Messages in this thread | | | From | Dmitry Safonov <> | Subject | [PATCH v3 00/23] Add generic vdso_base tracking | Date | Fri, 11 Jun 2021 19:02:19 +0100 |
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v3 Changes: - Migrated arch/powerpc to vdso_base - Added x86/selftest for unmapped vdso & no landing on fast syscall - Review comments from Andy & Christophe (thanks!) - Amended s/born process/execed process/ everywhere I noticed - Build robot warning on cast from __user pointer
I've tested it on x86, I would appreciate any help with Tested-by on arm/arm64/mips/powerpc/s390/... platforms.
One thing I've noticed while cooking this and haven't found a clean way to solve is zero-terminated .pages[] array in vdso mappings, which is not always zero-terminated but works by the reason of VM_DONTEXPAND on mappings.
v2 Changes: - Rename user_landing to vdso_base as it tracks vDSO VMA start address, rather than the explicit address to land (Andy) - Reword and don't use "new-execed" and "new-born" task (Andy) - Fix failures reported by build robot
Started from discussion [1], where was noted that currently a couple of architectures support mremap() for vdso/sigpage, but not munmap(). If an application maps something on the ex-place of vdso/sigpage, later after processing signal it will land there (good luck!)
Patches set is based on linux-next (next-20201123) and it depends on changes in x86/cleanups (those reclaim TIF_IA32/TIF_X32) and also on my changes in akpm (fixing several mremap() issues).
Logically, the patches set divides on: - patch 1: a cleanup for patches in x86/cleanups - patches 2-13: cleanups for arch_setup_additional_pages() - patches 13-14: x86 signal changes for unmapped vdso - patches 15-22: provide generic vdso_base in mm_struct - patch 23: selftest for unmapped vDSO & fast syscalls
In the end, besides cleanups, it's now more predictable what happens for applications with unmapped vdso on architectures those support .mremap() for vdso/sigpage.
I'm aware of only one user that unmaps vdso - Valgrind [2]. (there possibly are more, but this one is "special", it unmaps vdso, but not vvar, which confuses CRIU [Checkpoint Restore In Userspace], that's why I'm aware of it)
Patches as a .git branch: https://github.com/0x7f454c46/linux/tree/vdso_base-v3
v2 Link: https://lore.kernel.org/lkml/20201124002932.1220517-1-dima@arista.com/ v1 Link: https://lore.kernel.org/lkml/20201108051730.2042693-1-dima@arista.com/
[1]: https://lore.kernel.org/linux-arch/CAJwJo6ZANqYkSHbQ+3b+Fi_VT80MtrzEV5yreQAWx-L8j8x2zA@mail.gmail.com/ [2]: https://github.com/checkpoint-restore/criu/issues/488
Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Guo Ren <guoren@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will@kernel.org> Cc: x86@kernel.org
Dmitry Safonov (23): x86/elf: Check in_x32_syscall() in compat_arch_setup_additional_pages() elf: Move arch_setup_additional_pages() to generic elf.h arm/elf: Remove needless ifdef CONFIG_MMU arm64: Use in_compat_task() in arch_setup_additional_pages() x86: Remove compat_arch_setup_additional_pages() elf: Remove compat_arch_setup_additional_pages() vdso: Set mm->context.vdso only on success of _install_special_mapping() elf/vdso: Modify arch_setup_additional_pages() parameters elf: Use sysinfo_ehdr in ARCH_DLINFO() arm/vdso: Remove vdso pointer from mm->context s390/vdso: Remove vdso_base pointer from mm->context sparc/vdso: Remove vdso pointer from mm->context mm/mmap: Make vm_special_mapping::mremap return void x86/signal: Land on &frame->retcode when vdso isn't mapped x86/signal: Check if vdso_image_32 is mapped before trying to land on it mm: Add vdso_base in mm_struct x86/vdso: Migrate to generic vdso_base arm/vdso: Migrate to generic vdso_base arm64/vdso: Migrate compat signals to generic vdso_base arm64/vdso: Migrate native signals to generic vdso_base mips/vdso: Migrate to generic vdso_base powerpc/vdso: Migrate native signals to generic vdso_base x86/vdso/selftest: Add a test for unmapping vDSO
