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The descriptors may be either interrupt gates, trap gates or, for 32-bit protected mode only, task gates. Interrupt and trap gates point to a memory location containing code to execute by specifying both a segment (present in either the GDT or LDT) and an offset within that segment. The only difference between trap and interrupt gates is that ...
Ideally, only highly trusted kernel code is allowed to execute in the unrestricted mode; everything else (including non-supervisory portions of the operating system) runs in a restricted mode and must use a system call (via interrupt) to request the kernel perform on its behalf any operation that could damage or compromise the system, making it ...
the segment selector in a call, interrupt or trap gate does not point to a code segment; violating privilege rules; enabling paging whilst disabling protection; referencing the interrupt descriptor table following an interrupt or exception that is not an interrupt, trap, or a task gate; Legacy SSE: Memory operand is not 16-byte aligned.
For example, INT 13H will generate the 20th software interrupt (0x13 is nineteen (19) in hexadecimal notation, and the count starts at 0), causing the function pointed to by the 20th vector in the interrupt table to be executed. INT is widely used in real mode. In protected mode, INT is a privileged instruction. [1]
In systems that support privileged mode, only privileged applications (usually the OS kernel) may modify the Interrupt flag. In an x86 system this only applies to protected mode code (Real mode code may always modify the Interrupt flag). CLI and STI are privileged instructions, which cause a general protection fault if an unprivileged ...
In modern operating systems, a triple fault is typically caused by a buffer overflow or underflow in a device driver which writes over the interrupt descriptor table (IDT). If the IDT is corrupted, when the next interrupt happens, the processor will be unable to call either the needed interrupt handler or the double fault handler because the ...
In computer systems programming, an interrupt handler, also known as an interrupt service routine or ISR, is a special block of code associated with a specific interrupt condition. Interrupt handlers are initiated by hardware interrupts, software interrupt instructions, or software exceptions , and are used for implementing device drivers or ...
The SIGINT signal is sent to a process by its controlling terminal when a user wishes to interrupt the process. This is typically initiated by pressing Ctrl + C , but on some systems, the " delete " character or " break " key can be used.