From 3092eb45637573c5e435fbf5eaf9516316e5f9c6 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Tue, 5 Apr 2022 15:13:11 +0800 Subject: [PATCH] riscv: compat: vdso: Add setup additional pages implementation Reconstruct __setup_additional_pages() by appending vdso info pointer argument to meet compat_vdso_info requirement. And change vm_special_mapping *dm, *cm initialization into static. Signed-off-by: Guo Ren Signed-off-by: Guo Ren Reviewed-by: Palmer Dabbelt Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20220405071314.3225832-18-guoren@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/elf.h | 5 ++ arch/riscv/include/asm/mmu.h | 1 + arch/riscv/kernel/vdso.c | 105 +++++++++++++++++++++++------------ 3 files changed, 76 insertions(+), 35 deletions(-) diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index 754fdb8cee96..14fc7342490b 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -130,5 +130,10 @@ do { if ((ex).e_ident[EI_CLASS] == ELFCLASS32) \ typedef compat_ulong_t compat_elf_greg_t; typedef compat_elf_greg_t compat_elf_gregset_t[ELF_NGREG]; +extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm, + int uses_interp); +#define compat_arch_setup_additional_pages \ + compat_arch_setup_additional_pages + #endif /* CONFIG_COMPAT */ #endif /* _ASM_RISCV_ELF_H */ diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h index 0099dc116168..cedcf8ea3c76 100644 --- a/arch/riscv/include/asm/mmu.h +++ b/arch/riscv/include/asm/mmu.h @@ -16,6 +16,7 @@ typedef struct { atomic_long_t id; #endif void *vdso; + void *vdso_info; #ifdef CONFIG_SMP /* A local icache flush is needed before user execution can resume. */ cpumask_t icache_stale_mask; diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c index a9436a65161a..50fe4c877603 100644 --- a/arch/riscv/kernel/vdso.c +++ b/arch/riscv/kernel/vdso.c @@ -23,6 +23,9 @@ struct vdso_data { #endif extern char vdso_start[], vdso_end[]; +#ifdef CONFIG_COMPAT +extern char compat_vdso_start[], compat_vdso_end[]; +#endif enum vvar_pages { VVAR_DATA_PAGE_OFFSET, @@ -30,6 +33,11 @@ enum vvar_pages { VVAR_NR_PAGES, }; +enum rv_vdso_map { + RV_VDSO_MAP_VVAR, + RV_VDSO_MAP_VDSO, +}; + #define VVAR_SIZE (VVAR_NR_PAGES << PAGE_SHIFT) /* @@ -52,12 +60,6 @@ struct __vdso_info { struct vm_special_mapping *cm; }; -static struct __vdso_info vdso_info __ro_after_init = { - .name = "vdso", - .vdso_code_start = vdso_start, - .vdso_code_end = vdso_end, -}; - static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma) { @@ -66,37 +68,33 @@ static int vdso_mremap(const struct vm_special_mapping *sm, return 0; } -static int __init __vdso_init(void) +static void __init __vdso_init(struct __vdso_info *vdso_info) { unsigned int i; struct page **vdso_pagelist; unsigned long pfn; - if (memcmp(vdso_info.vdso_code_start, "\177ELF", 4)) { - pr_err("vDSO is not a valid ELF object!\n"); - return -EINVAL; - } + if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4)) + panic("vDSO is not a valid ELF object!\n"); - vdso_info.vdso_pages = ( - vdso_info.vdso_code_end - - vdso_info.vdso_code_start) >> + vdso_info->vdso_pages = ( + vdso_info->vdso_code_end - + vdso_info->vdso_code_start) >> PAGE_SHIFT; - vdso_pagelist = kcalloc(vdso_info.vdso_pages, + vdso_pagelist = kcalloc(vdso_info->vdso_pages, sizeof(struct page *), GFP_KERNEL); if (vdso_pagelist == NULL) - return -ENOMEM; + panic("vDSO kcalloc failed!