| Message ID | 20220908150421.323-1-jszhang@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] riscv: vdso: fix NULL deference in vdso_join_timens() when vfork | expand |
Great job! I've tested it on rv32-rootfs, and everything seems to be working. Tested-by: Guo Ren <guoren@kernel.org> On Thu, Sep 8, 2022 at 11:13 PM Jisheng Zhang <jszhang@kernel.org> wrote: > > Testing tools/testing/selftests/timens/vfork_exec.c got below > kernel log: > > [ 6.838454] Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000020 > [ 6.842255] Oops [#1] > [ 6.842871] Modules linked in: > [ 6.844249] CPU: 1 PID: 64 Comm: vfork_exec Not tainted 6.0.0-rc3-rt15+ #8 > [ 6.845861] Hardware name: riscv-virtio,qemu (DT) > [ 6.848009] epc : vdso_join_timens+0xd2/0x110 > [ 6.850097] ra : vdso_join_timens+0xd2/0x110 > [ 6.851164] epc : ffffffff8000635c ra : ffffffff8000635c sp : ff6000000181fbf0 > [ 6.852562] gp : ffffffff80cff648 tp : ff60000000fdb700 t0 : 3030303030303030 > [ 6.853852] t1 : 0000000000000030 t2 : 3030303030303030 s0 : ff6000000181fc40 > [ 6.854984] s1 : ff60000001e6c000 a0 : 0000000000000010 a1 : ffffffff8005654c > [ 6.856221] a2 : 00000000ffffefff a3 : 0000000000000000 a4 : 0000000000000000 > [ 6.858114] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 > [ 6.859484] s2 : ff60000001e6c068 s3 : ff6000000108abb0 s4 : 0000000000000000 > [ 6.860751] s5 : 0000000000001000 s6 : ffffffff8089dc40 s7 : ffffffff8089dc38 > [ 6.862029] s8 : ffffffff8089dc30 s9 : ff60000000fdbe38 s10: 000000000000005e > [ 6.863304] s11: ffffffff80cc3510 t3 : ffffffff80d1112f t4 : ffffffff80d1112f > [ 6.864565] t5 : ffffffff80d11130 t6 : ff6000000181fa00 > [ 6.865561] status: 0000000000000120 badaddr: 0000000000000020 cause: 000000000000000d > [ 6.868046] [<ffffffff8008dc94>] timens_commit+0x38/0x11a > [ 6.869089] [<ffffffff8008dde8>] timens_on_fork+0x72/0xb4 > [ 6.870055] [<ffffffff80190096>] begin_new_exec+0x3c6/0x9f0 > [ 6.871231] [<ffffffff801d826c>] load_elf_binary+0x628/0x1214 > [ 6.872304] [<ffffffff8018ee7a>] bprm_execve+0x1f2/0x4e4 > [ 6.873243] [<ffffffff8018f90c>] do_execveat_common+0x16e/0x1ee > [ 6.874258] [<ffffffff8018f9c8>] sys_execve+0x3c/0x48 > [ 6.875162] [<ffffffff80003556>] ret_from_syscall+0x0/0x2 > [ 6.877484] ---[ end trace 0000000000000000 ]--- > > This is because the mm->context.vdso_info is NULL in vfork case. From > another side, mm->context.vdso_info either points to vdso info > for RV64 or vdso info for compat, there's no need to bloat riscv's > mm_context_t, we can handle the difference when setup the additional > page for vdso. > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > Fixes: 3092eb456375 ("riscv: compat: vdso: Add setup additional pages implementation") > --- > > since v1: > - add "Fixes" tag > - fix build error when CONFIG_COMPAT is enabled. > > arch/riscv/include/asm/mmu.h | 1 - > arch/riscv/kernel/vdso.c | 178 +++++++++++++++++++---------------- > 2 files changed, 95 insertions(+), 84 deletions(-) > > diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h > index cedcf8ea3c76..0099dc116168 100644 > --- a/arch/riscv/include/asm/mmu.h > +++ b/arch/riscv/include/asm/mmu.h > @@ -16,7 +16,6 @@ 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 69b05b6c181b..8ca3b821e1b5 100644 > --- a/arch/riscv/kernel/vdso.c > +++ b/arch/riscv/kernel/vdso.c > @@ -27,6 +27,11 @@ extern char vdso_start[], vdso_end[]; > extern char compat_vdso_start[], compat_vdso_end[]; > #endif > > +enum vdso_abi { > + VDSO_ABI_RV64, > + VDSO_ABI_RV32, > +}; > + > enum vvar_pages { > VVAR_DATA_PAGE_OFFSET, > VVAR_TIMENS_PAGE_OFFSET, > @@ -68,67 +73,7 @@ static int vdso_mremap(const struct vm_special_mapping *sm, > return 0; > } > > -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)) > - panic("vDSO is not a valid ELF object!\n"); > - > - vdso_info->vdso_pages = ( > - vdso_info->vdso_code_end - > - vdso_info->vdso_code_start) >> > - PAGE_SHIFT; > - > - vdso_pagelist = kcalloc(vdso_info->vdso_pages, > - sizeof(struct page *), > - GFP_KERNEL); > - if (vdso_pagelist == NULL) > - panic("vDSO kcalloc failed!\n"); > - > - /* Grab the vDSO code pages. */ > - pfn = sym_to_pfn(vdso_info->vdso_code_start); > - > - for (i = 0; i < vdso_info->vdso_pages; i++) > - vdso_pagelist[i] = pfn_to_page(pfn + i); > - > - vdso_info->cm->pages = vdso_pagelist; > -} > - > #ifdef CONFIG_TIME_NS > -struct vdso_data *arch_get_vdso_data(void *vvar_page) > -{ > - return (struct vdso_data *)(vvar_page); > -} > - > -/* > - * The vvar mapping contains data for a specific time namespace, so when a task > - * changes namespace we must unmap its vvar data for the old namespace. > - * Subsequent faults will map in data for the new namespace. > - * > - * For more details see timens_setup_vdso_data(). > - */ > -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)) > - zap_page_range(vma, vma->vm_start, size); > - } > - > - mmap_read_unlock(mm); > - return 0; > -} > - > static struct page *find_timens_vvar_page(struct vm_area_struct *vma) > { > if (likely(vma->vm_mm == current->mm)) > @@ -197,13 +142,6 @@ 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 vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = { > @@ -216,21 +154,97 @@ static struct vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = { > .mremap = vdso_mremap, > }, > }; > +#endif > > -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_compat_vdso_maps[RV_VDSO_MAP_VVAR], > - .cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO], > +static struct __vdso_info vdso_info[] __ro_after_init = { > + [VDSO_ABI_RV64] = { > + .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 > + [VDSO_ABI_RV32] = { > + .name = "compat_vdso", > + .vdso_code_start = compat_vdso_start, > + .vdso_code_end = compat_vdso_end, > + .dm = &rv_compat_vdso_maps[RV_VDSO_MAP_VVAR], > + .cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO], > + }, > +#endif > }; > + > +static void __init __vdso_init(enum vdso_abi abi) > +{ > + unsigned int i; > + struct page **vdso_pagelist; > + unsigned long pfn; > + > + if (memcmp(vdso_info[abi].vdso_code_start, "\177ELF", 4)) > + panic("vDSO is not a valid ELF object!