linux_dsm_epyc7002/arch/x86/kvm
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
..
mmu KVM: MMU: pass arbitrary CR0/CR4/EFER to kvm_init_shadow_mmu 2020-06-01 04:26:03 -04:00
svm KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE 2020-06-01 04:26:05 -04:00
vmx KVM: VMX: Replace zero-length array with flexible-array 2020-06-01 04:26:05 -04:00
cpuid.c kvm: x86: Cleanup vcpu->arch.guest_xstate_size 2020-05-15 12:26:10 -04:00
cpuid.h KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE 2020-06-01 04:26:05 -04:00
debugfs.c KVM: no need to check return value of debugfs_create functions 2019-08-05 12:55:49 +02:00
emulate.c KVM: x86: handle wrap around 32-bit address space 2020-05-13 12:14:59 -04:00
hyperv.c Merge branch 'kvm-amd-fixes' into HEAD 2020-05-13 12:14:05 -04:00
hyperv.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
i8254.c KVM: x86: Fix print format and coding style 2020-03-16 17:57:08 +01:00
i8254.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
i8259.c KVM: x86: Refactor picdev_write() to prevent Spectre-v1/L1TF attacks 2020-01-27 19:59:37 +01:00
ioapic.c kvm: ioapic: Restrict lazy EOI update to edge-triggered interrupts 2020-05-04 12:29:05 -04:00
ioapic.h kvm/x86: Remove redundant function implementations 2020-05-27 13:11:10 -04:00
irq_comm.c KVM: x86: don't notify userspace IOAPIC on edge-triggered interrupt EOI 2020-02-21 18:04:57 +01:00
irq.c KVM: nSVM: extract svm_set_gif 2020-06-01 04:26:01 -04:00
irq.h kvm/x86: Remove redundant function implementations 2020-05-27 13:11:10 -04:00
Kconfig vhost: refine vhost and vringh kconfig 2020-04-01 12:06:26 -04:00
kvm_cache_regs.h KVM: VMX: Add proper cache tracking for CR0 2020-05-13 12:15:12 -04:00
kvm_emulate.h ARM: 2020-04-02 15:13:15 -07:00
lapic.c kvm/x86: Remove redundant function implementations 2020-05-27 13:11:10 -04:00
lapic.h KVM: x86: introduce kvm_can_use_hv_timer 2020-05-15 12:26:21 -04:00
Makefile kvm: Disable objtool frame pointer checking for vmenter.S 2020-04-20 17:11:19 -04:00
mmu_audit.c KVM: x86/mmu: Drop KVM's hugepage enums in favor of the kernel's enums 2020-05-15 12:26:11 -04:00
mmu.h KVM: MMU: pass arbitrary CR0/CR4/EFER to kvm_init_shadow_mmu 2020-06-01 04:26:03 -04:00
mmutrace.h KVM: x86: fix incorrect comparison in trace event 2020-02-20 18:13:44 +01:00
mtrr.c KVM: x86: Protect MSR-based index computations in fixed_msr_to_seg_unit() from Spectre-v1/L1TF attacks 2020-01-27 19:59:39 +01:00
pmu.c KVM: x86: Copy kvm_x86_ops by value to eliminate layer of indirection 2020-03-31 10:48:08 -04:00
pmu.h KVM: x86: Copy kvm_x86_ops by value to eliminate layer of indirection 2020-03-31 10:48:08 -04:00
trace.h KVM: x86: Print symbolic names of VMX VM-Exit flags in traces 2020-05-15 12:26:18 -04:00
tss.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
x86.c KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE 2020-06-01 04:26:05 -04:00
x86.h KVM: X86: Introduce more exit_fastpath_completion enum values 2020-05-15 12:26:19 -04:00