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-rw-r--r--arch/um/kernel/trap_kern.c11
-rw-r--r--arch/um/kernel/tt/uaccess_user.c11
2 files changed, 19 insertions, 3 deletions
diff --git a/arch/um/kernel/trap_kern.c b/arch/um/kernel/trap_kern.c
index 87cc6fd..90690b9 100644
--- a/arch/um/kernel/trap_kern.c
+++ b/arch/um/kernel/trap_kern.c
@@ -18,6 +18,7 @@
#include "asm/a.out.h"
#include "asm/current.h"
#include "asm/irq.h"
+#include "sysdep/sigcontext.h"
#include "user_util.h"
#include "kern_util.h"
#include "kern.h"
@@ -125,7 +126,15 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
}
else if(current->mm == NULL)
panic("Segfault with no mm");
- err = handle_page_fault(address, ip, is_write, is_user, &si.si_code);
+
+ if (SEGV_IS_FIXABLE(&fi))
+ err = handle_page_fault(address, ip, is_write, is_user, &si.si_code);
+ else {
+ err = -EFAULT;
+ /* A thread accessed NULL, we get a fault, but CR2 is invalid.
+ * This code is used in __do_copy_from_user() of TT mode. */
+ address = 0;
+ }
catcher = current->thread.fault_catcher;
if(!err)
diff --git a/arch/um/kernel/tt/uaccess_user.c b/arch/um/kernel/tt/uaccess_user.c
index f014755..8c220f0 100644
--- a/arch/um/kernel/tt/uaccess_user.c
+++ b/arch/um/kernel/tt/uaccess_user.c
@@ -22,8 +22,15 @@ int __do_copy_from_user(void *to, const void *from, int n,
__do_copy, &faulted);
TASK_REGS(get_current())->tt = save;
- if(!faulted) return(0);
- else return(n - (fault - (unsigned long) from));
+ if(!faulted)
+ return 0;
+ else if (fault)
+ return n - (fault - (unsigned long) from);
+ else
+ /* In case of a general protection fault, we don't have the
+ * fault address, so NULL is used instead. Pretend we didn't
+ * copy anything. */
+ return n;
}
static void __do_strncpy(void *dst, const void *src, int count)
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