\n"); > + > + vdso_info[abi].vdso_pages = ( > + vdso_info[abi].vdso_code_end - > + vdso_info[abi].vdso_code_start) >> > + PAGE_SHIFT; > + > + vdso_pagelist = kcalloc(vdso_info[abi].vdso_pages, > + sizeof(struct page *), > + GFP_KERNEL); > + if (vdso_pagelist == NULL) > + panic("vDSO kcalloc failed!\n"); > + > + /* Grab the vDSO code pages. */ > + pfn = sym_to_pfn(vdso_info[abi].vdso_code_start); > + > + for (i = 0; i < vdso_info[abi].vdso_pages; i++) > + vdso_pagelist[i] = pfn_to_page(pfn + i); > + > + vdso_info[abi].cm->pages = vdso_pagelist; > +} > + > +#ifdef CONFIG_TIME_NS > +struct vdso_data *arch_get_vdso_data(void *vvar_page) > +{ > + return (struct vdso_data *)(vvar_page); > +} > + > +/* > + * The vvar mapping contains data for a specific time namespace, so when a task > + * changes namespace we must unmap its vvar data for the old namespace. > + * Subsequent faults will map in data for the new namespace. > + * > + * For more details see timens_setup_vdso_data(). > + */ > +int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) > +{ > + struct mm_struct *mm = task->mm; > + struct vm_area_struct *vma; > + > + 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[VDSO_ABI_RV64].dm)) > + zap_page_range(vma, vma->vm_start, size); > +#ifdef CONFIG_COMPAT > + if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_RV32].dm)) > + zap_page_range(vma, vma->vm_start, size); > +#endif > + } > + > + mmap_read_unlock(mm); > + return 0; > +} > #endif > > static int __init vdso_init(void) > { > - __vdso_init(&vdso_info); > + __vdso_init(VDSO_ABI_RV64); > #ifdef CONFIG_COMPAT > - __vdso_init(&compat_vdso_info); > + __vdso_init(VDSO_ABI_RV32); > #endif > > return 0; > @@ -240,14 +254,14 @@ arch_initcall(vdso_init); > static int __setup_additional_pages(struct mm_struct *mm, > struct linux_binprm *bprm, > int uses_interp, > - struct __vdso_info *vdso_info) > + enum vdso_abi abi) > { > 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[abi].vdso_pages << PAGE_SHIFT; > /* Be sure to map the data page */ > vdso_mapping_len = vdso_text_len + VVAR_SIZE; > > @@ -258,18 +272,17 @@ 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[abi].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[abi].cm); > > if (IS_ERR(ret)) > goto up_fail; > @@ -291,8 +304,7 @@ int compat_arch_setup_additional_pages(struct linux_binprm *bprm, > if (mmap_write_lock_killable(mm)) > return -EINTR; > > - ret = __setup_additional_pages(mm, bprm, uses_interp, > - &compat_vdso_info); > + ret = __setup_additional_pages(mm, bprm, uses_interp, VDSO_ABI_RV32); > mmap_write_unlock(mm); > > return ret; > @@ -307,7 +319,7 @@ 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, &vdso_info); > + ret = __setup_additional_pages(mm, bprm, uses_interp, VDSO_ABI_RV64); > mmap_write_unlock(mm); > > return ret; > -- > 2.34.1 >
On Thu, 08 Sep 2022 08:04:21 PDT (-0700), jszhang@kernel.org wrote: > Testing tools/testing/selftests/timens/vfork_exec.c got below > kernel log: > > [ 6.838454] Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000020 > [ 6.842255] Oops [#1] > [ 6.842871] Modules linked in: > [ 6.844249] CPU: 1 PID: 64 Comm: vfork_exec Not tainted 6.0.0-rc3-rt15+ #8 > [ 6.845861] Hardware name: riscv-virtio,qemu (DT) > [ 6.848009] epc : vdso_join_timens+0xd2/0x110 > [ 6.850097] ra : vdso_join_timens+0xd2/0x110 > [ 6.851164] epc : ffffffff8000635c ra : ffffffff8000635c sp : ff6000000181fbf0 > [ 6.852562] gp : ffffffff80cff648 tp : ff60000000fdb700 t0 : 3030303030303030 > [ 6.853852] t1 : 0000000000000030 t2 : 3030303030303030 s0 : ff6000000181fc40 > [ 6.854984] s1 : ff60000001e6c000 a0 : 0000000000000010 a1 : ffffffff8005654c > [ 6.856221] a2 : 00000000ffffefff a3 : 0000000000000000 a4 : 0000000000000000 > [ 6.858114] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 > [ 6.859484] s2 : ff60000001e6c068 s3 : ff6000000108abb0 s4 : 0000000000000000 > [ 6.860751] s5 : 0000000000001000 s6 : ffffffff8089dc40 s7 : ffffffff8089dc38 > [ 6.862029] s8 : ffffffff8089dc30 s9 : ff60000000fdbe38 s10: 000000000000005e > [ 6.863304] s11: ffffffff80cc3510 t3 : ffffffff80d1112f t4 : ffffffff80d1112f > [ 6.864565] t5 : ffffffff80d11130 t6 : ff6000000181fa00 > [ 6.865561] status: 0000000000000120 badaddr: 0000000000000020 cause: 000000000000000d > [ 6.868046] [<ffffffff8008dc94>] timens_commit+0x38/0x11a > [ 6.869089] [<ffffffff8008dde8>] timens_on_fork+0x72/0xb4 > [ 6.870055] [<ffffffff80190096>] begin_new_exec+0x3c6/0x9f0 > [ 6.871231] [<ffffffff801d826c>] load_elf_binary+0x628/0x1214 > [ 6.872304] [<ffffffff8018ee7a>] bprm_execve+0x1f2/0x4e4 > [ 6.873243] [<ffffffff8018f90c>] do_execveat_common+0x16e/0x1ee > [ 6.874258] [<ffffffff8018f9c8>] sys_execve+0x3c/0x48 > [ 6.875162] [<ffffffff80003556>] ret_from_syscall+0x0/0x2 > [ 6.877484] ---[ end trace 0000000000000000 ]--- > > This is because the mm->context.vdso_info is NULL in vfork case. From > another side, mm->context.vdso_info either points to vdso info > for RV64 or vdso info for compat, there's no need to bloat riscv's > mm_context_t, we can handle the difference when setup the additional > page for vdso. Makes sense, but I think there's a lot more diff here than we need in order to just fix the bug. Does something like the following still fix it? Also at kernel.org/palmer/vdso-fix-v3 . Maybe it's a bit pedantic , but this late in the cycle with everyone traveling I'd prefer to keep the fixes smaller when possible. diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h index cedcf8ea3c76..0099dc116168 100644 --- a/arch/riscv/include/asm/mmu.h +++ b/arch/riscv/include/asm/mmu.h @@ -16,7 +16,6 @@ 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 69b05b6c181b..58b8d73a4b1f 100644 --- a/arch/riscv/kernel/vdso.c +++ b/arch/riscv/kernel/vdso.c @@ -23,8 +23,10 @@ struct vdso_data { #endif extern char vdso_start[], vdso_end[]; +static struct __vdso_info vdso_info; #ifdef CONFIG_COMPAT extern char compat_vdso_start[], compat_vdso_end[]; +static struct __vdso_info compat_vdso_info; #endif enum vvar_pages { @@ -114,15 +116,18 @@ 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); +#ifdef CONFIG_COMPAT + if (vma_is_special_mapping(vma, compat_vdso_info.dm)) + zap_page_range(vma, vma->vm_start, size); +#endif } mmap_read_unlock(mm); @@ -264,7 +269,6 @@ static int __setup_additional_pages(struct mm_struct *mm, 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, > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > Fixes: 3092eb456375 ("riscv: compat: vdso: Add setup additional pages implementation") > --- > > since v1: > - add "Fixes" tag > - fix build error when CONFIG_COMPAT is enabled. > > arch/riscv/include/asm/mmu.h | 1 - > arch/riscv/kernel/vdso.c | 178 +++++++++++++++++++---------------- > 2 files changed, 95 insertions(+), 84 deletions(-) > > diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h > index cedcf8ea3c76..0099dc116168 100644 > --- a/arch/riscv/include/asm/mmu.h > +++ b/arch/riscv/include/asm/mmu.h > @@ -16,7 +16,6 @@ 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 69b05b6c181b..8ca3b821e1b5 100644 > --- a/arch/riscv/kernel/vdso.c > +++ b/arch/riscv/kernel/vdso.c > @@ -27,6 +27,11 @@ extern char vdso_start[], vdso_end[]; > extern char compat_vdso_start[], compat_vdso_end[]; > #endif > > +enum vdso_abi { > + VDSO_ABI_RV64, > + VDSO_ABI_RV32, > +}; > + > enum vvar_pages { > VVAR_DATA_PAGE_OFFSET, > VVAR_TIMENS_PAGE_OFFSET, > @@ -68,67 +73,7 @@ static int vdso_mremap(const struct vm_special_mapping *sm, > return 0; > } > > -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)) > - panic("vDSO is not a valid ELF object!\n"); > - > - vdso_info->vdso_pages = ( > - vdso_info->vdso_code_end - > - vdso_info->vdso_code_start) >> > - PAGE_SHIFT; > - > - vdso_pagelist = kcalloc(vdso_info->vdso_pages, > - sizeof(struct page *), > - GFP_KERNEL); > - if (vdso_pagelist == NULL) > - panic("vDSO kcalloc failed!\n"); > - > - /* Grab the vDSO code pages. */ > - pfn = sym_to_pfn(vdso_info->vdso_code_start); > - > - for (i = 0; i < vdso_info->vdso_pages; i++) > - vdso_pagelist[i] = pfn_to_page(pfn + i); > - > - vdso_info->cm->pages = vdso_pagelist; > -} > - > #ifdef CONFIG_TIME_NS > -struct vdso_data *arch_get_vdso_data(void *vvar_page) > -{ > - return (struct vdso_data *)(vvar_page); > -} > - > -/* > - * The vvar mapping contains data for a specific time namespace, so when a task > - * changes namespace we must unmap its vvar data for the old namespace. > - * Subsequent faults will map in data for the new namespace. > - * > - * For more details see timens_setup_vdso_data(). > - */ > -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)) > - zap_page_range(vma, vma->vm_start, size); > - } > - > - mmap_read_unlock(mm); > - return 0; > -} > - > static struct page *find_timens_vvar_page(struct vm_area_struct *vma) > { > if (likely(vma->vm_mm == current->mm)) > @@ -197,13 +142,6 @@ 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 vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = { > @@ -216,21 +154,97 @@ static struct vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = { > .mremap = vdso_mremap, > }, > }; > +#endif > > -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_compat_vdso_maps[RV_VDSO_MAP_VVAR], > - .cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO], > +static struct __vdso_info vdso_info[] __ro_after_init = { > + [VDSO_ABI_RV64] = { > + .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 > + [VDSO_ABI_RV32] = { > + .name = "compat_vdso", > + .vdso_code_start = compat_vdso_start, > + .vdso_code_end = compat_vdso_end, > + .dm = &rv_compat_vdso_maps[RV_VDSO_MAP_VVAR], > + .cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO], > + }, > +#endif > }; > + > +static void __init __vdso_init(enum vdso_abi abi) > +{ > + unsigned int i; > + struct page **vdso_pagelist; > + unsigned long pfn; > + > + if (memcmp(vdso_info[abi].vdso_code_start, "\177ELF", 4)) > + panic("vDSO is not a valid ELF object!\n"); > + > + vdso_info[abi].vdso_pages = ( > + vdso_info[abi].vdso_code_end - > + vdso_info[abi].vdso_code_start) >> > + PAGE_SHIFT; > + > + vdso_pagelist = kcalloc(vdso_info[abi].vdso_pages, > + sizeof(struct page *), > + GFP_KERNEL); > + if (vdso_pagelist == NULL) > + panic("vDSO kcalloc failed!\n"); > + > + /* Grab the vDSO code pages. */ > + pfn = sym_to_pfn(vdso_info[abi].vdso_code_start); > + > + for (i = 0; i < vdso_info[abi].vdso_pages; i++) > + vdso_pagelist[i] = pfn_to_page(pfn + i); > + > + vdso_info[abi].cm->pages = vdso_pagelist; > +} > + > +#ifdef CONFIG_TIME_NS > +struct vdso_data *arch_get_vdso_data(void *vvar_page) > +{ > + return (struct vdso_data *)(vvar_page); > +} > + > +/* > + * The vvar mapping contains data for a specific time namespace, so when a task > + * changes namespace we must unmap its vvar data for the old namespace. > + * Subsequent faults will map in data for the new namespace. > + * > + * For more details see timens_setup_vdso_data(). > + */ > +int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) > +{ > + struct mm_struct *mm = task->mm; > + struct vm_area_struct *vma; > + > + 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[VDSO_ABI_RV64].dm)) > + zap_page_range(vma, vma->vm_start, size); > +#ifdef CONFIG_COMPAT > + if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_RV32].dm)) > + zap_page_range(vma, vma->vm_start, size); > +#endif > + } > + > + mmap_read_unlock(mm); > + return 0; > +} > #endif > > static int __init vdso_init(void) > { > - __vdso_init(&vdso_info); > + __vdso_init(VDSO_ABI_RV64); > #ifdef CONFIG_COMPAT > - __vdso_init(&compat_vdso_info); > + __vdso_init(VDSO_ABI_RV32); > #endif > > return 0; > @@ -240,14 +254,14 @@ arch_initcall(vdso_init); > static int __setup_additional_pages(struct mm_struct *mm, > struct linux_binprm *bprm, > int uses_interp, > - struct __vdso_info *vdso_info) > + enum vdso_abi abi) > { > 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[abi].vdso_pages << PAGE_SHIFT; > /* Be sure to map the data page */ > vdso_mapping_len = vdso_text_len + VVAR_SIZE; > > @@ -258,18 +272,17 @@ 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[abi].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[abi].cm); > > if (IS_ERR(ret)) > goto up_fail; > @@ -291,8 +304,7 @@ int compat_arch_setup_additional_pages(struct linux_binprm *bprm, > if (mmap_write_lock_killable(mm)) > return -EINTR; > > - ret = __setup_additional_pages(mm, bprm, uses_interp, > - &compat_vdso_info); > + ret = __setup_additional_pages(mm, bprm, uses_interp, VDSO_ABI_RV32); > mmap_write_unlock(mm); > > return ret; > @@ -307,7 +319,7 @@ 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, &vdso_info); > + ret = __setup_additional_pages(mm, bprm, uses_interp, VDSO_ABI_RV64); > mmap_write_unlock(mm); > > return ret;
