linux-kernel - [RFC PATCH v2 makedumpfile 2/3] makedumpfile.c: Exclude all pmem pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230427101838.12267-7-lizhijian@fujitsu.com>
Date:   Thu, 27 Apr 2023 18:18:37 +0800
From:   Li Zhijian <lizhijian@...itsu.com>
To:     x86@...nel.org, nvdimm@...ts.linux.dev, kexec@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, y-goto@...itsu.com,
        yangx.jy@...itsu.com, ruansy.fnst@...itsu.com,
        Li Zhijian <lizhijian@...itsu.com>,
        Baoquan He <bhe@...hat.com>, Vivek Goyal <vgoyal@...hat.com>,
        Dave Young <dyoung@...hat.com>
Subject: [RFC PATCH v2 makedumpfile 2/3] makedumpfile.c: Exclude all pmem pages

Generally, the pmem is too large to suitable to be dumped. Further, only
the namespace of the pmem is dumpable, but actually currently we have no
idea the excatly layout of the namespace in pmem.

CC: Baoquan He <bhe@...hat.com>
CC: Vivek Goyal <vgoyal@...hat.com>
CC: Dave Young <dyoung@...hat.com>
Signed-off-by: Li Zhijian <lizhijian@...itsu.com>
---
 makedumpfile.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/makedumpfile.c b/makedumpfile.c
index f40368364cf3..98c3b8c7ced9 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -100,6 +100,7 @@ mdf_pfn_t pfn_user;
 mdf_pfn_t pfn_free;
 mdf_pfn_t pfn_hwpoison;
 mdf_pfn_t pfn_offline;
+mdf_pfn_t pfn_pmem_userdata;
 mdf_pfn_t pfn_elf_excluded;
 
 mdf_pfn_t num_dumped;
@@ -6326,6 +6327,7 @@ __exclude_unnecessary_pages(unsigned long mem_map,
 	unsigned int order_offset, dtor_offset;
 	unsigned long flags, mapping, private = 0;
 	unsigned long compound_dtor, compound_head = 0;
+	unsigned int is_pmem;
 
 	/*
 	 * If a multi-page exclusion is pending, do it first
@@ -6377,6 +6379,13 @@ __exclude_unnecessary_pages(unsigned long mem_map,
 				continue;
 		}
 
+		is_pmem = is_pmem_pt_load_range(pfn << PAGESHIFT(), (pfn + 1) << PAGESHIFT());
+		if (is_pmem) {
+			pfn_pmem_userdata++;
+			clear_bit_on_2nd_bitmap_for_kernel(pfn, cycle);
+			continue;
+		}
+
 		index_pg = pfn % PGMM_CACHED;
 		pcache  = page_cache + (index_pg * SIZE(page));
 
@@ -8084,7 +8093,7 @@ write_elf_pages_cyclic(struct cache_data *cd_header, struct cache_data *cd_page)
 	 */
 	if (info->flag_cyclic) {
 		pfn_zero = pfn_cache = pfn_cache_private = 0;
-		pfn_user = pfn_free = pfn_hwpoison = pfn_offline = 0;
+		pfn_user = pfn_free = pfn_hwpoison = pfn_offline = pfn_pmem_userdata = 0;
 		pfn_memhole = info->max_mapnr;
 	}
 
@@ -9422,7 +9431,7 @@ write_kdump_pages_and_bitmap_cyclic(struct cache_data *cd_header, struct cache_d
 		 * Reset counter for debug message.
 		 */
 		pfn_zero = pfn_cache = pfn_cache_private = 0;
-		pfn_user = pfn_free = pfn_hwpoison = pfn_offline = 0;
+		pfn_user = pfn_free = pfn_hwpoison = pfn_offline = pfn_pmem_userdata = 0;
 		pfn_memhole = info->max_mapnr;
 
 		/*
@@ -10370,7 +10379,7 @@ print_report(void)
 	 */
 	pfn_original = info->max_mapnr - pfn_memhole;
 
-	pfn_excluded = pfn_zero + pfn_cache + pfn_cache_private
+	pfn_excluded = pfn_zero + pfn_cache + pfn_cache_private + pfn_pmem_userdata
 	    + pfn_user + pfn_free + pfn_hwpoison + pfn_offline;
 
 	REPORT_MSG("\n");
@@ -10387,6 +10396,7 @@ print_report(void)
 	REPORT_MSG("    Free pages              : 0x%016llx\n", pfn_free);
 	REPORT_MSG("    Hwpoison pages          : 0x%016llx\n", pfn_hwpoison);
 	REPORT_MSG("    Offline pages           : 0x%016llx\n", pfn_offline);
+	REPORT_MSG("    pmem userdata pages     : 0x%016llx\n", pfn_pmem_userdata);
 	REPORT_MSG("  Remaining pages  : 0x%016llx\n",
 	    pfn_original - pfn_excluded);
 
@@ -10426,7 +10436,7 @@ print_mem_usage(void)
 	*/
 	pfn_original = info->max_mapnr - pfn_memhole;
 
-	pfn_excluded = pfn_zero + pfn_cache + pfn_cache_private
+	pfn_excluded = pfn_zero + pfn_cache + pfn_cache_private + pfn_pmem_userdata
 	    + pfn_user + pfn_free + pfn_hwpoison + pfn_offline;
 	shrinking = (pfn_original - pfn_excluded) * 100;
 	shrinking = shrinking / pfn_original;
-- 
2.29.2