\n"); /* Grab the vDSO code pages. */ - pfn = sym_to_pfn(vdso_info.vdso_code_start); + pfn = sym_to_pfn(vdso_info->vdso_code_start); - for (i = 0; i < vdso_info.vdso_pages; i++) + for (i = 0; i < vdso_info->vdso_pages; i++) vdso_pagelist[i] = pfn_to_page(pfn + i); - vdso_info.cm->pages = vdso_pagelist; - - return 0; + vdso_info->cm->pages = vdso_pagelist; } #ifdef CONFIG_TIME_NS @@ -116,13 +114,14 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) { struct mm_struct *mm = task->mm; struct vm_area_struct *vma; + struct __vdso_info *vdso_info = mm->context.vdso_info; mmap_read_lock(mm); for (vma = mm->mmap; vma; vma = vma->vm_next) { unsigned long size = vma->vm_end - vma->vm_start; - if (vma_is_special_mapping(vma, vdso_info.dm)) + if (vma_is_special_mapping(vma, vdso_info->dm)) zap_page_range(vma, vma->vm_start, size); } @@ -187,11 +186,6 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, return vmf_insert_pfn(vma, vmf->address, pfn); } -enum rv_vdso_map { - RV_VDSO_MAP_VVAR, - RV_VDSO_MAP_VDSO, -}; - static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = { [RV_VDSO_MAP_VVAR] = { .name = "[vvar]", @@ -203,25 +197,46 @@ static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = { }, }; +static struct __vdso_info vdso_info __ro_after_init = { + .name = "vdso", + .vdso_code_start = vdso_start, + .vdso_code_end = vdso_end, + .dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR], + .cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO], +}; + +#ifdef CONFIG_COMPAT +static struct __vdso_info compat_vdso_info __ro_after_init = { + .name = "compat_vdso", + .vdso_code_start = compat_vdso_start, + .vdso_code_end = compat_vdso_end, + .dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR], + .cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO], +}; +#endif + static int __init vdso_init(void) { - vdso_info.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR]; - vdso_info.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO]; + __vdso_init(&vdso_info); +#ifdef CONFIG_COMPAT + __vdso_init(&compat_vdso_info); +#endif - return __vdso_init(); + return 0; } arch_initcall(vdso_init); static int __setup_additional_pages(struct mm_struct *mm, struct linux_binprm *bprm, - int uses_interp) + int uses_interp, + struct __vdso_info *vdso_info) { unsigned long vdso_base, vdso_text_len, vdso_mapping_len; void *ret; BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES); - vdso_text_len = vdso_info.vdso_pages << PAGE_SHIFT; + vdso_text_len = vdso_info->vdso_pages << PAGE_SHIFT; /* Be sure to map the data page */ vdso_mapping_len = vdso_text_len + VVAR_SIZE; @@ -232,16 +247,18 @@ static int __setup_additional_pages(struct mm_struct *mm, } ret = _install_special_mapping(mm, vdso_base, VVAR_SIZE, - (VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info.dm); + (VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info->dm); if (IS_ERR(ret)) goto up_fail; vdso_base += VVAR_SIZE; mm->context.vdso = (void *)vdso_base; + mm->context.vdso_info = (void *)vdso_info; + ret = _install_special_mapping(mm, vdso_base, vdso_text_len, (VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC), - vdso_info.cm); + vdso_info->cm); if (IS_ERR(ret)) goto up_fail; @@ -253,6 +270,24 @@ up_fail: return PTR_ERR(ret); } +#ifdef CONFIG_COMPAT +int compat_arch_setup_additional_pages(struct linux_binprm *bprm, + int uses_interp) +{ + struct mm_struct *mm = current->mm; + int ret; + + if (mmap_write_lock_killable(mm)) + return -EINTR; + + ret = __setup_additional_pages(mm, bprm, uses_interp, + &compat_vdso_info); + mmap_write_unlock(mm); + + return ret; +} +#endif + int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { struct mm_struct *mm = current->mm; @@ -261,7 +296,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) if (mmap_write_lock_killable(mm)) return -EINTR; - ret = __setup_additional_pages(mm, bprm, uses_interp); + ret = __setup_additional_pages(mm, bprm, uses_interp, &vdso_info); mmap_write_unlock(mm); return ret;