On Fri, Mar 10, 2023 at 10:28 AM HAGIO KAZUHITO(萩尾 一仁) <k-hagio...@nec.com> wrote:
> On 2023/03/10 10:48, lijiang wrote: > >> Thank you for the fix, Kazu. > >> On Thu, Mar 9, 2023 at 9:44 AM HAGIO KAZUHITO(萩尾 一仁) < > k-hagio...@nec.com <mailto:k-hagio...@nec.com>> 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...@nec.com <mailto: > k-hagio...@nec.com>> > >> --- > >> 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 < > http://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? > > As the buf array has 8 bytes and the last is set to \0, so > > "memory" -> memory\0\0 > "memory_tiering" -> memory_\0 > > So we can distinguish these with STREQ(buf, "memory"). Thank you for the explanation, Kazu. > > >> > >> + 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. > > Yes, I was not sure what is the max length of the name, so chose the > minimum length in order to avoid read error due to out of bounds. > > But ok, looking at the usage of read_string() in crash, most of them > have BUF_SIZE-1. Maybe we don't need to care about it so much. > I will change it to 32 in v2. > > It should be good enough to distinguish it from the various subsys names. an example without "break;" > > kobject: ffff8e1d83d83a18 name: platform > kobject: ffff8e1d83d80e18 name: cpu > kobject: ffff8e1d83d83c18 name: memory > kobject: ffff8e1d83d81c18 name: node > kobject: ffff8e1d83d80c18 name: container > kobject: ffff8e1d83d80a18 name: workqueue > kobject: ffff8e1d83d82e18 name: gpio > kobject: ffff8e1d83d83418 name: virtio > kobject: ffff8e19cb77da18 name: pci > kobject: ffff8e19cb77e018 name: pci_express > kobject: ffff8e19cb77ce18 name: spi > kobject: ffff8e19cb77f818 name: i2c > kobject: ffff8e19cb7c7a18 name: memory_tiering > kobject: ffff8e1d8466ee18 name: acpi > kobject: ffff8e1605d4e418 name: pnp > kobject: ffff8e1605d4d018 name: xen > kobject: ffff8e1605d4c418 name: dax > kobject: ffff8e1605d4fc18 name: cxl > kobject: ffff8e1605d4fa18 name: scsi > kobject: ffff8e1605d4e218 name: mdio_bus > kobject: ffff8e1605d4fe18 name: usb > kobject: ffff8e1605d4c018 name: typec > kobject: ffff8e1605d4f618 name: serio > kobject: ffff8e1605e43018 name: edac > kobject: ffff8e1605e41218 name: nvmem > kobject: ffff8e16047d8a18 name: thunderbolt > kobject: ffff8e160451e018 name: clocksource > kobject: ffff8e160451da18 name: clockevents > kobject: ffff8e160451f418 name: event_source > kobject: ffff8e1d83e76018 name: usb-serial > kobject: ffff8e1d86135418 name: hid > kobject: ffff8e1611eea418 name: machinecheck > kobject: ffff8e1d8d108618 name: wmi > kobject: ffff8e160c187e18 name: mei > > Thanks for the information. Thanks. Lianbo
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