#ifndef __LUNAIX_I386ABI_H
#define __LUNAIX_I386ABI_H
-#define store_retval(retval) __current->intr_ctx.registers.eax = (retval)
+#define store_retval(retval) __current->intr_ctx->registers.eax = (retval)
-#define store_retval_to(proc, retval) (proc)->intr_ctx.registers.eax = (retval)
+#define store_retval_to(proc, retval) (proc)->intr_ctx->registers.eax = (retval)
#define j_usr(sp, pc) \
asm volatile("movw %0, %%ax\n" \
struct exec_param;
+struct regcontext
+{
+ reg32 eax;
+ reg32 ebx;
+ reg32 ecx;
+ reg32 edx;
+ reg32 edi;
+ reg32 ebp;
+ reg32 esi;
+ reg32 ds;
+ reg32 es;
+ reg32 fs;
+ reg32 gs;
+} __attribute__((packed));
+
typedef struct
{
unsigned int depth;
- struct
- {
- reg32 eax;
- reg32 ebx;
- reg32 ecx;
- reg32 edx;
- reg32 edi;
- reg32 ebp;
- reg32 esi;
- reg32 ds;
- reg32 es;
- reg32 fs;
- reg32 gs;
- } __attribute__((packed)) registers;
-
+ struct regcontext registers;
union
{
reg32 esp;
struct exec_param
{
- isr_param saved_prev_ctx;
+ isr_param* saved_prev_ctx;
u32_t vector;
u32_t err_code;
u32_t eip;
#ifndef __LUNAIX_TSS_H
#define __LUNAIX_TSS_H
-#include <lunaix/types.h>
+#define tss_esp0_off 4
+
+#ifndef __ASM__
+#include <lunaix/types.h>
struct x86_tss
{
u32_t link;
void
tss_update_esp(u32_t esp0);
+#endif
#endif /* __LUNAIX_TSS_H */
void
cpu_wrmsr(u32_t msr_idx, u32_t reg_high, u32_t reg_low);
+static inline void
+cpu_ldvmspace(ptr_t vms)
+{
+ cpu_lcr3(vms);
+}
+
#endif
\ No newline at end of file
pid_t pid; // offset = 0
struct proc_info* parent; // offset = 4
- isr_param intr_ctx; // offset = 8
- ptr_t ustack_top; // offset = 84 -> 56 -> 60
- ptr_t page_table; // offset = 88 -> 60 -> 64
- void* fxstate; // offset = 92 -> 64 -> 68
+ isr_param* intr_ctx; // offset = 8
+ ptr_t ustack_top; // offset = 84 -> 56 -> 60 -> 12
+ ptr_t page_table; // offset = 88 -> 60 -> 64 -> 16
+ void* fxstate; // offset = 92 -> 64 -> 68 -> 20
/* ---- critical section end ---- */
destroy_process(pid_t pid);
void
-setup_proc_mem(struct proc_info* proc, ptr_t kstack_from);
+copy_kernel_stack(struct proc_info* proc, ptr_t kstack_from);
/**
* @brief 复制当前进程（LunaixOS的类 fork (unix) 实现）
#define __ASM__
#include <arch/x86/interrupts.h>
#include <arch/x86/i386_asm.h>
+#include <arch/x86/tss.h>
#include <lunaix/syscall.h>
#define __ASM_INTR_DIAGNOSIS
*/
+#define regsize 4
+
+/* stack layout: saved interrupt context */
+ .struct 0
+idepth:
+ .struct idepth + regsize
+ieax:
+ .struct ieax + regsize
+iebx:
+ .struct iebx + regsize
+iecx:
+ .struct iecx + regsize
+iedx:
+ .struct iedx + regsize
+iedi:
+ .struct iedi + regsize
+iebp:
+ .struct iebp + regsize
+iesi:
