On Tue, Dec 06, 2022 at 09:48:55AM -0800, Jeff Xu wrote:
On Tue, Dec 6, 2022 at 8:35 AM Greg KH gregkh@linuxfoundation.org wrote:
On Tue, Dec 06, 2022 at 08:26:30AM -0800, Jeff Xu wrote:
On Tue, Dec 6, 2022 at 8:04 AM Greg KH gregkh@linuxfoundation.org wrote:
On Tue, Dec 06, 2022 at 03:23:55PM +0000, jeffxu@chromium.org wrote:
--- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -110,6 +110,11 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns ns->ucounts = ucounts; ns->pid_allocated = PIDNS_ADDING;
+#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
ns->memfd_noexec_scope =task_active_pid_ns(current)->memfd_noexec_scope;+#endif
.c files should never have #if in them. Can't you put this in a .h file properly so that this does not get really messy over time?
Thanks for reviewing. It seems to me that checking for CONFIG_XXX is common in c code in kernel/ path.
Maybe, but please don't make it any worse if at all possible. It's tough to maintain code like that.
Do you have a sample code pattern (link/function) that I can follow?
Any of the zillions of #if statements in .h files :)
Thanks. I will take the approach of having real/stub implementation in the h file, and the c file using it without a compile flag. Please kindly let me know if this is not right.
Right; for example:
in .h:
#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE) static inline void ns_copy_memfd_scope(... dst, ... src) { dst->memfd_noexec_scope = src->memfd_noexec_scope; } #else static inline void ns_set_memfd_scope(... ns, ... scope) { } #endif
in .c:
ns_copy_memfd_scope(ns, task_active_pid_ns(current));