mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-13 11:42:38 +03:00
3da6d89d1f
This can be implemented entirely in userspace by calling tcgetattr(). To avoid screwing up the syscall indexes, this patch also adds a mechanism for removing a syscall without shifting the index of other syscalls. Note that ports will still have to be rebuilt after this change, as their LibC code will try to make the isatty() syscall on startup.
117 lines
3.2 KiB
C++
117 lines
3.2 KiB
C++
#include <Kernel/Arch/i386/CPU.h>
|
|
#include <Kernel/Process.h>
|
|
#include <Kernel/ProcessTracer.h>
|
|
#include <Kernel/Syscall.h>
|
|
#include <Kernel/VM/MemoryManager.h>
|
|
|
|
extern "C" void syscall_trap_entry(RegisterDump);
|
|
extern "C" void syscall_trap_handler();
|
|
|
|
asm(
|
|
".globl syscall_trap_handler \n"
|
|
"syscall_trap_handler:\n"
|
|
" pushl $0x0\n"
|
|
" pusha\n"
|
|
" pushw %ds\n"
|
|
" pushw %es\n"
|
|
" pushw %fs\n"
|
|
" pushw %gs\n"
|
|
" pushw %ss\n"
|
|
" pushw %ss\n"
|
|
" pushw %ss\n"
|
|
" pushw %ss\n"
|
|
" pushw %ss\n"
|
|
" popw %ds\n"
|
|
" popw %es\n"
|
|
" popw %fs\n"
|
|
" popw %gs\n"
|
|
" cld\n"
|
|
" call syscall_trap_entry\n"
|
|
" popw %gs\n"
|
|
" popw %gs\n"
|
|
" popw %fs\n"
|
|
" popw %es\n"
|
|
" popw %ds\n"
|
|
" popa\n"
|
|
" add $0x4, %esp\n"
|
|
" iret\n");
|
|
|
|
namespace Syscall {
|
|
|
|
static int handle(RegisterDump&, u32 function, u32 arg1, u32 arg2, u32 arg3);
|
|
|
|
void initialize()
|
|
{
|
|
register_user_callable_interrupt_handler(0x82, syscall_trap_handler);
|
|
kprintf("Syscall: int 0x82 handler installed\n");
|
|
}
|
|
|
|
#pragma GCC diagnostic ignored "-Wcast-function-type"
|
|
typedef int (Process::*Handler)(u32, u32, u32);
|
|
#define __ENUMERATE_REMOVED_SYSCALL(x) nullptr,
|
|
#define __ENUMERATE_SYSCALL(x) reinterpret_cast<Handler>(&Process::sys$##x),
|
|
static Handler s_syscall_table[] = {
|
|
ENUMERATE_SYSCALLS
|
|
};
|
|
#undef __ENUMERATE_SYSCALL
|
|
#undef __ENUMERATE_REMOVED_SYSCALL
|
|
|
|
int handle(RegisterDump& regs, u32 function, u32 arg1, u32 arg2, u32 arg3)
|
|
{
|
|
ASSERT_INTERRUPTS_ENABLED();
|
|
auto& process = current->process();
|
|
process.did_syscall();
|
|
|
|
if (function == SC_exit || function == SC_exit_thread) {
|
|
// These syscalls need special handling since they never return to the caller.
|
|
cli();
|
|
if (auto* tracer = process.tracer())
|
|
tracer->did_syscall(function, arg1, arg2, arg3, 0);
|
|
if (function == SC_exit)
|
|
process.sys$exit((int)arg1);
|
|
else
|
|
process.sys$exit_thread((void*)arg1);
|
|
ASSERT_NOT_REACHED();
|
|
return 0;
|
|
}
|
|
|
|
if (function == SC_fork)
|
|
return process.sys$fork(regs);
|
|
|
|
if (function == SC_sigreturn)
|
|
return process.sys$sigreturn(regs);
|
|
|
|
if (function >= Function::__Count) {
|
|
dbg() << process << ": Unknown syscall %u requested (" << arg1 << ", " << arg2 << ", " << arg3 << ")";
|
|
return -ENOSYS;
|
|
}
|
|
|
|
return (process.*(s_syscall_table[function]))(arg1, arg2, arg3);
|
|
}
|
|
|
|
}
|
|
|
|
void syscall_trap_entry(RegisterDump regs)
|
|
{
|
|
auto& process = current->process();
|
|
|
|
if (!MM.validate_user_stack(process, VirtualAddress(regs.esp_if_crossRing))) {
|
|
dbgprintf("Invalid stack pointer: %p\n", regs.esp_if_crossRing);
|
|
handle_crash(regs, "Bad stack on syscall entry", SIGSTKFLT);
|
|
ASSERT_NOT_REACHED();
|
|
}
|
|
|
|
process.big_lock().lock();
|
|
u32 function = regs.eax;
|
|
u32 arg1 = regs.edx;
|
|
u32 arg2 = regs.ecx;
|
|
u32 arg3 = regs.ebx;
|
|
regs.eax = (u32)Syscall::handle(regs, function, arg1, arg2, arg3);
|
|
if (auto* tracer = process.tracer())
|
|
tracer->did_syscall(function, arg1, arg2, arg3, regs.eax);
|
|
process.big_lock().unlock();
|
|
|
|
// Check if we're supposed to return to userspace or just die.
|
|
current->die_if_needed();
|
|
}
|