duane voth wrote:
> ... I've attached a patch that
> can be used to watch for the problem. The following is a 2.2 patch (2.4
> will follow in a few minutes). If you see "vmalloc error" you might want
> to uncomment the look_for_dangling_pgds function to get a better feel for
> the pgds that cause the probem.
Here is the 2.4.1 version.
duane
--- mm/vmalloc.c.orig Thu Feb 1 15:25:19 2001
+++ mm/vmalloc.c Thu Feb 1 15:40:25 2001
@@ -225,6 +225,52 @@
printk(KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", addr);
}
+int
+duanev_ensure_pgds_same(unsigned long addr, unsigned long size)
+{
+ struct task_struct * p;
+ unsigned long va;
+ int errs = 0;
+
+ for_each_task(p) {
+ for (va = addr; va < addr + size; va = (va + PGDIR_SIZE) & PGDIR_MASK)
+{
+ pgd_t kpgd = *pgd_offset_k(va);
+ if (pgd_val(*pgd_offset(p->mm, va)) != pgd_val(kpgd)) {
+ printk("vmalloc error: pgd %03lx is %08lx not %08lx in
+%s\n",
+ va >> PGDIR_SHIFT,
+ pgd_val(*pgd_offset(p->mm, va)),
+ pgd_val(kpgd),
+ p->comm);
+ errs++;
+ }
+ }
+ }
+
+ return errs;
+}
+
+void
+duanev_look_for_dangling_pgds(unsigned long addr, unsigned long size)
+{
+ struct task_struct * p;
+ unsigned long va;
+
+ /* can't use for_each_task: it skips the swapper! */
+ p = &init_task;
+ do {
+ if (pgd_val(*pgd_offset(p->mm, addr))) {
+ for (va = (addr + PGDIR_SIZE) & PGDIR_MASK; va < addr + size;
+ va = (va + PGDIR_SIZE) &
+PGDIR_MASK) {
+ if (pgd_val(*pgd_offset(p->mm, va)) == 0)
+ printk("vfree: pgd %03lx is NULL but %03lx is not
+(in %s)\n",
+ va >> PGDIR_SHIFT,
+ addr >> PGDIR_SHIFT,
+ p->comm);
+ }
+ }
+ } while ((p = p->next_task) != &init_task);
+}
+
void * __vmalloc (unsigned long size, int gfp_mask, pgprot_t prot)
{
void * addr;
@@ -241,8 +287,11 @@
addr = area->addr;
if (vmalloc_area_pages(VMALLOC_VMADDR(addr), size, gfp_mask, prot)) {
vfree(addr);
+// duanev_look_for_dangling_pgds((unsigned long)addr, size);
return NULL;
}
+ if (duanev_ensure_pgds_same((unsigned long)addr, size))
+ printk(" vmalloc size = 0x%08lx\n", size);
return addr;
}
-
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