[IA64] Fix fast syscall version of getcpu()

GETCPU(2) says:
  int getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache);
  ...
  When either cpu or node is NULL nothing is written to the respective pointer.

But the fast system call path had no checks for NULL, and would
thus return -EFAULT if either (or both) of these were NULL.

Reported-by: Mike Frysinger <vapier@gentoo.org>
Tested-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 12 insertions, 8 deletions

diff --git a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys.S
index cc26edac0ec6..e2dfae24c0f4 100644
--- a/arch/ia64/kernel/fsys.S
+++ b/arch/ia64/kernel/fsys.S
@@ -559,11 +559,15 @@ ENTRY(fsys_getcpu)
         ;;
         tnat.nz p7,p0 = r33                     // I guard against NaT argument
 (p7)    br.cond.spnt.few .fail_einval           // B
+        ;;
+        cmp.ne p6,p0=r32,r0
+        cmp.ne p7,p0=r33,r0
+        ;;
 #ifdef CONFIG_NUMA
         movl r17=cpu_to_node_map
         ;;
-EX(.fail_efault, probe.w.fault r32, 3)          // M This takes 5 cycles
-EX(.fail_efault, probe.w.fault r33, 3)          // M This takes 5 cycles
+EX(.fail_efault, (p6) probe.w.fault r32, 3)             // M This takes 5 cycles
+EX(.fail_efault, (p7) probe.w.fault r33, 3)             // M This takes 5 cycles
         shladd r18=r3,1,r17
         ;;
         ld2 r20=[r18]                           // r20 = cpu_to_node_map[cpu]
@@ -573,20 +577,20 @@ EX(.fail_efault, probe.w.fault r33, 3)		// M This takes 5 cycles
 (p8)    br.spnt.many fsys_fallback_syscall
         ;;
         ;;
-EX(.fail_efault, st4 [r32] = r3)
-EX(.fail_efault, st2 [r33] = r20)
+EX(.fail_efault, (p6) st4 [r32] = r3)
+EX(.fail_efault, (p7) st2 [r33] = r20)
         mov r8=0
         ;;
 #else
-EX(.fail_efault, probe.w.fault r32, 3)          // M This takes 5 cycles
-EX(.fail_efault, probe.w.fault r33, 3)          // M This takes 5 cycles
+EX(.fail_efault, (p6) probe.w.fault r32, 3)             // M This takes 5 cycles
+EX(.fail_efault, (p7) probe.w.fault r33, 3)             // M This takes 5 cycles
         and r2 = TIF_ALLWORK_MASK,r2
         ;;
         cmp.ne p8,p0=0,r2
 (p8)    br.spnt.many fsys_fallback_syscall
         ;;
-EX(.fail_efault, st4 [r32] = r3)
-EX(.fail_efault, st2 [r33] = r0)
+EX(.fail_efault, (p6) st4 [r32] = r3)
+EX(.fail_efault, (p7) st2 [r33] = r0)
         mov r8=0
         ;;
 #endif