[PATCH v1 7/9] powerpc/vdso: Move vdso datapage up front
From: Christophe Leroy <hidden>
Date: 2020-08-25 13:54:34
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Move the vdso datapage in front of the VDSO area, before vdso test. This will allow to remove the __kernel_datapage_offset symbol and simplify __get_datapage() in the following patch. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/include/asm/mmu_context.h | 4 +++- arch/powerpc/kernel/vdso.c | 22 ++++++++++------------ 2 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 7f3658a97384..be18ad12bb54 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h@@ -262,7 +262,9 @@ extern void arch_exit_mmap(struct mm_struct *mm); static inline void arch_unmap(struct mm_struct *mm, unsigned long start, unsigned long end) { - if (start <= mm->context.vdso_base && mm->context.vdso_base < end) + unsigned long vdso_base = mm->context.vdso_base - PAGE_SIZE; + + if (start <= vdso_base && vdso_base < end) mm->context.vdso_base = 0; }
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index b9270923452e..1d72c4b7672f 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c@@ -124,7 +124,7 @@ static int vdso_mremap(unsigned long vdso_pages, if (new_size != vdso_size) return -EINVAL; - current->mm->context.vdso_base = (unsigned long)new_vma->vm_start; + current->mm->context.vdso_base = (unsigned long)new_vma->vm_start + PAGE_SIZE; return 0; }
@@ -217,7 +217,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) * install_special_mapping or the perf counter mmap tracking code * will fail to recognise it as a vDSO (since arch_vma_name fails). */ - current->mm->context.vdso_base = vdso_base; + current->mm->context.vdso_base = vdso_base + PAGE_SIZE; /* * our vma flags don't have VM_WRITE so by default, the process isn't
@@ -516,8 +516,7 @@ static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32, return -1; } *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) = - (vdso64_pages << PAGE_SHIFT) - - (sym64->st_value - VDSO64_LBASE); + (sym64->st_value - VDSO64_LBASE) - PAGE_SIZE; #endif /* CONFIG_PPC64 */ #ifdef CONFIG_VDSO32
@@ -528,8 +527,7 @@ static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32, return -1; } *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) = - (vdso32_pages << PAGE_SHIFT) - - (sym32->st_value - VDSO32_LBASE); + (sym32->st_value - VDSO32_LBASE) - PAGE_SIZE; #endif return 0;
@@ -771,10 +769,10 @@ static int __init vdso_init(void) if (!pagelist) goto alloc_failed; - for (i = 0; i < vdso32_pages; i++) - pagelist[i] = virt_to_page(vdso32_kbase + i * PAGE_SIZE); + pagelist[0] = virt_to_page(vdso_data); - pagelist[i++] = virt_to_page(vdso_data); + for (i = 0; i < vdso32_pages; i++) + pagelist[i + 1] = virt_to_page(vdso32_kbase + i * PAGE_SIZE); vdso32_spec.pages = pagelist; }
@@ -784,10 +782,10 @@ static int __init vdso_init(void) if (!pagelist) goto alloc_failed; - for (i = 0; i < vdso64_pages; i++) - pagelist[i] = virt_to_page(vdso64_kbase + i * PAGE_SIZE); + pagelist[0] = virt_to_page(vdso_data); - pagelist[i++] = virt_to_page(vdso_data); + for (i = 0; i < vdso64_pages; i++) + pagelist[i + 1] = virt_to_page(vdso64_kbase + i * PAGE_SIZE); vdso64_spec.pages = pagelist; }
--
2.25.0