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charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) X-Rspamd-Server: rspam05 X-Stat-Signature: mczeqjfpqy69iwghzr94zz87u7ziw8qa X-Rspamd-Queue-Id: 85A801C0012 X-Rspam-User: X-HE-Tag: 1736943452-709831 X-HE-Meta: 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 VqeX2DiU 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000009, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Jan 14, 2025 at 07:15:05PM -0800, Suren Baghdasaryan wrote: >On Tue, Jan 14, 2025 at 6:27 PM Wei Yang wrote: >> >> On Fri, Jan 10, 2025 at 08:26:03PM -0800, Suren Baghdasaryan wrote: >> >> >diff --git a/kernel/fork.c b/kernel/fork.c >> >index 9d9275783cf8..151b40627c14 100644 >> >--- a/kernel/fork.c >> >+++ b/kernel/fork.c >> >@@ -449,6 +449,42 @@ struct vm_area_struct *vm_area_alloc(struct mm_struct *mm) >> > return vma; >> > } >> > >> >+static void vm_area_init_from(const struct vm_area_struct *src, >> >+ struct vm_area_struct *dest) >> >+{ >> >+ dest->vm_mm = src->vm_mm; >> >+ dest->vm_ops = src->vm_ops; >> >+ dest->vm_start = src->vm_start; >> >+ dest->vm_end = src->vm_end; >> >+ dest->anon_vma = src->anon_vma; >> >+ dest->vm_pgoff = src->vm_pgoff; >> >+ dest->vm_file = src->vm_file; >> >+ dest->vm_private_data = src->vm_private_data; >> >+ vm_flags_init(dest, src->vm_flags); >> >+ memcpy(&dest->vm_page_prot, &src->vm_page_prot, >> >+ sizeof(dest->vm_page_prot)); >> >+ /* >> >+ * src->shared.rb may be modified concurrently when called from >> >+ * dup_mmap(), but the clone will reinitialize it. >> >+ */ >> >+ data_race(memcpy(&dest->shared, &src->shared, sizeof(dest->shared))); >> >+ memcpy(&dest->vm_userfaultfd_ctx, &src->vm_userfaultfd_ctx, >> >+ sizeof(dest->vm_userfaultfd_ctx)); >> >+#ifdef CONFIG_ANON_VMA_NAME >> >+ dest->anon_name = src->anon_name; >> >+#endif >> >+#ifdef CONFIG_SWAP >> >+ memcpy(&dest->swap_readahead_info, &src->swap_readahead_info, >> >+ sizeof(dest->swap_readahead_info)); >> >+#endif >> >+#ifndef CONFIG_MMU >> >+ dest->vm_region = src->vm_region; >> >+#endif >> >+#ifdef CONFIG_NUMA >> >+ dest->vm_policy = src->vm_policy; >> >+#endif >> >+} >> >> Would this be difficult to maintain? We should make sure not miss or overwrite >> anything. > >Yeah, it is less maintainable than a simple memcpy() but I did not >find a better alternative. I added a warning above the struct >vm_area_struct definition to update this function every time we change >that structure. Not sure if there is anything else I can do to help >with this. > For !PER_VMA_LOCK, maybe we can use memcpy() as usual. For PER_VMA_LOCK, I just come up the same idea with you:-) >> >> -- >> Wei Yang >> Help you, Help me -- Wei Yang Help you, Help me