Make syscall handler stub easier to debug

This commit is contained in:
Alex 2023-05-04 22:40:18 +03:00
parent 533b945e84
commit 71c9306828
Signed by untrusted user who does not match committer: enderice2
GPG Key ID: EACC3AD603BAB4DD

View File

@ -31,17 +31,17 @@ extern "C" void SystemCallHandlerStub();
extern "C" __naked __used __no_stack_protector __aligned(16) void SystemCallHandlerStub()
{
asmv("swapgs\n"
asmv("swapgs\n");
"mov %rsp, %gs:0x8\n" // CPUData->TempStack
"mov %gs:0x0, %rsp\n" // CPUData->SystemCallStack
"push $0x1b\n" // user data segment
"push %gs:0x8\n" // saved stack
"push %r11\n" // saved rflags
"push $0x23\n" // user code segment
"push %rcx\n" // Current RIP
asmv("mov %rsp, %gs:0x8\n"); // CPUData->TempStack
asmv("mov %gs:0x0, %rsp\n"); // CPUData->SystemCallStack
asmv("push $0x1b\n"); // user data segment
asmv("push %gs:0x8\n"); // saved stack
asmv("push %r11\n"); // saved rflags
asmv("push $0x23\n"); // user code segment
asmv("push %rcx\n"); // Current RIP
"push %rax\n"
asmv("push %rax\n"
"push %rbx\n"
"push %rcx\n"
"push %rdx\n"
@ -55,13 +55,13 @@ extern "C" __naked __used __no_stack_protector __aligned(16) void SystemCallHand
"push %r12\n"
"push %r13\n"
"push %r14\n"
"push %r15\n"
"push %r15\n");
"mov %rsp, %rdi\n"
"mov $0, %rbp\n"
"call SystemCallsHandler\n"
asmv("mov %rsp, %rdi\n");
asmv("mov $0, %rbp\n");
asmv("call SystemCallsHandler\n");
"pop %r15\n"
asmv("pop %r15\n"
"pop %r14\n"
"pop %r13\n"
"pop %r12\n"
@ -74,13 +74,16 @@ extern "C" __naked __used __no_stack_protector __aligned(16) void SystemCallHand
"pop %rsi\n"
"pop %rdx\n"
"pop %rcx\n"
"pop %rbx\n"
"pop %rbx\n");
"mov %gs:0x8, %rsp\n" // CPUData->TempStack
asmv("mov %gs:0x8, %rsp\n"); // CPUData->TempStack
#ifdef DEBUG
asmv("movq $0, %gs:0x8\n"); // Easier to debug stacks // FIXME: Can't use xor
#endif
"swapgs\n"
"sti\n"
"sysretq\n");
asmv("swapgs\n");
asmv("sti\n");
asmv("sysretq\n");
}
void InitializeSystemCalls()