16 Jun
2021
16 Jun
'21
11:48 p.m.
On Wed, Jun 16, 2021, at 11:52 AM, Andy Lutomirski wrote:
On 6/15/21 9:45 PM, Nicholas Piggin wrote:
Excerpts from Andy Lutomirski's message of June 16, 2021 1:21 pm:
The old sync_core_before_usermode() comments suggested that a non-icache-syncing return-to-usermode instruction is x86-specific and that all other architectures automatically notice cross-modified code on return to userspace.
+/*
- XXX: can a powerpc person put an appropriate comment here?
- */
+static inline void membarrier_sync_core_before_usermode(void) +{ +}
+#endif /* _ASM_POWERPC_SYNC_CORE_H */
powerpc's can just go in asm/membarrier.h
$ ls arch/powerpc/include/asm/membarrier.h ls: cannot access 'arch/powerpc/include/asm/membarrier.h': No such file or directory
Which is because I deleted it. Duh. I'll clean this up.
/*
- The RFI family of instructions are context synchronising, and
- that is how we return to userspace, so nothing is required here.
*/
Thanks!