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* revert "fs/binfmt_elf: use PT_LOAD p_align values for static PIE"Andrew Morton2022-04-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Despite Mike's attempted fix (925346c129da117122), regressions reports continue: https://lore.kernel.org/lkml/cb5b81bd-9882-e5dc-cd22-54bdbaaefbbc@leemhuis.info/ https://bugzilla.kernel.org/show_bug.cgi?id=215720 https://lkml.kernel.org/r/b685f3d0-da34-531d-1aa9-479accd3e21b@leemhuis.info So revert this patch. Fixes: 9630f0d60fec ("fs/binfmt_elf: use PT_LOAD p_align values for static PIE") Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Chris Kennelly <ckennelly@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Fangrui Song <maskray@google.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Sandeep Patil <sspatil@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* revert "fs/binfmt_elf: fix PT_LOAD p_align values for loaders"Andrew Morton2022-04-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 925346c129da11 ("fs/binfmt_elf: fix PT_LOAD p_align values for loaders") was an attempt to fix regressions due to 9630f0d60fec5f ("fs/binfmt_elf: use PT_LOAD p_align values for static PIE"). But regressionss continue to be reported: https://lore.kernel.org/lkml/cb5b81bd-9882-e5dc-cd22-54bdbaaefbbc@leemhuis.info/ https://bugzilla.kernel.org/show_bug.cgi?id=215720 https://lkml.kernel.org/r/b685f3d0-da34-531d-1aa9-479accd3e21b@leemhuis.info This patch reverts the fix, so the original can also be reverted. Fixes: 925346c129da11 ("fs/binfmt_elf: fix PT_LOAD p_align values for loaders") Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Chris Kennelly <ckennelly@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Song Liu <songliubraving@fb.com> Cc: David Rientjes <rientjes@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sandeep Patil <sspatil@google.com> Cc: Fangrui Song <maskray@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: Mike Rapoport <rppt@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'execve-v5.18-rc1' of ↵Linus Torvalds2022-03-211-70/+83
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull execve updates from Kees Cook: "Execve and binfmt updates. Eric and I have stepped up to be the active maintainers of this area, so here's our first collection. The bulk of the work was in coredump handling fixes; additional details are noted below: - Handle unusual AT_PHDR offsets (Akira Kawata) - Fix initial mapping size when PT_LOADs are not ordered (Alexey Dobriyan) - Move more code under CONFIG_COREDUMP (Alexey Dobriyan) - Fix missing mmap_lock in file_files_note (Eric W. Biederman) - Remove a.out support for alpha and m68k (Eric W. Biederman) - Include first pages of non-exec ELF libraries in coredump (Jann Horn) - Don't write past end of notes for regset gap in coredump (Rick Edgecombe) - Comment clean-ups (Tom Rix) - Force single empty string when argv is empty (Kees Cook) - Add NULL argv selftest (Kees Cook) - Properly redefine PT_GNU_* in terms of PT_LOOS (Kees Cook) - MAINTAINERS: Update execve entry with tree (Kees Cook) - Introduce initial KUnit testing for binfmt_elf (Kees Cook)" * tag 'execve-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: binfmt_elf: Don't write past end of notes for regset gap a.out: Stop building a.out/osf1 support on alpha and m68k coredump: Don't compile flat_core_dump when coredumps are disabled coredump: Use the vma snapshot in fill_files_note coredump/elf: Pass coredump_params into fill_note_info coredump: Remove the WARN_ON in dump_vma_snapshot coredump: Snapshot the vmas in do_coredump coredump: Move definition of struct coredump_params into coredump.h binfmt_elf: Introduce KUnit test ELF: Properly redefine PT_GNU_* in terms of PT_LOOS MAINTAINERS: Update execve entry with more details exec: cleanup comments fs/binfmt_elf: Refactor load_elf_binary function fs/binfmt_elf: Fix AT_PHDR for unusual ELF files binfmt: move more stuff undef CONFIG_COREDUMP selftests/exec: Test for empty string on NULL argv exec: Force single empty string when argv is empty coredump: Also dump first pages of non-executable ELF libraries ELF: fix overflow in total mapping size calculation
| * binfmt_elf: Don't write past end of notes for regset gapRick Edgecombe2022-03-181-10/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In fill_thread_core_info() the ptrace accessible registers are collected to be written out as notes in a core file. The note array is allocated from a size calculated by iterating the user regset view, and counting the regsets that have a non-zero core_note_type. However, this only allows for there to be non-zero core_note_type at the end of the regset view. If there are any gaps in the middle, fill_thread_core_info() will overflow the note allocation, as it iterates over the size of the view and the allocation would be smaller than that. There doesn't appear to be any arch that has gaps such that they exceed the notes allocation, but the code is brittle and tries to support something it doesn't. It could be fixed by increasing the allocation size, but instead just have the note collecting code utilize the array better. This way the allocation can stay smaller. Even in the case of no arch's that have gaps in their regset views, this introduces a change in the resulting indicies of t->notes. It does not introduce any changes to the core file itself, because any blank notes are skipped in write_note_info(). In case, the allocation logic between fill_note_info() and fill_thread_core_info() ever diverges from the usage logic, warn and skip writing any notes that would overflow the array. This fix is derrived from an earlier one[0] by Yu-cheng Yu. [0] https://lore.kernel.org/lkml/20180717162502.32274-1-yu-cheng.yu@intel.com/ Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220317192013.13655-4-rick.p.edgecombe@intel.com
