There is no need to go through handle_page_fault().
If we try to access the zero page in kernel mode just panic().
Signed-off-by: Richard Weinberger <rich...@nod.at>
---
arch/um/kernel/trap.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 974b874..b0a3017 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -218,10 +218,15 @@ unsigned long segv(struct faultinfo fi, unsigned long ip,
int is_user,
panic("Segfault with no mm");
}
- if (SEGV_IS_FIXABLE(&fi) || SEGV_MAYBE_FIXABLE(&fi))
+ if (SEGV_IS_FIXABLE(&fi) || SEGV_MAYBE_FIXABLE(&fi)) {
+ if (!is_user && address < PAGE_SIZE) {
+ show_regs(container_of(regs, struct pt_regs, regs));
+ panic("NULL pointer dereference at ip:0x%lx
address:0x%lx", ip, address);
+ }
+
err = handle_page_fault(address, ip, is_write, is_user,
&si.si_code);
- else {
+ } else {
err = -EFAULT;
/*
* A thread accessed NULL, we get a fault, but CR2 is invalid.
--
1.8.4.2
------------------------------------------------------------------------------
Time is money. Stop wasting it! Get your web API in 5 minutes.
www.restlet.com/download
http://p.sf.net/sfu/restlet
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