+ .struct iesi + regsize
+ids:
+ .struct ids + regsize
+ies:
+ .struct ies + regsize
+ifs:
+ .struct ifs + regsize
+igs:
+ .struct igs + regsize
+iesp:
+ .struct iesp + regsize
+isave_prev:
+ .struct isave_prev + regsize
+ivec:
+ .struct ivec + regsize
+iecode:
+ .struct iecode + regsize
+ieip:
+ .struct ieip + regsize
+ics:
+ .struct ics + regsize
+ieflags:
+ .struct ieflags + regsize
+iuesp:
+ .struct iuesp + regsize
+iuss:
+
+
+/* stack layout: execution (flow-control) state context */
+ .struct 0
+exsave_prev:
+ .struct exsave_prev + regsize
+exvec:
+ .struct exvec + regsize
+execode:
+ .struct execode + regsize
+exeip:
+ .struct exeip + regsize
+excs:
+ .struct excs + regsize
+exeflags:
+ .struct exeflags + regsize
+exuesp:
+ .struct exuesp + regsize
+exuss:
+
+/* struct layout: critical section of struct proc_info */
+ .struct 0
+proc_pid:
+ .struct proc_pid + regsize
+proc_parent:
+ .struct proc_parent + regsize
+proc_intr_ctx:
+ .struct proc_intr_ctx + regsize
+proc_ustack_top:
+ .struct proc_ustack_top + regsize
+proc_page_table:
+ .struct proc_page_table + regsize
+proc_fxstate:
+
.section .text
.global interrupt_wrapper
interrupt_wrapper:
/*
Stack layout (layout of struct isr_param)
- msa: [ss] > 76
- [esp] > 72
- eflags > 68
- cs > 64
- eip > 60
- err_code > 56
- vector > offset = 52
+ msa: [ss] > 76 -> 28
+ [esp] > 72 -> 24
+ eflags > 68 -> 20
+ cs > 64 -> 16
+ eip > 60 -> 12
+ err_code > 56 -> 8
+ vector > offset = 52 -> 4
[saved_prev_ctx] > offset = 0
---
- esp
+ esp > 12 * 4 = 48
gs
fs
es
- ds > offset = 7 * 4 = 28 + 4
+ ds > offset = 8 * 4 = 32
esi
ebp
edi
*/
cld
- subl $52, %esp
+ subl $4, %esp
pushl %esp
subl $16, %esp
pushl %eax
movl __current, %eax
- movl 8(%eax), %eax
+ movl proc_intr_ctx(%eax), %eax
incl %eax
pushl %eax # nested intr: current depth
- movl 116(%esp), %eax /* 取出 %cs */
+ movl ics(%esp), %eax /* 取出 %cs */
andl $0x3, %eax /* 判断 RPL */
jz 1f
# FIXME: Save x87 context to user stack, rather than kernel's memory.
# 保存x87FPU的状态
- movl 68(%eax), %ebx
+ movl proc_fxstate(%eax), %ebx
fxsave (%ebx)
# 保存用户栈顶指针。因为我们允许同级中断的产生，所以需要该手段跟踪用户栈的地址。
- movl 124(%esp), %ebx # 取出esp
- movl %ebx, 60(%eax) # 存入__current->ustack_top
+ movl iuesp(%esp), %ebx # 取出esp
+ movl %ebx, proc_ustack_top(%eax) # 存入__current->ustack_top
1:
movl %esp, %eax
#ifdef __ASM_INTR_DIAGNOSIS
movl %eax, (debug_resv + 8)
- movl 48(%esp), %eax
- movl 60(%eax), %eax
+ movl iesp(%esp), %eax
+ movl exeip(%eax), %eax
movl %eax, (debug_resv + 4) # eip
#endif
movl __current, %eax
- movl 68(%eax), %eax
+ movl proc_fxstate(%eax), %eax
test %eax, %eax # do we have stored x87 context?
