From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9E36C1170E for ; Mon, 11 Sep 2023 14:21:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EFF2C433C7; Mon, 11 Sep 2023 14:21:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694442104; bh=alv9pXKHkadZbXb9Ev0JpZm2ku/B35WJ/qnAVzxFvSU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j+2oTDGMDLjuq3ke6xjLJ6Yu8MD80QC6MttBDLA0pC/bt080ThEX3EUrntvQvgaS1 nKKqfP2or0prA2t0EsbvBVvDArNyBvPp8Cy0bMIGNsemHB6Ay0ckeYdFgnGi/FOjyx 69i5/rYb6Dr/ADXlGVi5K9zE+ZVayTa9Wh+Mq/z0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Joel Fernandes (Google)" , "Uladzislau Rezki (Sony)" , Zhen Lei , "Paul E. McKenney" , Zqiang , "Matthew Wilcox (Oracle)" , Andrew Morton Subject: [PATCH 6.5 648/739] mm/vmalloc: add a safer version of find_vm_area() for debug Date: Mon, 11 Sep 2023 15:47:27 +0200 Message-ID: <20230911134709.205569262@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134650.921299741@linuxfoundation.org> References: <20230911134650.921299741@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joel Fernandes (Google) commit 0818e739b5c061b0251c30152380600fb9b84c0c upstream. It is unsafe to dump vmalloc area information when trying to do so from some contexts. Add a safer trylock version of the same function to do a best-effort VMA finding and use it from vmalloc_dump_obj(). [applied test robot feedback on unused function fix.] [applied Uladzislau feedback on locking.] Link: https://lkml.kernel.org/r/20230904180806.1002832-1-joel@joelfernandes.org Fixes: 98f180837a89 ("mm: Make mem_dump_obj() handle vmalloc() memory") Signed-off-by: Joel Fernandes (Google) Reviewed-by: Uladzislau Rezki (Sony) Reported-by: Zhen Lei Cc: Paul E. McKenney Cc: Zqiang Cc: Cc: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/vmalloc.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -4278,14 +4278,32 @@ void pcpu_free_vm_areas(struct vm_struct #ifdef CONFIG_PRINTK bool vmalloc_dump_obj(void *object) { - struct vm_struct *vm; void *objp = (void *)PAGE_ALIGN((unsigned long)object); + const void *caller; + struct vm_struct *vm; + struct vmap_area *va; + unsigned long addr; + unsigned int nr_pages; + + if (!spin_trylock(&vmap_area_lock)) + return false; + va = __find_vmap_area((unsigned long)objp, &vmap_area_root); + if (!va) { + spin_unlock(&vmap_area_lock); + return false; + } - vm = find_vm_area(objp); - if (!vm) + vm = va->vm; + if (!vm) { + spin_unlock(&vmap_area_lock); return false; + } + addr = (unsigned long)vm->addr; + caller = vm->caller; + nr_pages = vm->nr_pages; + spin_unlock(&vmap_area_lock); pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n", - vm->nr_pages, (unsigned long)vm->addr, vm->caller); + nr_pages, addr, caller); return true; } #endif