From: Kris Van Hees <kris.van.hees@oracle.com>
Date: Mon, 18 Jan 2016 09:19:53 +0000 (-0500)
Subject: dtrace: ensure that PID 0 has a psinfo struct
X-Git-Tag: v4.1.12-92~204^2~2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f6c672dade320d03c23756927cd4239f9bb08f59;p=users%2Fjedix%2Flinux-maple.git

dtrace: ensure that PID 0 has a psinfo struct

Test builtinvar/tst.psinfo.d lists a large amount of memory access
errors trying to read from non-existant psinfo information for PID 0.
This commit enusres that prior to dtrace doing any work, PID 0 (the
init_task) has a psinfo structure associated with it.

Orabug: 22561297
Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
Acked-by: Nick Alcock <nick.alcock@oracle.com>
---

diff --git a/kernel/dtrace/dtrace_os.c b/kernel/dtrace/dtrace_os.c
index cb07fb10d92f..ff94fd9b4420 100644
--- a/kernel/dtrace/dtrace_os.c
+++ b/kernel/dtrace/dtrace_os.c
@@ -85,6 +85,11 @@ void dtrace_os_init(void)
 				SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK,
 				NULL);
 
+	/*
+	 * We need to set up a psinfo structure for PID 0 (swapper).
+	 */
+	dtrace_psinfo_alloc(&init_task);
+
 	dtrace_sdt_init();
 	dtrace_sdt_register(dtrace_kmod);
 }