Messages in this thread Patch in this message | | | Date | Fri, 29 May 2020 23:27:35 +0200 | From | Peter Zijlstra <> | Subject | [PATCH 07/14] x86/entry, mce: Disallow #DB during #MC |
| |
#MC is fragile as heck, don't tempt fate.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- arch/x86/kernel/cpu/mce/core.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
--- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -1936,22 +1936,34 @@ static __always_inline void exc_machine_ /* MCE hit kernel mode */ DEFINE_IDTENTRY_MCE(exc_machine_check) { + unsigned long dr7; + + dr7 = local_db_save(); exc_machine_check_kernel(regs); + local_db_restore(dr7); } /* The user mode variant. */ DEFINE_IDTENTRY_MCE_USER(exc_machine_check) { + unsigned long dr7; + + dr7 = local_db_save(); exc_machine_check_user(regs); + local_db_restore(dr7); } #else /* 32bit unified entry point */ DEFINE_IDTENTRY_MCE(exc_machine_check) { + unsigned long dr7; + + dr7 = local_db_save(); if (user_mode(regs)) exc_machine_check_user(regs); else exc_machine_check_kernel(regs); + local_db_restore(dr7); } #endif
| |