summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorGustavo A. R. Silva <gustavo@embeddedor.com>2020-02-26 16:31:25 -0600
committerUlf Hansson <ulf.hansson@linaro.org>2020-03-24 14:39:45 +0100
commit1a91a36aba9c232c73e4a5fce038147f5d29e566 (patch)
tree556ba35f35e808f13f5f51cc08f47c0a2b2b5d2c
parentea21e9b2b33fd06c131415cc66ca5499ab2aef5f (diff)
mmc: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Link: https://lore.kernel.org/r/20200226223125.GA20630@embeddedor Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
-rw-r--r--drivers/mmc/host/sdhci-acpi.c2
-rw-r--r--drivers/mmc/host/sdhci-cadence.c2
-rw-r--r--drivers/mmc/host/sdhci-pci.h2
-rw-r--r--drivers/mmc/host/sdhci-pltfm.h2
-rw-r--r--drivers/mmc/host/sdhci.h2
-rw-r--r--drivers/mmc/host/vub300.c2
-rw-r--r--include/linux/mmc/host.h2
-rw-r--r--include/linux/mmc/sdio_func.h2
-rw-r--r--include/uapi/linux/mmc/ioctl.h2
9 files changed, 9 insertions, 9 deletions
diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
index 2a2173d953f5..68cf41747fa5 100644
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -75,7 +75,7 @@ struct sdhci_acpi_host {
bool use_runtime_pm;
bool is_intel;
bool reset_signal_volt_on_suspend;
- unsigned long private[0] ____cacheline_aligned;
+ unsigned long private[] ____cacheline_aligned;
};
enum {
diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
index e573495f8726..6da6d4fb5edd 100644
--- a/drivers/mmc/host/sdhci-cadence.c
+++ b/drivers/mmc/host/sdhci-cadence.c
@@ -68,7 +68,7 @@ struct sdhci_cdns_priv {
void __iomem *hrs_addr;
bool enhanced_strobe;
unsigned int nr_phy_params;
- struct sdhci_cdns_phy_param phy_params[0];
+ struct sdhci_cdns_phy_param phy_params[];
};
struct sdhci_cdns_phy_cfg {
diff --git a/drivers/mmc/host/sdhci-pci.h b/drivers/mmc/host/sdhci-pci.h
index 981bbbe63aff..42ccd123b046 100644
--- a/drivers/mmc/host/sdhci-pci.h
+++ b/drivers/mmc/host/sdhci-pci.h
@@ -163,7 +163,7 @@ struct sdhci_pci_slot {
bool cd_override_level;
void (*hw_reset)(struct sdhci_host *host);
- unsigned long private[0] ____cacheline_aligned;
+ unsigned long private[] ____cacheline_aligned;
};
struct sdhci_pci_chip {
diff --git a/drivers/mmc/host/sdhci-pltfm.h b/drivers/mmc/host/sdhci-pltfm.h
index 2af445b8c325..6301b81cf573 100644
--- a/drivers/mmc/host/sdhci-pltfm.h
+++ b/drivers/mmc/host/sdhci-pltfm.h
@@ -25,7 +25,7 @@ struct sdhci_pltfm_host {
unsigned int clock;
u16 xfer_mode_shadow;
- unsigned long private[0] ____cacheline_aligned;
+ unsigned long private[] ____cacheline_aligned;
};
#ifdef CONFIG_MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index cac2d97782e6..249635692112 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -614,7 +614,7 @@ struct sdhci_host {
u64 data_timeout;
- unsigned long private[0] ____cacheline_aligned;
+ unsigned long private[] ____cacheline_aligned;
};
struct sdhci_ops {
diff --git a/drivers/mmc/host/vub300.c b/drivers/mmc/host/vub300.c
index 6ced1b7f642f..a5a90d133f1f 100644
--- a/drivers/mmc/host/vub300.c
+++ b/drivers/mmc/host/vub300.c
@@ -95,7 +95,7 @@ struct sd_response_header {
u8 port_number;
u8 command_type;
u8 command_index;
- u8 command_response[0];
+ u8 command_response[];
} __packed;
struct sd_status_header {
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index f5db24a6a860..c318fb5b6a94 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -468,7 +468,7 @@ struct mmc_host {
/* Host Software Queue support */
bool hsq_enabled;
- unsigned long private[0] ____cacheline_aligned;
+ unsigned long private[] ____cacheline_aligned;
};
struct device_node;
diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
index 5a177f7a83c3..fa2aaab5e57a 100644
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -25,7 +25,7 @@ struct sdio_func_tuple {
struct sdio_func_tuple *next;
unsigned char code;
unsigned char size;
- unsigned char data[0];
+ unsigned char data[];
};
/*
diff --git a/include/uapi/linux/mmc/ioctl.h b/include/uapi/linux/mmc/ioctl.h
index 00c08120f3ba..98e29e7f54ac 100644
--- a/include/uapi/linux/mmc/ioctl.h
+++ b/include/uapi/linux/mmc/ioctl.h
@@ -57,7 +57,7 @@ struct mmc_ioc_cmd {
*/
struct mmc_ioc_multi_cmd {
__u64 num_of_cmds;
- struct mmc_ioc_cmd cmds[0];
+ struct mmc_ioc_cmd cmds[];
};
#define MMC_IOC_CMD _IOWR(MMC_BLOCK_MAJOR, 0, struct mmc_ioc_cmd)