gcc-10 warns that the 32-bit zero cannot be shifted more than 32 bits to the right:
arch/arm64/kvm/../../../virt/kvm/arm/mmu.c: In function 'clear_hyp_p4d_entry': arch/arm64/include/asm/pgtable.h:630:35: error: right shift count >= width of type [-Werror=shift-count-overflow] 630 | #define pud_index(addr) (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)) | ^~ arch/arm64/include/asm/memory.h:271:45: note: in definition of macro '__phys_to_virt' 271 | #define __phys_to_virt(x) ((unsigned long)((x) - physvirt_offset)) | ^ arch/arm64/include/asm/pgtable.h:633:42: note: in expansion of macro '__va' 633 | #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr)))) | ^~~~ arch/arm64/include/asm/pgtable.h:632:73: note: in expansion of macro 'pud_index' 632 | #define pud_offset_phys(dir, addr) (p4d_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t)) | ^~~~~~~~~ arch/arm64/include/asm/pgtable.h:633:47: note: in expansion of macro 'pud_offset_phys' 633 | #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr)))) | ^~~~~~~~~~~~~~~ arch/arm64/kvm/../../../virt/kvm/arm/mmu.c:510:36: note: in expansion of macro 'pud_offset' 510 | pud_t *pud_table __maybe_unused = pud_offset(p4d, 0); | ^~~~~~~~~~ This is harmless, and the warning is a little bit silly for a zero constant, but it's trivial to fix by making it an unsigned long, so do that. Fixes: 22998131ab33 ("arm64: add support for folded p4d page tables") Signed-off-by: Arnd Bergmann <a...@arndb.de> --- virt/kvm/arm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 48d4288c5f1b..534d9798c3cb 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -507,7 +507,7 @@ static void clear_hyp_pgd_entry(pgd_t *pgd) static void clear_hyp_p4d_entry(p4d_t *p4d) { - pud_t *pud_table __maybe_unused = pud_offset(p4d, 0); + pud_t *pud_table __maybe_unused = pud_offset(p4d, 0UL); VM_BUG_ON(p4d_huge(*p4d)); p4d_clear(p4d); pud_free(NULL, pud_table); -- 2.26.0 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm