Messages in this thread | | | From | Andy Shevchenko <> | Date | Sat, 11 Jul 2020 18:08:24 +0300 | Subject | Re: [PATCH v3 1/3] devres: provide devm_krealloc() |
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On Fri, Jul 10, 2020 at 7:17 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote: > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com> > > Implement the managed variant of krealloc(). This function works with > all memory allocated by devm_kmalloc() (or devres functions using it > implicitly like devm_kmemdup(), devm_kstrdup() etc.). > > Managed realloc'ed chunks can be manually released with devm_kfree().
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> devm_kfree() > devm_kmalloc() > devm_kmalloc_array() > + devm_krealloc() > devm_kmemdup() > devm_kstrdup() > devm_kvasprintf()
Order?
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> +void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
Do we really need the 'new_' prefix in the parameter?
> +{ > + struct devres *old_dr, *new_dr; > + struct list_head old_head; > + unsigned long flags; > + void *ret = NULL; > + size_t tot_size;
tot -> total.
> + > + if (unlikely(!new_size)) { > + devm_kfree(dev, ptr); > + return ZERO_SIZE_PTR; > + }
I guess here we need a comment of the possibilities below to have ZERO_SIZE_PTR as input.
> + if (unlikely(ZERO_OR_NULL_PTR(ptr))) > + return devm_kmalloc(dev, new_size, gfp); > + > + if (WARN_ON(is_kernel_rodata((unsigned long)ptr))) > + /* > + * We cannot reliably realloc a const string returned by > + * devm_kstrdup_const(). > + */ > + return NULL; > + > + if (!check_dr_size(new_size, &tot_size)) > + return NULL; > + > + spin_lock_irqsave(&dev->devres_lock, flags); > + > + old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
> + if (WARN_ON(!old_dr))
Under spin lock? I would rather see spin unlock followed by WARN.
> + /* Memory chunk not managed or managed by a different device. */ > + goto out; > + > + old_head = old_dr->node.entry; > + > + new_dr = krealloc(old_dr, tot_size, gfp); > + if (!new_dr) > + goto out; > + > + if (new_dr != old_dr) > + list_replace(&old_head, &new_dr->node.entry); > + > + ret = new_dr->data; > + > +out: > + spin_unlock_irqrestore(&dev->devres_lock, flags); > + return ret; > +}
-- With Best Regards, Andy Shevchenko
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