?????9

1
?????? ?????

• ?????9 ?????? ?-Linux

2
???? ??????

• ???? ??????? ?-Linux
• ?????? ?-IA32
• ???? ???????
• ???? ??????? (IDT)
• ????? ???????
• ????? ?-IDT ?-Linux
• ????? ??????? ?-Linux
• ????? ???????
• ????? ??????? ?????
• ?????? ???????
• ???? ??????

3
???? ??????? ?-Linux (1)

• ????? ??? ??? ????? ????? ????? ????? ????? ?????
  ?? ?????? ??????
• ???? ????? ?????? ???? ?? ???? ?????? ?????? ????
  ??? ????? ?????? ??????
• ?????? ??? ?????? ?????? ????Interrupt Service
  Routine.
• ?-Linux ?? ????? ?? ?????? ????, ??? ????? ?????.
• ????? ????? ?????? ?????? ????? ??? ???? ?????
• ?????? ????? ??? ?????? ????? ?????? ????? ?????
  ????? ??-??? ????? ?? ????? ?? ???? ?????

4
???? ??????? ?-Linux (2)

• ????? ???? ????? ????? ?????? ?????? ?????? ???
  ??? ????? ?? ???? ?????? ?? ?????? ???? ?????? ??
  ???? ?????? ?????? ??????
• ?????? ????? ????? ?-0 ????? ??????
• ??????? IA32 ?? 256 ???? ??????
• ???????? 0-255
• ???? ?????? ???? ?? ????? ?????? (interrupt
  vector)
• ?????? ????? ??????, ?????? ?????? ?????? ?? ???
  ?????? ??????
• ???? ????? ????? ??????? ??????

5
???? ??????? ?-Linux (3)

• ????? ???? ?? ?? ?????? ??????? ?????? ??? ?????
  ?? ?? ??? ?????? ?????? ????
• ????? ???? ????? ????? ?? ????? ????? ??????
• ???? ???? ?????? ??????, ????? ???? ?????? ??????
  ???? ?????? (????? ????? ????? ???? ?????? ?????
  ??????)
• ????? ????? ????? ????? ????? ?????????, ??? ???
  ???? ????? ????
• ????? (nesting)- ?????? ?????? ????? ???? ??????
  ???? ?????? ?????
• ?????? ????? ??????, ???? ?????? ?????? ????
  ??????? ????? ??-?????

6
???? ??????? ?-Linux (4)

• ?????? ??????? ?-Linux ??? ????? ??????? ??
  ?????? ????
• ?????? ?? ????? ????? ????? ???? ?????? (Kernel
  Control Path)
• ?????? ???? ?????? ?? ????? ????? ??????? ??? ???
  ???? ????? ???? ?????? ???? ??????? ?? ???????
  (??????? ?????)
• ????? ?????? ???? ????? ?????? ?? ?????? ??????
• ?? ?? ?????? ??? ??? ?????? ?????
• ????? ?????? ????? ???? ?-Kernel Mode ???? ?????
  ??????? ??? ????? ???? ?????? ??????
• ?????? ?????? ??? ????? ??????? ?? ????? ??? ????
  ?-Kernel Mode

7
?????? ?-IA32 Interrupts

• ?????? ?? ????? ????? ????????? ?"? ????? ?????
  ????????
• ???? ?????? ?????? (masking) ?"? ??? ?-Interrupt
  Flag (IF), ??????? ??????
• ????? ????? ???? ?????? ?? ??????? ?????
• ?????? ?????? cli ?-sti ?????? ??????? ?? ??????
  ?"? ????? ?????? ???? IF
• ????? ????? ?????? ????? ?????? ????? ?????
  ???????
• ?????? ??????? ?? ?????? ??????
• ?????? NMI Non-Maskable Interrupts
• ?????? ?????? ?? ????? ????? ???????, ???? ?????
  ???

