WSL2-Linux-Kernel/arch
Tony Luck c0ab7ffce2 x86/mce: Recover from poison found while copying from user space
Existing kernel code can only recover from a machine check on code that
is tagged in the exception table with a fault handling recovery path.

Add two new fields in the task structure to pass information from
machine check handler to the "task_work" that is queued to run before
the task returns to user mode:

+ mce_vaddr: will be initialized to the user virtual address of the fault
  in the case where the fault occurred in the kernel copying data from
  a user address.  This is so that kill_me_maybe() can provide that
  information to the user SIGBUS handler.

+ mce_kflags: copy of the struct mce.kflags needed by kill_me_maybe()
  to determine if mce_vaddr is applicable to this error.

Add code to recover from a machine check while copying data from user
space to the kernel. Action for this case is the same as if the user
touched the poison directly; unmap the page and send a SIGBUS to the task.

Use a new helper function to share common code between the "fault
in user mode" case and the "fault while copying from user" case.

New code paths will be activated by the next patch which sets
MCE_IN_KERNEL_COPYIN.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201006210910.21062-6-tony.luck@intel.com
2020-10-07 11:29:41 +02:00
..
alpha iomap: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
arc mm/gup: remove task_struct pointer for all gup code 2020-08-12 10:58:04 -07:00
arm all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
arm64 all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
c6x Merge branch 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 09:29:25 -07:00
csky mm/csky: use general page fault accounting 2020-08-12 10:58:03 -07:00
h8300 uaccess: remove segment_eq 2020-08-12 10:57:58 -07:00
hexagon mm/hexagon: use general page fault accounting 2020-08-12 10:58:03 -07:00
ia64 all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
m68k Cleanup, SECCOMP_FILTER support, message printing fixes, and other 2020-08-15 18:50:32 -07:00
microblaze all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
mips all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
nds32 mm/nds32: use general page fault accounting 2020-08-12 10:58:03 -07:00
nios2 mm/nios2: use general page fault accounting 2020-08-12 10:58:03 -07:00
openrisc OpenRISC updates for 5.9 2020-08-14 14:04:53 -07:00
parisc parisc: fix PMD pages allocation by restoring pmd_alloc_one() 2020-08-16 10:53:13 -07:00
powerpc x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}() 2020-10-06 11:18:04 +02:00
riscv A RISC-V Fix for 5.9 2020-08-15 18:54:42 -07:00
s390 all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
sh Cleanup, SECCOMP_FILTER support, message printing fixes, and other 2020-08-15 18:50:32 -07:00
sparc all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
um Cleanup, SECCOMP_FILTER support, message printing fixes, and other 2020-08-15 18:50:32 -07:00
x86 x86/mce: Recover from poison found while copying from user space 2020-10-07 11:29:41 +02:00
xtensa all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
.gitignore
Kconfig A set oftimekeeping/VDSO updates: 2020-08-14 14:26:08 -07:00