On Tue 27-11-12 10:17:13, Jianguo Wu wrote:
> I enable CONFIG_DEBUG_VIRTUAL and CONFIG_SPARSEMEM_VMEMMAP, when doing memory hotremove,
> there is a kernel BUG at arch/x86/mm/physaddr.c:20.
>
> It is caused by free_section_usemap()->virt_to_page(),
> virt_to_page() is only used for kernel direct mapping address,
> but sparse-vmemmap uses vmemmap address, so it is going wrong here.
>
> [ 517.727381] ------------[ cut here ]------------
> [ 517.728851] kernel BUG at arch/x86/mm/physaddr.c:20!
> [ 517.728851] invalid opcode: 0000 [#1] SMP
> [ 517.740170] Modules linked in: acpihp_drv acpihp_slot edd cpufreq_conservativ
> e cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf fuse vfat fat loop dm_m
> od coretemp kvm crc32c_intel ipv6 ixgbe igb iTCO_wdt i7core_edac edac_core pcspk
> r iTCO_vendor_support ioatdma microcode joydev sr_mod i2c_i801 dca lpc_ich mfd_c
> ore mdio tpm_tis i2c_core hid_generic tpm cdrom sg tpm_bios rtc_cmos button ext3
> jbd mbcache usbhid hid uhci_hcd ehci_hcd usbcore usb_common sd_mod crc_t10dif p
> rocessor thermal_sys hwmon scsi_dh_alua scsi_dh_hp_sw scsi_dh_rdac scsi_dh_emc s
> csi_dh ata_generic ata_piix libata megaraid_sas scsi_mod
> [ 517.740170] CPU 39
> [ 517.740170] Pid: 6454, comm: sh Not tainted 3.7.0-rc1-acpihp-final+ #45 QCI Q
> SSC-S4R/QSSC-S4R
> [ 517.740170] RIP: 0010:[<ffffffff8103c908>] [<ffffffff8103c908>] __phys_addr+
> 0x88/0x90
> [ 517.740170] RSP: 0018:ffff8804440d7c08 EFLAGS: 00010006
> [ 517.740170] RAX: 0000000000000006 RBX: ffffea0012000000 RCX: 000000000000002c
>
> [ 517.740170] RDX: 0000620012000000 RSI: 0000000000000000 RDI: ffffea0012000000
>
> [ 517.740170] RBP: ffff8804440d7c08 R08: 0070000000000400 R09: 0000000000488000
>
> [ 517.740170] R10: 0000000000000091 R11: 0000000000000001 R12: ffff88047fb87800
>
> [ 517.740170] R13: ffffea0000000000 R14: ffff88047ffb3440 R15: 0000000000480000
>
> [ 517.740170] FS: 00007f0462b49700(0000) GS:ffff8804570c0000(0000) knlGS:00000
> 00000000000
> [ 517.740170] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [ 517.740170] CR2: 00007f006dc5fd14 CR3: 0000000440e85000 CR4: 00000000000007e0
>
> [ 517.740170] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>
> [ 517.896799] DR3: 0000000000000000 DR6
>
> Signed-off-by: Jianguo Wu <wujianguo@xxxxxxxxxx>
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Reviewed-by: Michal Hocko <mhocko@xxxxxxx>
Hmm, this is quite old. AFAIU this has been introduced by 0c0a4a51
(memory hotplug: free memmaps allocated by bootmem) introduced in 2.6.26
so this should be marked for stable.
Thanks!
> ---
> mm/sparse.c | 10 ++++------
> 1 files changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/mm/sparse.c b/mm/sparse.c
> index fac95f2..a83de2f 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c
> @@ -617,7 +617,7 @@ static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
> {
> return; /* XXX: Not implemented yet */
> }
> -static void free_map_bootmem(struct page *page, unsigned long nr_pages)
> +static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
> {
> }
> #else
> @@ -658,10 +658,11 @@ static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
> get_order(sizeof(struct page) * nr_pages));
> }
>
> -static void free_map_bootmem(struct page *page, unsigned long nr_pages)
> +static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
> {
> unsigned long maps_section_nr, removing_section_nr, i;
> unsigned long magic;
> + struct page *page = virt_to_page(memmap);
>
> for (i = 0; i < nr_pages; i++, page++) {
> magic = (unsigned long) page->lru.next;
> @@ -710,13 +711,10 @@ static void free_section_usemap(struct page *memmap, unsigned long *usemap)
> */
>
> if (memmap) {
> - struct page *memmap_page;
> - memmap_page = virt_to_page(memmap);
> -
> nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
> >> PAGE_SHIFT;
>
> - free_map_bootmem(memmap_page, nr_pages);
> + free_map_bootmem(memmap, nr_pages);
> }
> }
>
> --
> 1.7.1
>
>
--
Michal Hocko
SUSE Labs
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