• Ian Mitchell's avatar
    Fix kmalloc overflow in LPFC driver at large core count · c0365c06
    Ian Mitchell authored
    This patch allows the LPFC to start up without a fatal kernel bug based
    on an exceeded KMALLOC_MAX_SIZE and a too large NR_CPU-based maskbits
    field. The bug was based on the number of CPU cores in a system.
    Using the get_cpu_mask() function declared in kernel/cpu.c allows the
    driver to load on the community kernel 4.2 RC1.
    
    Below is the kernel bug reproduced:
    
    8<--------------------------------------------------------------------
    2199382.828437 (    0.005216)| lpfc 0003:02:00.0: enabling device (0140 -> 0142)
    2199382.999272 (    0.170835)| ------------[ cut here ]------------
    2199382.999337 (    0.000065)| WARNING: CPU: 84 PID: 404 at mm/slab_common.c:653 kmalloc_slab+0x2f/0x89()
    2199383.004534 (    0.005197)| Modules linked in: lpfc(+) usbcore(+) mptctl scsi_transport_fc sg lpc_ich i2c_i801 usb_common tpm_tis mfd_core tpm acpi_cpufreq button scsi_dh_alua scsi_dh_rdacusbcore: registered new device driver usb
    2199383.020568 (    0.016034)|
    2199383.020581 (    0.000013)|  scsi_dh_hp_sw scsi_dh_emc scsi_dh gru thermal sata_nv processor piix fan thermal_sysehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
    2199383.035288 (    0.014707)|
    2199383.035306 (    0.000018)|  hwmon ata_piix
    2199383.035336 (    0.000030)| CPU: 84 PID: 404 Comm: kworker/84:0 Not tainted 3.18.0-rc2-gat-00106-ga7ca10f2-dirty #178
    2199383.047077 (    0.011741)| ehci-pci: EHCI PCI platform driver
    2199383.047134 (    0.000057)| Hardware name: SGI UV2000/ROMLEY, BIOS SGI UV 2000/3000 series BIOS 01/15/2013
    2199383.056245 (    0.009111)| Workqueue: events work_for_cpu_fn
    2199383.066174 (    0.009929)|  000000000000028d ffff88eef827bbe8 ffffffff815a542f 000000000000028d
    2199383.069545 (    0.003371)|  ffffffff810ea142 ffff88eef827bc28 ffffffff8104365c ffff88eefe4006c8
    2199383.076214 (    0.006669)|  0000000000000000 00000000000080d0 0000000000000000 0000000000000004
    2199383.079213 (    0.002999)| Call Trace:
    2199383.084084 (    0.004871)|  [<ffffffff815a542f>] dump_stack+0x49/0x62
    2199383.087283 (    0.003199)|  [<ffffffff810ea142>] ? kmalloc_slab+0x2f/0x89
    2199383.091415 (    0.004132)|  [<ffffffff8104365c>] warn_slowpath_common+0x77/0x92
    2199383.095197 (    0.003782)|  [<ffffffff8104368c>] warn_slowpath_null+0x15/0x17
    2199383.103336 (    0.008139)|  [<ffffffff810ea142>] kmalloc_slab+0x2f/0x89
    2199383.107082 (    0.003746)|  [<ffffffff8110fd9e>] __kmalloc+0x13/0x16a
    2199383.112531 (    0.005449)|  [<ffffffffa01a8ed9>] lpfc_pci_probe_one_s4+0x105b/0x1644 [lpfc]
    2199383.115316 (    0.002785)|  [<ffffffff81302b92>] ? pci_bus_read_config_dword+0x75/0x87
    2199383.123431 (    0.008115)|  [<ffffffffa01a951f>] lpfc_pci_probe_one+0x5d/0xcb5 [lpfc]
    2199383.127364 (    0.003933)|  [<ffffffff81497119>] ? dbs_check_cpu+0x168/0x177
    2199383.136438 (    0.009074)|  [<ffffffff81496fa5>] ? gov_queue_work+0xb4/0xc0
    2199383.140407 (    0.003969)|  [<ffffffff8130b2a1>] local_pci_probe+0x1e/0x52
    2199383.143105 (    0.002698)|  [<ffffffff81052c47>] work_for_cpu_fn+0x13/0x1b
    2199383.147315 (    0.004210)|  [<ffffffff81054965>] process_one_work+0x222/0x35e
    2199383.151379 (    0.004064)|  [<ffffffff81054e76>] worker_thread+0x3d5/0x46e
    2199383.159402 (    0.008023)|  [<ffffffff81054aa1>] ? process_one_work+0x35e/0x35e
    2199383.163097 (    0.003695)|  [<ffffffff810599c6>] kthread+0xc8/0xd2
    2199383.167476 (    0.004379)|  [<ffffffff810598fe>] ? kthread_freezable_should_stop+0x5b/0x5b
    2199383.176434 (    0.008958)|  [<ffffffff815a8cac>] ret_from_fork+0x7c/0xb0
    2199383.180086 (    0.003652)|  [<ffffffff810598fe>] ? kthread_freezable_should_stop+0x5b/0x5b
    2199383.192333 (    0.012247)| ehci-pci 0000:00:1a.0: EHCI Host Controller
    -------------------------------------------------------------------->8
    
    The proposed solution was approved by James Smart at Emulex and tested
    on a UV2 machine with 6144 cores. With the fix, the LPFC module loads
    with no unwanted effects on the system.
    Signed-off-by: default avatarIan Mitchell <imitchell@sgi.com>
    Signed-off-by: default avatarAlex Thorlton <athorlton@sgi.com>
    Suggested-by: default avatarRobert Elliot <elliott@hp.com>
    [james.smart: resolve unused variable warning]
    Signed-off-by: default avatarJames Smart <james.smart@avagotech.com>
    Signed-off-by: default avatarJames Bottomley <JBottomley@Odin.com>
    c0365c06
lpfc_sli4.h 23.4 KB