9592747538
We currently pretend that IST context is like standard exception context, but this is incorrect. IST entries from userspace are like standard exceptions except that they use per-cpu stacks, so they are atomic. IST entries from kernel space are like NMIs from RCU's perspective -- they are not quiescent states even if they interrupted the kernel during a quiescent state. Add and use ist_enter and ist_exit to track IST context. Even though x86_32 has no IST stacks, we track these interrupts the same way. This fixes two issues: - Scheduling from an IST interrupt handler will now warn. It would previously appear to work as long as we got lucky and nothing overwrote the stack frame. (I don't know of any bugs in this that would trigger the warning, but it's good to be on the safe side.) - RCU handling in IST context was dangerous. As far as I know, only machine checks were likely to trigger this, but it's good to be on the safe side. Note that the machine check handlers appears to have been missing any context tracking at all before this patch. Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Signed-off-by: Andy Lutomirski <luto@amacapital.net>
143 lines
5.0 KiB
C
143 lines
5.0 KiB
C
#ifndef _ASM_X86_TRAPS_H
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#define _ASM_X86_TRAPS_H
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#include <linux/context_tracking_state.h>
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#include <linux/kprobes.h>
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#include <asm/debugreg.h>
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#include <asm/siginfo.h> /* TRAP_TRACE, ... */
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#define dotraplinkage __visible
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asmlinkage void divide_error(void);
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asmlinkage void debug(void);
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asmlinkage void nmi(void);
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asmlinkage void int3(void);
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asmlinkage void xen_debug(void);
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asmlinkage void xen_int3(void);
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asmlinkage void xen_stack_segment(void);
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asmlinkage void overflow(void);
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asmlinkage void bounds(void);
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asmlinkage void invalid_op(void);
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asmlinkage void device_not_available(void);
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#ifdef CONFIG_X86_64
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asmlinkage void double_fault(void);
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#endif
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asmlinkage void coprocessor_segment_overrun(void);
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asmlinkage void invalid_TSS(void);
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asmlinkage void segment_not_present(void);
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asmlinkage void stack_segment(void);
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asmlinkage void general_protection(void);
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asmlinkage void page_fault(void);
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asmlinkage void async_page_fault(void);
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asmlinkage void spurious_interrupt_bug(void);
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asmlinkage void coprocessor_error(void);
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asmlinkage void alignment_check(void);
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#ifdef CONFIG_X86_MCE
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asmlinkage void machine_check(void);
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#endif /* CONFIG_X86_MCE */
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asmlinkage void simd_coprocessor_error(void);
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#ifdef CONFIG_TRACING
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asmlinkage void trace_page_fault(void);
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#define trace_stack_segment stack_segment
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#define trace_divide_error divide_error
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#define trace_bounds bounds
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#define trace_invalid_op invalid_op
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#define trace_device_not_available device_not_available
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#define trace_coprocessor_segment_overrun coprocessor_segment_overrun
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#define trace_invalid_TSS invalid_TSS
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#define trace_segment_not_present segment_not_present
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#define trace_general_protection general_protection
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#define trace_spurious_interrupt_bug spurious_interrupt_bug
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#define trace_coprocessor_error coprocessor_error
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#define trace_alignment_check alignment_check
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#define trace_simd_coprocessor_error simd_coprocessor_error
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#define trace_async_page_fault async_page_fault
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#endif
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dotraplinkage void do_divide_error(struct pt_regs *, long);
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dotraplinkage void do_debug(struct pt_regs *, long);
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dotraplinkage void do_nmi(struct pt_regs *, long);
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dotraplinkage void do_int3(struct pt_regs *, long);
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dotraplinkage void do_overflow(struct pt_regs *, long);
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dotraplinkage void do_bounds(struct pt_regs *, long);
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dotraplinkage void do_invalid_op(struct pt_regs *, long);
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dotraplinkage void do_device_not_available(struct pt_regs *, long);
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dotraplinkage void do_coprocessor_segment_overrun(struct pt_regs *, long);
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dotraplinkage void do_invalid_TSS(struct pt_regs *, long);
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dotraplinkage void do_segment_not_present(struct pt_regs *, long);
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dotraplinkage void do_stack_segment(struct pt_regs *, long);
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#ifdef CONFIG_X86_64
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dotraplinkage void do_double_fault(struct pt_regs *, long);
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asmlinkage struct pt_regs *sync_regs(struct pt_regs *);
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#endif
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dotraplinkage void do_general_protection(struct pt_regs *, long);
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dotraplinkage void do_page_fault(struct pt_regs *, unsigned long);
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#ifdef CONFIG_TRACING
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dotraplinkage void trace_do_page_fault(struct pt_regs *, unsigned long);
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#else
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static inline void trace_do_page_fault(struct pt_regs *regs, unsigned long error)
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{
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do_page_fault(regs, error);
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}
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#endif
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dotraplinkage void do_spurious_interrupt_bug(struct pt_regs *, long);
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dotraplinkage void do_coprocessor_error(struct pt_regs *, long);
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dotraplinkage void do_alignment_check(struct pt_regs *, long);
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#ifdef CONFIG_X86_MCE
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dotraplinkage void do_machine_check(struct pt_regs *, long);
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#endif
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dotraplinkage void do_simd_coprocessor_error(struct pt_regs *, long);
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#ifdef CONFIG_X86_32
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dotraplinkage void do_iret_error(struct pt_regs *, long);
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#endif
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static inline int get_si_code(unsigned long condition)
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{
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if (condition & DR_STEP)
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return TRAP_TRACE;
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else if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3))
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return TRAP_HWBKPT;
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else
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return TRAP_BRKPT;
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}
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extern int panic_on_unrecovered_nmi;
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void math_emulate(struct math_emu_info *);
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#ifndef CONFIG_X86_32
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asmlinkage void smp_thermal_interrupt(void);
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asmlinkage void mce_threshold_interrupt(void);
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#endif
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extern enum ctx_state ist_enter(struct pt_regs *regs);
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extern void ist_exit(struct pt_regs *regs, enum ctx_state prev_state);
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/* Interrupts/Exceptions */
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enum {
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X86_TRAP_DE = 0, /* 0, Divide-by-zero */
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X86_TRAP_DB, /* 1, Debug */
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X86_TRAP_NMI, /* 2, Non-maskable Interrupt */
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X86_TRAP_BP, /* 3, Breakpoint */
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X86_TRAP_OF, /* 4, Overflow */
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X86_TRAP_BR, /* 5, Bound Range Exceeded */
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X86_TRAP_UD, /* 6, Invalid Opcode */
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X86_TRAP_NM, /* 7, Device Not Available */
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X86_TRAP_DF, /* 8, Double Fault */
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X86_TRAP_OLD_MF, /* 9, Coprocessor Segment Overrun */
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X86_TRAP_TS, /* 10, Invalid TSS */
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X86_TRAP_NP, /* 11, Segment Not Present */
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X86_TRAP_SS, /* 12, Stack Segment Fault */
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X86_TRAP_GP, /* 13, General Protection Fault */
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X86_TRAP_PF, /* 14, Page Fault */
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X86_TRAP_SPURIOUS, /* 15, Spurious Interrupt */
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X86_TRAP_MF, /* 16, x87 Floating-Point Exception */
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X86_TRAP_AC, /* 17, Alignment Check */
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X86_TRAP_MC, /* 18, Machine Check */
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X86_TRAP_XF, /* 19, SIMD Floating-Point Exception */
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X86_TRAP_IRET = 32, /* 32, IRET Exception */
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};
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#endif /* _ASM_X86_TRAPS_H */
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