thanks to tomas: fix for level0() race condition - global variable can

be used concurrently.  pass the function in eax instead; this gets rid
of the global variable.  also execute the function directly if we're
already trapped into the kernel.

revert of u32_t endpoint_t to int (some code assumes endpoints are
negative for negative slot numbers).

diff --git a/kernel/arch/i386/klib386.s b/kernel/arch/i386/klib386.s
index d506059f99e6627f0c63af31da750b2f12ed15ec..ed0cc22cb55134987c09a80cf92fc07e090414ea 100755 (executable)
--- a/kernel/arch/i386/klib386.s
+++ b/kernel/arch/i386/klib386.s
@@ -489,11 +489,11 @@ idt_zero: .data4  0, 0
 _idle_task:
 ! This task is called when the system has nothing else to do.  The HLT
 ! instruction puts the processor in a state where it draws minimum power.
-       push    halt
+       push    _halt
        call    _level0         ! level0(halt)
        pop     eax
        jmp     _idle_task
-halt:
+_halt:
        sti
        hlt
        cli
@@ -508,10 +508,15 @@ halt:
 !
 _level0:
        mov     eax, 4(esp)
-       mov     (_level0_func), eax
+       cmpb    (_k_reenter), -1
+       jne     direct
        int     LEVEL0_VECTOR
        ret
 
+direct:
+       call    eax
+       ret
+
 
 !*===========================================================================*
 !*                           read_flags                                             *

diff --git a/kernel/arch/i386/memory.c b/kernel/arch/i386/memory.c
index c5eb9de6e1a0be937f561e3494f024f2c3ad0492..013e609db25eeb177b35df0e59f279a537c0403e 100644 (file)
--- a/kernel/arch/i386/memory.c
+++ b/kernel/arch/i386/memory.c
@@ -36,7 +36,6 @@ PRIVATE int nfreepdes = 0, freepdes[WANT_FREEPDES], inusepde = NOPDE;
 #define HASPT(procptr) ((procptr)->p_seg.p_cr3 != 0)
 
 FORWARD _PROTOTYPE( u32_t phys_get32, (vir_bytes v)                    );
-FORWARD _PROTOTYPE( void set_cr3, (void)                               );
 FORWARD _PROTOTYPE( void vm_enable_paging, (void)                      );
 
        
@@ -241,26 +240,23 @@ phys_bytes addr;
 
 PRIVATE u32_t vm_cr3;  /* temp arg to level0() func */
 
+PRIVATE void set_cr3()
+{
+       write_cr3(vm_cr3);
+}
+
 PUBLIC void vm_set_cr3(struct proc *newptproc)
 {
        int u = 0;
        if(!intr_disabled()) { lock; u = 1; }
        vm_cr3= newptproc->p_seg.p_cr3;
        if(vm_cr3) {
-               vmassert(intr_disabled());
                level0(set_cr3);
-               vmassert(intr_disabled());
                ptproc = newptproc;
-               vmassert(intr_disabled());
        }
        if(u) { unlock; }
 }
 
-PRIVATE void set_cr3()
-{
-       write_cr3(vm_cr3);
-}
-
 char *cr0_str(u32_t e)
 {
        static char str[80];

diff --git a/kernel/arch/i386/mpx386.s b/kernel/arch/i386/mpx386.s
index 742891545750b790b4e9e7db041ef940a96289f3..ccebabfd614554ca0b9c641922e69012a43f54fb 100755 (executable)
--- a/kernel/arch/i386/mpx386.s
+++ b/kernel/arch/i386/mpx386.s
@@ -585,8 +585,12 @@ _reload_cr3:
 !*                             level0_call                                  *
 !*===========================================================================*
 _level0_call:
+! which level0 function to call was passed here by putting it in eax, so
+! we get that from the saved state.
        call    save
-       jmp     (_level0_func)
+       mov     eax, (_proc_ptr)
+       mov     eax, AXREG(eax)
+       jmp     eax
 
 !*===========================================================================*
 !*                             data                                         *

diff --git a/kernel/arch/i386/proto.h b/kernel/arch/i386/proto.h
index 5ab71ea578394ecf3b2a6ee23c85b4db8529394c..dccb92256d10227a28520480b74cace3786c3e13 100644 (file)
--- a/kernel/arch/i386/proto.h
+++ b/kernel/arch/i386/proto.h
@@ -76,7 +76,6 @@ _PROTOTYPE( void phys_insb, (U16_t port, phys_bytes buf, size_t count)  );
 _PROTOTYPE( void phys_insw, (U16_t port, phys_bytes buf, size_t count)  );
 _PROTOTYPE( void phys_outsb, (U16_t port, phys_bytes buf, size_t count) );
 _PROTOTYPE( void phys_outsw, (U16_t port, phys_bytes buf, size_t count) );
-_PROTOTYPE( void i386_invlpg_level0, (void) );
 _PROTOTYPE( int _memcpy_k, (void *dst, void *src, size_t n) );
 _PROTOTYPE( int _memcpy_k_fault, (void) );
 _PROTOTYPE( u32_t read_cr3, (void) );

diff --git a/kernel/glo.h b/kernel/glo.h
index 7c340560cb715440b352c24b60a246b288eef6ba..b6f289392ec11aa62b135fdc1901dd73915246a4 100755 (executable)
--- a/kernel/glo.h
+++ b/kernel/glo.h
@@ -78,6 +78,4 @@ extern struct boot_image image[];     /* system image processes */
 extern char *t_stack[];                        /* task stack space */
 extern struct segdesc_s gdt[];         /* global descriptor table */
 
-EXTERN _PROTOTYPE( void (*level0_func), (void) );
-
 #endif /* GLO_H */