linux_dsm_epyc7002/arch
Gustavo A. R. Silva f4a9fdd5f1 KVM: VMX: 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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Message-Id: <20200507185618.GA14831@embeddedor>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:05 -04:00
..
alpha mm/special: create generic fallbacks for pte_special() and pte_mkspecial() 2020-04-10 15:36:21 -07:00
arc arch: split MODULE_ARCH_VERMAGIC definitions out to <asm/vermagic.h> 2020-04-23 10:50:26 +09:00
arm ARM: futex: Address build warning 2020-05-07 00:41:47 +02:00
arm64 Merge tag 'noinstr-x86-kvm-2020-05-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into HEAD 2020-05-20 03:40:09 -04:00
c6x mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS 2020-04-10 15:36:21 -07:00
csky mm/special: create generic fallbacks for pte_special() and pte_mkspecial() 2020-04-10 15:36:21 -07:00
h8300 h8300: ignore vmlinux.lds 2020-04-23 16:41:26 +09:00
hexagon arch: split MODULE_ARCH_VERMAGIC definitions out to <asm/vermagic.h> 2020-04-23 10:50:26 +09:00
ia64 arch: split MODULE_ARCH_VERMAGIC definitions out to <asm/vermagic.h> 2020-04-23 10:50:26 +09:00
m68k m68k: Drop redundant generic-y += hardirq.h 2020-04-13 11:08:52 -07:00
microblaze mm/special: create generic fallbacks for pte_special() and pte_mkspecial() 2020-04-10 15:36:21 -07:00
mips Merge tag 'noinstr-x86-kvm-2020-05-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into HEAD 2020-05-20 03:40:09 -04:00
nds32 arch: split MODULE_ARCH_VERMAGIC definitions out to <asm/vermagic.h> 2020-04-23 10:50:26 +09:00
nios2 nios2 update for v5.7-rc1 2020-04-11 11:38:44 -07:00
openrisc mm/special: create generic fallbacks for pte_special() and pte_mkspecial() 2020-04-10 15:36:21 -07:00
parisc mm/special: create generic fallbacks for pte_special() and pte_mkspecial() 2020-04-10 15:36:21 -07:00
powerpc Merge tag 'noinstr-x86-kvm-2020-05-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into HEAD 2020-05-20 03:40:09 -04:00
riscv RISC-V: Remove unused code from STRICT_KERNEL_RWX 2020-05-05 17:02:14 -07:00
s390 KVM: s390: Cleanups for 5.8 2020-05-27 13:10:21 -04:00
sh Kbuild fixes for v5.7 2020-04-24 10:39:32 -07:00
sparc mm/special: create generic fallbacks for pte_special() and pte_mkspecial() 2020-04-10 15:36:21 -07:00
um um: ensure make ARCH=um mrproper removes arch/$(SUBARCH)/include/generated/ 2020-04-23 10:50:26 +09:00
unicore32 mm/special: create generic fallbacks for pte_special() and pte_mkspecial() 2020-04-10 15:36:21 -07:00
x86 KVM: VMX: Replace zero-length array with flexible-array 2020-06-01 04:26:05 -04:00
xtensa arch: split MODULE_ARCH_VERMAGIC definitions out to <asm/vermagic.h> 2020-04-23 10:50:26 +09:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
Kconfig dma-mapping updates for 5.7 2020-04-04 10:12:47 -07:00