[PATCH 1/2] power/intel_uncore: fix crash closing uninitialized driver

[PATCH 1/2] power/intel_uncore: fix crash closing uninitialized driver

[Bruce Richardson]

When the power_intel_uncore_autotest unit test is run as an unprivileged
user which cannot init the power library, it crashes the unit test
binary due to calling "rte_power_uncore_exit" after the first test case
(initialization) fails. This crash is due to trying to write to NULL
file handles.

Fix the crash by checking each file handle is non-null before writing to
it and closing it.

Fixes: 60b8a661a957 ("power: add Intel uncore frequency control")
Cc: stable@dpdk.org

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 drivers/power/intel_uncore/intel_uncore.c | 35 ++++++++++++-----------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/drivers/power/intel_uncore/intel_uncore.c b/drivers/power/intel_uncore/intel_uncore.c
index 804ad5d755..6759ea1445 100644
--- a/drivers/power/intel_uncore/intel_uncore.c
+++ b/drivers/power/intel_uncore/intel_uncore.c
@@ -307,27 +307,28 @@ power_intel_uncore_exit(unsigned int pkg, unsigned int die)
 
 	ui = &uncore_info[pkg][die];
 
-	if (fprintf(ui->f_cur_min, "%u", ui->org_min_freq) < 0) {
-		POWER_LOG(ERR, "Fail to write original uncore frequency for "
-				"pkg %02u die %02u", ui->pkg, ui->die);
-		return -1;
+	if (ui->f_cur_min != NULL) {
+		if (fprintf(ui->f_cur_min, "%u", ui->org_min_freq) < 0) {
+			POWER_LOG(ERR, "Fail to write original uncore frequency for pkg %02u die %02u",
+					 ui->pkg, ui->die);
+			return -1;
+		}
+		fflush(ui->f_cur_min);
+		fclose(ui->f_cur_min);
+		ui->f_cur_min = NULL;
 	}
 
-	if (fprintf(ui->f_cur_max, "%u", ui->org_max_freq) < 0) {
-		POWER_LOG(ERR, "Fail to write original uncore frequency for "
-				"pkg %02u die %02u", ui->pkg, ui->die);
-		return -1;
+	if (ui->f_cur_max != NULL) {
+		if (fprintf(ui->f_cur_max, "%u", ui->org_max_freq) < 0) {
+			POWER_LOG(ERR, "Fail to write original uncore frequency for pkg %02u die %02u",
+					 ui->pkg, ui->die);
+			return -1;
+		}
+		fflush(ui->f_cur_max);
+		fclose(ui->f_cur_max);
+		ui->f_cur_max = NULL;
 	}
 
-	fflush(ui->f_cur_min);
-	fflush(ui->f_cur_max);
-
-	/* Close FD of setting freq */
-	fclose(ui->f_cur_min);
-	fclose(ui->f_cur_max);
-	ui->f_cur_min = NULL;
-	ui->f_cur_max = NULL;
-
 	return 0;
 }
 
-- 
2.48.1