| * coredump: Use the vma snapshot in fill_files_noteEric W. Biederman2022-03-081-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Matthew Wilcox reported that there is a missing mmap_lock in file_files_note that could possibly lead to a user after free. Solve this by using the existing vma snapshot for consistency and to avoid the need to take the mmap_lock anywhere in the coredump code except for dump_vma_snapshot. Update the dump_vma_snapshot to capture vm_pgoff and vm_file that are neeeded by fill_files_note. Add free_vma_snapshot to free the captured values of vm_file. Reported-by: Matthew Wilcox <willy@infradead.org> Link: https://lkml.kernel.org/r/20220131153740.2396974-1-willy@infradead.org Cc: stable@vger.kernel.org Fixes: a07279c9a8cd ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot") Fixes: 2aa362c49c31 ("coredump: extend core dump note section to contain file names of mapped files") Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * coredump/elf: Pass coredump_params into fill_note_infoEric W. Biederman2022-03-081-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | Instead of individually passing cprm->siginfo and cprm->regs into fill_note_info pass all of struct coredump_params. This is preparation to allow fill_files_note to use the existing vma snapshot. Reviewed-by: Jann Horn <jannh@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * coredump: Snapshot the vmas in do_coredumpEric W. Biederman2022-03-081-13/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the call of dump_vma_snapshot and kvfree(vma_meta) out of the individual coredump routines into do_coredump itself. This makes the code less error prone and easier to maintain. Make the vma snapshot available to the coredump routines in struct coredump_params. This makes it easier to change and update what is captures in the vma snapshot and will be needed for fixing fill_file_notes. Reviewed-by: Jann Horn <jannh@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * binfmt_elf: Introduce KUnit testKees Cook2022-03-031-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adds simple KUnit test for some binfmt_elf internals: specifically a regression test for the problem fixed by commit 8904d9cd90ee ("ELF: fix overflow in total mapping size calculation"). $ ./tools/testing/kunit/kunit.py run --arch x86_64 \ --kconfig_add CONFIG_IA32_EMULATION=y '*binfmt_elf' ... [19:41:08] ================== binfmt_elf (1 subtest) ================== [19:41:08] [PASSED] total_mapping_size_test [19:41:08] =================== [PASSED] binfmt_elf ==================== [19:41:08] ============== compat_binfmt_elf (1 subtest) =============== [19:41:08] [PASSED] total_mapping_size_test [19:41:08] ================ [PASSED] compat_binfmt_elf ================ [19:41:08] ============================================================ [19:41:08] Testing complete. Passed: 2, Failed: 0, Crashed: 0, Skipped: 0, Errors: 0 Cc: Eric Biederman <ebiederm@xmission.com> Cc: David Gow <davidgow@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Magnus Groß" <magnus.gross@rwth-aachen.de> Cc: kunit-dev@googlegroups.com Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- v1: https://lore.kernel.org/lkml/20220224054332.1852813-1-keescook@chromium.org v2: - improve commit log - fix comment URL (Daniel) - drop redundant KUnit Kconfig help info (Daniel) - note in Kconfig help that COMPAT builds add a compat test (David)
| * fs/binfmt_elf: Refactor load_elf_binary functionAkira Kawata2022-03-011-8/+6
| | | | | | | | | | | | | | | | | | | | | | I delete load_addr because it is not used anymore. And I rename load_addr_set to first_pt_load because it is used only to capture the first iteration of the loop. Signed-off-by: Akira Kawata <akirakawata1@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220127124014.338760-3-akirakawata1@gmail.com
| * fs/binfmt_elf: Fix AT_PHDR for unusual ELF filesAkira Kawata2022-03-011-6/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=197921 As pointed out in the discussion of buglink, we cannot calculate AT_PHDR as the sum of load_addr and exec->e_phoff. : The AT_PHDR of ELF auxiliary vectors should point to the memory address : of program header. But binfmt_elf.c calculates this address as follows: : : NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff); : : which is wrong since e_phoff is the file offset of program header and : load_addr is the memory base address from PT_LOAD entry. : : The ld.so uses AT_PHDR as the memory address of program header. In normal : case, since the e_phoff is usually 64 and in the first PT_LOAD region, it : is the correct program header address. : : But if the address of program header isn't equal to the first PT_LOAD : address + e_phoff (e.g. Put the program header in other non-consecutive : PT_LOAD region), ld.so will try to read program header from wrong address : then crash or use incorrect program header. This is because exec->e_phoff is the offset of PHDRs in the file and the address of PHDRs in the memory may differ from it. This patch fixes the bug by calculating the address of program headers from PT_LOADs directly. Signed-off-by: Akira Kawata <akirakawata1@gmail.com> Reported-by: kernel test robot <lkp@intel.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220127124014.338760-2-akirakawata1@gmail.com
| * binfmt: move more stuff undef CONFIG_COREDUMPAlexey Dobriyan2022-03-011-0/+2
| | | | | | | | | | | | | | | | | | | | struct linux_binfmt::core_dump and struct min_coredump::min_coredump are used under CONFIG_COREDUMP only. Shrink those embedded configs a bit. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/YglbIFyN+OtwVyjW@localhost.localdomain
| * ELF: fix overflow in total mapping size calculationAlexey Dobriyan2022-03-011-12/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kernel assumes that ELF program headers are ordered by mapping address, but doesn't enforce it. It is possible to make mapping size extremely huge by simply shuffling first and last PT_LOAD segments. As long as PT_LOAD segments do not overlap, it is silly to require sorting by v_addr anyway because mmap() doesn't care. Don't assume PT_LOAD segments are sorted and calculate min and max addresses correctly. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Tested-by: "Magnus Groß" <magnus.gross@rwth-aachen.de> Link: https://lore.kernel.org/all/Yfqm7HbucDjPbES+@fractal.localdomain/ Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/lkml/YVmd7D0M6G%2FDcP4O@localhost.localdomain
* | Merge tag 'binfmt_elf-v5.17-rc7' of ↵Linus Torvalds2022-03-011-7/+18
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull binfmt_elf fix from Kees Cook: "This addresses a regression[1] under ia64 where some ET_EXEC binaries were not loading" Link: https://linux-regtracking.leemhuis.info/regzbot/regression/a3edd529-c42d-3b09-135c-7e98a15b150f@leemhuis.info/ [1] - Fix ia64 ET_EXEC loading * tag 'binfmt_elf-v5.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: binfmt_elf: Avoid total_mapping_size for ET_EXEC
