Thank you for the fix, Kazu.
On Thu, Mar 9, 2023 at 9:44 AM HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab@xxxxxxx> wrote:
Kernel commit d2bf38c088e0 ("driver core: remove private pointer from
struct bus_type") removed the bus_type.p member, and the "kmem -n"
option fails with the following error before displaying memory block
information on Linux 6.3-rc1 and later kernels.
kmem: invalid structure member offset: bus_type_p
FILE: memory.c LINE: 17852 FUNCTION: init_memory_block()
Search bus_kset.list instead for subsys_private of memory subsys.
Signed-off-by: Kazuhito Hagio <k-hagio-ab@xxxxxxx>
---
defs.h | 2 ++
memory.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++------
symbols.c | 2 ++
3 files changed, 62 insertions(+), 6 deletions(-)
diff --git a/defs.h b/defs.h
index 1f2cf6e0ce01..12ad6aaa0998 100644
--- a/defs.h
+++ b/defs.h
@@ -2214,6 +2214,8 @@ struct offset_table { /* stash of commonly-used offsets */
long inet6_ifaddr_if_list;
long inet6_ifaddr_if_next;
long in6_addr_in6_u;
+ long kset_kobj;
+ long subsys_private_subsys;
};
struct size_table { /* stash of commonly-used sizes */
diff --git a/memory.c b/memory.c
index c4a6ecd18004..292b15a0dbab 100644
--- a/memory.c
+++ b/memory.c
@@ -17822,6 +17822,13 @@ static void
init_memory_block_offset(void)
{
MEMBER_OFFSET_INIT(bus_type_p, "bus_type", "p");
+ if (INVALID_MEMBER(bus_type_p)) {
+ MEMBER_OFFSET_INIT(kset_list, "kset", "list");
+ MEMBER_OFFSET_INIT(kset_kobj, "kset", "kobj");
+ MEMBER_OFFSET_INIT(kobject_name, "kobject", "name");
+ MEMBER_OFFSET_INIT(kobject_entry, "kobject", "entry");
+ MEMBER_OFFSET_INIT(subsys_private_subsys, "subsys_private", "subsys");
+ }
MEMBER_OFFSET_INIT(subsys_private_klist_devices,
"subsys_private", "klist_devices");
MEMBER_OFFSET_INIT(klist_k_list, "klist", "k_list");
@@ -17842,15 +17849,61 @@ init_memory_block_offset(void)
}
static void
-init_memory_block(struct list_data *ld, int *klistcnt, ulong **klistbuf)
+init_memory_block(int *klistcnt, ulong **klistbuf)
{
- ulong memory_subsys = symbol_value("memory_subsys");
ulong private, klist, start;
+ struct list_data list_data, *ld;
+
+ ld = &list_data;
+ private = 0;
init_memory_block_offset();
- readmem(memory_subsys + OFFSET(bus_type_p), KVADDR, &private,
- sizeof(void *), "memory_subsys.private", FAULT_ON_ERROR);
+ /*
+ * v6.3-rc1
+ * d2bf38c088e0 driver core: remove private pointer from struct bus_type
+ */
+ if (INVALID_MEMBER(bus_type_p)) {
+ int i, cnt;
+ char buf[8]; /* need 8 at least to exclude "memory_tiering" */
+ ulong bus_kset, list, name;
+
+ BZERO(ld, sizeof(struct list_data));
+
+ get_symbol_data("bus_kset", sizeof(ulong), &bus_kset);
+ readmem(bus_kset + OFFSET(kset_list), KVADDR, &list,
+ sizeof(ulong), "bus_kset.list", FAULT_ON_ERROR);
+
+ ld->flags |= LIST_ALLOCATE;
+ ld->start = list;
+ ld->end = bus_kset + OFFSET(kset_list);
+ ld->list_head_offset = OFFSET(kobject_entry);
+
+ cnt = do_list(ld);
+ for (i = 0; i < cnt; i++) {
+ readmem(ld->list_ptr[i] + OFFSET(kobject_name), KVADDR, &name,
+ sizeof(ulong), "kobject.name", FAULT_ON_ERROR);
+ read_string(name, buf, sizeof(buf));
+ buf[7] = '\0';
The full name will be truncated, and the STREQ(buf, "memory") will include two kinds of the "memory" and "memory_tiering", but the above code comment says to exclude "memory_tiering", looks weird to me. Do I misunderstand this?
+ if (CRASHDEBUG(1))
+ fprintf(fp, "kobject: %lx name: %s\n", ld->list_ptr[i], buf);
BTW: for the debug information, it might be good to output the full name of the memory subsys.
Other changes look good to me.
Thanks.
Lianbo
+ if (STREQ(buf, "memory")) {
+ /* entry is subsys_private.subsys.kobj. See bus_to_subsys(). */
+ private = ld->list_ptr[i] - OFFSET(kset_kobj)
+ - OFFSET(subsys_private_subsys);
+ break;
+ }
+ }
+ FREEBUF(ld->list_ptr);
+ } else {
+ ulong memory_subsys = symbol_value("memory_subsys");
+ readmem(memory_subsys + OFFSET(bus_type_p), KVADDR, &private,
+ sizeof(void *), "memory_subsys.private", FAULT_ON_ERROR);
+ }
+
+ if (!private)
+ error(FATAL, "cannot determine subsys_private for memory.\n");
+
klist = private + OFFSET(subsys_private_klist_devices) +
OFFSET(klist_k_list);
BZERO(ld, sizeof(struct list_data));
@@ -17875,7 +17928,6 @@ dump_memory_blocks(int initialize)
ulong memory_block, device;
ulong *klistbuf;
int klistcnt, i;
- struct list_data list_data;
char mb_hdr[BUFSIZE];
char paddr_hdr[BUFSIZE];
char buf1[BUFSIZE];
@@ -17892,7 +17944,7 @@ dump_memory_blocks(int initialize)
if (initialize)
return;
- init_memory_block(&list_data, &klistcnt, &klistbuf);
+ init_memory_block(&klistcnt, &klistbuf);
if ((symbol_exists("memory_block_size_probed")) ||
(MEMBER_EXISTS("memory_block", "end_section_nr")))
diff --git a/symbols.c b/symbols.c
index 28846d06273c..f0721023816d 100644
--- a/symbols.c
+++ b/symbols.c
@@ -10404,6 +10404,7 @@ dump_offset_table(char *spec, ulong makestruct)
OFFSET(kobject_entry));
fprintf(fp, " kset_list: %ld\n",
OFFSET(kset_list));
+ fprintf(fp, " kset_kobj: %ld\n", OFFSET(kset_kobj));
fprintf(fp, " request_list_count: %ld\n",
OFFSET(request_list_count));
fprintf(fp, " request_cmd_flags: %ld\n",
@@ -10441,6 +10442,7 @@ dump_offset_table(char *spec, ulong makestruct)
fprintf(fp, " blk_mq_tags_rqs: %ld\n",
OFFSET(blk_mq_tags_rqs));
+ fprintf(fp, " subsys_private_subsys: %ld\n", OFFSET(subsys_private_subsys));
fprintf(fp, " subsys_private_klist_devices: %ld\n",
OFFSET(subsys_private_klist_devices));
fprintf(fp, " subsystem_kset: %ld\n",
--
2.31.1
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