From mboxrd@z Thu Jan 1 00:00:00 1970 From: walter harms Date: Thu, 18 Aug 2016 07:25:39 +0000 Subject: Re: [PATCH 1/4] KVM-S390: Improve determination of sizes in kvm_s390_import_bp_data() Message-Id: <57B562F3.1080004@bfs.de> List-Id: References: <82b84c9c-38a4-4d17-910f-312668dbae01@users.sourceforge.net> <033d8595-d051-1fa8-95b1-5d2056eb5667@users.sourceforge.net> In-Reply-To: <033d8595-d051-1fa8-95b1-5d2056eb5667@users.sourceforge.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: SF Markus Elfring Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, =?UTF-8?B?Q2hyaXN0aWE=?= =?UTF-8?B?biBCb3JudHLDpGdlcg==?= , Cornelia Huck , David Hildenbrand , Heiko Carstens , Martin Schwidefsky , Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , LKML , kernel-janitors@vger.kernel.org, Julia Lawall Am 17.08.2016 20:06, schrieb SF Markus Elfring: > From: Markus Elfring > Date: Wed, 17 Aug 2016 18:29:04 +0200 > > Replace the specification of data structures by pointer dereferences > to make the corresponding size determination a bit safer according to > the Linux coding style convention. > > Signed-off-by: Markus Elfring > --- > arch/s390/kvm/guestdbg.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/s390/kvm/guestdbg.c b/arch/s390/kvm/guestdbg.c > index d1f8241..b68db4b 100644 > --- a/arch/s390/kvm/guestdbg.c > +++ b/arch/s390/kvm/guestdbg.c > @@ -216,7 +216,7 @@ int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu, > else if (dbg->arch.nr_hw_bp > MAX_BP_COUNT) > return -EINVAL; > > - size = dbg->arch.nr_hw_bp * sizeof(struct kvm_hw_breakpoint); > + size = dbg->arch.nr_hw_bp * sizeof(*bp_data); > bp_data = kmalloc(size, GFP_KERNEL); > if (!bp_data) { > ret = -ENOMEM; > @@ -241,7 +241,7 @@ int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu, > } > } > > - size = nr_wp * sizeof(struct kvm_hw_wp_info_arch); > + size = nr_wp * sizeof(*wp_info); > if (size > 0) { > wp_info = kmalloc(size, GFP_KERNEL); > if (!wp_info) { > @@ -249,7 +249,7 @@ int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu, > goto error; > } > } > - size = nr_bp * sizeof(struct kvm_hw_bp_info_arch); > + size = nr_bp * sizeof(*bp_info); > if (size > 0) { > bp_info = kmalloc(size, GFP_KERNEL); > if (!bp_info) { IMHO the common pattern for kmalloc is bp_info = kmalloc( nr_bp * sizeof(*bp_info), GFP_KERNEL); i can not remember code with a check for size < 0, i guess it is here to avoid an overflow ? since kmalloc takes a size_t argument this would cause a malloc failure an can be ignored. just my 2 cents. re, wh