On Thu, Sep 15, 2022 at 11:02:19AM -0700, Palmer Dabbelt wrote: > On Thu, 08 Sep 2022 08:04:21 PDT (-0700), jszhang@kernel.org wrote: > > Testing tools/testing/selftests/timens/vfork_exec.c got below > > kernel log: > > > > [ 6.838454] Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000020 > > [ 6.842255] Oops [#1] > > [ 6.842871] Modules linked in: > > [ 6.844249] CPU: 1 PID: 64 Comm: vfork_exec Not tainted 6.0.0-rc3-rt15+ #8 > > [ 6.845861] Hardware name: riscv-virtio,qemu (DT) > > [ 6.848009] epc : vdso_join_timens+0xd2/0x110 > > [ 6.850097] ra : vdso_join_timens+0xd2/0x110 > > [ 6.851164] epc : ffffffff8000635c ra : ffffffff8000635c sp : ff6000000181fbf0 > > [ 6.852562] gp : ffffffff80cff648 tp : ff60000000fdb700 t0 : 3030303030303030 > > [ 6.853852] t1 : 0000000000000030 t2 : 3030303030303030 s0 : ff6000000181fc40 > > [ 6.854984] s1 : ff60000001e6c000 a0 : 0000000000000010 a1 : ffffffff8005654c > > [ 6.856221] a2 : 00000000ffffefff a3 : 0000000000000000 a4 : 0000000000000000 > > [ 6.858114] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 > > [ 6.859484] s2 : ff60000001e6c068 s3 : ff6000000108abb0 s4 : 0000000000000000 > > [ 6.860751] s5 : 0000000000001000 s6 : ffffffff8089dc40 s7 : ffffffff8089dc38 > > [ 6.862029] s8 : ffffffff8089dc30 s9 : ff60000000fdbe38 s10: 000000000000005e > > [ 6.863304] s11: ffffffff80cc3510 t3 : ffffffff80d1112f t4 : ffffffff80d1112f > > [ 6.864565] t5 : ffffffff80d11130 t6 : ff6000000181fa00 > > [ 6.865561] status: 0000000000000120 badaddr: 0000000000000020 cause: 000000000000000d > > [ 6.868046] [<ffffffff8008dc94>] timens_commit+0x38/0x11a > > [ 6.869089] [<ffffffff8008dde8>] timens_on_fork+0x72/0xb4 > > [ 6.870055] [<ffffffff80190096>] begin_new_exec+0x3c6/0x9f0 > > [ 6.871231] [<ffffffff801d826c>] load_elf_binary+0x628/0x1214 > > [ 6.872304] [<ffffffff8018ee7a>] bprm_execve+0x1f2/0x4e4 > > [ 6.873243] [<ffffffff8018f90c>] do_execveat_common+0x16e/0x1ee > > [ 6.874258] [<ffffffff8018f9c8>] sys_execve+0x3c/0x48 > > [ 6.875162] [<ffffffff80003556>] ret_from_syscall+0x0/0x2 > > [ 6.877484] ---[ end trace 0000000000000000 ]--- > > > > This is because the mm->context.vdso_info is NULL in vfork case. From > > another side, mm->context.vdso_info either points to vdso info > > for RV64 or vdso info for compat, there's no need to bloat riscv's > > mm_context_t, we can handle the difference when setup the additional > > page for vdso. > > Makes sense, but I think there's a lot more diff here than we need in order The reason of "a lot more diff" is moving the code to avoid forward declaration. If you prefer smaller fix, I can provide a simpler one w/ forware declaration. And provide a new clean up patch for next window, what do you think? Thanks > to just fix the bug. Does something like the following still fix it? Also > at kernel.org/palmer/vdso-fix-v3 . Maybe it's a bit pedantic , but this > late in the cycle with everyone traveling I'd prefer to keep the fixes > smaller when possible. > > diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h > index cedcf8ea3c76..0099dc116168 100644 > --- a/arch/riscv/include/asm/mmu.h > +++ b/arch/riscv/include/asm/mmu.h > @@ -16,7 +16,6 @@ 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 69b05b6c181b..58b8d73a4b1f 100644 > --- a/arch/riscv/kernel/vdso.c > +++ b/arch/riscv/kernel/vdso.c > @@ -23,8 +23,10 @@ struct vdso_data { > #endif > > extern char vdso_start[], vdso_end[]; > +static struct __vdso_info vdso_info; > #ifdef CONFIG_COMPAT > extern char compat_vdso_start[], compat_vdso_end[]; > +static struct __vdso_info compat_vdso_info; > #endif > > enum vvar_pages { > @@ -114,15 +116,18 @@ 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); > +#ifdef CONFIG_COMPAT > + if (vma_is_special_mapping(vma, compat_vdso_info.dm)) > + zap_page_range(vma, vma->vm_start, size); > +#endif > } > > mmap_read_unlock(mm); > @@ -264,7 +269,6 @@ static int __setup_additional_pages(struct mm_struct *mm, > > 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, > > > > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > > Fixes: 3092eb456375 ("riscv: compat: vdso: Add setup additional pages implementation") > > --- > > > > since v1: > > - add "Fixes" tag > > - fix build error when CONFIG_COMPAT is enabled. > > > > arch/riscv/include/asm/mmu.h | 1 - > > arch/riscv/kernel/vdso.c | 178 +++++++++++++++++++---------------- > > 2 files changed, 95 insertions(+), 84 deletions(-) > > > > diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h > > index cedcf8ea3c76..0099dc116168 100644 > > --- a/arch/riscv/include/asm/mmu.h > > +++ b/arch/riscv/include/asm/mmu.h > > @@ -16,7 +16,6 @@ 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 69b05b6c181b..8ca3b821e1b5 100644 > > --- a/arch/riscv/kernel/vdso.c > > +++ b/arch/riscv/kernel/vdso.c > > @@ -27,6 +27,11 @@ extern char vdso_start[], vdso_end[]; > > extern char compat_vdso_start[], compat_vdso_end[]; > > #endif > > > > +enum vdso_abi { > > + VDSO_ABI_RV64, > > + VDSO_ABI_RV32, > > +}; > > + > > enum vvar_pages { > > VVAR_DATA_PAGE_OFFSET, > > VVAR_TIMENS_PAGE_OFFSET, > > @@ -68,67 +73,7 @@ static int vdso_mremap(const struct vm_special_mapping *sm, > > return 0; > > } > > > > -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)) > > - panic("vDSO is not a valid ELF object!\n"); > > - > > - vdso_info->vdso_pages = ( > > - vdso_info->vdso_code_end - > > - vdso_info->vdso_code_start) >> > > - PAGE_SHIFT; > > - > > - vdso_pagelist = kcalloc(vdso_info->vdso_pages, > > - sizeof(struct page *), > > - GFP_KERNEL); > > - if (vdso_pagelist == NULL) > > - panic("vDSO kcalloc failed!