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linux-next/drivers/hwspinlock
Gustavo A. R. Silva ef17f5193e hwspinlock: hwspinlock_internal.h: 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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200319213839.GA10669@embeddedor.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-03-25 22:30:46 -07:00
..
hwspinlock_core.c hwspinlock: Let the PM runtime can be optional 2019-11-08 16:42:00 -08:00
hwspinlock_internal.h hwspinlock: hwspinlock_internal.h: Replace zero-length array with flexible-array member 2020-03-25 22:30:46 -07:00
Kconfig hwspinlock: Allow drivers to be built with COMPILE_TEST 2020-03-25 22:30:46 -07:00
Makefile hwspinlock: add STM32 hwspinlock device 2018-12-05 12:45:21 -08:00
omap_hwspinlock.c hwspinlock: omap: Use devm_kzalloc() to allocate memory 2020-01-21 16:11:25 -08:00
qcom_hwspinlock.c hwspinlock: qcom: Use devm_hwspin_lock_register() to register hwlock controller 2020-01-21 16:10:07 -08:00
sirf_hwspinlock.c hwspinlock: sirf: Use devm_hwspin_lock_register() to register hwlock controller 2020-01-21 16:16:36 -08:00
sprd_hwspinlock.c hwspinlock: sprd: Remove redundant PM runtime implementation 2019-11-08 16:42:11 -08:00
stm32_hwspinlock.c hwspinlock: stm32: convert to devm_platform_ioremap_resource 2019-12-28 20:43:23 -08:00
u8500_hsem.c hwspinlock: u8500_hsem: Remove redundant PM runtime implementation 2019-11-08 16:42:26 -08:00