8
?????? ?-IA32 Interrupts (2)

• ??????? ?? ????? ??????? ??? ?????? ?????? ????
  ??? ???? (Advanced Programmable Interrupt
  Controller APIC)

????
????
IRQ0
APIC
?????
IRQ7
????? ???
IRQ11
????
9
?????? ?-IA32 Interrupts (3)

• ?? ???? ????? ????? ????? ????? ???? ??? IRQ
  (Interrupt ReQuest) ???? ????? ?????? ?? ???
  ??????? ???? ????? ?????
• ???? 16-24 ???? ????? ???????? IRQ0-IRQ15/IRQ23
• ???? ???? ??? ?????? ????? ?? (IRQ Sharing)
• ? ????? ?????? ????? ????? ????? ?? ??????? ?????
  ????? ??
• ???? ??? ??????? ????? ????? ????? ?????, ???
  ????? ??? ????? ????? ???? ??? ?????
• ???? ?????? ?????? ???? ?? IRQn ???? ??????.
• ???? ???, n32

10
?????? ?-IA32 exceptions

• ?????? ?????????? (??????), ??? ?????? ?"? ?????
  ?????? ?????? ????? ?????? ???? ??? ?"? ??????
  ????????
• ???? ?????? ???? ???????
• ????? ????? ?? ??????
• Faults ??????? ????? ??????? ?????? ??????
  ?????? ??????? ????
• ????? ????? ?-0
• ????? ????? ????? ?????? ??? ?? ?? ?????? ?????
  ?? ?????, ??? ???? ???? ????
• Traps ?????? ????? ????? ?"? ?????? ???????
  ????, ??? ?????? ?? ??? ?????? ??????
• ???? ??"? ????? ?? debuggers, ???? ??????
  breakpoint
• ????? ????? ????? ?????? ??? ?? ????? ??????
  ????? ?-trap
• Aborts ??????? ????? ?????? ?????? ??????
  ??????? ????
• ????? ?????? ????? ??????? ?? ??????? ???? ?????
  ????? ???? Machine Check ?????? ????? ?????
  ?????? ???????

11
programmed exceptions

• ?????? ???????? (programmed exceptions) ?? ??????
  ????? (software interrupts) ?? ??? ?? traps
  ??????? ?????? ?????? ?????
• ??? ???? ????? ???????? ??????
• ?????, ?-Linux ?????? int 0x80 ????? ??????? ?????

12
Interrupt Descriptor Table (1)

• ?????? ?-IA32 ??? ????? ????? ????? ??????
  ?????? ????? ??? ???? ?????? Interrupt
  Descriptor Table (IDT)
• ?????? ?????, idtr, ????? ????? ?-IDT
• ???? ?"? ????? ?????? ???? ??????, ?????? ?????
  lidt
• ?-IDT ?? ????? ???? ?? ????? ?????
• ??"? 256 ??????
• ?? ????? ????? 8 ????
• ?? ????? ????? interrupt descriptor

13
Interrupt Descriptor Table (2)

• ????? ?????
• ???? ??? ??????
• ????? ???? ?????? (segmentoffset)
• DPL ??? CPL ??????? ????? ???? ??????
• ??? ?????? ???? ????? ??????? ??????? (??????
  ?????, debugging), ??????? ?????? ?????
• ??? ?? ?????? ????? (???? ????? ?????)

• 3 ???? ?????? ?-IDT
• Interrupt Gate ??????? ?????
• ??? ?-IF ????? ???????? ????? ?????? ??? ????? ??
• Trap Gate ???????
• ??? ????? ?-IF ????? ?????? ?????? ??? ????? ??
• Task Gate ????? ????? ?????? ?????? ??????
• ??? ?? ???? ?????? ?-Linux, ?? ?????? ???? ???????

14
??????? ?? ?????? ????? ?-IDT
DPL ????? ???? ?????? segoffs ??? ?????? (gate) ?????
0 divide_error trap 0
3 int3 trap 3
0 general_protection trap 13
0 timer interrupt 32
0 disk interrupt 43
3 system_call trap 128
?????? ???? ?????
?? ?????? ???? ?????
15
????? ?-IDT ?-Linux (1)

