[PATCH 2/2] KVM: x86: Fix a typo about the usage of kvcalloc()

[PATCH 2/2] KVM: x86: Fix a typo about the usage of kvcalloc()

[Liao Chang]

Swap the 1st and 2nd arguments to be consistent with the usage of
kvcalloc().

Fixes: c9b8fecddb5b ("KVM: use kvcalloc for array allocations")
Signed-off-by: Liao Chang <liaochang1@huawei.com>
---
 arch/x86/kvm/cpuid.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 7065462378e2..b33c18b142c2 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -1331,7 +1331,7 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
 	if (sanity_check_entries(entries, cpuid->nent, type))
 		return -EINVAL;
 
-	array.entries = kvcalloc(sizeof(struct kvm_cpuid_entry2), cpuid->nent, GFP_KERNEL);
+	array.entries = kvcalloc(cpuid->nent, sizeof(struct kvm_cpuid_entry2), GFP_KERNEL);
 	if (!array.entries)
 		return -ENOMEM;
 
-- 
2.17.1

Re: [PATCH 2/2] KVM: x86: Fix a typo about the usage of kvcalloc()

[Bagas Sanjaya]

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On Thu, Nov 03, 2022 at 09:17:49AM +0800, Liao Chang wrote:
> Swap the 1st and 2nd arguments to be consistent with the usage of
> kvcalloc().
> 

This isn't typofix as suggested from the patch subject, right?

-- 
An old man doll... just what I always wanted! - Clara

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Re: [PATCH 2/2] KVM: x86: Fix a typo about the usage of kvcalloc()

[liaochang (A)]

在 2022/11/3 10:37, Bagas Sanjaya 写道:
> This isn't typofix as suggested from the patch subject, right?

Well, since kvcalloc uses the product of 1st and 2nd argument to do allocation,
hence current code supposes to work well, but the usage is obviously no sense,
that is why i name it a 'typo' and make it correct ;)

-- 
BR,
Liao, Chang

Re: [PATCH 2/2] KVM: x86: Fix a typo about the usage of kvcalloc()

[Joe Perches]

On Thu, 2022-11-03 at 12:18 +0800, liaochang (A) wrote:
> 
> 在 2022/11/3 10:37, Bagas Sanjaya 写道:
> > This isn't typofix as suggested from the patch subject, right?
> 
> Well, since kvcalloc uses the product of 1st and 2nd argument to do allocation,
> hence current code supposes to work well, but the usage is obviously no sense,
> that is why i name it a 'typo' and make it correct ;)
> 

Seems there are several of these typo/defects.

$ git grep -P 'calloc\s*\(\s*sizeof'
arch/x86/kvm/cpuid.c:   array.entries = kvcalloc(sizeof(struct kvm_cpuid_entry2), cpuid->nent, GFP_KERNEL);
drivers/gpu/drm/nouveau/nouveau_svm.c:  buffer->fault = kvcalloc(sizeof(*buffer->fault), buffer->entries, GFP_KERNEL);
drivers/scsi/bfa/bfad_bsg.c:    buf_base = kcalloc(sizeof(struct bfad_buf_info) +
drivers/soc/fsl/dpio/dpio-service.c:    ed = kcalloc(sizeof(struct qbman_eq_desc), 32, GFP_KERNEL);
fs/btrfs/send.c:        sctx->clone_roots = kvcalloc(sizeof(*sctx->clone_roots),
kernel/bpf/bpf_local_storage.c: smap->buckets = kvcalloc(sizeof(*smap->buckets), nbuckets,
kernel/watch_queue.c:   pages = kcalloc(sizeof(struct page *), nr_pages, GFP_KERNEL);
tools/lib/bpf/libbpf.c: gen = calloc(sizeof(*gen), 1);
tools/objtool/check.c:  struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
tools/objtool/check.c:  file->pv_ops = calloc(sizeof(struct pv_state), nr);
tools/perf/builtin-record.c:            rec->switch_output.filenames = calloc(sizeof(char *),
tools/perf/util/bpf-loader.c:   priv = calloc(sizeof(*priv), 1);
tools/perf/util/hist.c:         he->res_samples = calloc(sizeof(struct res_sample),
tools/perf/util/metricgroup.c:  metric_events = calloc(sizeof(void *), ids_size + 1);
tools/perf/util/stat-shadow.c:                  metric_events = calloc(sizeof(struct evsel *),
tools/perf/util/synthetic-events.c:     synthesize_threads = calloc(sizeof(pthread_t), thread_nr);
tools/perf/util/synthetic-events.c:     args = calloc(sizeof(*args), thread_nr);
tools/testing/selftests/arm64/fp/fp-stress.c:   children = calloc(sizeof(*children), tests);
tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c: link = calloc(sizeof(struct bpf_link *), prog_cnt);
tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c: prog = calloc(sizeof(struct bpf_program *), prog_cnt);
tools/testing/selftests/bpf/test_progs.c:       dispatcher_threads = calloc(sizeof(pthread_t), env.workers);
tools/testing/selftests/bpf/test_progs.c:       data = calloc(sizeof(struct dispatch_data), env.workers);
tools/testing/selftests/bpf/test_progs.c:       env.worker_current_test = calloc(sizeof(int), env.workers);
tools/testing/selftests/bpf/test_progs.c:               env.worker_pids = calloc(sizeof(__pid_t), env.workers);
tools/testing/selftests/bpf/test_progs.c:               env.worker_socks = calloc(sizeof(int), env.workers);
tools/testing/selftests/memfd/fuse_test.c:      zero = calloc(sizeof(*zero), mfd_def_size);

