Merge branch 'parisc-3.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull parisc fixes from Helge Deller:
 "There are two patches in here:

  The first patch greatly improves latency and corrects the memory
  ordering in our light-weight atomic locking syscall.

  The second patch ratelimits printing of userspace segfaults in the
  same way as it's done on other platforms.  This fixes a possible DOS
  on parisc since it prevents the syslog to grow too fast.  For example,
  when the debian acl2 package was built on our debian buildd servers,
  this package produced lots of gigabytes in syslog in very short time
  and thus filled our harddisks, which then turned the server nearly
  completely unaccessible and unresponsive"

* 'parisc-3.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Improve LWS-CAS performance
  parisc: ratelimit userspace segfault printing

1 files changed, 30 insertions, 14 deletions

diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c
index 747550762f3..3ca9c1131cf 100644
--- a/arch/parisc/mm/fault.c
+++ b/arch/parisc/mm/fault.c
@@ -19,10 +19,6 @@
 #include <asm/uaccess.h>
 #include <asm/traps.h>
 
-#define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */
-			 /*  dumped to the console via printk)          */
-
-
 /* Various important other fields */
 #define bit22set(x)		(x & 0x00000200)
 #define bits23_25set(x)		(x & 0x000001c0)
@@ -34,6 +30,8 @@
 
 DEFINE_PER_CPU(struct exception_data, exception_data);
 
+int show_unhandled_signals = 1;
+
 /*
  * parisc_acctyp(unsigned int inst) --
  *    Given a PA-RISC memory access instruction, determine if the
@@ -173,6 +171,32 @@ int fixup_exception(struct pt_regs *regs)
 	return 0;
 }
 
+/*
+ * Print out info about fatal segfaults, if the show_unhandled_signals
+ * sysctl is set:
+ */
+static inline void
+show_signal_msg(struct pt_regs *regs, unsigned long code,
+		unsigned long address, struct task_struct *tsk,
+		struct vm_area_struct *vma)
+{
+	if (!unhandled_signal(tsk, SIGSEGV))
+		return;
+
+	if (!printk_ratelimit())
+		return;
+
+	pr_warn("\n");
+	pr_warn("do_page_fault() command='%s' type=%lu address=0x%08lx",
+	    tsk->comm, code, address);
+	print_vma_addr(KERN_CONT " in ", regs->iaoq[0]);
+	if (vma)
+		pr_warn(" vm_start = 0x%08lx, vm_end = 0x%08lx\n",
+				vma->vm_start, vma->vm_end);
+
+	show_regs(regs);
+}
+
 void do_page_fault(struct pt_regs *regs, unsigned long code,
 			      unsigned long address)
 {
@@ -270,16 +294,8 @@ bad_area:
 	if (user_mode(regs)) {
 		struct siginfo si;
 
-#ifdef PRINT_USER_FAULTS
-		printk(KERN_DEBUG "\n");
-		printk(KERN_DEBUG "do_page_fault() pid=%d command='%s' type=%lu address=0x%08lx\n",
-		    task_pid_nr(tsk), tsk->comm, code, address);
-		if (vma) {
-			printk(KERN_DEBUG "vm_start = 0x%08lx, vm_end = 0x%08lx\n",
-					vma->vm_start, vma->vm_end);
-		}
-		show_regs(regs);
-#endif
+		show_signal_msg(regs, code, address, tsk, vma);
+
 		switch (code) {
 		case 15:	/* Data TLB miss fault/Data page fault */
 			/* send SIGSEGV when outside of vma */