• ???? ?-IDT ??????? ????? ?"? ?-BIOS
• Linux ?????? ?? ?? ?????, ???? ??????.
• ?????, ?????? ???????? setup_idt() ??????? ?? ??
  ??????? ????? ????? ????? ???? ?????
• Interrupt Gate
• ????? ????? ignore_int()
• ???? ?? ?????? ????? "Unknown Interrupt" ?? ????
  ?????? ?????? ?? ????? ????? ?????? ????? (????
  ??? ?? ???? ?????)
• DPL0
• setup_idt() ?-ignore_int() ??????? ??????? ?????
  ?????? arch/i386/kernel/head.S
• ???? ??????, ???? ???? ?? ?-IDT ????? ?? ???????
  ???????? ?????? ??????? ???????? ??????? ???????
• ????? ????? ?????? ????? ????? ???? ?? ????? ???
  ????? drivers

16
????? ?-IDT ?-Linux (2)

• ????? ????? ????? ???? ????????? ?????, ????????
  ????? ?????? arch/i386/kernel/traps.c
• set_intr_gate(n, addr)
• ?????? ?????? ??????? ?????
• ????? interrupt gate ?????? n ?????, ?? DPL0
  ?????? ???? ????? kcsaddr (kcs ????? ?? ?-code
  segment ?? ??????)
• set_system_gate(n, addr)
• ????? system gate (trap gate ?????? ?????? ?????)
  ?????? n ?????
• ????? kcsaddr, DPL3
• ????? ????? ?????? ??????? ????? ?? ?????? ???
  ?????? ?????
• ????? ??????? debugging ??????? 128 (0x80)
  ??????? ??????? ?????
• set_trap_gate(n,addr)
• ????? trap gate ?????? n ?????, ?? ????? kcsaddr
  ?-DPL0
• ????? ?????? ???????

17
????? ?-IDT ?-Linux (3)

• ???????? trap_init(), ??????? ????? ??????
  arch/i386/kernel/traps.c, ????? ??? ??????? ?????
  ?? ???? ?-IDT. ???? ??? ?????????
• set_trap_gate(0, divide_error)
• ...
• set_system_gate(4, overflow)
• ...
• set_trap_gate(6, invalid_op)
• ...
• set_trap_gate(13, general_protection)
• set_intr_gate(14, page_fault)
• set_trap_gate(16, coprocessor_error)
• ...
• set_system_gate(128, system_call)

18
????? ??????? ?-Linux (1)

• ???? ??? ???????? ???? ??????? ??? ????? -
  hardware error code
• ????, ???? ????? ?????? ???? ??? ??????
• ??? ?????? ?? ???? ????? ??????
• handler_name
• pushl 0 / only if no handler error code /
• pushl do_handler_name / C handler function /
• jmp error_code
• ????? error_code ????? ?? ??? ?????? ??????
  ??????? ???? ?????? ??????? (-1) ?????? ??
  ????????? ????? ?????? (????? ?-SAVE_ALL)
• ?????, error_code ???? ????? ?-do_handler_name ??
  ???????? hardware error code, ?????? ??????
  ????????? (???? struct pt_regs ).
• ???? ????? ?????? ???????, error_code ?????? ??
  ???????? ?? ????? ??????? ???????? ??????
  ?-ret_from_exception ????? ??????

19
????? ??????? ?-Linux (2)

• ????? ????? ?????? ?????? ??????? ?????? signal
  ?????? ?????? ??? ????? ????? ??????
• ??? ?-signal ???? ??-?? ??? ?????? ???????
• ?????? ???? floating point exception ???? SIGFPE
• ????? ?-signal ??????? ??????? ?????? force_sig()
  ??????? ????? ?????? kernel/signal.c
• force_sig(sig_number, current)
• ???? ????? ?-User Mode, ?????? ???? ??? signal
  ?????? ??, ????? ???? ?-signal ??.

