diff options
Diffstat (limited to 'arch/powerpc/kernel/vdso.c')
| -rw-r--r-- | arch/powerpc/kernel/vdso.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index a0abce251d0a..137dc22afa42 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -1,3 +1,4 @@ + /* * Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp. * <benh@kernel.crashing.org> @@ -49,6 +50,9 @@ /* Max supported size for symbol names */ #define MAX_SYMNAME 64 +/* The alignment of the vDSO */ +#define VDSO_ALIGNMENT (1 << 16) + extern char vdso32_start, vdso32_end; static void *vdso32_kbase = &vdso32_start; static unsigned int vdso32_pages; @@ -74,7 +78,7 @@ static int vdso_ready; static union { struct vdso_data data; u8 page[PAGE_SIZE]; -} vdso_data_store __attribute__((__section__(".data.page_aligned"))); +} vdso_data_store __page_aligned_data; struct vdso_data *vdso_data = &vdso_data_store.data; /* Format of the patch table */ @@ -230,15 +234,28 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) * pick a base address for the vDSO in process space. We try to put it * at vdso_base which is the "natural" base for it, but we might fail * and end up putting it elsewhere. + * Add enough to the size so that the result can be aligned. */ down_write(&mm->mmap_sem); vdso_base = get_unmapped_area(NULL, vdso_base, - vdso_pages << PAGE_SHIFT, 0, 0); + (vdso_pages << PAGE_SHIFT) + + ((VDSO_ALIGNMENT - 1) & PAGE_MASK), + 0, 0); if (IS_ERR_VALUE(vdso_base)) { rc = vdso_base; goto fail_mmapsem; } + /* Add required alignment. */ + vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT); + + /* + * Put vDSO base into mm struct. We need to do this before calling + * 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; + /* * our vma flags don't have VM_WRITE so by default, the process isn't * allowed to write those pages. @@ -259,11 +276,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC| VM_ALWAYSDUMP, vdso_pagelist); - if (rc) + if (rc) { + current->mm->context.vdso_base = 0; goto fail_mmapsem; - - /* Put vDSO base into mm struct */ - current->mm->context.vdso_base = vdso_base; + } up_write(&mm->mmap_sem); return 0; |