This patchset adds support for the Memory Protection Extensions (MPX) feature found in future Intel processors. MPX can be used in conjunction with compiler changes to check memory references, for those references whose compile-time normal intentions are usurped at runtime due to buffer overflow or underflow. MPX provides this capability at very low performance overhead for newly compiled code, and provides compatibility mechanisms with legacy software components. MPX architecture is designed allow a machine to run both MPX enabled software and legacy software that is MPX unaware. In such a case, the legacy software does not benefit from MPX, but it also does not experience any change in functionality or reduction in performance. More information about Intel MPX can be found in "Intel(R) Architecture Instruction Set Extensions Programming Reference". To get the advantage of MPX, changes are required in the OS kernel, binutils, compiler, system libraries support. New GCC option -fmpx is introduced to utilize MPX instructions. Currently GCC compiler sources with MPX support is available in a separate branch in common GCC SVN repository. See GCC SVN page (http://gcc.gnu.org/svn.html) for details. To have the full protection, we had to add MPX instrumentation to all the necessary Glibc routines (e.g. memcpy) written on assembler, and compile Glibc with the MPX enabled GCC compiler. Currently MPX enabled Glibc source can be found in Glibc git repository. Enabling an application to use MPX will generally not require source code updates but there is some runtime code, which is responsible for configuring and enabling MPX, needed in order to make use of MPX. For most applications this runtime support will be available by linking to a library supplied by the compiler or possibly it will come directly from the OS once OS versions that support MPX are available. MPX kernel code, namely this patchset, has mainly the 2 responsibilities: provide handlers for bounds faults (#BR), and manage bounds memory. The high-level areas modified in the patchset are as follow: 1) struct siginfo is extended to include bound violation information. 2) two prctl() commands are added to do performance optimization. Currently no hardware with MPX ISA is available but it is always possible to use SDE (Intel(R) software Development Emulator) instead, which can be downloaded from http://software.intel.com/en-us/articles/intel-software-development-emulator In addition, this patchset has been tested on Intel internal hardware platform for MPX testing. Future TODO items: 1) support 32-bit binaries on 64-bit kernels. Changes since v1: * check to see if #BR occurred in userspace or kernel space. * use generic structure and macro as much as possible when decode mpx instructions. Changes since v2: * fix some compile warnings. * update documentation. Changes since v3: * correct some syntax errors at documentation, and document extended struct siginfo. * for kill the process when the error code of BNDSTATUS is 3. * add some comments. * remove new prctl() commands. * fix some compile warnings for 32-bit. Changes since v4: * raise SIGBUS if the allocations of the bound tables fail. Changes since v5: * hook unmap() path to cleanup unused bounds tables, and use new prctl() command to register bounds directory address to struct mm_struct to check whether one process is MPX enabled during unmap(). * in order track precisely MPX memory usage, add MPX specific mmap interface and one VM_MPX flag to check whether a VMA is MPX bounds table. * add macro cpu_has_mpx to do performance optimization. * sync struct figinfo for mips with general version to avoid build issue. Changes since v6: * because arch_vma_name is removed, this patchset have toset MPX specific ->vm_ops to do the same thing. * fix warnings for 32 bit arch. * add more description into these patches. Qiaowei Ren (10): x86, mpx: introduce VM_MPX to indicate that a VMA is MPX specific x86, mpx: add MPX specific mmap interface x86, mpx: add macro cpu_has_mpx x86, mpx: hook #BR exception handler to allocate bound tables x86, mpx: extend siginfo structure to include bound violation information mips: sync struct siginfo with general version x86, mpx: decode MPX instruction to get bound violation information x86, mpx: add prctl commands PR_MPX_REGISTER, PR_MPX_UNREGISTER x86, mpx: cleanup unused bound tables x86, mpx: add documentation on Intel MPX Documentation/x86/intel_mpx.txt | 127 +++++++++++ arch/mips/include/uapi/asm/siginfo.h | 4 + arch/x86/Kconfig | 4 + arch/x86/include/asm/cpufeature.h | 6 + arch/x86/include/asm/mmu_context.h | 16 ++ arch/x86/include/asm/mpx.h | 91 ++++++++ arch/x86/include/asm/processor.h | 18 ++ arch/x86/kernel/Makefile | 1 + arch/x86/kernel/mpx.c | 415 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/traps.c | 61 +++++- arch/x86/mm/Makefile | 2 + arch/x86/mm/mpx.c | 260 +++++++++++++++++++++ fs/proc/task_mmu.c | 1 + include/asm-generic/mmu_context.h | 6 + include/linux/mm.h | 2 + include/linux/mm_types.h | 3 + include/uapi/asm-generic/siginfo.h | 9 +- include/uapi/linux/prctl.h | 6 + kernel/signal.c | 4 + kernel/sys.c | 12 + mm/mmap.c | 2 + 21 files changed, 1048 insertions(+), 2 deletions(-) create mode 100644 Documentation/x86/intel_mpx.txt create mode 100644 arch/x86/include/asm/mpx.h create mode 100644 arch/x86/kernel/mpx.c create mode 100644 arch/x86/mm/mpx.c -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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