| Message ID | 20220201150545.1512822-18-guoren@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | riscv: compat: Add COMPAT mode support for rv64 | expand |
On Tue, 01 Feb 2022 07:05:41 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> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Palmer Dabbelt <palmer@dabbelt.com> > --- > arch/riscv/include/asm/elf.h | 5 ++ > arch/riscv/include/asm/mmu.h | 1 + > arch/riscv/kernel/vdso.c | 104 +++++++++++++++++++++++++---------- > 3 files changed, 81 insertions(+), 29 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..deca69524799 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) > { > @@ -66,35 +68,35 @@ static int vdso_mremap(const struct vm_special_mapping *sm, > return 0; > } > > -static int __init __vdso_init(void) > +static int __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)) { > + if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4)) { > pr_err("vDSO is not a valid ELF object!\n"); > return -EINVAL; > } > > - 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; > > /* 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; > + vdso_info->cm->pages = vdso_pagelist; > > return 0; > } > @@ -116,13 +118,14 @@ 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; IIUC this is the only use for context.vdso_info? If that's the case, can we just switch between VDSO targets based on __is_compat_task(task)? That'd save an mm_struct pointer, which is always nice. It'd probably be worth cleaning up the arm64 port too, which zaps both mappings. > > 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 +190,6 @@ 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 +201,53 @@ 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]; > + int ret; > + > + ret = __vdso_init(&vdso_info); > + if (ret) > + goto out; > > - return __vdso_init(); > +#ifdef CONFIG_COMPAT > + ret = __vdso_init(&compat_vdso_info); > + if (ret) > + goto out; It's a bit pedantic (we're just going to crash anyway), but this is mising the cleanup for the first __vdso_init(). > +#endif > +out: > + return ret; > } > 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 +258,18 @@ 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 +281,24 @@ 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 +307,7 @@ 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; Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> As I don't think either of these are big enough of a deal to keep from merging this.
On Wed, Feb 23, 2022 at 9:42 AM Palmer Dabbelt <palmer@dabbelt.com> wrote: > > On Tue, 01 Feb 2022 07:05:41 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> > > Cc: Arnd Bergmann <arnd@arndb.de> > > Cc: Palmer Dabbelt <palmer@dabbelt.com> > > --- > > arch/riscv/include/asm/elf.h | 5 ++ > > arch/riscv/include/asm/mmu.h | 1 + > > arch/riscv/kernel/vdso.c | 104 +++++++++++++++++++++++++---------- > > 3 files changed, 81 insertions(+), 29 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..deca69524799 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) > > { > > @@ -66,35 +68,35 @@ static int vdso_mremap(const struct vm_special_mapping *sm, > > return 0; > > } > > > > -static int __init __vdso_init(void) > > +static int __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)) { > > + if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4)) { > > pr_err("vDSO is not a valid ELF object!\n"); > > return -EINVAL; > > } > > > > - 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; > > > > /* 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; > > + vdso_info->cm->pages = vdso_pagelist; > > > > return 0; > > } > > @@ -116,13 +118,14 @@ 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; > > IIUC this is the only use for context.vdso_info? If that's the case, > can we just switch between VDSO targets based on __is_compat_task(task)? > That'd save an mm_struct pointer, which is always nice. It'd probably > be worth cleaning up the arm64 port too, which zaps both mappings. > > > > > 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 +190,6 @@ 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 +201,53 @@ 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]; > > + int ret; > > + > > + ret = __vdso_init(&vdso_info); > > + if (ret) > > + goto out; > > > > - return __vdso_init(); > > +#ifdef CONFIG_COMPAT > > + ret = __vdso_init(&compat_vdso_info); > > + if (ret) > > + goto out; > > It's a bit pedantic (we're just going to crash anyway), but this is > mising the cleanup for the first __vdso_init(). I would use panic in __vdso_init: static void __init __vdso_init(struct __vdso_info *vdso_info) { ... if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4)) { - pr_err("vDSO is not a valid ELF object!\n"); - return -EINVAL; + panic("vDSO is not a valid ELF object!\n"); } > > > +#endif > > +out: > > + return ret; > > } > > 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 +258,18 @@ 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 +281,24 @@ 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 +307,7 @@ 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; > > Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> > > As I don't think either of these are big enough of a deal to keep from merging > this.