\n"); > > - > > - /* Grab the vDSO code pages. */ > > - pfn = sym_to_pfn(vdso_info->vdso_code_start); > > - > > - for (i = 0; i < vdso_info->vdso_pages; i++) > > - vdso_pagelist[i] = pfn_to_page(pfn + i); > > - > > - vdso_info->cm->pages = vdso_pagelist; > > -} > > - > > #ifdef CONFIG_TIME_NS > > -struct vdso_data *arch_get_vdso_data(void *vvar_page) > > -{ > > - return (struct vdso_data *)(vvar_page); > > -} > > - > > -/* > > - * The vvar mapping contains data for a specific time namespace, so when a task > > - * changes namespace we must unmap its vvar data for the old namespace. > > - * Subsequent faults will map in data for the new namespace. > > - * > > - * For more details see timens_setup_vdso_data(). > > - */ > > -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)) > > - zap_page_range(vma, vma->vm_start, size); > > - } > > - > > - mmap_read_unlock(mm); > > - return 0; > > -} > > - > > static struct page *find_timens_vvar_page(struct vm_area_struct *vma) > > { > > if (likely(vma->vm_mm == current->mm)) > > @@ -197,13 +142,6 @@ 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 vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = { > > @@ -216,21 +154,97 @@ static struct vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = { > > .mremap = vdso_mremap, > > }, > > }; > > +#endif > > > > -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_compat_vdso_maps[RV_VDSO_MAP_VVAR], > > - .cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO], > > +static struct __vdso_info vdso_info[] __ro_after_init = { > > + [VDSO_ABI_RV64] = { > > + .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 > > + [VDSO_ABI_RV32] = { > > + .name = "compat_vdso", > > + .vdso_code_start = compat_vdso_start, > > + .vdso_code_end = compat_vdso_end, > > + .dm = &rv_compat_vdso_maps[RV_VDSO_MAP_VVAR], > > + .cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO], > > + }, > > +#endif > > }; > > + > > +static void __init __vdso_init(enum vdso_abi abi) > > +{ > > + unsigned int i; > > + struct page **vdso_pagelist; > > + unsigned long pfn; > > + > > + if (memcmp(vdso_info[abi].vdso_code_start, "\177ELF", 4)) > > + panic("vDSO is not a valid ELF object!\n"); > > + > > + vdso_info[abi].vdso_pages = ( > > + vdso_info[abi].vdso_code_end - > > + vdso_info[abi].vdso_code_start) >> > > + PAGE_SHIFT; > > + > > + vdso_pagelist = kcalloc(vdso_info[abi].vdso_pages, > > + sizeof(struct page *), > > + GFP_KERNEL); > > + if (vdso_pagelist == NULL) > > + panic("vDSO kcalloc failed!\n"); > > + > > + /* Grab the vDSO code pages. */ > > + pfn = sym_to_pfn(vdso_info[abi].vdso_code_start); > > + > > + for (i = 0; i < vdso_info[abi].vdso_pages; i++) > > + vdso_pagelist[i] = pfn_to_page(pfn + i); > > + > > + vdso_info[abi].cm->pages = vdso_pagelist; > > +} > > + > > +#ifdef CONFIG_TIME_NS > > +struct vdso_data *arch_get_vdso_data(void *vvar_page) > > +{ > > + return (struct vdso_data *)(vvar_page); > > +} > > + > > +/* > > + * The vvar mapping contains data for a specific time namespace, so when a task > > + * changes namespace we must unmap its vvar data for the old namespace. > > + * Subsequent faults will map in data for the new namespace. > > + * > > + * For more details see timens_setup_vdso_data(). > > + */ > > +int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) > > +{ > > + struct mm_struct *mm = task->mm; > > + struct vm_area_struct *vma; > > + > > + 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[VDSO_ABI_RV64].dm)) > > + zap_page_range(vma, vma->vm_start, size); > > +#ifdef CONFIG_COMPAT > > + if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_RV32].dm)) > > + zap_page_range(vma, vma->vm_start, size); > > +#endif > > + } > > + > > + mmap_read_unlock(mm); > > + return 0; > > +} > > #endif > > > > static int __init vdso_init(void) > > { > > - __vdso_init(&vdso_info); > > + __vdso_init(VDSO_ABI_RV64); > > #ifdef CONFIG_COMPAT > > - __vdso_init(&compat_vdso_info); > > + __vdso_init(VDSO_ABI_RV32); > > #endif > > > > return 0; > > @@ -240,14 +254,14 @@ arch_initcall(vdso_init); > > static int __setup_additional_pages(struct mm_struct *mm, > > struct linux_binprm *bprm, > > int uses_interp, > > - struct __vdso_info *vdso_info) > > + enum vdso_abi abi) > > { > > 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[abi].vdso_pages << PAGE_SHIFT; > > /* Be sure to map the data page */ > > vdso_mapping_len = vdso_text_len + VVAR_SIZE; > > > > @@ -258,18 +272,17 @@ 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[abi].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[abi].cm); > > > > if (IS_ERR(ret)) > > goto up_fail; > > @@ -291,8 +304,7 @@ int compat_arch_setup_additional_pages(struct linux_binprm *bprm, > > if (mmap_write_lock_killable(mm)) > > return -EINTR; > > > > - ret = __setup_additional_pages(mm, bprm, uses_interp, > > - &compat_vdso_info); > > + ret = __setup_additional_pages(mm, bprm, uses_interp, VDSO_ABI_RV32); > > mmap_write_unlock(mm); > > > > return ret; > > @@ -307,7 +319,7 @@ 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, &vdso_info); > > + ret = __setup_additional_pages(mm, bprm, uses_interp, VDSO_ABI_RV64); > > mmap_write_unlock(mm); > > > > return ret;
On Thu, 22 Sep 2022 05:07:44 PDT (-0700), jszhang@kernel.org wrote: > On Thu, Sep 15, 2022 at 11:02:19AM -0700, Palmer Dabbelt wrote: >> On Thu, 08 Sep 2022 08:04:21 PDT (-0700), jszhang@kernel.org wrote: >> > Testing tools/testing/selftests/timens/vfork_exec.c got below >> > kernel log: >> > >> > [ 6.838454] Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000020 >> > [ 6.842255] Oops [#1] >> > [ 6.842871] Modules linked in: >> > [ 6.844249] CPU: 1 PID: 64 Comm: vfork_exec Not tainted 6.0.0-rc3-rt15+ #8 >> > [ 6.845861] Hardware name: riscv-virtio,qemu (DT) >> > [ 6.848009] epc : vdso_join_timens+0xd2/0x110 >> > [ 6.850097] ra : vdso_join_timens+0xd2/0x110 >> > [ 6.851164] epc : ffffffff8000635c ra : ffffffff8000635c sp : ff6000000181fbf0 >> > [ 6.852562] gp : ffffffff80cff648 tp : ff60000000fdb700 t0 : 3030303030303030 >> > [ 6.853852] t1 : 0000000000000030 t2 : 3030303030303030 s0 : ff6000000181fc40 >> > [ 6.854984] s1 : ff60000001e6c000 a0 : 