jz 1f
- fxrstor (%eax)
+ fxrstor (%eax)
+
1:
popl %eax # discard isr_param::depth
popl %eax
movl %eax, tmp_store
movl __current, %eax
+
+
# nested intr: restore saved context
- popl 8(%eax) # depth
- popl 12(%eax) # eax
- popl 16(%eax) # ebx
- popl 20(%eax) # ecx
- popl 24(%eax) # edx
- popl 28(%eax) # edi
- popl 32(%eax) # ebp
- popl 36(%eax) # esi
- popl 40(%eax) # ds
- popl 44(%eax) # es
- popl 48(%eax) # fs
- popl 52(%eax) # gs
- popl 56(%eax) # esp
+ popl proc_intr_ctx(%eax)
addl $8, %esp
shll $3, %eax
addl $12, %eax
addl %esp, %eax
- movl %eax, (_tss + 4)
+ movl %eax, (_tss + tss_esp0_off)
movl tmp_store, %eax
+
iret
.global switch_to
popl %ebx # next
movl __current, %eax
- movl 64(%eax), %ecx # __current->pagetable
- movl 64(%ebx), %eax # next->pagetable
+ movl proc_page_table(%eax), %ecx # __current->pagetable
+ movl proc_page_table(%ebx), %eax # next->pagetable
cmpl %ecx, %eax # if(next->pagtable != __current->pagetable) {
jz 1f
# 我们已经处在了新的地址空间，为了避免影响其先前的栈布局
# 需要使用一个临时的栈空间
movl $tmp_stack, %esp
+
+ # 更新 tss
+ movl proc_intr_ctx(%ebx), %eax # proc->intr_ctx
+ movl iesp(%eax), %eax # intr_ctx->esp
+ movl %eax, (tss_esp0_off + _tss)
+
call signal_dispatch # kernel/signal.c
test %eax, %eax # do we have signal to handle?
jz 1f
jmp handle_signal
1:
- leal 8(%ebx), %eax
+ movl proc_intr_ctx(%ebx), %eax
jmp soft_iret
.global handle_signal
intr_handler(isr_param* param)
{
param->execp->saved_prev_ctx = __current->intr_ctx;
- __current->intr_ctx = *param;
+ __current->intr_ctx = param;
- volatile struct exec_param* execp = __current->intr_ctx.execp;
+ volatile struct exec_param* execp = __current->intr_ctx->execp;
if (execp->vector <= 255) {
isr_cb subscriber = isrm_get(execp->vector);
#include <arch/x86/tss.h>
#include <lunaix/common.h>
+#include <lunaix/process.h>
volatile struct x86_tss _tss = { .link = 0,
.esp0 = KSTACK_TOP,
- .ss0 = KDATA_SEG };
-
-void
-tss_update_esp(u32_t esp0)
-{
- _tss.esp0 = esp0;
-}
\ No newline at end of file
+ .ss0 = KDATA_SEG };
\ No newline at end of file
// we will jump to new entry point (_u_start) upon syscall's
// return so execve 'will not return' from the perspective of it's invoker
- volatile struct exec_param* execp = __current->intr_ctx.execp;
+ volatile struct exec_param* execp = __current->intr_ctx->execp;
execp->esp = container.stack_top;
execp->eip = container.exe.entry;
* 目前的解决方案是2
*/
- proc0->intr_ctx = (isr_param){ .registers = { .ds = KDATA_SEG,
- .es = KDATA_SEG,
- .fs = KDATA_SEG,
- .gs = KDATA_SEG } };
proc0->parent = proc0;
// 方案1：必须在读取eflags之后禁用。否则当进程被调度时，中断依然是关闭的！
proc0->page_table = vmm_dup_vmspace(proc0->pid);
// 直接切换到新的拷贝，进行配置。
- cpu_lcr3(proc0->page_table);
+ cpu_ldvmspace(proc0->page_table);
// 为内核创建一个专属栈空间。
for (size_t i = 0; i < (KSTACK_SIZE >> PG_SIZE_BITS); i++) {
struct exec_param* execp =
(struct exec_param*)(KSTACK_TOP - sizeof(struct exec_param));
+ isr_param* isrp = (isr_param*)((ptr_t)execp - sizeof(isr_param));
*execp = (struct exec_param){ .cs = KCODE_SEG,
.eip = (ptr_t)__proc0,
.ss = KDATA_SEG,
.eflags = cpu_reflags() };
- proc0->intr_ctx.execp = execp;
+ *isrp = (isr_param){ .registers = { .ds = KDATA_SEG,
+ .es = KDATA_SEG,
+ .fs = KDATA_SEG,
+ .gs = KDATA_SEG },
+ .execp = execp };
+
+ proc0->intr_ctx = isrp;
// 加载x87默认配置
asm volatile("fninit\n"
__copy_fdtable(pcb);
region_copy(&__current->mm, &pcb->mm);
- setup_proc_mem(pcb, VMS_SELF);
+ /*
+ * store the return value for forked process.
