fix: previous interrupt context lost after a nested interrupt

fix: disable function inlining optimization as it could potentially cause BUGS!

diff --git a/lunaix-os/config/make-cc b/lunaix-os/config/make-cc
index 4491370c42fd1fa3fa5570f97e98f6398784df31..a7c24680518417518dc76d2ead79bfb843738878 100644 (file)
--- a/lunaix-os/config/make-cc
+++ b/lunaix-os/config/make-cc
@@ -16,7 +16,10 @@ OFLAGS := -fno-gcse\
                  -fno-cse-follow-jumps\
                  -fno-cse-skip-blocks\
                  -fno-optimize-strlen\
-                 -fno-tree-builtin-call-dce 
+                 -fno-inline-functions-called-once \
+                 -fno-inline-functions \
+                 -fno-inline-small-functions \
+                 -fno-indirect-inlining
 
 CFLAGS := -std=gnu99 -ffreestanding $(O) $(OFLAGS) $(W) $(ARCH_OPT)
 LDFLAGS := -ffreestanding $(O) -nostdlib -lgcc
\ No newline at end of file

diff --git a/lunaix-os/includes/arch/x86/interrupts.h b/lunaix-os/includes/arch/x86/interrupts.h
index 395cfe27ee0d599638bf287c36cc62309d3dabc2..f1684a8ad1398d52919a4a28d41c01457ecfb886 100644 (file)
--- a/lunaix-os/includes/arch/x86/interrupts.h
+++ b/lunaix-os/includes/arch/x86/interrupts.h
@@ -6,19 +6,11 @@
 #ifndef __ASM__
 #include <hal/cpu.h>
 
-struct exec_param
-{
-    unsigned int vector;
-    unsigned int err_code;
-    unsigned int eip;
-    unsigned int cs;
-    unsigned int eflags;
-    unsigned int esp;
-    unsigned int ss;
-} __attribute__((packed));
+struct exec_param;
 
 typedef struct
 {
+    unsigned int depth;
     struct
     {
         reg32 eax;
@@ -32,16 +24,29 @@ typedef struct
         reg32 es;
         reg32 fs;
         reg32 gs;
-        // reg32 esp;
     } __attribute__((packed)) registers;
 
     union
     {
         reg32 esp;
-        struct exec_param* execp;
+        volatile struct exec_param* execp;
     };
 } __attribute__((packed)) isr_param;
 
+struct exec_param
+{
+    isr_param saved_prev_ctx;
+    unsigned int vector;
+    unsigned int err_code;
+    unsigned int eip;
+    unsigned int cs;
+    unsigned int eflags;
+    unsigned int esp;
+    unsigned int ss;
+} __attribute__((packed));
+
+#define ISR_PARAM_SIZE sizeof(isr_param)
+
 void
 intr_handler(isr_param* param);
 

diff --git a/lunaix-os/includes/lunaix/process.h b/lunaix-os/includes/lunaix/process.h
index 291aba2d2a731f343621fb422412038a1af67049..0b8d302e6e093e7122d7afcc93222f64b3e1ef43 100644 (file)
--- a/lunaix-os/includes/lunaix/process.h
+++ b/lunaix-os/includes/lunaix/process.h
@@ -57,9 +57,9 @@ struct proc_info
     pid_t pid;                // offset = 0
     struct proc_info* parent; // offset = 4
     isr_param intr_ctx;       // offset = 8
-    uintptr_t ustack_top;     // offset = 84 -> 56
-    void* page_table;         // offset = 88 -> 60
-    void* fxstate;            // offset = 92 -> 64
+    uintptr_t ustack_top;     // offset = 84 -> 56 -> 60
+    void* page_table;         // offset = 88 -> 60 -> 64
+    void* fxstate;            // offset = 92 -> 64 -> 68
 
     /* ---- critical section end ---- */
 

diff --git a/lunaix-os/kernel/asm/x86/interrupt.S b/lunaix-os/kernel/asm/x86/interrupt.S
index e88c32f3f1dbdf8736f20cfd480e47be554b4e13..c869db0ede48fda280d41beb6c59c2cfba7f4216 100644 (file)
--- a/lunaix-os/kernel/asm/x86/interrupt.S
+++ b/lunaix-os/kernel/asm/x86/interrupt.S
@@ -9,6 +9,8 @@
     .global debug_resv
     debug_resv:
         .skip 16
+    tmp_store:
+        .skip 4
 #endif
 
 .section .bss
@@ -22,30 +24,35 @@
     interrupt_wrapper:
         /*
          Stack layout (layout of struct isr_param)
-    msa:   [ss]
-           [esp]
-           eflags     > offset = 48 + 16 = 64
-           cs
-           eip
-           err_code   
-           vector     > offset = 28 + 16 + 4 = 48
+    msa:   [ss]             > 76
+           [esp]            > 72
+           eflags           > 68
+           cs               > 64
+           eip              > 60
+           err_code         > 56
+           vector           > offset = 52
+           [saved_prev_ctx] > offset = 0
+           ---
            esp
            gs
            fs
            es
-           ds         > offset = 7 * 4 = 28
+           ds         > offset = 7 * 4 = 28 + 4
            esi
            ebp
            edi
            edx
            ecx
            ebx
-    lsa:   eax        > offset = 0
+           eax
+    lsa:   depth       > offset = 0
 
             las: Least Significant Address
             msa: Most Significant Address
         */
         cld
+
+        subl $52, %esp
         pushl %esp
 
         subl $16, %esp
@@ -62,7 +69,12 @@
         pushl %ebx
         pushl %eax
 
-        movl 60(%esp), %eax   /* 取出 %cs */
+        movl __current, %eax
+        movl 8(%eax), %eax
+        incl %eax
+        pushl %eax          # nested intr: current depth
+
+        movl 116(%esp), %eax   /* 取出 %cs */
         andl $0x3, %eax          /* 判断 RPL */
         jz 1f
 
