On 2024-10-14 11:58:51+0100, Ryan Roberts wrote: > Increase alignment of sections in nvhe hyp, vdso and final vmlinux image > from PAGE_SIZE to PAGE_SIZE_MAX. For compile-time PAGE_SIZE, > PAGE_SIZE_MAX == PAGE_SIZE so there is no change. For boot-time > PAGE_SIZE, PAGE_SIZE_MAX is the largest selectable page size. > > For a boot-time page size build, image size is comparable to a 64K page > size compile-time build. In future, it may be desirable to optimize > run-time memory consumption by freeing unused padding pages when the > boot-time selected page size is less than PAGE_SIZE_MAX. > > Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx> > --- > > ***NOTE*** > Any confused maintainers may want to read the cover note here for context: > https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@xxxxxxx/ > > arch/arm64/include/asm/memory.h | 4 +-- > arch/arm64/kernel/vdso-wrap.S | 4 +-- > arch/arm64/kernel/vdso.c | 7 +++--- > arch/arm64/kernel/vdso/vdso.lds.S | 4 +-- > arch/arm64/kernel/vdso32-wrap.S | 4 +-- > arch/arm64/kernel/vdso32/vdso.lds.S | 4 +-- > arch/arm64/kernel/vmlinux.lds.S | 38 ++++++++++++++--------------- > arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 2 +- > 8 files changed, 34 insertions(+), 33 deletions(-) > diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c > index 89b6e78400023..1efe98909a2e0 100644 > --- a/arch/arm64/kernel/vdso.c > +++ b/arch/arm64/kernel/vdso.c > @@ -195,7 +195,7 @@ static int __setup_additional_pages(enum vdso_abi abi, > > vdso_text_len = vdso_info[abi].vdso_pages << PAGE_SHIFT; > /* Be sure to map the data page */ > - vdso_mapping_len = vdso_text_len + VVAR_NR_PAGES * PAGE_SIZE; > + vdso_mapping_len = vdso_text_len + VVAR_NR_PAGES * PAGE_SIZE_MAX; > > vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0); > if (IS_ERR_VALUE(vdso_base)) { > @@ -203,7 +203,8 @@ static int __setup_additional_pages(enum vdso_abi abi, > goto up_fail; > } > > - ret = _install_special_mapping(mm, vdso_base, VVAR_NR_PAGES * PAGE_SIZE, > + ret = _install_special_mapping(mm, vdso_base, > + VVAR_NR_PAGES * PAGE_SIZE_MAX, > VM_READ|VM_MAYREAD|VM_PFNMAP, > vdso_info[abi].dm); > if (IS_ERR(ret)) > @@ -212,7 +213,7 @@ static int __setup_additional_pages(enum vdso_abi abi, > if (system_supports_bti_kernel()) > gp_flags = VM_ARM64_BTI; > > - vdso_base += VVAR_NR_PAGES * PAGE_SIZE; > + vdso_base += VVAR_NR_PAGES * PAGE_SIZE_MAX; > mm->context.vdso = (void *)vdso_base; > ret = _install_special_mapping(mm, vdso_base, vdso_text_len, > VM_READ|VM_EXEC|gp_flags| > diff --git a/arch/arm64/kernel/vdso/vdso.lds.S b/arch/arm64/kernel/vdso/vdso.lds.S > index 45354f2ddf706..f7d1537a689e8 100644 > --- a/arch/arm64/kernel/vdso/vdso.lds.S > +++ b/arch/arm64/kernel/vdso/vdso.lds.S > @@ -18,9 +18,9 @@ OUTPUT_ARCH(aarch64) > > SECTIONS > { > - PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE); > + PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE_MAX); > #ifdef CONFIG_TIME_NS > - PROVIDE(_timens_data = _vdso_data + PAGE_SIZE); > + PROVIDE(_timens_data = _vdso_data + PAGE_SIZE_MAX); This looks like it also needs a change to vvar_fault() in vdso.c. The symbols are now always PAGE_SIZE_MAX apart, while vvar_fault() works in page offsets (vmf->pgoff) that are based on the runtime PAGE_SIZE and it expects hardcoded offsets. As test you can use tools/testing/selftests/timens/timens. (I can't test this right now, so it's only a suspicion) > #endif > . = VDSO_LBASE + SIZEOF_HEADERS; > diff --git a/arch/arm64/kernel/vdso32/vdso.lds.S b/arch/arm64/kernel/vdso32/vdso.lds.S > index 8d95d7d35057d..c46d18a69d1ce 100644 > --- a/arch/arm64/kernel/vdso32/vdso.lds.S > +++ b/arch/arm64/kernel/vdso32/vdso.lds.S > @@ -18,9 +18,9 @@ OUTPUT_ARCH(arm) > > SECTIONS > { > - PROVIDE_HIDDEN(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE); > + PROVIDE_HIDDEN(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE_MAX); > #ifdef CONFIG_TIME_NS > - PROVIDE_HIDDEN(_timens_data = _vdso_data + PAGE_SIZE); > + PROVIDE_HIDDEN(_timens_data = _vdso_data + PAGE_SIZE_MAX); > #endif > . = VDSO_LBASE + SIZEOF_HEADERS;