| * binfmt_elf: Avoid total_mapping_size for ET_EXECKees Cook2022-03-011-7/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Partially revert commit 5f501d555653 ("binfmt_elf: reintroduce using MAP_FIXED_NOREPLACE"), which applied the ET_DYN "total_mapping_size" logic also to ET_EXEC. At least ia64 has ET_EXEC PT_LOAD segments that are not virtual-address contiguous (but _are_ file-offset contiguous). This would result in a giant mapping attempting to cover the entire span, including the virtual address range hole, and well beyond the size of the ELF file itself, causing the kernel to refuse to load it. For example: $ readelf -lW /usr/bin/gcc ... Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz ... ... LOAD 0x000000 0x4000000000000000 0x4000000000000000 0x00b5a0 0x00b5a0 ... LOAD 0x00b5a0 0x600000000000b5a0 0x600000000000b5a0 0x0005ac 0x000710 ... ... ^^^^^^^^ ^^^^^^^^^^^^^^^^^^ ^^^^^^^^ ^^^^^^^^ File offset range : 0x000000-0x00bb4c 0x00bb4c bytes Virtual address range : 0x4000000000000000-0x600000000000bcb0 0x200000000000bcb0 bytes Remove the total_mapping_size logic for ET_EXEC, which reduces the ET_EXEC MAP_FIXED_NOREPLACE coverage to only the first PT_LOAD (better than nothing), and retains it for ET_DYN. Ironically, this is the reverse of the problem that originally caused problems with MAP_FIXED_NOREPLACE: overlapping PT_LOAD segments. Future work could restore full coverage if load_elf_binary() were to perform mappings in a separate phase from the loading (where it could resolve both overlaps and holes). Cc: Eric Biederman <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Reported-by: matoro <matoro_bugzilla_kernel@matoro.tk> Fixes: 5f501d555653 ("binfmt_elf: reintroduce using MAP_FIXED_NOREPLACE") Link: https://lore.kernel.org/r/a3edd529-c42d-3b09-135c-7e98a15b150f@leemhuis.info Tested-by: matoro <matoro_mailinglist_kernel@matoro.tk> Link: https://lore.kernel.org/lkml/ce8af9c13bcea9230c7689f3c1e0e2cd@matoro.tk Tested-By: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Link: https://lore.kernel.org/lkml/49182d0d-708b-4029-da5f-bc18603440a6@physik.fu-berlin.de Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* | fs/binfmt_elf: fix PT_LOAD p_align values for loadersMike Rapoport2022-02-111-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | Rui Salvaterra reported that Aisleroit solitaire crashes with "Wrong __data_start/_end pair" assertion from libgc after update to v5.17-rc1. Bisection pointed to commit 9630f0d60fec ("fs/binfmt_elf: use PT_LOAD p_align values for static PIE") that fixed handling of static PIEs, but made the condition that guards load_bias calculation to exclude loader binaries. Restoring the check for presence of interpreter fixes the problem. Link: https://lkml.kernel.org/r/20220202121433.3697146-1-rppt@kernel.org Fixes: 9630f0d60fec ("fs/binfmt_elf: use PT_LOAD p_align values for static PIE") Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reported-by: Rui Salvaterra <rsalvaterra@gmail.com> Tested-by: Rui Salvaterra <rsalvaterra@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Eric Biederman <ebiederm@xmission.com> Cc: "H.J. Lu" <hjl.tools@gmail.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/binfmt_elf: use PT_LOAD p_align values for static PIEH.J. Lu2022-01-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extend commit ce81bb256a22 ("fs/binfmt_elf: use PT_LOAD p_align values for suitable start address") which fixed PIE binaries built with -Wl,-z,max-page-size=0x200000, to cover static PIE binaries. This fixes: https://bugzilla.kernel.org/show_bug.cgi?id=215275 Tested by verifying static PIE binaries with -Wl,-z,max-page-size=0x200000 loading. Link: https://lkml.kernel.org/r/20211209174052.370537-1-hjl.tools@gmail.com Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Cc: Chris Kennelly <ckennelly@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Song Liu <songliubraving@fb.com> Cc: David Rientjes <rientjes@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sandeep Patil <sspatil@google.com> Cc: Fangrui Song <maskray@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/binfmt_elf: replace open-coded string copy with get_task_commYafang Shao2022-01-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is better to use get_task_comm() instead of the open coded string copy as we do in other places. struct elf_prpsinfo is used to dump the task information in userspace coredump or kernel vmcore. Below is the verification of vmcore, crash> ps PID PPID CPU TASK ST %MEM VSZ RSS COMM 0 0 0 ffffffff9d21a940 RU 0.0 0 0 [swapper/0] > 0 0 1 ffffa09e40f85e80 RU 0.0 0 0 [swapper/1] > 0 0 2 ffffa09e40f81f80 RU 0.0 0 0 [swapper/2] > 0 0 3 ffffa09e40f83f00 RU 0.0 0 0 [swapper/3] > 0 0 4 ffffa09e40f80000 RU 0.0 0 0 [swapper/4] > 0 0 5 ffffa09e40f89f80 RU 0.0 0 0 [swapper/5] 0 0 6 ffffa09e40f8bf00 RU 0.0 0 0 [swapper/6] > 0 0 7 ffffa09e40f88000 RU 0.0 0 0 [swapper/7] > 0 0 8 ffffa09e40f8de80 RU 0.0 0 0 [swapper/8] > 0 0 9 ffffa09e40f95e80 RU 0.0 0 0 [swapper/9] > 0 0 10 ffffa09e40f91f80 RU 0.0 0 0 [swapper/10] > 0 0 11 ffffa09e40f93f00 RU 0.0 0 0 [swapper/11] > 0 0 12 ffffa09e40f90000 RU 0.0 0 0 [swapper/12] > 0 0 13 ffffa09e40f9bf00 RU 0.0 0 0 [swapper/13] > 0 0 14 ffffa09e40f98000 RU 0.0 0 0 [swapper/14] > 0 0 15 ffffa09e40f9de80 RU 0.0 0 0 [swapper/15] It works well as expected. Some comments are added to explain why we use the hard-coded 16. Link: https://lkml.kernel.org/r/20211120112738.45980-5-laoar.shao@gmail.com Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2021-11-091-10/+23
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge more updates from Andrew Morton: "87 patches. Subsystems affected by this patch series: mm (pagecache and hugetlb), procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs, init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork, sysvfs, kcov, gdb, resource, selftests, and ipc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (87 commits) ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL ipc: check checkpoint_restore_ns_capable() to modify C/R proc files selftests/kselftest/runner/run_one(): allow running non-executable files virtio-mem: disallow mapping virtio-mem memory via /dev/mem kernel/resource: disallow access to exclusive system RAM regions kernel/resource: clean up and optimize iomem_is_exclusive() scripts/gdb: handle split debug for vmlinux kcov: replace local_irq_save() with a local_lock_t kcov: avoid enable+disable interrupts if !in_task() kcov: allocate per-CPU memory on the relevant node Documentation/kcov: define `ip' in the example Documentation/kcov: include types.h in the example sysv: use BUILD_BUG_ON instead of runtime check kernel/fork.c: unshare(): use swap() to make code cleaner seq_file: fix passing wrong private data seq_file: move seq_escape() to a header signal: remove duplicate include in signal.h crash_dump: remove duplicate include in crash_dump.h crash_dump: fix boolreturn.cocci warning hfs/hfsplus: use WARN_ON for sanity check ...
