Messages in this thread Patch in this message | | | Subject | [PATCH v2 1/2] KVM: s390: Improve determination of sizes in kvm_s390_import_bp_data() | From | SF Markus Elfring <> | Date | Wed, 24 Aug 2016 20:36:26 +0200 |
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From: Markus Elfring <elfring@users.sourceforge.net> Date: Wed, 24 Aug 2016 19:45:23 +0200
* A multiplication for the size determination of a memory allocation indicated that an array data structure should be processed. Thus reuse the corresponding function "kmalloc_array".
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
This issue was detected also by using the Coccinelle software.
* 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.
* Delete the local variable "size" which became unnecessary with this refactoring.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> ---
v2: Rebased on source files from "Linux next-20160824". Advices were integrated from source code review.
arch/s390/kvm/guestdbg.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-)
diff --git a/arch/s390/kvm/guestdbg.c b/arch/s390/kvm/guestdbg.c index d1f8241..70b71ac 100644 --- a/arch/s390/kvm/guestdbg.c +++ b/arch/s390/kvm/guestdbg.c @@ -206,7 +206,7 @@ static int __import_wp_info(struct kvm_vcpu *vcpu, int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) { - int ret = 0, nr_wp = 0, nr_bp = 0, i, size; + int ret = 0, nr_wp = 0, nr_bp = 0, i; struct kvm_hw_breakpoint *bp_data = NULL; struct kvm_hw_wp_info_arch *wp_info = NULL; struct kvm_hw_bp_info_arch *bp_info = NULL; @@ -216,14 +216,17 @@ 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); - bp_data = kmalloc(size, GFP_KERNEL); + bp_data = kmalloc_array(dbg->arch.nr_hw_bp, + sizeof(*bp_data), + GFP_KERNEL); if (!bp_data) { ret = -ENOMEM; goto error; } - if (copy_from_user(bp_data, dbg->arch.hw_bp, size)) { + if (copy_from_user(bp_data, + dbg->arch.hw_bp, + sizeof(*bp_data) * dbg->arch.nr_hw_bp)) { ret = -EFAULT; goto error; } @@ -241,17 +244,19 @@ int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu, } } - size = nr_wp * sizeof(struct kvm_hw_wp_info_arch); - if (size > 0) { - wp_info = kmalloc(size, GFP_KERNEL); + if (nr_wp > 0) { + wp_info = kmalloc_array(nr_wp, + sizeof(*wp_info), + GFP_KERNEL); if (!wp_info) { ret = -ENOMEM; goto error; } } - size = nr_bp * sizeof(struct kvm_hw_bp_info_arch); - if (size > 0) { - bp_info = kmalloc(size, GFP_KERNEL); + if (nr_bp > 0) { + bp_info = kmalloc_array(nr_bp, + sizeof(*bp_info), + GFP_KERNEL); if (!bp_info) { ret = -ENOMEM; goto error; -- 2.9.3
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