0000000000000010 a1 : ffffffff8005654c >> > [ 6.856221] a2 : 00000000ffffefff a3 : 0000000000000000 a4 : 0000000000000000 >> > [ 6.858114] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 >> > [ 6.859484] s2 : ff60000001e6c068 s3 : ff6000000108abb0 s4 : 0000000000000000 >> > [ 6.860751] s5 : 0000000000001000 s6 : ffffffff8089dc40 s7 : ffffffff8089dc38 >> > [ 6.862029] s8 : ffffffff8089dc30 s9 : ff60000000fdbe38 s10: 000000000000005e >> > [ 6.863304] s11: ffffffff80cc3510 t3 : ffffffff80d1112f t4 : ffffffff80d1112f >> > [ 6.864565] t5 : ffffffff80d11130 t6 : ff6000000181fa00 >> > [ 6.865561] status: 0000000000000120 badaddr: 0000000000000020 cause: 000000000000000d >> > [ 6.868046] [<ffffffff8008dc94>] timens_commit+0x38/0x11a >> > [ 6.869089] [<ffffffff8008dde8>] timens_on_fork+0x72/0xb4 >> > [ 6.870055] [<ffffffff80190096>] begin_new_exec+0x3c6/0x9f0 >> > [ 6.871231] [<ffffffff801d826c>] load_elf_binary+0x628/0x1214 >> > [ 6.872304] [<ffffffff8018ee7a>] bprm_execve+0x1f2/0x4e4 >> > [ 6.873243] [<ffffffff8018f90c>] do_execveat_common+0x16e/0x1ee >> > [ 6.874258] [<ffffffff8018f9c8>] sys_execve+0x3c/0x48 >> > [ 6.875162] [<ffffffff80003556>] ret_from_syscall+0x0/0x2 >> > [ 6.877484] ---[ end trace 0000000000000000 ]--- >> > >> > This is because the mm->context.vdso_info is NULL in vfork case. From >> > another side, mm->context.vdso_info either points to vdso info >> > for RV64 or vdso info for compat, there's no need to bloat riscv's >> > mm_context_t, we can handle the difference when setup the additional >> > page for vdso. >> >> Makes sense, but I think there's a lot more diff here than we need in order > > The reason of "a lot more diff" is moving the code to avoid forward declaration. > If you prefer smaller fix, I can provide a simpler one w/ forware > declaration. And provide a new clean up patch for next window, what do you > think? Works for me. If you put the two back-to-back on 6.0-rc1 then I can avoid the merge conflict. Thanks! > > Thanks >> to just fix the bug. Does something like the following still fix it? Also >> at kernel.org/palmer/vdso-fix-v3 . Maybe it's a bit pedantic , but this >> late in the cycle with everyone traveling I'd prefer to keep the fixes >> smaller when possible. >> >> diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h >> index cedcf8ea3c76..0099dc116168 100644 >> --- a/arch/riscv/include/asm/mmu.h >> +++ b/arch/riscv/include/asm/mmu.h >> @@ -16,7 +16,6 @@ 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 69b05b6c181b..58b8d73a4b1f 100644 >> --- a/arch/riscv/kernel/vdso.c >> +++ b/arch/riscv/kernel/vdso.c >> @@ -23,8 +23,10 @@ struct vdso_data { >> #endif >> >> extern char vdso_start[], vdso_end[]; >> +static struct __vdso_info vdso_info; >> #ifdef CONFIG_COMPAT >> extern char compat_vdso_start[], compat_vdso_end[]; >> +static struct __vdso_info compat_vdso_info; >> #endif >> >> enum vvar_pages { >> @@ -114,15 +116,18 @@ 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); >> +#ifdef CONFIG_COMPAT >> + if (vma_is_special_mapping(vma, compat_vdso_info.dm)) >> + zap_page_range(vma, vma->vm_start, size); >> +#endif >> } >> >> mmap_read_unlock(mm); >> @@ -264,7 +269,6 @@ static int __setup_additional_pages(struct mm_struct *mm, >> >> 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, >> >> > >> > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> >> > Fixes: 3092eb456375 ("riscv: compat: vdso: Add setup additional pages implementation") >> > --- >> > >> > since v1: >> > - add "Fixes" tag >> > - fix build error when CONFIG_COMPAT is enabled. >> > >> > arch/riscv/include/asm/mmu.h | 1 - >> > arch/riscv/kernel/vdso.c | 178 +++++++++++++++++++---------------- >> > 2 files changed, 95 insertions(+), 84 deletions(-) >> > >> > diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h >> > index cedcf8ea3c76..0099dc116168 100644 >> > --- a/arch/riscv/include/asm/mmu.h >> > +++ b/arch/riscv/include/asm/mmu.h >> > @@ -16,7 +16,6 @@ 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 69b05b6c181b..8ca3b821e1b5 100644 >> > --- a/arch/riscv/kernel/vdso.c >> > +++ b/arch/riscv/kernel/vdso.c >> > @@ -27,6 +27,11 @@ extern char vdso_start[], vdso_end[]; >> > extern char compat_vdso_start[], compat_vdso_end[]; >> > #endif >> > >> > +enum vdso_abi { >> > + VDSO_ABI_RV64, >> > + VDSO_ABI_RV32, >> > +}; >> > + >> > enum vvar_pages { >> > VVAR_DATA_PAGE_OFFSET, >> > VVAR_TIMENS_PAGE_OFFSET, >> > @@ -68,67 +73,7 @@ static int vdso_mremap(const struct vm_special_mapping *sm, >> > return 0; >> > } >> > >> > -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)) >> > - panic("vDSO is not a valid ELF object!\n"); >> > - >> > - vdso_info->vdso_pages = ( >> > - vdso_info->vdso_code_end - >> > - vdso_info->vdso_code_start) >> >> > - PAGE_SHIFT; >> > - >> > - vdso_pagelist = kcalloc(vdso_info->vdso_pages, >> > - sizeof(struct page *), >> > - GFP_KERNEL); >> > - if (vdso_pagelist == NULL) >> > - panic("vDSO kcalloc failed!\n"); >> > - >> > - /* Grab the vDSO code pages. */ >> > - pfn = sym_to_pfn(vdso_info->vdso_code_start); >> > - >> > - for (i = 0; i < vdso_info->vdso_pages; i++) >> > - vdso_pagelist[i] = pfn_to_page(pfn + i); >> > - >> > - vdso_info->cm->pages = vdso_pagelist; >> > -} >> > - >> > #ifdef CONFIG_TIME_NS >> > -struct vdso_data *arch_get_vdso_data(void *vvar_page) >> > -{ >> > - return (struct vdso_data *)(vvar_page); >> > -} >> > - >> > -/* >> > - * The vvar mapping contains data for a specific time namespace, so when a task >> > - * changes namespace we must unmap its vvar data for the old namespace. >> > - * Subsequent faults will map in data for the new namespace. >> > - * >> > - * For more details see timens_setup_vdso_data(). >> > - */ >> > -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)) >> > - zap_page_range(vma, vma->vm_start, size); >> > - } >> > - >> > - mmap_read_unlock(mm); >> > - return 0; >> > -} >> > - >> > static struct page *find_timens_vvar_page(struct vm_area_struct *vma) >> > { >> > if (likely(vma->vm_mm == current->mm)) >> > @@ -197,13 +142,6 @@ 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 vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = { >> > @@ -216,21 +154,97 @@ static struct vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = { >> > .mremap = vdso_mremap, >> > }, >> > }; >> > +#endif >> > >> > -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_compat_vdso_maps[RV_VDSO_MAP_VVAR], >> > - .cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO], >> > +static struct __vdso_info vdso_info[] __ro_after_init = { >> > + [VDSO_ABI_RV64] = { >> > + .