From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + binfmt_elf-remove-the-set_fskernel_ds-in-elf_core_dump.patch added to -mm tree Date: Tue, 05 May 2020 12:29:58 -0700 Message-ID: <20200505192958.70Uf6Db9U%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:41330 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726350AbgEET37 (ORCPT ); Tue, 5 May 2020 15:29:59 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: arnd@arndb.de, benh@kernel.crashing.org, ebiederm@xmission.com, hch@lst.de, jk@ozlabs.org, mm-commits@vger.kernel.org, mpe@ellerman.id.au, oleg@redhat.com, paulus@samba.org, viro@zeniv.linux.org.uk The patch titled Subject: binfmt_elf: remove the set_fs(KERNEL_DS) in elf_core_dump has been added to the -mm tree. Its filename is binfmt_elf-remove-the-set_fskernel_ds-in-elf_core_dump.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/binfmt_elf-remove-the-set_fskernel_ds-in-elf_core_dump.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/binfmt_elf-remove-the-set_fskernel_ds-in-elf_core_dump.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Christoph Hellwig Subject: binfmt_elf: remove the set_fs(KERNEL_DS) in elf_core_dump There is no logic in elf_core_dump itself or in the various arch helpers called from it which use uaccess routines on kernel pointers except for the file writes thate are nicely encapsulated by using __kernel_write in dump_emit. Link: http://lkml.kernel.org/r/20200505101256.3121270-7-hch@lst.de Signed-off-by: Christoph Hellwig Cc: Alexander Viro Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: "Eric W . Biederman" Cc: Jeremy Kerr Cc: Michael Ellerman Cc: Oleg Nesterov Cc: Paul Mackerras Signed-off-by: Andrew Morton --- fs/binfmt_elf.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) --- a/fs/binfmt_elf.c~binfmt_elf-remove-the-set_fskernel_ds-in-elf_core_dump +++ a/fs/binfmt_elf.c @@ -1351,7 +1351,6 @@ static unsigned long vma_dump_size(struc vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { u32 __user *header = (u32 __user *) vma->vm_start; u32 word; - mm_segment_t fs = get_fs(); /* * Doing it this way gets the constant folded by GCC. */ @@ -1364,14 +1363,8 @@ static unsigned long vma_dump_size(struc magic.elfmag[EI_MAG1] = ELFMAG1; magic.elfmag[EI_MAG2] = ELFMAG2; magic.elfmag[EI_MAG3] = ELFMAG3; - /* - * Switch to the user "segment" for get_user(), - * then put back what elf_core_dump() had in place. - */ - set_fs(USER_DS); if (unlikely(get_user(word, header))) word = 0; - set_fs(fs); if (word == magic.cmp) return PAGE_SIZE; } @@ -2179,7 +2172,6 @@ static void fill_extnum_info(struct elfh static int elf_core_dump(struct coredump_params *cprm) { int has_dumped = 0; - mm_segment_t fs; int segs, i; size_t vma_data_size = 0; struct vm_area_struct *vma, *gate_vma; @@ -2228,13 +2220,10 @@ static int elf_core_dump(struct coredump * notes. This also sets up the file header. */ if (!fill_note_info(&elf, e_phnum, &info, cprm->siginfo, cprm->regs)) - goto cleanup; + goto end_coredump; has_dumped = 1; - fs = get_fs(); - set_fs(KERNEL_DS); - offset += sizeof(elf); /* Elf header */ offset += segs * sizeof(struct elf_phdr); /* Program headers */ @@ -2362,9 +2351,6 @@ static int elf_core_dump(struct coredump } end_coredump: - set_fs(fs); - -cleanup: free_note_info(&info); kfree(shdr4extnum); kvfree(vma_filesz); _ Patches currently in -mm which might be from hch@lst.de are x86-hyperv-use-vmalloc_exec-for-the-hypercall-page.patch x86-fix-vmap-arguments-in-map_irq_stack.patch staging-android-ion-use-vmap-instead-of-vm_map_ram.patch staging-media-ipu3-use-vmap-instead-of-reimplementing-it.patch dma-mapping-use-vmap-insted-of-reimplementing-it.patch powerpc-add-an-ioremap_phb-helper.patch powerpc-remove-__ioremap_at-and-__iounmap_at.patch mm-remove-__get_vm_area.patch mm-unexport-unmap_kernel_range_noflush.patch mm-rename-config_pgtable_mapping-to-config_zsmalloc_pgtable_mapping.patch mm-only-allow-page-table-mappings-for-built-in-zsmalloc.patch mm-pass-addr-as-unsigned-long-to-vb_free.patch mm-remove-vmap_page_range_noflush-and-vunmap_page_range.patch mm-rename-vmap_page_range-to-map_kernel_range.patch mm-dont-return-the-number-of-pages-from-map_kernel_range_noflush.patch mm-remove-map_vm_range.patch mm-remove-unmap_vmap_area.patch mm-remove-the-prot-argument-from-vm_map_ram.patch mm-enforce-that-vmap-cant-map-pages-executable.patch gpu-drm-remove-the-powerpc-hack-in-drm_legacy_sg_alloc.patch mm-remove-the-pgprot-argument-to-__vmalloc.patch mm-remove-the-prot-argument-to-__vmalloc_node.patch mm-remove-both-instances-of-__vmalloc_node_flags.patch mm-remove-__vmalloc_node_flags_caller.patch mm-switch-the-test_vmalloc-module-to-use-__vmalloc_node.patch mm-remove-vmalloc_user_node_flags.patch arm64-use-__vmalloc_node-in-arch_alloc_vmap_stack.patch powerpc-use-__vmalloc_node-in-alloc_vm_stack.patch s390-use-__vmalloc_node-in-stack_alloc.patch powerpc-spufs-stop-using-access_ok.patch powerpc-spufs-simplify-spufs-core-dumping.patch signal-refactor-copy_siginfo_to_user32.patch binfmt_elf-remove-the-set_fskernel_ds-in-elf_core_dump.patch binfmt_elf_fdpic-remove-the-set_fskernel_ds-in-elf_fdpic_core_dump.patch exec-simplify-the-copy_strings_kernel-calling-convention.patch exec-open-code-copy_string_kernel.patch amdgpu-a-null-mm-does-not-mean-a-thread-is-a-kthread.patch kernel-move-use_mm-unuse_mm-to-kthreadc.patch kernel-move-use_mm-unuse_mm-to-kthreadc-v2.patch kernel-better-document-the-use_mm-unuse_mm-api-contract.patch kernel-better-document-the-use_mm-unuse_mm-api-contract-v2.patch kernel-set-user_ds-in-kthread_use_mm.patch