Changeset 69a5600 in mainline

Timestamp:

2006-04-29T11:32:44Z (19 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

2382d09

Parents:

429ff2ea

Message:

I/O Permission bitmap fixes. The trailing all-one sequence must be 8 bits long.
Update TSS limit in a proper way.

Location:

arch

Files:

• amd64/src/proc/scheduler.c (modified) (3 diffs)
• ia32/src/proc/scheduler.c (modified) (2 diffs)

arch/amd64/src/proc/scheduler.c

@@ -48 +48 @@
         ptr_16_64_t cpugdtr;
         descriptor_t *gdt_p;
+        tss_descriptor_t *tss_desc;
 
         /*
@@ -62 +63 @@
                 bitmap_copy(&iomap, &TASK->arch.iomap, TASK->arch.iomap.bits);
                 /*
-                 * It is safe to set the trailing four bits because of the extra
+                 * It is safe to set the trailing eight bits because of the extra
                  * convenience byte in TSS_IOMAP_SIZE.
                  */
-                bitmap_set_range(&iomap, TASK->arch.iomap.bits, 4);
+                bitmap_set_range(&iomap, TASK->arch.iomap.bits, 8);
         }
         spinlock_unlock(&TASK->lock);
@@ -74 +75 @@
         gdt_tss_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE + BITS2BYTES(bits) - 1);
         gdtr_load(&cpugdtr);
+        
+        /*
+         * Before we load new TSS limit, the current TSS descriptor
+         * type must be changed to describe inactive TSS.
+         */
+        tss_desc = (tss_descriptor_t *) &gdt_p[TSS_DES];
+        tss_desc->type = AR_TSS;
+        tr_load(gdtselector(TSS_DES));
 }
 

arch/ia32/src/proc/scheduler.c

@@ -62 +62 @@
                 bitmap_copy(&iomap, &TASK->arch.iomap, TASK->arch.iomap.bits);
                 /*
-                 * It is safe to set the trailing four bits because of the extra
+                 * It is safe to set the trailing eight bits because of the extra
                  * convenience byte in TSS_IOMAP_SIZE.
                  */
-                bitmap_set_range(&iomap, TASK->arch.iomap.bits, 4);
+                bitmap_set_range(&iomap, TASK->arch.iomap.bits, 8);
         }
         spinlock_unlock(&TASK->lock);
@@ -74 +74 @@
         gdt_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE + BITS2BYTES(bits) - 1);
         gdtr_load(&cpugdtr);
+
+        /*
+         * Before we load new TSS limit, the current TSS descriptor
+         * type must be changed to describe inactive TSS.
+         */
+        gdt_p[TSS_DES].access = AR_PRESENT | AR_TSS | DPL_KERNEL;
+        tr_load(selector(TSS_DES));
 }