20
????? ??????? ????? ?-Linux

• ?? ????? ?? ????? ????? ?????? ???? ?????? ????
• IRQn_interrupt
• pushl n-256
• call common_interrupt
• ?????? ??? ?????? ?????? ???? ??? ?????? ?????
  ??? ?????? ?-common_interrupt, ???? ?????? ???
  ??????? ??? ??????? ???? ????? ??????? ??? ??????
  ???? ??????
• ????? common_interrupt
• common_interrupt
• SAVE_ALL / save registers /
• call do_IRQ / handle interrupt /
• jmp ret_from_intr / resume execution /

21
???????? do_IRQ()
????? ??????? ????? ?-Linux

• ???????? do_IRQ(), ?????? ?-C, ????? ?? ??????
  ?????? ???? ????? ?-APIC ?????? ????????
  handle_IRQ_event() ?????? ?-ISRs
• ???? ????? arch/i386/kernel/irq.c
• do_IRQ() ?????? ??????
• unsigned int do_IRQ(struct pt_regs regs)
• ?????? regs ????? ???????? ???? ????????? ???????
  ???????, ????? ?? ???? ????? ????? ?? ???? ??????
  (???? ????? orig_eax)
• ???? ?????? ???? ?????? ???? common_interrupt

22
????? ?-APIC
????? ??????? ????? ?-Linux

• ???? ????? ????? ?????, ?-APIC ????? ?? ??????
  ?????
• "????" ????? ????? ?? ?????? ?????? ?? ?????
  ????? ??????
• ?????? ?????? (????? ?-Linux) ?????? ?-APIC
  ?????? ????? ??? ????? ?? ????? ????? ?????? ??
  ?????? ????? ??? ????? ????? ?????? ????
• ????? ??, ???? ???????? ?????? ?????, ???? ????
  ???? "??????" (?????? ???? ?????) ??????? ?????
  ??????
• ??? ???, ???? re-entrancy ???? ?????? ????? ???
  ?????
• ????? ?????? ??????, ?? ????? ?-APIC ?????? ?? ??
  ????? ????? ?????

23
???????? do_IRQ() (2)
????? ??????? ????? ?-Linux

• ??? ??????? ?? do_IRQ()
• ????? ??? ?????? ???????
• ????? ????? ??????? ?-APIC
• ????? ????? ????? ?????? ?"? handle_IRQ_event()
• ISR Interrupt Service Routine (????? ?????)
• ????? ??? ?????? ??????? ?-APIC
• ????? ?????? ??????? (????? ?????)

24
????? ?-ISRs (1)
????? ??????? ????? ?-Linux

• ?? ISR ????? ????-??? ???? ????? ????? ??????
  ?????? ????? ??????
• ISR ???? ?????? ???? ?? ??? ???? ?????
• ISR ???? ????? ???? ???? ?????? ??????? ?????
• ??? ???????? ?-Handle_IRQ_event() ????? ??? ?????
  ?????? ?? ISRs ???? ????? ?????? ???????.
• ??? ??? ??-ISRs ??????? ????? ???? ???? ??????
• ????? handle_IRQ_event() ?????? ?? ?? ?-ISRs
  ??????? ???? ?????? ??????? ??? ??? ??.
• ????? ?? ??????? ????? ????? ??????

25
????? ?-ISRs (2)
????? ??????? ????? ?-Linux

• ???????? handle_IRQ_event() ????? ?????
• ?????? ?????? ????? ??? ?? ????? ??? ????
  SA_INTERRUPT
• ????? ?? ?? ?????? ?? ?-ISR ?????? ??????
• ?????? ?? ?-ISRs ??????? ??? ??? ??
• ????? ?? ??????? ???? ?????

26
????? ?????? ??????? ?????

• ????? ??????? ????? ??????? ?????? ????? ??? ??
• ?????, ??????? ????? ?????? (IF ????) ??????
  ?????? ?????? ?????
• ????? ???? ????? ?????? ??????? ?????? ????
  ????? ?????? ?????? ??????? ?????
• ????? ????????
• ????? ?????? ?????? ?????? ????? (???? ?????
  ?????)
• ???, ????? ????? ???????? ?? ??????? ??????
  ??????? ??????

27
????? ?????? ?????? ??????? ?????

