kernel/include/linux/fsl/bestcomm/bestcomm.h, branch linux-5.11.yHosts the 0x221E linux distro kernel.https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-5.11.y2020-05-22T21:19:31Ztreewide: Replace zero-length array with flexible-array2020-05-22T21:19:31ZGustavo A. R. Silvagustavoars@kernel.org2020-05-07T18:53:01Zurn:sha1:d3e81989c0f028aa80cb97fcba83df40585b640d
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]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
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 <gustavoars@kernel.org>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
powerpc, dma: move bestcomm driver from arch/powerpc/sysdev to drivers/dma2013-01-03T14:41:20ZPhilippe De Muyterphdm@macqel.be2012-10-12T15:52:45Zurn:sha1:9a32299394d8cce79ca7d0098dc32c4f14032dcd
The bestcomm dma hardware, and some of its users like the FEC ethernet
component, is used in different FreeScale parts, including non-powerpc
parts like the ColdFire MCF547x & MCF548x families. Don't keep the
driver hidden in arch/powerpc where it is inaccessible for other arches.
.c files are moved to drivers/dma/bestcomm, while .h files are moved to
include/linux/fsl/bestcomm. Makefiles, Kconfigs and #include directives
are updated for the new file locations.
Tested by recompiling for MPC5200 with all bestcomm users enabled.
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Anatolij Gustschin <agust@denx.de>