@@ -74,14 +86,14 @@
 
         # 保存用户栈顶指针。这是因为我们允许系统调用内进行上下文切换，而这样一来，我们就失去了用户栈的信息，
         # 这样一来，就无法设置信号上下文。这主要是为了实现了pause()而做的准备
-        movl (__current), %eax
+        movl __current, %eax
 
         # 保存x87FPU的状态
-        movl 64(%eax), %ebx
+        movl 68(%eax), %ebx
         fxsave (%ebx)
 
-        movl 68(%esp), %ebx     # 取出esp
-        movl %ebx, 56(%eax)     # 存入__current->ustack_top
+        movl 124(%esp), %ebx     # 取出esp
+        movl %ebx, 60(%eax)     # 存入__current->ustack_top
 
     1:
         movl %esp, %eax
@@ -99,17 +111,18 @@
 
 #ifdef __ASM_INTR_DIAGNOSIS
         movl %eax, (debug_resv + 8)
-        movl 44(%esp), %eax
-        movl 8(%eax), %eax
+        movl 48(%esp), %eax
+        movl 60(%eax), %eax
         movl %eax, (debug_resv + 4) # eip
 #endif
-        movl (__current), %eax
-        movl 64(%eax), %eax
+        movl __current, %eax
+        movl 68(%eax), %eax
         
         test %eax, %eax     # do we have stored x87 context?
         jz 1f 
         fxrstor (%eax)      
 1:
+        popl %eax   # discard isr_param::depth
         popl %eax
         popl %ebx
         popl %ecx
@@ -125,24 +138,40 @@
 
         movl 16(%esp), %esp
 
+        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
+
         addl $8, %esp
 
-        pushl %eax
 #ifdef __ASM_INTR_DIAGNOSIS
-        movl 4(%esp), %eax
+        movl (%esp), %eax
         movl %eax, debug_resv
 #endif
         # 处理TSS.ESP的一些边界条件。如果是正常iret（即从内核模式*优雅地*退出）
         # 那么TSS.ESP0应该为iret进行弹栈后，%esp的值。
         # 所以这里的边界条件是：如返回用户模式，iret会额外弹出8个字节（ss,esp）
-        movl 8(%esp), %eax
+        movl 4(%esp), %eax
         andl $3, %eax
         setnz %al
         shll $3, %eax
-        addl $16, %eax
+        addl $12, %eax
         addl %esp, %eax
         movl %eax, (_tss + 4)
-        popl %eax
+        movl tmp_store, %eax
         iret
 
     .global switch_to
@@ -152,8 +181,8 @@
 
         popl %ebx               # next
         movl __current, %eax    
-        movl 60(%eax), %ecx     # __current->pagetable
-        movl 60(%ebx), %eax     # next->pagetable
+        movl 64(%eax), %ecx     # __current->pagetable
+        movl 64(%ebx), %eax     # next->pagetable
         
         cmpl %ecx, %eax         # if(next->pagtable != __current->pagetable) {
         jz 1f
@@ -182,7 +211,8 @@
 
         pushl $UDATA_SEG        # proc_sig->prev_context.proc_regs.ss
         pushl %eax              # esp
-        pushl 64(%ebx)          # proc_sig->prev_context.proc_regs.eflags
+        movl 48(%ebx), %ebx
+        pushl 68(%ebx)          # proc_sig->prev_context.proc_regs.execp->eflags
         pushl $UCODE_SEG        # cs
         pushl $sig_wrapper      # eip for sig wrapper
 
@@ -202,7 +232,7 @@
         pushl %eax              # Addr to proc_sig structure 
         pushl 4(%eax)           # proc_sig->sig_num     ---- 16 bytes aligned
 
-        call (%eax)             # invoke signal handler
+        call *(%eax)             # invoke signal handler
 
         # invoke the sigreturn syscall to exit the signal wrapper
         movl $__SYSCALL_sigreturn, %eax

diff --git a/lunaix-os/kernel/asm/x86/interrupts.c b/lunaix-os/kernel/asm/x86/interrupts.c
index b4a443f10376812bd94cb3abb4051fe090b1ee08..3fb24cbc054eab3d955078da2a27d42d35ee00e7 100644 (file)
--- a/lunaix-os/kernel/asm/x86/interrupts.c
+++ b/lunaix-os/kernel/asm/x86/interrupts.c
@@ -19,9 +19,10 @@ extern x86_page_table* __kernel_ptd;
 void
 intr_handler(isr_param* param)
 {
+    param->execp->saved_prev_ctx = __current->intr_ctx;
     __current->intr_ctx = *param;
 
-    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);

diff --git a/lunaix-os/kernel/asm/x86/syscall.S b/lunaix-os/kernel/asm/x86/syscall.S
index 93ea1c7bf63230b1faf7c330c4c71d4142b1d483..ff30f444d9c6b8d32352cf030768b84d928de89b 100644 (file)
--- a/lunaix-os/kernel/asm/x86/syscall.S
+++ b/lunaix-os/kernel/asm/x86/syscall.S
@@ -69,10 +69,11 @@
 .section .text
     syscall_hndlr:
         pushl %ebp
-        movl 8(%esp), %ebp
+        movl 8(%esp), %ebp          // isr_param*
 
-        movl  (%ebp), %eax          /* eax: call code as well as the return value from syscall */
-        cmpl  $__SYSCALL_MAX, %eax
+        addl $4, %ebp
+        movl (%ebp), %eax          /* eax: call code as well as the return value from syscall */
+        cmpl $__SYSCALL_MAX, %eax
         jae 2f
 
         shll $2, %eax