[Crash-utility] [PATCH] Fix "kmem -i" option on Linux 5.9-rc1 and later kernels
On kernels that contain commit 1008fe6dc36d ("block: remove the all_bdevs
list"), without the patch, the "kmem -i" option fails halfway with the
error message 'kmem: cannot resolve: "all_bdevs"'.
Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com>
---
# sorry, resending this because I sent with inappropriate setting..
defs.h | 2 ++
memory.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
symbols.c | 4 ++++
3 files changed, 64 insertions(+)
diff --git a/defs.h b/defs.h
index 17e98763362b..dfc09bc86618 100644
--- a/defs.h
+++ b/defs.h
@@ -2089,6 +2089,8 @@ struct offset_table { /* stash of commonly-used
offsets */
long size_class_size;
long gendisk_private_data;
long zram_table_entry;
+ long super_block_s_inodes;
+ long inode_i_sb_list;
};
struct size_table { /* stash of commonly-used sizes */
diff --git a/memory.c b/memory.c
index 2bea1288251a..c951827162cb 100644
--- a/memory.c
+++ b/memory.c
@@ -252,6 +252,7 @@ static ulonglong get_vm_flags(char *);
static void PG_reserved_flag_init(void);
static void PG_slab_flag_init(void);
static ulong nr_blockdev_pages(void);
+static ulong nr_blockdev_pages_v2(void);
void sparse_mem_init(void);
void dump_mem_sections(int);
void dump_memory_blocks(int);
@@ -501,6 +502,9 @@ vm_init(void)
if (INVALID_MEMBER(address_space_nrpages))
MEMBER_OFFSET_INIT(address_space_nrpages, "address_space",
"__nrpages");
+ MEMBER_OFFSET_INIT(super_block_s_inodes, "super_block",
"s_inodes");
+ MEMBER_OFFSET_INIT(inode_i_sb_list, "inode", "i_sb_list");
+
MEMBER_OFFSET_INIT(gendisk_major, "gendisk", "major");
MEMBER_OFFSET_INIT(gendisk_fops, "gendisk", "fops");
MEMBER_OFFSET_INIT(gendisk_disk_name, "gendisk", "disk_name");
@@ -8608,6 +8612,9 @@ nr_blockdev_pages(void)
ulong nrpages;
char *block_device_buf, *inode_buf, *address_space_buf;
+ if (!kernel_symbol_exists("all_bdevs"))
+ return nr_blockdev_pages_v2();
+
ld = &list_data;
BZERO(ld, sizeof(struct list_data));
get_symbol_data("all_bdevs", sizeof(void *), &ld->start);
@@ -8652,6 +8659,57 @@ nr_blockdev_pages(void)
}
/*
+ * Emulate 5.9 nr_blockdev_pages() function.
+ */
+static ulong
+nr_blockdev_pages_v2(void)
+{
+ struct list_data list_data, *ld;
+ ulong bd_sb, address_space;
+ ulong nrpages;
+ int i, inode_count;
+ char *inode_buf, *address_space_buf;
+
+ ld = &list_data;
+ BZERO(ld, sizeof(struct list_data));
+
+ get_symbol_data("blockdev_superblock", sizeof(void *), &bd_sb);
+ readmem(bd_sb + OFFSET(super_block_s_inodes), KVADDR, &ld->start,
+ sizeof(ulong), "blockdev_superblock.s_inodes", FAULT_ON_ERROR);
+
+ if (empty_list(ld->start))
+ return 0;
+ ld->flags |= LIST_ALLOCATE;
+ ld->end = bd_sb + OFFSET(super_block_s_inodes);
+ ld->list_head_offset = OFFSET(inode_i_sb_list);
+
+ inode_buf = GETBUF(SIZE(inode));
+ address_space_buf = GETBUF(SIZE(address_space));
+
+ inode_count = do_list(ld);
+
+ /*
+ * go through the s_inodes list, emulating:
+ *
+ * ret += inode->i_mapping->nrpages;
+ */
+ for (i = nrpages = 0; i < inode_count; i++) {
+ readmem(ld->list_ptr[i], KVADDR, inode_buf, SIZE(inode), "inode buffer",
+ FAULT_ON_ERROR);
+ address_space = ULONG(inode_buf + OFFSET(inode_i_mapping));
+ readmem(address_space, KVADDR, address_space_buf, SIZE(address_space),
+ "address_space buffer", FAULT_ON_ERROR);
+ nrpages += ULONG(address_space_buf + OFFSET(address_space_nrpages));
+ }
+
+ FREEBUF(ld->list_ptr);
+ FREEBUF(inode_buf);
+ FREEBUF(address_space_buf);
+
+ return nrpages;
+}
+
+/*
* dump_vmlist() displays information from the vmlist.
*/
diff --git a/symbols.c b/symbols.c
index 2fecaee093a2..123ed00913e1 100644
--- a/symbols.c
+++ b/symbols.c
@@ -9452,6 +9452,8 @@ dump_offset_table(char *spec, ulong makestruct)
OFFSET(inode_i_fop));
fprintf(fp, " inode_i_mapping: %ld\n",
OFFSET(inode_i_mapping));
+ fprintf(fp, " inode_i_sb_list: %ld\n",
+ OFFSET(inode_i_sb_list));
fprintf(fp, " vfsmount_mnt_next: %ld\n",
OFFSET(vfsmount_mnt_next));
@@ -9488,6 +9490,8 @@ dump_offset_table(char *spec, ulong makestruct)
OFFSET(super_block_s_type));
fprintf(fp, " super_block_s_files: %ld\n",
OFFSET(super_block_s_files));
+ fprintf(fp, " super_block_s_inodes: %ld\n",
+ OFFSET(super_block_s_inodes));
fprintf(fp, " nlm_file_f_file: %ld\n",
OFFSET(nlm_file_f_file));
--
1.8.3.1