> @@ -66,35 +68,35 @@ static int vdso_mremap(const struct vm_special_mapping > *sm, return 0; > } > > -static int __init __vdso_init(void) > +static int __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)) { > + if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4)) { > pr_err("vDSO is not a valid ELF object!\n"); > return -EINVAL; > } > Does anyone actually guarantee that this is at least this 4 bytes long? Eike
On Wed, Feb 23, 2022 at 8:19 PM Rolf Eike Beer <eb@emlix.com> wrote: > > > @@ -66,35 +68,35 @@ static int vdso_mremap(const struct vm_special_mapping > > *sm, return 0; > > } > > > > -static int __init __vdso_init(void) > > +static int __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)) { > > + if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4)) { > > pr_err("vDSO is not a valid ELF object!\n"); > > return -EINVAL; > > } > > > > Does anyone actually guarantee that this is at least this 4 bytes long? You can ref: arch/arm64/kernel/vdso.c arch/arm/kernel/vdso.c arch/nds32/kernel/vdso.c and in arch/powerpc/boot/elf.h: arch/powerpc/kernel/fadump.c: memcpy(elf->e_ident, ELFMAG, SELFMAG); arch/powerpc/boot/elf.h:#define ELFMAG0 0x7f /* EI_MAG */ arch/powerpc/boot/elf.h:#define ELFMAG1 'E' arch/powerpc/boot/elf.h:#define ELFMAG2 'L' arch/powerpc/boot/elf.h:#define ELFMAG3 'F' arch/powerpc/boot/elf.h:#define ELFMAG "\177ELF" arch/powerpc/boot/elf.h:#define SELFMAG 4 > > Eike > -- > Rolf Eike Beer, emlix GmbH, https://www.emlix.com > Fon +49 551 30664-0, Fax +49 551 30664-11 > Gothaer Platz 3, 37083 Göttingen, Germany > Sitz der Gesellschaft: Göttingen, Amtsgericht Göttingen HR B 3160 > Geschäftsführung: Heike Jordan, Dr. Uwe Kracke – Ust-IdNr.: DE 205 198 055 > > emlix - smart embedded open source
On Wed, Feb 23, 2022 at 9:42 AM Palmer Dabbelt <palmer@dabbelt.com> wrote: > > On Tue, 01 Feb 2022 07:05:41 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> > > Cc: Arnd Bergmann <arnd@arndb.de> > > Cc: Palmer Dabbelt <palmer@dabbelt.com> > > --- > > arch/riscv/include/asm/elf.h | 5 ++ > > arch/riscv/include/asm/mmu.h | 1 + > > arch/riscv/kernel/vdso.c | 104 +++++++++++++++++++++++++---------- > > 3 files changed, 81 insertions(+), 29 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..deca69524799 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) > > { > > @@ -66,35 +68,35 @@ static int vdso_mremap(const struct vm_special_mapping *sm, > > return 0; > > } > > > > -static int __init __vdso_init(void) > > +static int __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)) { > > + if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4)) { > > pr_err("vDSO is not a valid ELF object!\n"); > > return -EINVAL; > > } > > > > - 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; > > > > /* 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; > > + vdso_info->cm->pages = vdso_pagelist; > > > > return 0; > > } > > @@ -116,13 +118,14 @@ 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; > > IIUC this is the only use for context.vdso_info? If that's the case, > can we just switch between VDSO targets based on __is_compat_task(task)? > That'd save an mm_struct pointer, which is always nice. It'd probably > be worth cleaning up the arm64 port too, which zaps both mappings. Do you want rv32 to support HAVE_GENERIC_VDSO_NS in the future? > > > > > 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 +190,6 @@ 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 +201,53 @@ 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]; > > + int ret; > > + > > + ret = __vdso_init(&vdso_info); > > + if (ret) > > + goto out; > > > > - return __vdso_init(); > > +#ifdef CONFIG_COMPAT > > + ret = __vdso_init(&compat_vdso_info); > > + if (ret) > > + goto out; > > It's a bit pedantic (we're just going to crash anyway), but this is > mising the cleanup for the first __vdso_init(). > > > +#endif > > +out: > > + return ret; > > } > > 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 +258,18 @@ 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 +281,24 @@ 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 +307,7 @@ 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; > > Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> > > As I don't think either of these are big enough of a deal to keep from merging > this.
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..deca69524799 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) { @@ -66,35 +68,35 @@ static int vdso_mremap(const struct vm_special_mapping *sm, return 0; } -static int __init __vdso_init(void) +static int __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)) { + if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4)) { pr_err("vDSO is not a valid ELF object!\n"); return -EINVAL; } - 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; /* 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; + vdso_info->cm->pages = vdso_pagelist; return 0; } @@ -116,13 +118,14 @@ 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 +190,6 @@ 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 +201,53 @@ 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]; + int ret; + + ret = __vdso_init(&vdso_info); + if (ret) + goto out; - return __vdso_init(); +#ifdef CONFIG_COMPAT + ret = __vdso_init(&compat_vdso_info); + if (ret) + goto out; +#endif +out: + return ret; } 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 +258,18 @@ 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 +281,24 @@ 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 +307,7 @@ 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;