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2963795122
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.
Lastly, make use of the sizeof_field() helper instead of an open-coded
version.
This issue was found with the help of Coccinelle and audited _manually_.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit
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| .. | ||
| libstub | ||
| test | ||
| apple-properties.c | ||
| arm-init.c | ||
| arm-runtime.c | ||
| capsule-loader.c | ||
| capsule.c | ||
| cper-arm.c | ||
| cper-x86.c | ||
| cper.c | ||
| dev-path-parser.c | ||
| earlycon.c | ||
| efi-bgrt.c | ||
| efi-pstore.c | ||
| efi.c | ||
| efibc.c | ||
| efivars.c | ||
| embedded-firmware.c | ||
| esrt.c | ||
| fake_mem.c | ||
| fake_mem.h | ||
| fdtparams.c | ||
| Kconfig | ||
| Makefile | ||
| memattr.c | ||
| memmap.c | ||
| rci2-table.c | ||
| reboot.c | ||
| runtime-map.c | ||
| runtime-wrappers.c | ||
| tpm.c | ||
| vars.c | ||
| x86_fake_mem.c | ||