+ * this will be implicit carried over after kernel stack is copied.
+ */
+ store_retval(0);
+
+ copy_kernel_stack(pcb, VMS_SELF);
// 根据 mm_region 进一步配置页表
vmm_unmount_pd(VMS_MOUNT_1);
- // 正如同fork，返回两次。
- store_retval_to(pcb, 0);
-
commit_process(pcb);
return pcb->pid;
extern void __kernel_end;
void
-setup_proc_mem(struct proc_info* proc, ptr_t usedMnt)
+copy_kernel_stack(struct proc_info* proc, ptr_t usedMnt)
{
// copy the entire kernel page table
pid_t pid = proc->pid;
*ppte = (p & 0xfff) | ppa;
}
- // 我们不需要分配内核的区域，因为所有的内核代码和数据段只能通过系统调用来访问，任何非法的访问
- // 都会导致eip落在区域外面，从而segmentation fault.
-
- // 至于其他的区域我们暂时没有办法知道，因为那需要知道用户程序的信息。我们留到之后在处理。
proc->page_table = pt_copy;
}
\ No newline at end of file
+#include <arch/abi.h>
#include <arch/x86/interrupts.h>
-#include <arch/x86/tss.h>
#include <hal/apic.h>
#include <hal/cpu.h>
struct exec_param* execp =
(void*)dummy_stack + DUMMY_STACK_SIZE - sizeof(struct exec_param);
+ isr_param* isrp = (void*)execp - sizeof(isr_param);
+
*execp = (struct exec_param){
.cs = KCODE_SEG,
.eflags = cpu_reflags() | 0x0200,
.ss = KDATA_SEG,
};
+ *isrp = (isr_param){ .registers = { .ds = KDATA_SEG,
+ .es = KDATA_SEG,
+ .fs = KDATA_SEG,
+ .gs = KDATA_SEG },
+ .execp = execp };
+
// memset to 0
dummy_proc = (struct proc_info){};
- dummy_proc.intr_ctx = (isr_param){ .registers = { .ds = KDATA_SEG,
- .es = KDATA_SEG,
- .fs = KDATA_SEG,
- .gs = KDATA_SEG },
- .execp = execp };
+ dummy_proc.intr_ctx = isrp;
dummy_proc.page_table = cpu_rcr3();
dummy_proc.state = PS_READY;
由于这中间没有进行地址空间的交换，所以第二次跳转使用的是同一个内核栈，而之前默认tss.esp0的值是永远指向最顶部
这样一来就有可能会覆盖更早的上下文信息（比如嵌套的信号捕获函数）
*/
- tss_update_esp(proc->intr_ctx.esp);
apic_done_servicing();
llist_append(&root_proc->sleep.sleepers, &__current->sleep.sleepers);
}
- __current->intr_ctx.registers.eax = seconds;
+ store_retval(seconds);
block_current();
schedule();
解决办法就是先吧intr_ctx拷贝到一个静态分配的区域里，然后再注入到用户栈。
*/
static volatile struct proc_sigstate __temp_save;
- __temp_save.proc_regs = __current->intr_ctx;
+ __temp_save.proc_regs = *__current->intr_ctx;
memcpy(__temp_save.fxstate, __current->fxstate, 512);
sigframe->sig_num = sig_selected;
__DEFINE_LXSYSCALL1(int, sigreturn, struct proc_sig, *sig_ctx)
{
memcpy(__current->fxstate, sig_ctx->prev_context.fxstate, 512);
- __current->intr_ctx = sig_ctx->prev_context.proc_regs;
+ // FIXME: Interrupt context is exposed to user space!
+ *__current->intr_ctx = sig_ctx->prev_context.proc_regs;
struct sigact* current = __current->sigctx.inprogress;
if (current) {
git://scm.lunaixsky.com / lunaix-os.git / commitdiff