> Could you test Linus' proposal? It would definitely do the trick for ia64.
This patch vs 2.5.70 works fine for me on x86. include/asm-x86_64/fixmap.h
needs the macros added for its vsyscall page too.
Enjoy,
Roland
--- linux-2.5.70/include/asm-i386/fixmap.h.~1~ Mon May 26 18:00:21 2003
+++ linux-2.5.70/include/asm-i386/fixmap.h Thu Jun 12 23:46:11 2003
@@ -107,6 +107,14 @@ extern void __set_fixmap (enum fixed_add
#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
+/*
+ * This is the range that is readable by user mode, and things
+ * acting like user mode such as get_user_pages.
+ */
+#define FIXADDR_USER_START (__fix_to_virt(FIX_VSYSCALL))
+#define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE)
+
+
extern void __this_fixmap_does_not_exist(void);
/*
--- linux-2.5.70/mm/memory.c.~1~ Mon May 26 18:00:39 2003
+++ linux-2.5.70/mm/memory.c Thu Jun 12 23:41:04 2003
@@ -689,15 +689,16 @@ int get_user_pages(struct task_struct *t
vma = find_extend_vma(mm, start);
-#ifdef FIXADDR_START
- if (!vma && start >= FIXADDR_START && start < FIXADDR_TOP) {
+#ifdef FIXADDR_USER_START
+ if (!vma &&
+ start >= FIXADDR_USER_START && start < FIXADDR_USER_END) {
static struct vm_area_struct fixmap_vma = {
/* Catch users - if there are any valid
ones, we can make this be "&init_mm" or
something. */
.vm_mm = NULL,
- .vm_start = FIXADDR_START,
- .vm_end = FIXADDR_TOP,
+ .vm_start = FIXADDR_USER_START,
+ .vm_end = FIXADDR_USER_END,
.vm_page_prot = PAGE_READONLY,
.vm_flags = VM_READ | VM_EXEC,
};
@@ -705,6 +706,8 @@ int get_user_pages(struct task_struct *t
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
+ if (write) /* user fixmap pages are read-only */
+ return i ? : -EFAULT;
pgd = pgd_offset_k(pg);
if (!pgd)
return i ? : -EFAULT;
@@ -712,8 +715,7 @@ int get_user_pages(struct task_struct *t
if (!pmd)
return i ? : -EFAULT;
pte = pte_offset_kernel(pmd, pg);
- if (!pte || !pte_present(*pte) || !pte_user(*pte) ||
- !(write ? pte_write(*pte) : pte_read(*pte)))
+ if (!pte || !pte_present(*pte))
return i ? : -EFAULT;
if (pages) {
pages[i] = pte_page(*pte);
-
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This archive was generated by hypermail 2b29 : Sun Jun 15 2003 - 22:00:35 EST