Le 16/06/2021 à 20:52, Andy Lutomirski a écrit :
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
https://github.com/torvalds/linux/blob/master/arch/powerpc/include/asm/membarrier.h
Was added by https://github.com/torvalds/linux/commit/3ccfebedd8cf54e291c809c838d8ad5cc00f5688
/*
* The RFI family of instructions are context synchronising, and
* that is how we return to userspace, so nothing is required here.
*/
Thanks!
