From: shobhitkukreti at gmail.com (Shobhit Kukreti)
Subject: [Linux-kernel-mentees] [PATCH] video: atmel_lcdc: Fix Shifting signed 32 bit value by 31 bits problem
Date: Sat, 6 Jul 2019 10:41:03 -0700 [thread overview]
Message-ID: <20190706174059.GA14822@t-1000> (raw)
Fix ATMEL_LCDC_MEMOR and ATMEL_LCDC_MEMOR_LITTLE defines to use "U"
cast to avoid shifting signed 32 bit values by 31 bit problem. This
problem. This is not a problem for gcc built kernel.
However, this may be a problem since the header is part of pbulic API
which could be included for builds using compilers which do not handle
this condition safely resulting in undefined behavior
Signed-off-by: Shobhit Kukreti <shobhitkukreti at gmail.com>
---
include/video/atmel_lcdc.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/video/atmel_lcdc.h b/include/video/atmel_lcdc.h
index 43e497c..ac96b4f 100644
--- a/include/video/atmel_lcdc.h
+++ b/include/video/atmel_lcdc.h
@@ -103,9 +103,9 @@ struct atmel_lcdfb_pdata {
#define ATMEL_LCDC_CLKMOD (1 << 15)
#define ATMEL_LCDC_CLKMOD_ACTIVEDISPLAY (0 << 15)
#define ATMEL_LCDC_CLKMOD_ALWAYSACTIVE (1 << 15)
-#define ATMEL_LCDC_MEMOR (1 << 31)
+#define ATMEL_LCDC_MEMOR (1U << 31)
#define ATMEL_LCDC_MEMOR_BIG (0 << 31)
-#define ATMEL_LCDC_MEMOR_LITTLE (1 << 31)
+#define ATMEL_LCDC_MEMOR_LITTLE (1U << 31)
#define ATMEL_LCDC_TIM1 0x0808
#define ATMEL_LCDC_VFP (0xffU << 0)
--
2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: shobhitkukreti@gmail.com (Shobhit Kukreti)
Subject: [Linux-kernel-mentees] [PATCH] video: atmel_lcdc: Fix Shifting signed 32 bit value by 31 bits problem
Date: Sat, 6 Jul 2019 10:41:03 -0700 [thread overview]
Message-ID: <20190706174059.GA14822@t-1000> (raw)
Message-ID: <20190706174103.veEL60RBUgv9wz0_Lk78NT45v3xjr4m6xrjc_WGc8H0@z> (raw)
Fix ATMEL_LCDC_MEMOR and ATMEL_LCDC_MEMOR_LITTLE defines to use "U"
cast to avoid shifting signed 32 bit values by 31 bit problem. This
problem. This is not a problem for gcc built kernel.
However, this may be a problem since the header is part of pbulic API
which could be included for builds using compilers which do not handle
this condition safely resulting in undefined behavior
Signed-off-by: Shobhit Kukreti <shobhitkukreti at gmail.com>
---
include/video/atmel_lcdc.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/video/atmel_lcdc.h b/include/video/atmel_lcdc.h
index 43e497c..ac96b4f 100644
--- a/include/video/atmel_lcdc.h
+++ b/include/video/atmel_lcdc.h
@@ -103,9 +103,9 @@ struct atmel_lcdfb_pdata {
#define ATMEL_LCDC_CLKMOD (1 << 15)
#define ATMEL_LCDC_CLKMOD_ACTIVEDISPLAY (0 << 15)
#define ATMEL_LCDC_CLKMOD_ALWAYSACTIVE (1 << 15)
-#define ATMEL_LCDC_MEMOR (1 << 31)
+#define ATMEL_LCDC_MEMOR (1U << 31)
#define ATMEL_LCDC_MEMOR_BIG (0 << 31)
-#define ATMEL_LCDC_MEMOR_LITTLE (1 << 31)
+#define ATMEL_LCDC_MEMOR_LITTLE (1U << 31)
#define ATMEL_LCDC_TIM1 0x0808
#define ATMEL_LCDC_VFP (0xffU << 0)
--
2.7.4
next reply other threads:[~2019-07-06 17:41 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-06 17:41 shobhitkukreti [this message]
2019-07-06 17:41 ` [Linux-kernel-mentees] [PATCH] video: atmel_lcdc: Fix Shifting signed 32 bit value by 31 bits problem Shobhit Kukreti
2019-07-06 18:28 ` [Linux-kernel-mentees] [PATCH v2] " shobhitkukreti
2019-07-06 18:28 ` shobhitkukreti
2019-07-15 11:33 ` b.zolnierkie
2019-07-15 11:33 ` Bartlomiej Zolnierkiewicz
2019-07-22 0:42 ` [Linux-kernel-mentees] [PATCH v3] " shobhitkukreti
2019-07-22 0:42 ` Shobhit Kukreti
2019-08-19 14:29 ` b.zolnierkie
2019-08-19 14:29 ` Bartlomiej Zolnierkiewicz
2020-01-08 13:08 ` Nicolas.Ferre
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