diff options
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/irq_64.c | 19 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 8 |
2 files changed, 14 insertions, 13 deletions
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index 206d0b90a3ab..e39d7197f9fb 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -25,9 +25,18 @@ int sysctl_panic_on_stackoverflow; /* * Probabilistic stack overflow check: * - * Only check the stack in process context, because everything else - * runs on the big interrupt stacks. Checking reliably is too expensive, - * so we just check from interrupts. + * Regular device interrupts can enter on the following stacks: + * + * - User stack + * + * - Kernel task stack + * + * - Interrupt stack if a device driver reenables interrupts + * which should only happen in really old drivers. + * + * - Debug IST stack + * + * All other contexts are invalid. */ static inline void stack_overflow_check(struct pt_regs *regs) { @@ -53,8 +62,8 @@ static inline void stack_overflow_check(struct pt_regs *regs) return; oist = this_cpu_ptr(&orig_ist); - estack_top = (u64)oist->ist[0] - EXCEPTION_STKSZ + STACK_TOP_MARGIN; - estack_bottom = (u64)oist->ist[N_EXCEPTION_STACKS - 1]; + estack_bottom = (u64)oist->ist[DEBUG_STACK]; + estack_top = estack_bottom - DEBUG_STKSZ + STACK_TOP_MARGIN; if (regs->sp >= estack_top && regs->sp <= estack_bottom) return; diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 6223929fc621..8c73bf1492b8 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -61,7 +61,6 @@ #include <asm/alternative.h> #include <asm/fpu/xstate.h> #include <asm/trace/mpx.h> -#include <asm/nospec-branch.h> #include <asm/mpx.h> #include <asm/vm86.h> @@ -338,13 +337,6 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) regs->ip = (unsigned long)general_protection; regs->sp = (unsigned long)&normal_regs->orig_ax; - /* - * This situation can be triggered by userspace via - * modify_ldt(2) and the return does not take the regular - * user space exit, so a CPU buffer clear is required when - * MDS mitigation is enabled. - */ - mds_user_clear_cpu_buffers(); return; } #endif |