v2: - resent previous version, rebase only This series is split out of userfaultfd-wp series to only cover the general page fault changes, since it seems to make sense itself. Basically it does two things: (a) Allows the page fault handlers to be more interactive on not only SIGKILL, but also the rest of userspace signals (especially for user-mode faults), and, (b) Allows the page fault retry (VM_FAULT_RETRY) to happen for more than once. I'm keeping the CC list as in uffd-wp v5, hopefully I'm not sending too much spams... And, instead of writting again the cover letter, I'm just copy-pasting my previous link here which has more details on why we do this: https://patchwork.kernel.org/cover/10691991/ The major change from that latest version should be that we introduced a new page fault flag FAULT_FLAG_INTERRUPTIBLE as suggested by Linus [1] to represents that we would like the fault handler to respond to non-fatal signals. Also, we're more careful now on when to do the immediate return of the page fault for such signals. For example, now we'll only check against signal_pending() for user-mode page faults and we keep the kernel-mode page fault patch untouched for it. More information can be found in separate patches. The patchset is only lightly tested on x86. All comments are greatly welcomed. Thanks, [1] https://lkml.org/lkml/2019/6/25/1382 Peter Xu (7): mm/gup: Rename "nonblocking" to "locked" where proper mm: Introduce FAULT_FLAG_DEFAULT mm: Introduce FAULT_FLAG_INTERRUPTIBLE mm: Return faster for non-fatal signals in user mode faults userfaultfd: Don't retake mmap_sem to emulate NOPAGE mm: Allow VM_FAULT_RETRY for multiple times mm/gup: Allow VM_FAULT_RETRY for multiple times arch/alpha/mm/fault.c | 7 +-- arch/arc/mm/fault.c | 8 +++- arch/arm/mm/fault.c | 14 +++--- arch/arm64/mm/fault.c | 16 +++---- arch/hexagon/mm/vm_fault.c | 6 +-- arch/ia64/mm/fault.c | 6 +-- arch/m68k/mm/fault.c | 10 ++-- arch/microblaze/mm/fault.c | 6 +-- arch/mips/mm/fault.c | 6 +-- arch/nds32/mm/fault.c | 12 ++--- arch/nios2/mm/fault.c | 8 ++-- arch/openrisc/mm/fault.c | 6 +-- arch/parisc/mm/fault.c | 9 ++-- arch/powerpc/mm/fault.c | 10 ++-- arch/riscv/mm/fault.c | 12 ++--- arch/s390/mm/fault.c | 11 ++--- arch/sh/mm/fault.c | 7 ++- arch/sparc/mm/fault_32.c | 5 +- arch/sparc/mm/fault_64.c | 6 +-- arch/um/kernel/trap.c | 7 +-- arch/unicore32/mm/fault.c | 11 ++--- arch/x86/mm/fault.c | 6 +-- arch/xtensa/mm/fault.c | 6 +-- drivers/gpu/drm/ttm/ttm_bo_vm.c | 12 +++-- fs/userfaultfd.c | 28 +----------- include/linux/mm.h | 81 +++++++++++++++++++++++++++++---- include/linux/sched/signal.h | 12 +++++ mm/filemap.c | 2 +- mm/gup.c | 61 ++++++++++++++----------- mm/hugetlb.c | 14 +++--- mm/shmem.c | 2 +- 31 files changed, 227 insertions(+), 180 deletions(-) -- 2.21.0