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 >> > + [VDSO_ABI_RV32] = { >> > + .name = "compat_vdso", >> > + .vdso_code_start = compat_vdso_start, >> > + .vdso_code_end = compat_vdso_end, >> > + .dm = &rv_compat_vdso_maps[RV_VDSO_MAP_VVAR], >> > + .cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO], >> > + }, >> > +#endif >> > }; >> > + >> > +static void __init __vdso_init(enum vdso_abi abi) >> > +{ >> > + unsigned int i; >> > + struct page **vdso_pagelist; >> > + unsigned long pfn; >> > + >> > + if (memcmp(vdso_info[abi].vdso_code_start, "\177ELF", 4)) >> > + panic("vDSO is not a valid ELF object!\n"); >> > + >> > + vdso_info[abi].vdso_pages = ( >> > + vdso_info[abi].vdso_code_end - >> > + vdso_info[abi].vdso_code_start) >> >> > + PAGE_SHIFT; >> > + >> > + vdso_pagelist = kcalloc(vdso_info[abi].vdso_pages, >> > + sizeof(struct page *), >> > + GFP_KERNEL); >> > + if (vdso_pagelist == NULL) >> > + panic("vDSO kcalloc failed!\n"); >> > + >> > + /* Grab the vDSO code pages. */ >> > + pfn = sym_to_pfn(vdso_info[abi].vdso_code_start); >> > + >> > + for (i = 0; i < vdso_info[abi].vdso_pages; i++) >> > + vdso_pagelist[i] = pfn_to_page(pfn + i); >> > + >> > + vdso_info[abi].cm->pages = vdso_pagelist; >> > +} >> > + >> > +#ifdef CONFIG_TIME_NS >> > +struct vdso_data *arch_get_vdso_data(void *vvar_page) >> > +{ >> > + return (struct vdso_data *)(vvar_page); >> > +} >> > + >> > +/* >> > + * The vvar mapping contains data for a specific time namespace, so when a task >> > + * changes namespace we must unmap its vvar data for the old namespace. >> > + * Subsequent faults will map in data for the new namespace. >> > + * >> > + * For more details see timens_setup_vdso_data(). >> > + */ >> > +int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) >> > +{ >> > + struct mm_struct *mm = task->mm; >> > + struct vm_area_struct *vma; >> > + >> > + 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[VDSO_ABI_RV64].dm)) >> > + zap_page_range(vma, vma->vm_start, size); >> > +#ifdef CONFIG_COMPAT >> > + if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_RV32].dm)) >> > + zap_page_range(vma, vma->vm_start, size); >> > +#endif >> > + } >> > + >> > + mmap_read_unlock(mm); >> > + return 0; >> > +} >> > #endif >> > >> > static int __init vdso_init(void) >> > { >> > - __vdso_init(&vdso_info); >> > + __vdso_init(VDSO_ABI_RV64); >> > #ifdef CONFIG_COMPAT >> > - __vdso_init(&compat_vdso_info); >> > + __vdso_init(VDSO_ABI_RV32); >> > #endif >> > >> > return 0; >> > @@ -240,14 +254,14 @@ arch_initcall(vdso_init); >> > static int __setup_additional_pages(struct mm_struct *mm, >> > struct linux_binprm *bprm, >> > int uses_interp, >> > - struct __vdso_info *vdso_info) >> > + enum vdso_abi abi) >> > { >> > 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[abi].vdso_pages << PAGE_SHIFT; >> > /* Be sure to map the data page */ >> > vdso_mapping_len = vdso_text_len + VVAR_SIZE; >> > >> > @@ -258,18 +272,17 @@ 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[abi].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[abi].cm); >> > >> > if (IS_ERR(ret)) >> > goto up_fail; >> > @@ -291,8 +304,7 @@ int compat_arch_setup_additional_pages(struct linux_binprm *bprm, >> > if (mmap_write_lock_killable(mm)) >> > return -EINTR; >> > >> > - ret = __setup_additional_pages(mm, bprm, uses_interp, >> > - &compat_vdso_info); >> > + ret = __setup_additional_pages(mm, bprm, uses_interp, VDSO_ABI_RV32); >> > mmap_write_unlock(mm); >> > >> > return ret; >> > @@ -307,7 +319,7 @@ 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, &vdso_info); >> > + ret = __setup_additional_pages(mm, bprm, uses_interp, VDSO_ABI_RV64); >> > mmap_write_unlock(mm); >> > >> > return ret;
diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h index cedcf8ea3c76..0099dc116168 100644 --- a/arch/riscv/include/asm/mmu.h +++ b/arch/riscv/include/asm/mmu.h @@ -16,7 +16,6 @@ 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 69b05b6c181b..8ca3b821e1b5 100644 --- a/arch/riscv/kernel/vdso.c +++ b/arch/riscv/kernel/vdso.c @@ -27,6 +27,11 @@ extern char vdso_start[], vdso_end[]; extern char compat_vdso_start[], compat_vdso_end[]; #endif +enum vdso_abi { + VDSO_ABI_RV64, + VDSO_ABI_RV32, +}; + enum vvar_pages { VVAR_DATA_PAGE_OFFSET, VVAR_TIMENS_PAGE_OFFSET, @@ -68,67 +73,7 @@ static int vdso_mremap(const struct vm_special_mapping *sm, return 0; } -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)) - panic("vDSO is not a valid ELF object!\n"); - - vdso_info->vdso_pages = ( - vdso_info->vdso_code_end - - vdso_info->vdso_code_start) >> - PAGE_SHIFT; - - vdso_pagelist = kcalloc(vdso_info->vdso_pages, - sizeof(struct page *), - GFP_KERNEL); - if (vdso_pagelist == NULL) - panic("vDSO kcalloc failed!\n"); - - /* Grab the vDSO code pages. */ - pfn = sym_to_pfn(vdso_info->vdso_code_start); - - for (i = 0; i < vdso_info->vdso_pages; i++) - vdso_pagelist[i] = pfn_to_page(pfn + i); - - vdso_info->cm->pages = vdso_pagelist; -} - #ifdef CONFIG_TIME_NS -struct vdso_data *arch_get_vdso_data(void *vvar_page) -{ - return (struct vdso_data *)(vvar_page); -} - -/* - * The vvar mapping contains data for a specific time namespace, so when a task - * changes namespace we must unmap its vvar data for the old namespace. - * Subsequent faults will map in data for the new namespace. - * - * For more details see timens_setup_vdso_data(). - */ -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)) - zap_page_range(vma, vma->vm_start, size); - } - - mmap_read_unlock(mm); - return 0; -} - static struct page *find_timens_vvar_page(struct vm_area_struct *vma) { if (likely(vma->vm_mm == current->mm)) @@ -197,13 +142,6 @@ 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 vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = { @@ -216,21 +154,97 @@ static struct vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = { .mremap = vdso_mremap, }, }; +#endif -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_compat_vdso_maps[RV_VDSO_MAP_VVAR], - .cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO], +static struct __vdso_info vdso_info[] __ro_after_init = { + [VDSO_ABI_RV64] = { + .