[PATCH] RPC: Ensure rpc calls respects the RPC_NOINTR flag

 For internal purposes, the rpc_clnt_sigmask() call is replaced by
 a call to rpc_task_sigmask(), which ensures that the current task
 sigmask respects both the client cl_intr flag and the per-task NOINTR flag.

 Problem noted by Jiaying Zhang.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 37 insertions, 34 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index c979fcf88798..f17e6153b688 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -378,38 +378,41 @@ rpc_default_callback(struct rpc_task *task)
 }
 
 /*
- *      Export the signal mask handling for aysnchronous code that
+ *      Export the signal mask handling for synchronous code that
  *      sleeps on RPC calls
  */
+#define RPC_INTR_SIGNALS (sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGKILL))
  
+static void rpc_save_sigmask(sigset_t *oldset, int intr)
+{
+        unsigned long   sigallow = 0;
+        sigset_t sigmask;
+
+        /* Block all signals except those listed in sigallow */
+        if (intr)
+                sigallow |= RPC_INTR_SIGNALS;
+        siginitsetinv(&sigmask, sigallow);
+        sigprocmask(SIG_BLOCK, &sigmask, oldset);
+}
+
+static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
+{
+        rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
+}
+
+static inline void rpc_restore_sigmask(sigset_t *oldset)
+{
+        sigprocmask(SIG_SETMASK, oldset, NULL);
+}
+
 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 {
-        unsigned long   sigallow = sigmask(SIGKILL);
-        unsigned long   irqflags;
-        
-        /* Turn off various signals */
-        if (clnt->cl_intr) {
-                struct k_sigaction *action = current->sighand->action;
-                if (action[SIGINT-1].sa.sa_handler == SIG_DFL)
-                        sigallow |= sigmask(SIGINT);
-                if (action[SIGQUIT-1].sa.sa_handler == SIG_DFL)
-                        sigallow |= sigmask(SIGQUIT);
-        }
-        spin_lock_irqsave(&current->sighand->siglock, irqflags);
-        *oldset = current->blocked;
-        siginitsetinv(&current->blocked, sigallow & ~oldset->sig[0]);
-        recalc_sigpending();
-        spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
+        rpc_save_sigmask(oldset, clnt->cl_intr);
 }
 
 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 {
-        unsigned long   irqflags;
-        
-        spin_lock_irqsave(&current->sighand->siglock, irqflags);
-        current->blocked = *oldset;
-        recalc_sigpending();
-        spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
+        rpc_restore_sigmask(oldset);
 }
 
 /*
@@ -427,26 +430,26 @@ int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 
         BUG_ON(flags & RPC_TASK_ASYNC);
 
-        rpc_clnt_sigmask(clnt, &oldset);                
-
         status = -ENOMEM;
         task = rpc_new_task(clnt, NULL, flags);
         if (task == NULL)
                 goto out;
 
+        /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
+        rpc_task_sigmask(task, &oldset);
+
         rpc_call_setup(task, msg, 0);
 
         /* Set up the call info struct and execute the task */
-        if (task->tk_status == 0)
+        if (task->tk_status == 0) {
                 status = rpc_execute(task);
-        else {
+        } else {
                 status = task->tk_status;
                 rpc_release_task(task);
         }
 
+        rpc_restore_sigmask(&oldset);
 out:
-        rpc_clnt_sigunmask(clnt, &oldset);              
-
         return status;
 }
 
@@ -467,8 +470,6 @@ rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 
         flags |= RPC_TASK_ASYNC;
 
-        rpc_clnt_sigmask(clnt, &oldset);                
-
         /* Create/initialize a new RPC task */
         if (!callback)
                 callback = rpc_default_callback;
@@ -477,6 +478,9 @@ rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
                 goto out;
         task->tk_calldata = data;
 
+        /* Mask signals on GSS_AUTH upcalls */
+        rpc_task_sigmask(task, &oldset);                
+
         rpc_call_setup(task, msg, 0);
 
         /* Set up the call info struct and execute the task */
@@ -486,9 +490,8 @@ rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
         else
                 rpc_release_task(task);
 
+        rpc_restore_sigmask(&oldset);           
 out:
-        rpc_clnt_sigunmask(clnt, &oldset);              
-
         return status;
 }
 
@@ -666,7 +669,7 @@ call_allocate(struct rpc_task *task)
                 return;
         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task); 
 
-        if (RPC_IS_ASYNC(task) || !(task->tk_client->cl_intr && signalled())) {
+        if (RPC_IS_ASYNC(task) || !signalled()) {
                 xprt_release(task);
                 task->tk_action = call_reserve;
                 rpc_delay(task, HZ>>4);