arch/x86_64/syscall_entry.c


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#include "arch/processor.h"
#include "syscall/handler.h"

__attribute__((naked))
void _syscall_entry()
{
    __asm__ volatile(" \
    pushq %%r11; \
    pushq %%rcx; \
    swapgs; \
    movq %%gs:%c[tcb], %%rax; \
    movq %%rsp, %c[sp](%%rax); \
    movq %c[ksp](%%rax), %%rsp; \
    pushq %c[sp](%%rax); \
    callq _syscall_handler; \
    swapgs; \
    popq %%rsp; \
    popq %%rcx; \
    popq %%r11; \
    sysretq; \
    "
    :: [tcb] "i"(offsetof(processor_t, tcb)),
       [sp] "i"(offsetof(tcb_t, sp)),
       [ksp] "i"(offsetof(tcb_t, ksp)));
}