[PATCH 09/11] perf/imx_ddr: Fix undefined behavior due to shift overflowing the constant

[Borislav Petkov]

From: Borislav Petkov <bp@xxxxxxx>

Fix:

  In file included from <command-line>:0:0:
  In function ‘ddr_perf_counter_enable’,
      inlined from ‘ddr_perf_irq_handler’ at drivers/perf/fsl_imx8_ddr_perf.c:651:2:
  ././include/linux/compiler_types.h:352:38: error: call to ‘__compiletime_assert_729’ \
	declared with attribute error: FIELD_PREP: mask is not constant
    _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
...

See https://lore.kernel.org/r/YkwQ6%2BtIH8GQpuct@xxxxxxx for the gory
details as to why it triggers with older gccs only.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: Frank Li <Frank.li@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
Cc: Fabio Estevam <festevam@xxxxxxxxx>
Cc: NXP Linux Team <linux-imx@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
---
 drivers/perf/fsl_imx8_ddr_perf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/perf/fsl_imx8_ddr_perf.c b/drivers/perf/fsl_imx8_ddr_perf.c
index 94ebc1ecace7..b1b2a55de77f 100644
--- a/drivers/perf/fsl_imx8_ddr_perf.c
+++ b/drivers/perf/fsl_imx8_ddr_perf.c
@@ -29,7 +29,7 @@
 #define CNTL_OVER_MASK		0xFFFFFFFE
 
 #define CNTL_CSV_SHIFT		24
-#define CNTL_CSV_MASK		(0xFF << CNTL_CSV_SHIFT)
+#define CNTL_CSV_MASK		(0xFFU << CNTL_CSV_SHIFT)
 
 #define EVENT_CYCLES_ID		0
 #define EVENT_CYCLES_COUNTER	0
-- 
2.35.1