname, 0); \ >> + asmlinkage long sys_##sname(void); \ >> + ALLOW_ERROR_INJECTION(sys_##sname, ERRNO); \ > > sys_xyz() is not just the syscall itself; it's also a helper that's > used for entirely silly reasons by various bits of kernel code for > quite a few syscalls. Fortunately, Dominik has patches to fix that, > and Linus is even considering pulling them for 4.16. This patch will > most likely conflict with the final result of Dominik's series. > > Can you and Dominik coordinate a bit to get this patch or its > equivalent landed on top of Dominik's work? It might make sense for > Dominik to just add this patch to his series so it can land with the > rest of it. Dominik, Ingo, what do you think? > > --Andy >
Dominik, This patch applies cleanly on top of your patch series. Is there anything you'd need from me to get this in on top of your work? Howard