| * ELF: simplify STACK_ALLOC macroAlexey Dobriyan2021-11-091-1/+1
| | | | | | | | | | | | | | | | | | "A -= B; A" is equivalent to "A -= B". Link: https://lkml.kernel.org/r/YVmcP256fRMqCwgK@localhost.localdomain Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * binfmt_elf: reintroduce using MAP_FIXED_NOREPLACEKees Cook2021-11-091-9/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b212921b13bd ("elf: don't use MAP_FIXED_NOREPLACE for elf executable mappings") reverted back to using MAP_FIXED to map ELF LOAD segments because it was found that the segments in some binaries overlap and can cause MAP_FIXED_NOREPLACE to fail. The original intent of MAP_FIXED_NOREPLACE in the ELF loader was to prevent the silent clobbering of an existing mapping (e.g. stack) by the ELF image, which could lead to exploitable conditions. Quoting commit 4ed28639519c ("fs, elf: drop MAP_FIXED usage from elf_map"), which originally introduced the use of MAP_FIXED_NOREPLACE in the loader: Both load_elf_interp and load_elf_binary rely on elf_map to map segments [to a specific] address and they use MAP_FIXED to enforce that. This is however [a] dangerous thing prone to silent data corruption which can be even exploitable. ... Let's take CVE-2017-1000253 as an example ... we could end up mapping [the executable] over the existing stack ... The [stack layout] issue has been fixed since then ... So we should be safe and any [similar] attack should be impractical. On the other hand this is just too subtle [an] assumption ... it can break quite easily and [be] hard to spot. ... Address this [weakness] by changing MAP_FIXED to the newly added MAP_FIXED_NOREPLACE. This will mean that mmap will fail if there is an existing mapping clashing with the requested one [instead of silently] clobbering it. Then processing ET_DYN binaries the loader already calculates a total size for the image when the first segment is mapped, maps the entire image, and then unmaps the remainder before the remaining segments are then individually mapped. To avoid the earlier problems (legitimate overlapping LOAD segments specified in the ELF), apply the same logic to ET_EXEC binaries as well. For both ET_EXEC and ET_DYN+INTERP use MAP_FIXED_NOREPLACE for the initial total size mapping and then use MAP_FIXED to build the final (possibly legitimately overlapping) mappings. For ET_DYN w/out INTERP, continue to map at a system-selected address in the mmap region. Link: https://lkml.kernel.org/r/20210916215947.3993776-1-keescook@chromium.org Link: https://lore.kernel.org/lkml/1595869887-23307-2-git-send-email-anthony.yznaga@oracle.com Co-developed-by: Anthony Yznaga <anthony.yznaga@oracle.com> Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Chen Jingwen <chenjingwen6@huawei.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrei Vagin <avagin@openvz.org> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'per_signal_struct_coredumps-for-v5.16' of ↵Linus Torvalds2021-11-031-2/+2
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull per signal_struct coredumps from Eric Biederman: "Current coredumps are mixed up with the exit code, the signal handling code, and the ptrace code making coredumps much more complicated than necessary and difficult to follow. This series of changes starts with ptrace_stop and cleans it up, making it easier to follow what is happening in ptrace_stop. Then cleans up the exec interactions with coredumps. Then cleans up the coredump interactions with exit. Finally the coredump interactions with the signal handling code is cleaned up. The first and last changes are bug fixes for minor bugs. I believe the fact that vfork followed by execve can kill the process the called vfork if exec fails is sufficient justification to change the userspace visible behavior. In previous discussions some of these changes were organized differently and individually appeared to make the code base worse. As currently written I believe they all stand on their own as cleanups and bug fixes. Which means that even if the worst should happen and the last change needs to be reverted for some unimaginable reason, the code base will still be improved. If the worst does not happen there are a more cleanups that can be made. Signals that generate coredumps can easily become eligible for short circuit delivery in complete_signal. The entire rendezvous for generating a coredump can move into get_signal. The function force_sig_info_to_task be written in a way that does not modify the signal handling state of the target task (because coredumps are eligible for short circuit delivery). Many of these future cleanups can be done another way but nothing so cleanly as if coredumps become per signal_struct" * 'per_signal_struct_coredumps-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: coredump: Limit coredumps to a single thread group coredump: Don't perform any cleanups before dumping core exit: Factor coredump_exit_mm out of exit_mm exec: Check for a pending fatal signal instead of core_state ptrace: Remove the unnecessary arguments from arch_ptrace_stop signal: Remove the bogus sigkill_pending in ptrace_stop
| * coredump: Limit coredumps to a single thread groupEric W. Biederman2021-10-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today when a signal is delivered with a handler of SIG_DFL whose default behavior is to generate a core dump not only that process but every process that shares the mm is killed. In the case of vfork this looks like a real world problem. Consider the following well defined sequence. if (vfork() == 0) { execve(...); _exit(EXIT_FAILURE); } If a signal that generates a core dump is received after vfork but before the execve changes the mm the process that called vfork will also be killed (as the mm is shared). Similarly if the execve fails after the point of no return the kernel delivers SIGSEGV which will kill both the exec'ing process and because the mm is shared the process that called vfork as well. As far as I can tell this behavior is a violation of people's reasonable expectations, POSIX, and is unnecessarily fragile when the system is low on memory. Solve this by making a userspace visible change to only kill a single process/thread group. This is possible because Jann Horn recently modified[1] the coredump code so that the mm can safely be modified while the coredump is happening. With LinuxThreads long gone I don't expect anyone to have a notice this behavior change in practice. To accomplish this move the core_state pointer from mm_struct to signal_struct, which allows different thread groups to coredump simultatenously. In zap_threads remove the work to kill anything except for the current thread group. v2: Remove core_state from the VM_BUG_ON_MM print to fix compile failure when CONFIG_DEBUG_VM is enabled. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> [1] a07279c9a8cd ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot") Fixes: d89f3847def4 ("[PATCH] thread-aware coredumps, 2.5.43-C3") History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Link: https://lkml.kernel.org/r/87y27mvnke.fsf@disp2133 Link: https://lkml.kernel.org/r/20211007144701.67592574@canb.auug.org.au Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | elf: don't use MAP_FIXED_NOREPLACE for elf interpreter mappingsChen Jingwen2021-10-031-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit b212921b13bd ("elf: don't use MAP_FIXED_NOREPLACE for elf executable mappings") we still leave MAP_FIXED_NOREPLACE in place for load_elf_interp. Unfortunately, this will cause kernel to fail to start with: 1 (init): Uhuuh, elf segment at 00003ffff7ffd000 requested but the memory is mapped already Failed to execute /init (error -17) The reason is that the elf interpreter (ld.so) has overlapping segments. readelf -l ld-2.31.so Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flags Align LOAD 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x000000000002c94c 0x000000000002c94c R E 0x10000 LOAD 0x000000000002dae0 0x000000000003dae0 0x000000000003dae0 0x00000000000021e8 0x0000000000002320 RW 0x10000 LOAD 0x000000000002fe00 0x000000000003fe00 0x000000000003fe00 0x00000000000011ac 0x0000000000001328 RW 0x10000 The reason for this problem is the same as described in commit ad55eac74f20 ("elf: enforce MAP_FIXED on overlaying elf segments"). Not only executable binaries, elf interpreters (e.g. ld.so) can have overlapping elf segments, so we better drop MAP_FIXED_NOREPLACE and go back to MAP_FIXED in load_elf_interp. Fixes: 4ed28639519c ("fs, elf: drop MAP_FIXED usage from elf_map") Cc: <stable@vger.kernel.org> # v4.19 Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Chen Jingwen <chenjingwen6@huawei.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* binfmt: remove in-tree usage of MAP_DENYWRITEDavid Hildenbrand2021-09-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At exec time when we mmap the new executable via MAP_DENYWRITE we have it opened via do_open_execat() and already deny_write_access()'ed the file successfully. Once exec completes, we allow_write_acces(); however, we set mm->exe_file in begin_new_exec() via set_mm_exe_file() and also deny_write_access() as long as mm->exe_file remains set. We'll effectively deny write access to our executable via mm->exe_file until mm->exe_file is changed -- when the process is removed, on new exec, or via sys_prctl(PR_SET_MM_MAP/EXE_FILE). Let's remove all usage of MAP_DENYWRITE, it's no longer necessary for mm->exe_file. In case of an elf interpreter, we'll now only deny write access to the file during exec. This is somewhat okay, because the interpreter behaves (and sometime is) a shared library; all shared libraries, especially the ones loaded directly in user space like via dlopen() won't ever be mapped via MAP_DENYWRITE, because we ignore that from user space completely; these shared libraries can always be modified while mapped and executed. Let's only special-case the main executable, denying write access while being executed by a process. This can be considered a minor user space visible change. While this is a cleanup, it also fixes part of a problem reported with VM_DENYWRITE on overlayfs, as VM_DENYWRITE is effectively unused with this patch and will be removed next: "Overlayfs did not honor positive i_writecount on realfile for VM_DENYWRITE mappings." [1] [1] https://lore.kernel.org/r/YNHXzBgzRrZu1MrD@miu.piliscsaba.redhat.com/ Reported-by: Chengguang Xu <cgxu519@mykernel.net> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: David Hildenbrand <david@redhat.com>
* binfmt: don't use MAP_DENYWRITE when loading shared libraries via uselib()David Hildenbrand2021-09-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | uselib() is the legacy systemcall for loading shared libraries. Nowadays, applications use dlopen() to load shared libraries, completely implemented in user space via mmap(). For example, glibc uses MAP_COPY to mmap shared libraries. While this maps to MAP_PRIVATE | MAP_DENYWRITE on Linux, Linux ignores any MAP_DENYWRITE specification from user space in mmap. With this change, all remaining in-tree users of MAP_DENYWRITE use it to map an executable. We will be able to open shared libraries loaded via uselib() writable, just as we already can via dlopen() from user space. This is one step into the direction of removing MAP_DENYWRITE from the kernel. This can be considered a minor user space visible change. Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: David Hildenbrand <david@redhat.com>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2021-06-291-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: "191 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab, slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap, mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization, pagealloc, and memory-failure)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits) mm,hwpoison: make get_hwpoison_page() call get_any_page() mm,hwpoison: send SIGBUS with error virutal address mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes mm/page_alloc: allow high-order pages to be stored on the per-cpu lists mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA docs: remove description of DISCONTIGMEM arch, mm: remove stale mentions of DISCONIGMEM mm: remove CONFIG_DISCONTIGMEM m68k: remove support for DISCONTIGMEM arc: remove support for DISCONTIGMEM arc: update comment about HIGHMEM implementation alpha: remove DISCONTIGMEM and NUMA mm/page_alloc: move free_the_page mm/page_alloc: fix counting of managed_pages mm/page_alloc: improve memmap_pages dbg msg mm: drop SECTION_SHIFT in code comments mm/page_alloc: introduce vm.percpu_pagelist_high_fraction mm/page_alloc: limit the number of pages on PCP lists when reclaim is active mm/page_alloc: scale the number of pages that are batch freed ...
| * binfmt: remove in-tree usage of MAP_EXECUTABLEDavid Hildenbrand2021-06-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ever since commit e9714acf8c43 ("mm: kill vma flag VM_EXECUTABLE and mm->num_exe_file_vmas"), VM_EXECUTABLE is gone and MAP_EXECUTABLE is essentially completely ignored. Let's remove all usage of MAP_EXECUTABLE. [akpm@linux-foundation.org: fix blooper in fs/binfmt_aout.c. per David] Link: https://lkml.kernel.org/r/20210421093453.6904-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kevin Brodsky <Kevin.Brodsky@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | sched: Change task_struct::statePeter Zijlstra2021-06-181-3/+5
|/ | | | | | | | | | | | Change the type and name of task_struct::state. Drop the volatile and shrink it to an 'unsigned int'. Rename it in order to find all uses such that we can use READ_ONCE/WRITE_ONCE as appropriate. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Will Deacon <will@kernel.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Link: https://lore.kernel.org/r/20210611082838.550736351@infradead.org
* coredump: don't bother with do_truncate()Al Viro2021-03-081-3/+1
| | | | | | | | | | have dump_skip() just remember how much needs to be skipped, leave actual seeks/writing zeroes to the next dump_emit() or the end of coredump output, whichever comes first. And instead of playing with do_truncate() in the end, just write one NUL at the end of the last gap (if any). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'parisc-5.12-1' of ↵Linus Torvalds2021-02-211-1/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull parisc updates from Helge Deller: - Optimize parisc page table locks by using the existing page_table_lock - Export argv0-preserve flag in binfmt_misc for usage in qemu-user - Fix interrupt table (IVT) checksum so firmware will call crash handler (HPMC) - Increase IRQ stack to 64kb on 64-bit kernel - Switch to common devmem_is_allowed() implementation - Minor fix to get_whan() * 'parisc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: binfmt_misc: pass binfmt_misc flags to the interpreter parisc: Optimize per-pagetable spinlocks parisc: Replace test_ti_thread_flag() with test_tsk_thread_flag() parisc: Bump 64-bit IRQ stack size to 64 KB parisc: Fix IVT checksum calculation wrt HPMC parisc: Use the generic devmem_is_allowed() parisc: Drop out of get_whan() if task is running again
