This Linux kernel change "x86: make ZERO_PAGE() at least parse its argument" is included in the Linux 5.1 release. This change is authored by Linus Torvalds <torvalds [at] linux-foundation.org> on Mon Apr 29 09:51:29 2019 -0700. The commit for this change in Linux stable tree is 8087148 (patch).
x86: make ZERO_PAGE() at least parse its argument This doesn't really do anything, but at least we now parse teh ZERO_PAGE() address argument so that we'll catch the most obvious errors in usage next time they'll happen. See commit 6a5c5d26c4c6 ("rdma: fix build errors on s390 and MIPS due to bad ZERO_PAGE use") what happens when we don't have any use of the macro argument at all. Signed-off-by: Linus Torvalds <email@example.com>
There are 2 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.
arch/x86/include/asm/pgtable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 2779ace..50b3e2d 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -46,7 +46,7 @@ */ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __visible; -#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) +#define ZERO_PAGE(vaddr) ((void)(vaddr),virt_to_page(empty_zero_page)) extern spinlock_t pgd_lock; extern struct list_head pgd_list;