Messages in this thread | | | Date | Thu, 24 Feb 2022 09:57:26 -0800 (PST) | Subject | Re: [PATCH V6 17/20] riscv: compat: vdso: Add setup additional pages implementation | From | Palmer Dabbelt <> |
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On Thu, 24 Feb 2022 00:54:07 PST (-0800), guoren@kernel.org wrote: > From: Guo Ren <guoren@linux.alibaba.com> > > 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 <guoren@linux.alibaba.com> > Signed-off-by: Guo Ren <guoren@kernel.org> > Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> > Cc: Arnd Bergmann <arnd@arndb.de> > --- > arch/riscv/include/asm/elf.h | 5 ++ > arch/riscv/include/asm/mmu.h | 1 + > arch/riscv/kernel/vdso.c | 103 +++++++++++++++++++++++------------ > 3 files changed, 74 insertions(+), 35 deletions(-) > > diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h > index 3a4293dc7229..d87d3bcc758d 100644 > --- a/arch/riscv/include/asm/elf.h > +++ b/arch/riscv/include/asm/elf.h > @@ -134,5 +134,10 @@ 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..f864811aa011 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 +197,44 @@ 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); > + __vdso_init(&compat_vdso_info);
An autobuilder is pointing out an issue here. I'm assuming just an `#if defined(CONFIG_COMPAT)` will fix it, I'm OK squashing that in if it's the only issue -- a fixed one never hurts, though ;)
I'll try to take another look soon.
> - 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 +245,18 @@ 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 +268,24 @@ static int __setup_additional_pages(struct mm_struct *mm, > 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 +294,7 @@ 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;
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