Hi, First version of this series[1] was briefly in linux-next but had to be reverted due to a bug where schedule would end up being called while user_access was active[2].
After clarifications[3], rescheduling while in a user_access region is not allowed. * Patch 1 clarifies this restriction in the API and attempts to check against violations of the restriction. * Patch 2 implements the unsafe accessors for arm64 Changes since v1: - Add a way to detect code calling schedule within a user_access region - Make sure put_user/get_user arguments are evaluated before disabling PAN [1] https://www.spinics.net/lists/arm-kernel/msg674925.html [2] https://patchwork.kernel.org/patch/10634783/ [3] https://lkml.org/lkml/2018/11/28/50 Cheers, Julien --> Julien Thierry (2): uaccess: Check no rescheduling function is called in unsafe region arm64: uaccess: Implement unsafe accessors arch/arm64/include/asm/sysreg.h | 2 + arch/arm64/include/asm/uaccess.h | 89 +++++++++++++++++++++++++++++++--------- include/linux/kernel.h | 6 ++- include/linux/uaccess.h | 11 +++++ kernel/sched/core.c | 19 +++++++++ 5 files changed, 105 insertions(+), 22 deletions(-) -- 1.9.1