• critical ?????? ?????? ????? ???????
  ???????????? ??? ??????? ???????
• ????? ????? ?? ?-APIC
• ????? ?-ISR ?? ????? ???? ??????? ???? ?????
  ????? ????? ?????? ?? ??????. ????? ????? ?????
  ?-ISR ????? ????? ????? ????? ???? ????? ?? ?????
  ???? ?????? ???? ???????
• noncritical ?????? ??? ????? ??? ?????? ??????,
  ?? ??? ???? ?????? ???????
• ????? ????? ??? ???? ????? ????? ?? ????? ??????
  ?-ISR ?? ?????? ???? ?????? ?????? ??????
  ??????? (??? ?? ???? ?? ????? ???????) ??? ????
  ????? ????? ??????
• noncritical deferred ?????? ??? ???? ?????
  ?????? ??????, ?? ?? ????? ?????, ??? ????????
  ?????? ?????? ??????
• ????? ????? ????? ????? ????? ??????? ?????
  ????? ?????? ?????? ?????? ?? ????? ??????.
• ?????? ??? ??????? ?????? ?? ?????? ???????
  (deferrable functions) ?????? ?????

28
???? ?????? ??????? ?-Linux

• Softirq ?????? ?????, ???? ?? ?????? ??????
• ??????? ??????? ?-softirq ????? ????? ??????
  ?????? ???? ?????? ????? (re-entrant)
• Tasklet ??????? ??????, ?????? ????
• ??? ?? tasklet ???? ???? ????? ?????? ???????
  ????? ???? ????? ???? ????? re-entrant
• Bottom Halves tasklets ??????? ?????
• ?? ?-bottom halves ?????? ??? ????? ????, ?????,
  ??? bottom halves (????? ?? ??? ????) ?? ???????
  ?????? ??????? ?????
• ????? ????? ????????? ?????? ?????? ?????? ?????

29
????? ?????? ??????? ?-Linux

• ??? ???? ????, ??????? ???????? ??????? ?????
  ?????
• ?? ????? ???? ?? ?????? ?????? ???? ???? ??????
• ?????? ?? ?? ?????? ??????? ?????? ??????? ???
  ????? ????
• ????? do_IRQ() (??? ?????? ????)
• ???? ????? ??? ????? (kernel thread) ?????. ???
  ?? ?? ??????? ????? ??? ???? ????? ??????
  ???????? ????? ?? ?????? ??????? ??????
  ?-do_softirq()
• ????? ???? ????? ??? ???? ?????? ??????? ???????
• ?? ???? ksoftirqd_CPUn ???? ???? ???? n
• ???? ????? ??? ?? ?? ????? ????? "ps ax"
• ....

30
?????? ?????? ?????? ?????? (1)

• ???? ??? ????? ???? ?????? ?????? ???? ?????
  ?????? ????? (????? ?? ?????) ?-Linux
• ??? ????? ??????? ???? ????? ??? ????? ??????
• ?? ??????? ?????? ????? ?? 32 ???, ???? ?????
  segment registers
• ????? ?? ???? ?"???" ?? ?????? ?????? ????? ????
  ??? ???? ?????? ??? ??? ????? ????
• ????? ??????? ????? ?"? ?????? RESTORE_ALL, ?????
  ???? ??? ????? ?? ?? ???? ????? ??? ??? ?????

31
????? ????? ????? ????? ????? ????? ???????
????? ??????? ?????? ?-User Mode (?? ?????? ????? ???????) ????? ??????? ?????? ?-User Mode (?? ?????? ????? ???????) ????? ??????? ?????? ?-User Mode (?? ?????? ????? ???????) ss
????? ??????? ?????? ?-User Mode (?? ?????? ????? ???????) ????? ??????? ?????? ?-User Mode (?? ?????? ????? ???????) ????? ??????? ?????? ?-User Mode (?? ?????? ????? ???????) esp
??? ?????? ?????? ??? ?????? ?????? ??? ?????? ?????? eflags
????? ???? ???? ?????? ????? ???? ???? ?????? ????? ???? ???? ?????? cs
????? ???? ???? ?????? ????? ???? ???? ?????? ????? ???? ???? ?????? eip
hardware error code (?? 0 ?? ???) ???? ? (-1) ???? ?????? ???? 256 ???? ????? ?????? orig_eax
???? ????????? ????? ?????? ??? ?????? ?"? ????? error_code ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) es
???? ????????? ????? ?????? ??? ?????? ?"? ????? error_code ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ds
???? ????????? ????? ?????? ??? ?????? ?"? ????? error_code ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) eax
???? ????????? ????? ?????? ??? ?????? ?"? ????? error_code ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ebp
???? ????????? ????? ?????? ??? ?????? ?"? ????? error_code ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) edi
???? ????????? ????? ?????? ??? ?????? ?"? ????? error_code ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) esi
???? ????????? ????? ?????? ??? ?????? ?"? ????? error_code ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) edx
???? ????????? ????? ?????? ??? ?????? ?"? ????? error_code ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ecx
???? ????????? ????? ?????? ??? ?????? ?"? ????? error_code ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ???? ????????? ????? ?????? ??? ?????? ?"? ?????? SAVE_ALL (???? ?????? ?????, ??? eax ???? ????? ?? ???? ??????) ebx
32
?????? ?????? ?????? ?????? (3)

