Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[karo-tx-linux.git] / fs / proc / array.c

diff --git a/fs/proc/array.c b/fs/proc/array.c
index f60f0121e3319ec616d0a0151d3e4df146637c88..eed2050db9be9c7795acd2153f976d4742e2fe82 100644 (file)
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -375,7 +375,7 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
                        struct pid *pid, struct task_struct *task, int whole)
 {
-       unsigned long vsize, eip, esp, wchan = ~0UL;
+       unsigned long vsize, eip, esp, wchan = 0;
        int priority, nice;
        int tty_pgrp = -1, tty_nr = 0;
        sigset_t sigign, sigcatch;
@@ -507,7 +507,19 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
        seq_put_decimal_ull(m, ' ', task->blocked.sig[0] & 0x7fffffffUL);
        seq_put_decimal_ull(m, ' ', sigign.sig[0] & 0x7fffffffUL);
        seq_put_decimal_ull(m, ' ', sigcatch.sig[0] & 0x7fffffffUL);
-       seq_put_decimal_ull(m, ' ', wchan);
+
+       /*
+        * We used to output the absolute kernel address, but that's an
+        * information leak - so instead we show a 0/1 flag here, to signal
+        * to user-space whether there's a wchan field in /proc/PID/wchan.
+        *
+        * This works with older implementations of procps as well.
+        */
+       if (wchan)
+               seq_puts(m, " 1");
+       else
+               seq_puts(m, " 0");
+
        seq_put_decimal_ull(m, ' ', 0);
        seq_put_decimal_ull(m, ' ', 0);
        seq_put_decimal_ll(m, ' ', task->exit_signal);