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author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2020-05-07 14:19:43 -0500 |
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committer | Bjorn Andersson <bjorn.andersson@linaro.org> | 2020-05-12 15:00:37 -0700 |
commit | 529798bae7c155d38eec211436df736349dca2ee (patch) | |
tree | e3c347c03cd4683e02de324fc5e5ed26c0aa7edf /include | |
parent | 8a226e2c71bb3763e27a063d36eac5fa4ea53c3f (diff) | |
download | linux-stable-529798bae7c155d38eec211436df736349dca2ee.tar.gz linux-stable-529798bae7c155d38eec211436df736349dca2ee.tar.bz2 linux-stable-529798bae7c155d38eec211436df736349dca2ee.zip |
remoteproc: Replace zero-length array with flexible-array
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>
Link: https://lore.kernel.org/r/20200507191943.GA16033@embeddedor
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/remoteproc.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index 0468be4d02f4..e7b7bab8b235 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -73,7 +73,7 @@ struct resource_table { u32 ver; u32 num; u32 reserved[2]; - u32 offset[0]; + u32 offset[]; } __packed; /** @@ -87,7 +87,7 @@ struct resource_table { */ struct fw_rsc_hdr { u32 type; - u8 data[0]; + u8 data[]; } __packed; /** @@ -306,7 +306,7 @@ struct fw_rsc_vdev { u8 status; u8 num_of_vrings; u8 reserved[2]; - struct fw_rsc_vdev_vring vring[0]; + struct fw_rsc_vdev_vring vring[]; } __packed; struct rproc; |