arch/Kconfig | 3 + arch/alpha/include/asm/elf.h | 2 +- arch/arm/Kconfig | 2 + arch/arm/include/asm/elf.h | 10 +- arch/arm/include/asm/mmu.h | 3 - arch/arm/include/asm/vdso.h | 6 +- arch/arm/kernel/process.c | 14 +- arch/arm/kernel/signal.c | 6 +- arch/arm/kernel/vdso.c | 20 +-- arch/arm64/Kconfig | 2 + arch/arm64/include/asm/elf.h | 27 +--- arch/arm64/include/asm/mmu.h | 4 - arch/arm64/kernel/signal.c | 10 +- arch/arm64/kernel/signal32.c | 17 +- arch/arm64/kernel/vdso.c | 72 +++------ arch/csky/Kconfig | 1 + arch/csky/include/asm/elf.h | 4 - arch/csky/kernel/vdso.c | 11 +- arch/hexagon/Kconfig | 1 + arch/hexagon/include/asm/elf.h | 6 - arch/hexagon/kernel/vdso.c | 3 +- arch/ia64/include/asm/elf.h | 2 +- arch/mips/Kconfig | 2 + arch/mips/include/asm/elf.h | 10 +- arch/mips/include/asm/mmu.h | 2 - arch/mips/kernel/signal.c | 11 +- arch/mips/kernel/vdso.c | 5 +- arch/mips/vdso/genvdso.c | 9 -- arch/nds32/Kconfig | 1 + arch/nds32/include/asm/elf.h | 8 +- arch/nds32/kernel/vdso.c | 8 +- arch/nios2/Kconfig | 1 + arch/nios2/include/asm/elf.h | 4 - arch/nios2/mm/init.c | 2 +- arch/powerpc/Kconfig | 2 + arch/powerpc/include/asm/book3s/32/mmu-hash.h | 1 - arch/powerpc/include/asm/book3s/64/mmu.h | 1 - arch/powerpc/include/asm/elf.h | 9 +- arch/powerpc/include/asm/mmu_context.h | 9 -- arch/powerpc/include/asm/nohash/32/mmu-40x.h | 1 - arch/powerpc/include/asm/nohash/32/mmu-44x.h | 1 - arch/powerpc/include/asm/nohash/32/mmu-8xx.h | 1 - arch/powerpc/include/asm/nohash/mmu-book3e.h | 1 - arch/powerpc/kernel/signal_32.c | 8 +- arch/powerpc/kernel/signal_64.c | 4 +- arch/powerpc/kernel/vdso.c | 48 +----- arch/powerpc/perf/callchain_32.c | 8 +- arch/powerpc/perf/callchain_64.c | 4 +- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/elf.h | 9 +- arch/riscv/kernel/vdso.c | 11 +- arch/s390/Kconfig | 1 + arch/s390/include/asm/elf.h | 10 +- arch/s390/include/asm/mmu.h | 1 - arch/s390/kernel/vdso.c | 12 +- arch/sh/Kconfig | 1 + arch/sh/include/asm/elf.h | 16 +- arch/sh/kernel/vsyscall/vsyscall.c | 3 +- arch/sparc/Kconfig | 1 + arch/sparc/include/asm/elf_64.h | 11 +- arch/sparc/include/asm/mmu_64.h | 1 - arch/sparc/vdso/vma.c | 20 +-- arch/x86/Kconfig | 2 + arch/x86/entry/common.c | 10 +- arch/x86/entry/vdso/extable.c | 4 +- arch/x86/entry/vdso/vma.c | 79 ++++----- arch/x86/ia32/ia32_signal.c | 18 ++- arch/x86/include/asm/compat.h | 6 + arch/x86/include/asm/elf.h | 44 ++--- arch/x86/include/asm/mmu.h | 1 - arch/x86/include/asm/mmu_context.h | 5 - arch/x86/include/asm/vdso.h | 4 + arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 3 +- arch/x86/kernel/signal.c | 25 ++- arch/x86/um/asm/elf.h | 9 +- arch/x86/um/vdso/vma.c | 2 +- fs/Kconfig.binfmt | 3 + fs/aio.c | 3 +- fs/binfmt_elf.c | 19 ++- fs/binfmt_elf_fdpic.c | 17 +- fs/compat_binfmt_elf.c | 12 -- include/asm-generic/mm_hooks.h | 9 +- include/linux/elf.h | 24 ++- include/linux/mm.h | 3 +- include/linux/mm_types.h | 21 ++- kernel/fork.c | 1 + mm/mmap.c | 28 ++-- mm/mremap.c | 2 +- tools/testing/selftests/x86/.gitignore | 1 + tools/testing/selftests/x86/Makefile | 11 +- .../testing/selftests/x86/test_munmap_vdso.c | 151 ++++++++++++++++++ 91 files changed, 511 insertions(+), 491 deletions(-) create mode 100644 tools/testing/selftests/x86/test_munmap_vdso.c
base-commit: 614124bea77e452aa6df7a8714e8bc820b489922 -- 2.31.1
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