diff options
Diffstat (limited to 'src/kernel')
| -rw-r--r-- | src/kernel/proc.c | 1 | ||||
| -rw-r--r-- | src/kernel/syscalls.c | 41 |
2 files changed, 42 insertions, 0 deletions
diff --git a/src/kernel/proc.c b/src/kernel/proc.c index 350f3ee..8be1080 100644 --- a/src/kernel/proc.c +++ b/src/kernel/proc.c @@ -413,6 +413,7 @@ static void proc_intr_deliver(Proc *p) { d.rcx = p->regs.rcx; d.rax = p->regs.rax; d.rip = p->regs.rip; + d.flags = p->regs.flags; // one more because the buffer itself isn't NUL terminated // TODO ensure NUL termination diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c index 23a8883..ffd69b8 100644 --- a/src/kernel/syscalls.c +++ b/src/kernel/syscalls.c @@ -487,6 +487,46 @@ long _sys_duplex(hid_t from, hid_t to, int flags) { return -1; // dummy } +void _sys_intr_return(struct intr_data __user *intr, int flags) { + CpuRegs *r = &proc_cur->regs; + struct intr_data d; + if (flags != 0 || pcpy_from(proc_cur, &d, intr, sizeof(d)) < sizeof(d)) { + proc_kill(proc_cur, EFAULT); + proc_switch_any(); /* doesn't return */ + } + r->r15 = d.r15; + r->r14 = d.r14; + r->r13 = d.r13; + r->r12 = d.r12; + r->r11 = d.r11; + r->r10 = d.r10; + r->r9 = d.r9; + r->r8 = d.r8; + r->rdi = d.rdi; + r->rsi = d.rsi; + r->rbp = d.rbp; + r->rsp = d.rsp; + r->rbx = d.rbx; + r->rdx = d.rdx; + r->rcx = d.rcx; + r->rax = d.rax; + r->rip = d.rip; + /* preserved flags: (see intel vol 1 3.4.3.) + * 1<<0 = CF, carry flag + * 1<<2 = PF, parity flag + * 1<<4 = AC, auxilary carry + * 1<<6 = ZF, zero flag + * 1<<7 = SF, sign flag + * 1<<11 = OF, overflow flag + * 1<<10 = DF, direction flag + */ + static_assert( + ((1<<0) | (1<<2) | (1<<4) | (1<<6) | (1<<7) | (1<<10) | (1<<11)) + == 0xCD5 + ); + r->flags = (d.flags & 0xCD5) | (r->flags & ~0xCD5); +} + long _sys_execbuf(void __user *ubuf, size_t len) { if (len == 0) SYSCALL_RETURN(0); static_assert(EXECBUF_MAX_LEN <= KMALLOC_MAX); @@ -544,6 +584,7 @@ long _syscall(long num, long a, long b, long c, long d, long e) { break; case _SYS_TIME: _sys_time(a); break; case _SYS_GETNULL: _sys_getnull(a); break; case _SYS_DUPLEX: _sys_duplex(a, b, c); + break; case _SYS_INTR_RETURN: _sys_intr_return((userptr_t)a, b); break; case _SYS_EXECBUF: _sys_execbuf((userptr_t)a, b); break; case _SYS_DEBUG_KLOG: _sys_debug_klog((userptr_t)a, b); break; |