From: Andrea Righi <righiandr@users.sourceforge.net>

Limit the rate of the kernel logging for the segfaults of user
applications, to avoid potential message floods or denial-of-service
attacks.

Signed-off-by: Andrea Righi <a.righi@cineca.it>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/avr32/mm/fault.c |    2 +-
 x86_64/mm/fault.c     |    0 
 2 files changed, 1 insertion(+), 1 deletion(-)

diff -puN arch/avr32/mm/fault.c~avr32-ratelimit-segfault-reporting-rate arch/avr32/mm/fault.c
--- a/arch/avr32/mm/fault.c~avr32-ratelimit-segfault-reporting-rate
+++ a/arch/avr32/mm/fault.c
@@ -158,7 +158,7 @@ bad_area:
 	up_read(&mm->mmap_sem);
 
 	if (user_mode(regs)) {
-		if (exception_trace)
+		if (exception_trace && printk_ratelimit())
 			printk("%s%s[%d]: segfault at %08lx pc %08lx "
 			       "sp %08lx ecr %lu\n",
 			       is_init(tsk) ? KERN_EMERG : KERN_INFO,
diff -puN arch/x86_64/mm/fault.c~avr32-ratelimit-segfault-reporting-rate arch/x86_64/mm/fault.c
_