From: Deepak Nibade <dnibade@nvidia.com>
Date: Fri, 25 Jul 2014 07:05:45 +0000 (+0530)
Subject: misc: tegra-profiler: fix Coverity issue of NULL dereference
X-Git-Tag: tegra-l4t-r21-er-2015-02-02~12
X-Git-Url: http://rtime.felk.cvut.cz/gitweb/sojka/nv-tegra/linux-3.10.git/commitdiff_plain/e3676b21f65a6a271e063fd160aea44850d0d0a4

misc: tegra-profiler: fix Coverity issue of NULL dereference

Pointer "pt_regs *regs" is first dereferenced and then checked for NULL
To fix this move NULL checking to beginning of function
Coverity id : 26686

Bug 1416640
Bug 1598009

Change-Id: I40e97e38e5a61a5d77ea68fa511e996f24385cfc
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/447532
(cherry picked from commit 4651be4faa111a0ff64a924889b69ec56ae19ace)
Reviewed-on: http://git-master/r/672015
GVS: Gerrit_Virtual_Submit
Reviewed-by: Igor Nabirushkin <inabirushkin@nvidia.com>
Tested-by: Igor Nabirushkin <inabirushkin@nvidia.com>
Reviewed-by: Matthew Pedro <mapedro@nvidia.com>
---

diff --git a/drivers/misc/tegra-profiler/eh_unwind.c b/drivers/misc/tegra-profiler/eh_unwind.c
index 70ffebe8bb7..52ca7be9efe 100644
--- a/drivers/misc/tegra-profiler/eh_unwind.c
+++ b/drivers/misc/tegra-profiler/eh_unwind.c
@@ -1021,6 +1021,9 @@ quadd_get_user_callchain_ut(struct pt_regs *regs,
 	struct ex_region_info ri;
 	struct stackframe frame;
 
+	if (!regs || !mm)
+		return 0;
+
 #ifdef CONFIG_ARM64
 	if (!compat_user_mode(regs)) {
 		pr_warn_once("user_mode 64: unsupported\n");
@@ -1033,9 +1036,6 @@ quadd_get_user_callchain_ut(struct pt_regs *regs,
 
 	cc->unw_rc = QUADD_URC_FAILURE;
 
-	if (!regs || !mm)
-		return 0;
-
 	if (nr_prev > 0) {
 		ip = cc->curr_pc;
 		sp = cc->curr_sp;