Re: [PATCH 2/2] KVM: x86: Fix a typo about the usage of kvcalloc()

[Paolo Bonzini]

On 11/3/22 02:17, Liao Chang wrote:
> Swap the 1st and 2nd arguments to be consistent with the usage of
> kvcalloc().
> 
> Fixes: c9b8fecddb5b ("KVM: use kvcalloc for array allocations")
> Signed-off-by: Liao Chang<liaochang1@huawei.com>
> ---
>   arch/x86/kvm/cpuid.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 7065462378e2..b33c18b142c2 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -1331,7 +1331,7 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
>   	if (sanity_check_entries(entries, cpuid->nent, type))
>   		return -EINVAL;
>   
> -	array.entries = kvcalloc(sizeof(struct kvm_cpuid_entry2), cpuid->nent, GFP_KERNEL);
> +	array.entries = kvcalloc(cpuid->nent, sizeof(struct kvm_cpuid_entry2), GFP_KERNEL);
>   	if (!array.entries)
>   		return -ENOMEM;
>   

It doesn't make any difference, but scripts/checkpatch.pl checks it so
let's fix the sole occurrence in KVM.

However, please send a patch to scripts/checkpatch.pl to include calloc(),
kvmalloc_array and kvcalloc() in the matched functions:

# check for alloc argument mismatch
                 if ($line =~ /\b((?:devm_)?(?:kcalloc|kmalloc_array))\s*\(\s*sizeof\b/) {
                         WARN("ALLOC_ARRAY_ARGS",
                              "$1 uses number as first arg, sizeof is generally wrong\n" . $herecurr);
                 }


Paolo

Re: [PATCH 2/2] KVM: x86: Fix a typo about the usage of kvcalloc()

[liaochang (A)]

在 2022/11/3 21:39, Paolo Bonzini 写道:
> On 11/3/22 02:17, Liao Chang wrote:
>> Swap the 1st and 2nd arguments to be consistent with the usage of
>> kvcalloc().
>>
>> Fixes: c9b8fecddb5b ("KVM: use kvcalloc for array allocations")
>> Signed-off-by: Liao Chang<liaochang1@huawei.com>
>> ---
>>   arch/x86/kvm/cpuid.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
>> index 7065462378e2..b33c18b142c2 100644
>> --- a/arch/x86/kvm/cpuid.c
>> +++ b/arch/x86/kvm/cpuid.c
>> @@ -1331,7 +1331,7 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
>>       if (sanity_check_entries(entries, cpuid->nent, type))
>>           return -EINVAL;
>>   -    array.entries = kvcalloc(sizeof(struct kvm_cpuid_entry2), cpuid->nent, GFP_KERNEL);
>> +    array.entries = kvcalloc(cpuid->nent, sizeof(struct kvm_cpuid_entry2), GFP_KERNEL);
>>       if (!array.entries)
>>           return -ENOMEM;
>>   
> 
> It doesn't make any difference, but scripts/checkpatch.pl checks it so
> let's fix the sole occurrence in KVM.
> 
> However, please send a patch to scripts/checkpatch.pl to include calloc(),
> kvmalloc_array and kvcalloc() in the matched functions:
> 
> # check for alloc argument mismatch
>                 if ($line =~ /\b((?:devm_)?(?:kcalloc|kmalloc_array))\s*\(\s*sizeof\b/) {
>                         WARN("ALLOC_ARRAY_ARGS",
>                              "$1 uses number as first arg, sizeof is generally wrong\n" . $herecurr);
>                 }

I ready send a patch to enhance the checking for array allocator family,
please check out patch "checkpatch: Add check for array allocator family argument order".

Thanks.

> 
> 
> Paolo
> 
> 
> .

-- 
BR,
Liao, Chang