From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> To: Arnd Bergmann <arnd@arndb.de>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Liviu Dudau <liviu.dudau@arm.com>, Sudeep Holla <sudeep.holla@arm.com>, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" <gustavo@embeddedor.com> Subject: [PATCH] misc: vexpress: Replace zero-length array with flexible-array member Date: Tue, 11 Feb 2020 15:10:10 -0600 [thread overview] Message-ID: <20200211211010.GA32239@embeddedor> (raw) 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 inadvertenly introduced[3] to the codebase from now on. 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> --- drivers/misc/vexpress-syscfg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c index a3c6c773d9dc..5eb51f2be8f0 100644 --- a/drivers/misc/vexpress-syscfg.c +++ b/drivers/misc/vexpress-syscfg.c @@ -49,7 +49,7 @@ struct vexpress_syscfg_func { struct vexpress_syscfg *syscfg; struct regmap *regmap; int num_templates; - u32 template[0]; /* Keep it last! */ + u32 template[]; /* Keep it last! */ }; -- 2.25.0
WARNING: multiple messages have this Message-ID (diff)
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> To: Arnd Bergmann <arnd@arndb.de>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Liviu Dudau <liviu.dudau@arm.com>, Sudeep Holla <sudeep.holla@arm.com>, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, "Gustavo A. R. Silva" <gustavo@embeddedor.com> Subject: [PATCH] misc: vexpress: Replace zero-length array with flexible-array member Date: Tue, 11 Feb 2020 15:10:10 -0600 [thread overview] Message-ID: <20200211211010.GA32239@embeddedor> (raw) 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 inadvertenly introduced[3] to the codebase from now on. 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> --- drivers/misc/vexpress-syscfg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c index a3c6c773d9dc..5eb51f2be8f0 100644 --- a/drivers/misc/vexpress-syscfg.c +++ b/drivers/misc/vexpress-syscfg.c @@ -49,7 +49,7 @@ struct vexpress_syscfg_func { struct vexpress_syscfg *syscfg; struct regmap *regmap; int num_templates; - u32 template[0]; /* Keep it last! */ + u32 template[]; /* Keep it last! */ }; -- 2.25.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2020-02-11 21:07 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-11 21:10 Gustavo A. R. Silva [this message] 2020-02-11 21:10 ` [PATCH] misc: vexpress: Replace zero-length array with flexible-array member Gustavo A. R. Silva 2020-02-20 17:16 ` Sudeep Holla 2020-02-20 17:16 ` Sudeep Holla
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