[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20181026094105.GE3159@worktop.c.hoisthospitality.com>
Date: Fri, 26 Oct 2018 11:41:05 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: Igor Stoppa <igor.stoppa@...il.com>
Cc: Mimi Zohar <zohar@...ux.vnet.ibm.com>,
Kees Cook <keescook@...omium.org>,
Matthew Wilcox <willy@...radead.org>,
Dave Chinner <david@...morbit.com>,
James Morris <jmorris@...ei.org>, Michal Hocko <mhocko@...nel.org>,
kernel-hardening@...ts.openwall.com,
linux-integrity@...r.kernel.org,
linux-security-module@...r.kernel.org, igor.stoppa@...wei.com,
Dave Hansen <dave.hansen@...ux.intel.com>,
Jonathan Corbet <corbet@....net>, Laura Abbott <labbott@...hat.com>,
Vlastimil Babka <vbabka@...e.cz>,
"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Pavel Tatashin <pasha.tatashin@...cle.com>, linux-mm@...ck.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 02/17] prmem: write rare for static allocation
On Wed, Oct 24, 2018 at 12:34:49AM +0300, Igor Stoppa wrote:
> +static __always_inline
That's far too large for inline.
> +bool wr_memset(const void *dst, const int c, size_t n_bytes)
> +{
> + size_t size;
> + unsigned long flags;
> + uintptr_t d = (uintptr_t)dst;
> +
> + if (WARN(!__is_wr_after_init(dst, n_bytes), WR_ERR_RANGE_MSG))
> + return false;
> + while (n_bytes) {
> + struct page *page;
> + uintptr_t base;
> + uintptr_t offset;
> + uintptr_t offset_complement;
> +
> + local_irq_save(flags);
> + page = virt_to_page(d);
> + offset = d & ~PAGE_MASK;
> + offset_complement = PAGE_SIZE - offset;
> + size = min(n_bytes, offset_complement);
> + base = (uintptr_t)vmap(&page, 1, VM_MAP, PAGE_KERNEL);
> + if (WARN(!base, WR_ERR_PAGE_MSG)) {
> + local_irq_restore(flags);
> + return false;
> + }
> + memset((void *)(base + offset), c, size);
> + vunmap((void *)base);
BUG
> + d += size;
> + n_bytes -= size;
> + local_irq_restore(flags);
> + }
> + return true;
> +}
> +
> +static __always_inline
Similarly large
> +bool wr_memcpy(const void *dst, const void *src, size_t n_bytes)
> +{
> + size_t size;
> + unsigned long flags;
> + uintptr_t d = (uintptr_t)dst;
> + uintptr_t s = (uintptr_t)src;
> +
> + if (WARN(!__is_wr_after_init(dst, n_bytes), WR_ERR_RANGE_MSG))
> + return false;
> + while (n_bytes) {
> + struct page *page;
> + uintptr_t base;
> + uintptr_t offset;
> + uintptr_t offset_complement;
> +
> + local_irq_save(flags);
> + page = virt_to_page(d);
> + offset = d & ~PAGE_MASK;
> + offset_complement = PAGE_SIZE - offset;
> + size = (size_t)min(n_bytes, offset_complement);
> + base = (uintptr_t)vmap(&page, 1, VM_MAP, PAGE_KERNEL);
> + if (WARN(!base, WR_ERR_PAGE_MSG)) {
> + local_irq_restore(flags);
> + return false;
> + }
> + __write_once_size((void *)(base + offset), (void *)s, size);
> + vunmap((void *)base);
Similarly BUG.
> + d += size;
> + s += size;
> + n_bytes -= size;
> + local_irq_restore(flags);
> + }
> + return true;
> +}
> +static __always_inline
Guess what..
> +uintptr_t __wr_rcu_ptr(const void *dst_p_p, const void *src_p)
> +{
> + unsigned long flags;
> + struct page *page;
> + void *base;
> + uintptr_t offset;
> + const size_t size = sizeof(void *);
> +
> + if (WARN(!__is_wr_after_init(dst_p_p, size), WR_ERR_RANGE_MSG))
> + return (uintptr_t)NULL;
> + local_irq_save(flags);
> + page = virt_to_page(dst_p_p);
> + offset = (uintptr_t)dst_p_p & ~PAGE_MASK;
> + base = vmap(&page, 1, VM_MAP, PAGE_KERNEL);
> + if (WARN(!base, WR_ERR_PAGE_MSG)) {
> + local_irq_restore(flags);
> + return (uintptr_t)NULL;
> + }
> + rcu_assign_pointer((*(void **)(offset + (uintptr_t)base)), src_p);
> + vunmap(base);
Also still bug.
> + local_irq_restore(flags);
> + return (uintptr_t)src_p;
> +}
Also, I see an amount of duplication here that shows you're not nearly
lazy enough.
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