| * binfmt_misc: pass binfmt_misc flags to the interpreterLaurent Vivier2021-02-151-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It can be useful to the interpreter to know which flags are in use. For instance, knowing if the preserve-argv[0] is in use would allow to skip the pathname argument. This patch uses an unused auxiliary vector, AT_FLAGS, to add a flag to inform interpreter if the preserve-argv[0] is enabled. Note by Helge Deller: The real-world user of this patch is qemu-user, which needs to know if it has to preserve the argv[0]. See Debian bug #970460. Signed-off-by: Laurent Vivier <laurent@vivier.eu> Reviewed-by: YunQiang Su <ysu@wavecomp.com> URL: http://bugs.debian.org/970460 Signed-off-by: Helge Deller <deller@gmx.de>
* | elf_prstatus: collect the common part (everything before pr_reg) into a structAl Viro2021-01-061-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Preparations to doing i386 compat elf_prstatus sanely - rather than duplicating the beginning of compat_elf_prstatus, take these fields into a separate structure (compat_elf_prstatus_common), so that it could be reused. Due to the incestous relationship between binfmt_elf.c and compat_binfmt_elf.c we need the same shape change done to native struct elf_prstatus, gathering the fields prior to pr_reg into a new structure (struct elf_prstatus_common). Fortunately, offset of pr_reg is always a multiple of 16 with no padding right before it, so it's possible to turn all the stuff prior to it into a single member without disturbing the layout. [build fix from Geert Uytterhoeven folded in] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | binfmt_elf: partially sanitize PRSTATUS_SIZE and SET_PR_FPVALIDAl Viro2021-01-041-8/+5
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On 64bit architectures that support 32bit processes there are two possible layouts for NT_PRSTATUS note in ELF coredumps. For one thing, several fields are 64bit for native processes and 32bit for compat ones (pr_sigpend, etc.). For another, the register dump is obviously different - the size and number of registers are not going to be the same for 32bit and 64bit variants of processor. Usually that's handled by having two structures - elf_prstatus for native layout and compat_elf_prstatus for 32bit one. 32bit processes are handled by fs/compat_binfmt_elf.c, which defines a macro called 'elf_prstatus' that expands to compat_elf_prstatus. Then it includes fs/binfmt_elf.c, which makes all references to struct elf_prstatus to be textually replaced with struct compat_elf_prstatus. Ugly and somewhat brittle, but it works. However, amd64 is worse - there are _three_ possible layouts. One for native 64bit processes, another for i386 (32bit) processes and yet another for x32 (32bit address space with full 64bit registers). Both i386 and x32 processes are handled by fs/compat_binfmt_elf.c, with usual compat_binfmt_elf.c trickery. However, the layouts for i386 and x32 are not identical - they have the common beginning, but the register dump part (pr_reg) is bigger on x32. Worse, pr_reg is not the last field - it's followed by int pr_fpvalid, so that field ends up at different offsets for i386 and x32 layouts. Fortunately, there's not much code that cares about any of that - it's all encapsulated in fill_thread_core_info(). Since x32 variant is bigger, we define compat_elf_prstatus to match that layout. That way i386 processes have enough space to fit their layout into. Moreover, since these layouts are identical prior to pr_reg, we don't need to distinguish x32 and i386 cases when we are setting the fields prior to pr_reg. Filling pr_reg itself is done by calling ->get() method of appropriate regset, and that method knows what layout (and size) to use. We do need to distinguish x32 and i386 cases only for two things: setting ->pr_fpvalid (offset differs for x32 and i386) and choosing the right size for our note. The way it's done is Not Nice, for the lack of more accurate printable description. There are two macros (PRSTATUS_SIZE and SET_PR_FPVALID), that default essentially to sizeof(struct elf_prstatus) and (S)->pr_fpvalid = 1. On x86 asm/compat.h provides its own variants. Unfortunately, quite a few things go wrong there: * PRSTATUS_SIZE doesn't use the normal test for process being an x32 one; it compares the size reported by regset with the size of pr_reg. * it hardcodes the sizes of x32 and i386 variants (296 and 144 resp.), so if some change in includes leads to asm/compat.h pulled in by fs/binfmt_elf.c we are in trouble - it will end up using the size of x32 variant for 64bit processes. * it's in the wrong place; asm/compat.h couldn't define the structure for i386 layout, since it lacks quite a few types needed for it. Hardcoded sizes are largely due to that. The proper fix would be to have an explicitly defined i386 variant of structure and have PRSTATUS_SIZE/SET_PR_FPVALID check for TIF_X32 to choose the variant that should be used. Unfortunately, that requires some manipulations of headers; we'll do that later in the series, but for now let's go with the minimal variant - rename PRSTATUS_SIZE in asm/compat.h to COMPAT_PRSTATUS_SIZE, have fs/compat_binfmt_elf.c define PRSTATUS_SIZE to COMPAT_PRSTATUS_SIZE and use the normal TIF_X32 check in that macro. The size of i386 variant is kept hardcoded for now. Similar story for SET_PR_FPVALID. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'exec-for-v5.11' of ↵Linus Torvalds2020-12-151-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull execve updates from Eric Biederman: "This set of changes ultimately fixes the interaction of posix file lock and exec. Fundamentally most of the change is just moving where unshare_files is called during exec, and tweaking the users of files_struct so that the count of files_struct is not unnecessarily played with. Along the way fcheck and related helpers were renamed to more accurately reflect what they do. There were also many other small changes that fell out, as this is the first time in a long time much of this code has been touched. Benchmarks haven't turned up any practical issues but Al Viro has observed a possibility for a lot of pounding on task_lock. So I have some changes in progress to convert put_files_struct to always rcu free files_struct. That wasn't ready for the merge window so that will have to wait until next time" * 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits) exec: Move io_uring_task_cancel after the point of no return coredump: Document coredump code exclusively used by cell spufs file: Remove get_files_struct file: Rename __close_fd_get_file close_fd_get_file file: Replace ksys_close with close_fd file: Rename __close_fd to close_fd and remove the files parameter file: Merge __alloc_fd into alloc_fd file: In f_dupfd read RLIMIT_NOFILE once. file: Merge __fd_install into fd_install proc/fd: In fdinfo seq_show don't use get_files_struct bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu proc/fd: In proc_readfd_common use task_lookup_next_fd_rcu file: Implement task_lookup_next_fd_rcu kcmp: In get_file_raw_ptr use task_lookup_fd_rcu proc/fd: In tid_fd_mode use task_lookup_fd_rcu file: Implement task_lookup_fd_rcu file: Rename fcheck lookup_fd_rcu file: Replace fcheck_files with files_lookup_fd_rcu file: Factor files_lookup_fd_locked out of fcheck_files file: Rename __fcheck_files to files_lookup_fd_raw ...
