diff options
| author | Andi Kleen <ak@suse.de> | 2004-11-15 03:53:40 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-11-15 03:53:40 -0800 |
| commit | ce57094bd9472a2752d471c8dc7aadb5cbdf11e8 (patch) | |
| tree | 53440dedaa722c55a108b22e37a8db648c97ecbc /mm | |
| parent | 46ce6729f516eac3295f94dee0a18862a7e5db64 (diff) | |
| download | history-ce57094bd9472a2752d471c8dc7aadb5cbdf11e8.tar.gz | |
[PATCH] x86-64: Fix get_user_pages access to vsyscall page
The current kernel oopses on x86-64 when gdb steps into the vsyscall page.
This patch fixes it.
I also removed the bogus NULL checks of *_offset and replaced them with
proper _none checks. I made them BUGs because vsyscall pages should be
always mapped.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/mm/memory.c b/mm/memory.c index 2f2ba8b1b03278..2c2ff72c118ef5 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -739,19 +739,15 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, pte_t *pte; if (write) /* user gate pages are read-only */ return i ? : -EFAULT; - pgd = pgd_offset_gate(mm, pg); - if (!pgd) - return i ? : -EFAULT; + if (pg > TASK_SIZE) + pgd = pgd_offset_k(pg); + else + pgd = pgd_offset_gate(mm, pg); + BUG_ON(pgd_none(*pgd)); pmd = pmd_offset(pgd, pg); - if (!pmd) - return i ? : -EFAULT; + BUG_ON(pmd_none(*pmd)); pte = pte_offset_map(pmd, pg); - if (!pte) - return i ? : -EFAULT; - if (!pte_present(*pte)) { - pte_unmap(pte); - return i ? : -EFAULT; - } + BUG_ON(pte_none(*pte)); if (pages) { pages[i] = pte_page(*pte); get_page(pages[i]); |