This is a series of patches of nommu arch addition to UML. It would be nice to ask comments/opinions on this.
There are still several limitations/issues which we already found; here is the list of those issues. - there are no mechanism implemented to cache for mapped memory of exec(2) thus, always read files from filesystem upon every exec, which makes slow on some benchmark (lmbench). - memory mapped by loadable modules are not distinguished from userspace memory. -- Hajime v3: - add seccomp-based syscall hook in addition to zpoline [06/13] - remove RFC, add a line to MAINTAINERS file - fix kernel test robot warnings [02/13,08/13,10/13] - add base-commit tag to cover letter - pull the latest uml/next - clean up SIGSEGV handling [10/13] - detect fsgsbase availability with elf aux vector [08/13] - simplify vdso code with macros [09/13] RFC v2: - https://lore.kernel.org/linux-um/cover.1731290567.git.thehaj...@gmail.com/ - base branch is now uml/linux.git instead of torvalds/linux.git. - reorganize the patch series to clean up - fixed various coding styles issues - clean up exec code path [07/13] - fixed the crash/SIGSEGV case on userspace programs [10/13] - add seccomp filter to limit syscall caller address [06/13] - detect fsgsbase availability with sigsetjmp/siglongjmp [08/13] - removes unrelated changes - removes unneeded ifndef CONFIG_MMU - convert UML_CONFIG_MMU to CONFIG_MMU as using uml/linux.git - proposed a patch of maple-tree issue (resolving a limitation in RFC v1) https://lore.kernel.org/linux-mm/20241108222834.3625217-1-thehaj...@gmail.com/ RFC: - https://lore.kernel.org/linux-um/cover.1729770373.git.thehaj...@gmail.com/ Hajime Tazaki (13): fs: binfmt_elf_efpic: add architecture hook elf_arch_finalize_exec x86/um: nommu: elf loader for fdpic um: nommu: memory handling x86/um: nommu: syscall handling x86/um: nommu: syscall translation by zpoline um: nommu: syscalls handler from userspace by seccomp filter x86/um: nommu: process/thread handling um: nommu: configure fs register on host syscall invocation x86/um/vdso: nommu: vdso memory update x86/um: nommu: signal handling um: change machine name for uname output um: nommu: add documentation of nommu UML um: nommu: plug nommu code into build system Documentation/virt/uml/nommu-uml.rst | 230 +++++++++++++++++++++++ MAINTAINERS | 1 + arch/um/Kconfig | 14 +- arch/um/Makefile | 6 + arch/um/configs/x86_64_nommu_defconfig | 64 +++++++ arch/um/include/asm/Kbuild | 1 + arch/um/include/asm/futex.h | 4 + arch/um/include/asm/mmu.h | 8 + arch/um/include/asm/mmu_context.h | 13 +- arch/um/include/asm/ptrace-generic.h | 6 + arch/um/include/asm/tlbflush.h | 22 +++ arch/um/include/asm/uaccess.h | 7 +- arch/um/include/shared/kern_util.h | 2 + arch/um/include/shared/os.h | 15 ++ arch/um/kernel/Makefile | 3 +- arch/um/kernel/mem.c | 12 +- arch/um/kernel/physmem.c | 6 + arch/um/kernel/process.c | 33 +++- arch/um/kernel/skas/Makefile | 4 +- arch/um/kernel/trap.c | 16 ++ arch/um/kernel/um_arch.c | 4 + arch/um/os-Linux/main.c | 5 + arch/um/os-Linux/process.c | 96 +++++++++- arch/um/os-Linux/signal.c | 38 +++- arch/um/os-Linux/skas/process.c | 4 + arch/um/os-Linux/start_up.c | 20 ++ arch/um/os-Linux/util.c | 3 +- arch/x86/um/Makefile | 18 ++ arch/x86/um/asm/elf.h | 11 +- arch/x86/um/asm/module.h | 24 --- arch/x86/um/asm/processor.h | 12 ++ arch/x86/um/do_syscall_64.c | 109 +++++++++++ arch/x86/um/entry_64.S | 108 +++++++++++ arch/x86/um/os-Linux/mcontext.c | 22 +++ arch/x86/um/shared/sysdep/mcontext.h | 4 + arch/x86/um/shared/sysdep/syscalls_64.h | 6 + arch/x86/um/signal.c | 37 +++- arch/x86/um/syscalls_64.c | 69 +++++++ arch/x86/um/vdso/um_vdso.c | 41 ++-- arch/x86/um/vdso/vma.c | 14 ++ arch/x86/um/zpoline.c | 238 ++++++++++++++++++++++++ fs/Kconfig.binfmt | 2 +- fs/binfmt_elf_fdpic.c | 10 + include/linux/elf-fdpic.h | 3 + 44 files changed, 1307 insertions(+), 58 deletions(-) create mode 100644 Documentation/virt/uml/nommu-uml.rst create mode 100644 arch/um/configs/x86_64_nommu_defconfig delete mode 100644 arch/x86/um/asm/module.h create mode 100644 arch/x86/um/do_syscall_64.c create mode 100644 arch/x86/um/entry_64.S create mode 100644 arch/x86/um/zpoline.c base-commit: bed2cc482600296fe04edbc38005ba2851449c10 -- 2.43.0