| * coredump: Document coredump code exclusively used by cell spufsEric W. Biederman2020-12-101-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Oleg Nesterov recently asked[1] why is there an unshare_files in do_coredump. After digging through all of the callers of lookup_fd it turns out that it is arch/powerpc/platforms/cell/spufs/coredump.c:coredump_next_context that needs the unshare_files in do_coredump. Looking at the history[2] this code was also the only piece of coredump code that required the unshare_files when the unshare_files was added. Looking at that code it turns out that cell is also the only architecture that implements elf_coredump_extra_notes_size and elf_coredump_extra_notes_write. I looked at the gdb repo[3] support for cell has been removed[4] in binutils 2.34. Geoff Levand reports he is still getting questions on how to run modern kernels on the PS3, from people using 3rd party firmware so this code is not dead. According to Wikipedia the last PS3 shipped in Japan sometime in 2017. So it will probably be a little while before everyone's hardware dies. Add some comments briefly documenting the coredump code that exists only to support cell spufs to make it easier to understand the coredump code. Eventually the hardware will be dead, or their won't be userspace tools, or the coredump code will be refactored and it will be too difficult to update a dead architecture and these comments make it easy to tell where to pull to remove cell spufs support. [1] https://lkml.kernel.org/r/20201123175052.GA20279@redhat.com [2] 179e037fc137 ("do_coredump(): make sure that descriptor table isn't shared") [3] git://sourceware.org/git/binutils-gdb.git [4] abf516c6931a ("Remove Cell Broadband Engine debugging support"). Link: https://lkml.kernel.org/r/87h7pdnlzv.fsf_-_@x220.int.ebiederm.org Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* | Merge tag 'x86_cleanups_for_v5.11' of ↵Linus Torvalds2020-12-141-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Borislav Petkov: "Another branch with a nicely negative diffstat, just the way I like 'em: - Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in the end (Gabriel Krisman Bertazi) - All kinds of minor cleanups all over the tree" * tag 'x86_cleanups_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/ia32_signal: Propagate __user annotation properly x86/alternative: Update text_poke_bp() kernel-doc comment x86/PCI: Make a kernel-doc comment a normal one x86/asm: Drop unused RDPID macro x86/boot/compressed/64: Use TEST %reg,%reg instead of CMP $0,%reg x86/head64: Remove duplicate include x86/mm: Declare 'start' variable where it is used x86/head/64: Remove unused GET_CR2_INTO() macro x86/boot: Remove unused finalize_identity_maps() x86/uaccess: Document copy_from_user_nmi() x86/dumpstack: Make show_trace_log_lvl() static x86/mtrr: Fix a kernel-doc markup x86/setup: Remove unused MCA variables x86, libnvdimm/test: Remove COPY_MC_TEST x86: Reclaim TIF_IA32 and TIF_X32 x86/mm: Convert mmu context ia32_compat into a proper flags field x86/elf: Use e_machine to check for x32/ia32 in setup_additional_pages() elf: Expose ELF header on arch_setup_additional_pages() x86/elf: Use e_machine to select start_thread for x32 elf: Expose ELF header in compat_start_thread() ...
| * | elf: Expose ELF header on arch_setup_additional_pages()Gabriel Krisman Bertazi2020-10-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Like it is done for SET_PERSONALITY with ARM, which requires the ELF header to select correct personality parameters, x86 requires the headers when selecting which VDSO to load, instead of relying on the going-away TIF_IA32/X32 flags. Add an indirection macro to arch_setup_additional_pages(), that x86 can reimplement to receive the extra parameter just for ELF files. This requires no changes to other architectures, who can continue to use the original arch_setup_additional_pages for ELF and non-ELF binaries. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201004032536.1229030-8-krisman@collabora.com
| * | elf: Expose ELF header in compat_start_thread()Gabriel Krisman Bertazi2020-10-261-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Like it is done for SET_PERSONALITY with x86, which requires the ELF header to select correct personality parameters, x86 requires the headers on compat_start_thread() to choose starting CS for ELF32 binaries, instead of relying on the going-away TIF_IA32/X32 flags. Add an indirection macro to ELF invocations of START_THREAD, that x86 can reimplement to receive the extra parameter just for ELF files. This requires no changes to other architectures who don't need the header information, they can continue to use the original start_thread for ELF and non-ELF binaries, and it prevents affecting non-ELF code paths for x86. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201004032536.1229030-6-krisman@collabora.com
* / fs: Replace zero-length array with flexible-array memberGustavo A. R. Silva2020-10-291-1/+1
|/ | | | | | | | | | | | There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* binfmt_elf: take the mmap lock around find_extend_vma()Jann Horn2020-10-181-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | create_elf_tables() runs after setup_new_exec(), so other tasks can already access our new mm and do things like process_madvise() on it. (At the time I'm writing this commit, process_madvise() is not in mainline yet, but has been in akpm's tree for some time.) While I believe that there are currently no APIs that would actually allow another process to mess up our VMA tree (process_madvise() is limited to MADV_COLD and MADV_PAGEOUT, and uring and userfaultfd cannot reach an mm under which no syscalls have been executed yet), this seems like an accident waiting to happen. Let's make sure that we always take the mmap lock around GUP paths as long as another process might be able to see the mm. (Yes, this diff looks suspicious because we drop the lock before doing anything with `vma`, but that's because we actually don't do anything with it apart from the NULL check.) Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michel Lespinasse <walken@google.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Link: https://lkml.kernel.org/r/CAG48ez1-PBCdv3y8pn-Ty-b+FmBSLwDuVKFSt8h7wARLy0dF-Q@mail.gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshotJann Horn2020-10-161-78/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In both binfmt_elf and binfmt_elf_fdpic, use a new helper dump_vma_snapshot() to take a snapshot of the VMA list (including the gate VMA, if we have one) while protected by the mmap_lock, and then use that snapshot instead of walking the VMA list without locking. An alternative approach would be to keep the mmap_lock held across the entire core dumping operation; however, keeping the mmap_lock locked while we may be blocked for an unbounded amount of time (e.g. because we're dumping to a FUSE filesystem or so) isn't really optimal; the mmap_lock blocks things like the ->release handler of userfaultfd, and we don't really want critical system daemons to grind to a halt just because someone "gifted" them SCM_RIGHTS to an eternally-locked userfaultfd, or something like that. Since both the normal ELF code and the FDPIC ELF code need this functionality (and if any other binfmt wants to add coredump support in the future, they'd probably need it, too), implement this with a common helper in fs/coredump.c. A downside of this approach is that we now need a bigger amount of kernel memory per userspace VMA in the normal ELF case, and that we need O(n) kernel memory in the FDPIC ELF case at all; but 40 bytes per VMA shouldn't be terribly bad. There currently is a data race between stack expansion and anything that reads ->vm_start or ->vm_end under the mmap_lock held in read mode; to mitigate that for core dumping, take the mmap_lock in write mode when taking a snapshot of the VMA hierarchy. (If we only took the mmap_lock in read mode, we could end up with a corrupted core dump if someone does get_user_pages_remote() concurrently. Not really a major problem, but taking the mmap_lock either way works here, so we might as well avoid the issue.) (This doesn't do anything about the existing data races with stack expansion in other mm code.) Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-6-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump: rework elf/elf_fdpic vma_dump_size() into common helperJann Horn2020-10-161-120/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At the moment, the binfmt_elf and binfmt_elf_fdpic code have slightly different code to figure out which VMAs should be dumped, and if so, whether the dump should contain the entire VMA or just its first page. Eliminate duplicate code by reworking the binfmt_elf version into a generic core dumping helper in coredump.c. As part of that, change the heuristic for detecting executable/library header pages to check whether the inode is executable instead of looking at the file mode. This is less problematic in terms of locking because it lets us avoid get_user() under the mmap_sem. (And arguably it looks nicer and makes more sense in generic code.) Adjust a little bit based on the binfmt_elf_fdpic version: ->anon_vma is only meaningful under CONFIG_MMU, otherwise we have to assume that the VMA has been written to. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-5-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump: refactor page range dumping into common helperJann Horn2020-10-161-20/+2
| | | | | | | | | | | | | | | | Both fs/binfmt_elf.c and fs/binfmt_elf_fdpic.c need to dump ranges of pages into the coredump file. Extract that logic into a common helper. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-4-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/binfmt_elf: use PT_LOAD p_align values for suitable start addressChris Kennelly2020-10-161-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Selecting Load Addresses According to p_align", v3. The current ELF loading mechancism provides page-aligned mappings. This can lead to the program being loaded in a way unsuitable for file-backed, transparent huge pages when handling PIE executables. While specifying -z,max-page-size=0x200000 to the linker will generate suitably aligned segments for huge pages on x86_64, the executable needs to be loaded at a suitably aligned address as well. This alignment requires the binary's cooperation, as distinct segments need to be appropriately paddded to be eligible for THP. For binaries built with increased alignment, this limits the number of bits usable for ASLR, but provides some randomization over using fixed load addresses/non-PIE binaries. This patch (of 2): The current ELF loading mechancism provides page-aligned mappings. This can lead to the program being loaded in a way unsuitable for file-backed, transparent huge pages when handling PIE executables. For binaries built with increased alignment, this limits the number of bits usable for ASLR, but provides some randomization over using fixed load addresses/non-PIE binaries. Tested by verifying program with -Wl,-z,max-page-size=0x200000 loading. [akpm@linux-foundation.org: fix max() warning] [ckennelly@google.com: augment comment] Link: https://lkml.kernel.org/r/20200821233848.3904680-2-ckennelly@google.com Signed-off-by: Chris Kennelly <ckennelly@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Song Liu <songliubraving@fb.com> Cc: David Rientjes <rientjes@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Hugh Dickens <hughd@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sandeep Patil <sspatil@google.com> Cc: Fangrui Song <maskray@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Shuah Khan <shuah@kernel.org> Link: https://lkml.kernel.org/r/20200820170541.1132271-1-ckennelly@google.com Link: https://lkml.kernel.org/r/20200820170541.1132271-2-ckennelly@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kill elf_fpxregs_tAl Viro2020-07-271-30/+0
| | | | | | | all uses are conditional upon ELF_CORE_COPY_XFPREGS, which has not been defined on any architecture since 2010 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* introduction of regset ->get() wrappers, switching ELF coredumps to thoseAl Viro2020-07-271-28/+26
| | | | | | | | | | | | | | | | | | Two new helpers: given a process and regset, dump into a buffer. regset_get() takes a buffer and size, regset_get_alloc() takes size and allocates a buffer. Return value in both cases is the amount of data actually dumped in case of success or -E... on error. In both cases the size is capped by regset->n * regset->size, so ->get() is called with offset 0 and size no more than what regset expects. binfmt_elf.c callers of ->get() are switched to using those; the other caller (copy_regset_to_user()) will need some preparations to switch. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'uaccess.misc' of ↵Linus Torvalds2020-06-101-8/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc uaccess updates from Al Viro: "Assorted uaccess patches for this cycle - the stuff that didn't fit into thematic series" * 'uaccess.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: bpf: make bpf_check_uarg_tail_zero() use check_zeroed_user() x86: kvm_hv_set_msr(): use __put_user() instead of 32bit __clear_user() user_regset_copyout_zero(): use clear_user() TEST_ACCESS_OK _never_ had been checked anywhere x86: switch cp_stat64() to unsafe_put_user() binfmt_flat: don't use __put_user() binfmt_elf_fdpic: don't use __... uaccess primitives binfmt_elf: don't bother with __{put,copy_to}_user() pselect6() and friends: take handling the combined 6th/7th args into helper
| * binfmt_elf: don't bother with __{put,copy_to}_user()Al Viro2020-06-031-8/+8
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2020-06-041-4/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge yet more updates from Andrew Morton: - More MM work. 100ish more to go. Mike Rapoport's "mm: remove __ARCH_HAS_5LEVEL_HACK" series should fix the current ppc issue - Various other little subsystems * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits) lib/ubsan.c: fix gcc-10 warnings tools/testing/selftests/vm: remove duplicate headers selftests: vm: pkeys: fix multilib builds for x86 selftests: vm: pkeys: use the correct page size on powerpc selftests/vm/pkeys: override access right definitions on powerpc selftests/vm/pkeys: test correct behaviour of pkey-0 selftests/vm/pkeys: introduce a sub-page allocator selftests/vm/pkeys: detect write violation on a mapped access-denied-key page selftests/vm/pkeys: associate key on a mapped page and detect write violation selftests/vm/pkeys: associate key on a mapped page and detect access violation selftests/vm/pkeys: improve checks to determine pkey support selftests/vm/pkeys: fix assertion in test_pkey_alloc_exhaust() selftests/vm/pkeys: fix number of reserved powerpc pkeys selftests/vm/pkeys: introduce powerpc support selftests/vm/pkeys: introduce generic pkey abstractions selftests: vm: pkeys: use the correct huge page size selftests/vm/pkeys: fix alloc_random_pkey() to make it really random selftests/vm/pkeys: fix assertion in pkey_disable_set/clear() selftests/vm/pkeys: fix pkey_disable_clear() selftests: vm: pkeys: add helpers for pkey bits ...
| * | fs/binfmt_elf: remove redundant elf_map ifndefAnthony Iliopoulos2020-06-041-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ifndef was added a long time ago to support archs that would define their own mapping function. The last user was the metag arch which was removed from the tree, and as such there are no users left. Let's kill it. Signed-off-by: Anthony Iliopoulos <ailiop@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200402161543.4119-1-ailiop@suse.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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