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Yoshihiro YUNOMAE 2016-05-03 16:33:09 +09:00
parent c488370cc3
commit f057964f98

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@ -344,7 +344,7 @@ After this we can see the call of the `LOCKDEP_SYS_EXIT` macro from the [arch/x8
LOCKDEP_SYS_EXIT LOCKDEP_SYS_EXIT
``` ```
The implementation of this macro depends on the `CONFIG_DEBUG_LOCK_ALLOC` kernel configuration option that allows us to debug locks on exit from a system call. And again, we will not consider it in this chapter, but will return to it in a separate one. In the end of the `entry_SYSCALL_64` function we restore all general purpose registers besides `rxc` and `r11`, because the `rcx` register must contain the return address to the application that called system call and the `r11` register contains the old [flags register](https://en.wikipedia.org/wiki/FLAGS_register). After all general purpose registers are restored, we fill `rcx` with the return address, `r11` register with the flags and `rsp` with the old stack pointer: The implementation of this macro depends on the `CONFIG_DEBUG_LOCK_ALLOC` kernel configuration option that allows us to debug locks on exit from a system call. And again, we will not consider it in this chapter, but will return to it in a separate one. In the end of the `entry_SYSCALL_64` function we restore all general purpose registers besides `rcx` and `r11`, because the `rcx` register must contain the return address to the application that called system call and the `r11` register contains the old [flags register](https://en.wikipedia.org/wiki/FLAGS_register). After all general purpose registers are restored, we fill `rcx` with the return address, `r11` register with the flags and `rsp` with the old stack pointer:
```assembly ```assembly
RESTORE_C_REGS_EXCEPT_RCX_R11 RESTORE_C_REGS_EXCEPT_RCX_R11