[RFC PATCH 0/5] x86/hw_breakpoint: protects more cpu entry data

[Lai Jiangshan]

Hello

The patchset is based on (tag: entry-v9-the-rest, tglx-devel/x86/entry).
And it is complement of 3ea11ac991d
("x86/hw_breakpoint: Prevent data breakpoints on cpu_entry_area").

After reading the code, we can see that more data needs to be protected
against hw_breakpoint, otherwise it may cause
dangerous/recursive/unwanted #DB.


Lai Jiangshan (5):
  x86/hw_breakpoint: add within_area() to check data breakpoints
  x86/hw_breakpoint: Prevent data breakpoints on direct GDT
  x86/hw_breakpoint: Prevent data breakpoints on per_cpu cpu_tss_rw
  x86/hw_breakpoint: Prevent data breakpoints on user_pcid_flush_mask
  x86/hw_breakpoint: Prevent data breakpoints on debug_idt_table

Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20200505134058.272448010@xxxxxxxxxxxxx
Link: https://lore.kernel.org/lkml/20200521200513.656533920@xxxxxxxxxxxxx


 arch/x86/kernel/hw_breakpoint.c | 71 +++++++++++++++++++++++++++++----
 1 file changed, 63 insertions(+), 8 deletions(-)

-- 
2.20.1