• ???? ????? ?? ??????? (????? ssesp, eflags
  ?-cseip) ???? ????? ??????? ?"? ?????
• ssesp ???? ?? ?? ?????? ?????? ???? ??????
  ???????
• ??? ??????? ??????? ??????? ???? ?????? ????
  ??????
• ????? ???? ????? ????? orig_eax, ???? "??? ????"
  ????? ???? ??????? ??? ??? ??????, ?????? ?????
• ?????? ?????? ????? ??????? ?????, ??????
  SAVE_ALL ???? ?? ???? ??? ?????????, ??? ??????
  ????? ??????
• ?????? ??????, ?????? ????? ??? ???? ?????????
  ?"? ????? error_code

33
?????? ?????? ?????? ?????? (4)

• ?????? RESTORE_ALL
• popl ebx
• ..
• popl es
• addl 4, esp
• iret

• ?? ???? ????? ?????? ????? ?????? ?????? ???????
  ???? ????? ?? ????? ??????, ?? ??? ?????? ???? ??
  ??????? ??????? ????? ???? ?????? ?-RESTORE_ALL
• ???? ???? ????? ?????? ?????? ????? ??????
  ??????? ???, ?????? ?-C, ??????? ???????. ???????
  ??? ??????? ????? ?????? ??????? ???? ??????
  ?-RESTORE_ALL

????? ?????? ???? ????????? ????? ??????
????? orig_eax
????? ??? ??????? ?????
34
????? ???? ???? ????? ???????

• ??????, ???? ?????? ?????? ????? ?????? ??? ????
  ????? ????
• ????, ????? ?????? ???? ???? ?? ???? ??? ????
  ?????? ??????
• ?? ???? ?????? ??? ????? ????? ??????? ?? ??????
  ???? ?????
• ?-Linux ?? ???? ???? ????? ???? ???? ????? ??????
  ??????????
• ????? ???, ?? ?????? ?? ????? ????? ???? ???????
  ????? ???? need_resched ????? ??????
• ????? ?????? ??????, ???? ????? ?-User Mode,
  ?????? ?? ???? ?????? ????
• ????? ????, ?? ?????? ?? ?????? ???? signal
  ?????? ?? ???? ????? ?-User Mode

35
???? ????? ??????? (1)

• ??????? ?????? ??????, ?? ????? ????? ?? ????
  ????????? ????? ??????, ???? iret ?????? ??????
  ????? ??????? ?????? ??????
• ???, ???? ??, ?? ???? ???? ??????
• ??? ?????? ?????? ?? ??, ?? ?????? ?? ???????
  ????? ????????
• ??? ???? ?????? ???? ?? ??, ?????? ?-schedule()
• ??? ?? signals ??????? - ?? ???? ??? ?????
  (??????? do_signal())
• ??? ???? ?????? ??? ?????? ???? ???
• ?- ret_from_exception- ???? ???? ????? ??????
• ?-ret_from_intr ???? ???? ????? ?????? ?????
• ?-ret_from_sys_call ???? ???? ????? ??????
  ?????
• ????? ???? ??? ?????? ?? ??????? ???????, ??? ??
  ?????? ?-RESTORE_ALL ?????, ?????? ?????? ???? ???

36
???? ????? ??????? (2)
ret_from_exception
ret_from_intr
ret_from_sys_call
????? ???????
??
??? ?? ???? ?????? ?????
schedule()
??
??
??
??? ?? signals ????????
??
RESTORE_ALL
do_signal()
??