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 + [VDSO_ABI_RV32] = { + .name = "compat_vdso", + .vdso_code_start = compat_vdso_start, + .vdso_code_end = compat_vdso_end, + .dm = &rv_compat_vdso_maps[RV_VDSO_MAP_VVAR], + .cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO], + }, +#endif }; + +static void __init __vdso_init(enum vdso_abi abi) +{ + unsigned int i; + struct page **vdso_pagelist; + unsigned long pfn; + + if (memcmp(vdso_info[abi].vdso_code_start, "\177ELF", 4)) + panic("vDSO is not a valid ELF object!\n"); + + vdso_info[abi].vdso_pages = ( + vdso_info[abi].vdso_code_end - + vdso_info[abi].vdso_code_start) >> + PAGE_SHIFT; + + vdso_pagelist = kcalloc(vdso_info[abi].vdso_pages, + sizeof(struct page *), + GFP_KERNEL); + if (vdso_pagelist == NULL) + panic("vDSO kcalloc failed!\n"); + + /* Grab the vDSO code pages. */ + pfn = sym_to_pfn(vdso_info[abi].vdso_code_start); + + for (i = 0; i < vdso_info[abi].vdso_pages; i++) + vdso_pagelist[i] = pfn_to_page(pfn + i); + + vdso_info[abi].cm->pages = vdso_pagelist; +} + +#ifdef CONFIG_TIME_NS +struct vdso_data *arch_get_vdso_data(void *vvar_page) +{ + return (struct vdso_data *)(vvar_page); +} + +/* + * The vvar mapping contains data for a specific time namespace, so when a task + * changes namespace we must unmap its vvar data for the old namespace. + * Subsequent faults will map in data for the new namespace. + * + * For more details see timens_setup_vdso_data(). + */ +int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) +{ + struct mm_struct *mm = task->mm; + struct vm_area_struct *vma; + + 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[VDSO_ABI_RV64].dm)) + zap_page_range(vma, vma->vm_start, size); +#ifdef CONFIG_COMPAT + if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_RV32].dm)) + zap_page_range(vma, vma->vm_start, size); +#endif + } + + mmap_read_unlock(mm); + return 0; +} #endif static int __init vdso_init(void) { - __vdso_init(&vdso_info); + __vdso_init(VDSO_ABI_RV64); #ifdef CONFIG_COMPAT - __vdso_init(&compat_vdso_info); + __vdso_init(VDSO_ABI_RV32); #endif return 0; @@ -240,14 +254,14 @@ arch_initcall(vdso_init); static int __setup_additional_pages(struct mm_struct *mm, struct linux_binprm *bprm, int uses_interp, - struct __vdso_info *vdso_info) + enum vdso_abi abi) { 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[abi].vdso_pages << PAGE_SHIFT; /* Be sure to map the data page */ vdso_mapping_len = vdso_text_len + VVAR_SIZE; @@ -258,18 +272,17 @@ 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[abi].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[abi].cm); if (IS_ERR(ret)) goto up_fail; @@ -291,8 +304,7 @@ int compat_arch_setup_additional_pages(struct linux_binprm *bprm, if (mmap_write_lock_killable(mm)) return -EINTR; - ret = __setup_additional_pages(mm, bprm, uses_interp, - &compat_vdso_info); + ret = __setup_additional_pages(mm, bprm, uses_interp, VDSO_ABI_RV32); mmap_write_unlock(mm); return ret; @@ -307,7 +319,7 @@ 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, &vdso_info); + ret = __setup_additional_pages(mm, bprm, uses_interp, VDSO_ABI_RV64); mmap_write_unlock(mm); return ret;
Testing tools/testing/selftests/timens/vfork_exec.c got below kernel log: [ 6.838454] Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000020 [ 6.842255] Oops [#1] [ 6.842871] Modules linked in: [ 6.844249] CPU: 1 PID: 64 Comm: vfork_exec Not tainted 6.0.0-rc3-rt15+ #8 [ 6.845861] Hardware name: riscv-virtio,qemu (DT) [ 6.848009] epc : vdso_join_timens+0xd2/0x110 [ 6.850097] ra : vdso_join_timens+0xd2/0x110 [ 6.851164] epc : ffffffff8000635c ra : ffffffff8000635c sp : ff6000000181fbf0 [ 6.852562] gp : ffffffff80cff648 tp : ff60000000fdb700 t0 : 3030303030303030 [ 6.853852] t1 : 0000000000000030 t2 : 3030303030303030 s0 : ff6000000181fc40 [ 6.854984] s1 : ff60000001e6c000 a0 : 0000000000000010 a1 : ffffffff8005654c [ 6.856221] a2 : 00000000ffffefff a3 : 0000000000000000 a4 : 0000000000000000 [ 6.858114] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 [ 6.859484] s2 : ff60000001e6c068 s3 : ff6000000108abb0 s4 : 0000000000000000 [ 6.860751] s5 : 0000000000001000 s6 : ffffffff8089dc40 s7 : ffffffff8089dc38 [ 6.862029] s8 : ffffffff8089dc30 s9 : ff60000000fdbe38 s10: 000000000000005e [ 6.863304] s11: ffffffff80cc3510 t3 : ffffffff80d1112f t4 : ffffffff80d1112f [ 6.864565] t5 : ffffffff80d11130 t6 : ff6000000181fa00 [ 6.865561] status: 0000000000000120 badaddr: 0000000000000020 cause: 000000000000000d [ 6.868046] [<ffffffff8008dc94>] timens_commit+0x38/0x11a [ 6.869089] [<ffffffff8008dde8>] timens_on_fork+0x72/0xb4 [ 6.870055] [<ffffffff80190096>] begin_new_exec+0x3c6/0x9f0 [ 6.871231] [<ffffffff801d826c>] load_elf_binary+0x628/0x1214 [ 6.872304] [<ffffffff8018ee7a>] bprm_execve+0x1f2/0x4e4 [ 6.873243] [<ffffffff8018f90c>] do_execveat_common+0x16e/0x1ee [ 6.874258] [<ffffffff8018f9c8>] sys_execve+0x3c/0x48 [ 6.875162] [<ffffffff80003556>] ret_from_syscall+0x0/0x2 [ 6.877484] ---[ end trace 0000000000000000 ]--- This is because the mm->context.vdso_info is NULL in vfork case. From another side, mm->context.vdso_info either points to vdso info for RV64 or vdso info for compat, there's no need to bloat riscv's mm_context_t, we can handle the difference when setup the additional page for vdso. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Fixes: 3092eb456375 ("riscv: compat: vdso: Add setup additional pages implementation") --- since v1: - add "Fixes" tag - fix build error when CONFIG_COMPAT is enabled. arch/riscv/include/asm/mmu.h | 1 - arch/riscv/kernel/vdso.c | 178 +++++++++++++++++++---------------- 2 files changed, 95 insertions(+), 84 deletions(-)