[media] ttpci: address stringop overflow warning

gcc-7.0.1 warns about old code in ttpci:

In file included from drivers/media/pci/ttpci/av7110.c:63:0:
In function 'irdebi.isra.2',
    inlined from 'start_debi_dma' at drivers/media/pci/ttpci/av7110.c:376:3,
    inlined from 'gpioirq' at drivers/media/pci/ttpci/av7110.c:659:3:
drivers/media/pci/ttpci/av7110_hw.h:406:3: warning: 'memcpy': specified size between 18446744071562067968 and 18446744073709551615 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
   memcpy(av7110->debi_virt, (char *) &res, count);
In function 'irdebi.isra.2',
    inlined from 'start_debi_dma' at drivers/media/pci/ttpci/av7110.c:376:3,
    inlined from 'gpioirq' at drivers/media/pci/ttpci/av7110.c:668:3:
drivers/media/pci/ttpci/av7110_hw.h:406:3: warning: 'memcpy': specified size between 18446744071562067968 and 18446744073709551615 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
   memcpy(av7110->debi_virt, (char *) &res, count);

Apparently, 'count' can be negative here, which will then get turned
into a giant size argument for memcpy. Changing the sizes to 'unsigned
int' instead seems safe as we already check for maximum sizes, and it
also simplifies the code a bit.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/pci/ttpci/av7110_hw.c b/drivers/media/pci/ttpci/av7110_hw.c
index 041687abd759106a947d38bdf77a7135591ff541..b2b79bb739176c019aae693cc63de96690d47aad 100644 (file)
--- a/drivers/media/pci/ttpci/av7110_hw.c
+++ b/drivers/media/pci/ttpci/av7110_hw.c
@@ -53,11 +53,11 @@
    by Nathan Laredo <laredo@gnu.org> */
 
 int av7110_debiwrite(struct av7110 *av7110, u32 config,
-                    int addr, u32 val, int count)
+                    int addr, u32 val, unsigned int count)
 {
        struct saa7146_dev *dev = av7110->dev;
 
-       if (count <= 0 || count > 32764) {
+       if (count > 32764) {
                printk("%s: invalid count %d\n", __func__, count);
                return -1;
        }
@@ -75,12 +75,12 @@ int av7110_debiwrite(struct av7110 *av7110, u32 config,
        return 0;
 }
 
-u32 av7110_debiread(struct av7110 *av7110, u32 config, int addr, int count)
+u32 av7110_debiread(struct av7110 *av7110, u32 config, int addr, unsigned int count)
 {
        struct saa7146_dev *dev = av7110->dev;
        u32 result = 0;
 
-       if (count > 32764 || count <= 0) {
+       if (count > 32764) {
                printk("%s: invalid count %d\n", __func__, count);
                return 0;
        }

diff --git a/drivers/media/pci/ttpci/av7110_hw.h b/drivers/media/pci/ttpci/av7110_hw.h
index 1634aba5cb84693bfde178dba08f5dc32ab3ab91..ccb1480594068f4058ac8c774cbc888ea16818be 100644 (file)
--- a/drivers/media/pci/ttpci/av7110_hw.h
+++ b/drivers/media/pci/ttpci/av7110_hw.h
@@ -377,14 +377,14 @@ extern int av7110_fw_request(struct av7110 *av7110, u16 *request_buf,
 
 /* DEBI (saa7146 data extension bus interface) access */
 extern int av7110_debiwrite(struct av7110 *av7110, u32 config,
-                           int addr, u32 val, int count);
+                           int addr, u32 val, unsigned int count);
 extern u32 av7110_debiread(struct av7110 *av7110, u32 config,
-                          int addr, int count);
+                          int addr, unsigned int count);
 
 
 /* DEBI during interrupt */
 /* single word writes */
-static inline void iwdebi(struct av7110 *av7110, u32 config, int addr, u32 val, int count)
+static inline void iwdebi(struct av7110 *av7110, u32 config, int addr, u32 val, unsigned int count)
 {
        av7110_debiwrite(av7110, config, addr, val, count);
 }
@@ -397,7 +397,7 @@ static inline void mwdebi(struct av7110 *av7110, u32 config, int addr,
        av7110_debiwrite(av7110, config, addr, 0, count);
 }
 
-static inline u32 irdebi(struct av7110 *av7110, u32 config, int addr, u32 val, int count)
+static inline u32 irdebi(struct av7110 *av7110, u32 config, int addr, u32 val, unsigned int count)
 {
        u32 res;
 
@@ -408,7 +408,7 @@ static inline u32 irdebi(struct av7110 *av7110, u32 config, int addr, u32 val, i
 }
 
 /* DEBI outside interrupts, only for count <= 4! */
-static inline void wdebi(struct av7110 *av7110, u32 config, int addr, u32 val, int count)
+static inline void wdebi(struct av7110 *av7110, u32 config, int addr, u32 val, unsigned int count)
 {
        unsigned long flags;
 
@@ -417,7 +417,7 @@ static inline void wdebi(struct av7110 *av7110, u32 config, int addr, u32 val, i
        spin_unlock_irqrestore(&av7110->debilock, flags);
 }
 
-static inline u32 rdebi(struct av7110 *av7110, u32 config, int addr, u32 val, int count)
+static inline u32 rdebi(struct av7110 *av7110, u32 config, int addr, u32 val, unsigned int count)
 {
        unsigned long flags;
        u32 res;