From: Yasuaki Ishimatsu Date: Mon, 29 Apr 2013 22:08:56 +0000 (-0700) Subject: mem hotunplug: fix kfree() of bootmem memory X-Git-Tag: omap-for-v3.10/dt-fixes-for-merge-window~128^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ebff7d8f270d045338d9f4796014f4db429a17f9;p=pandora-kernel.git mem hotunplug: fix kfree() of bootmem memory When hot removing memory presented at boot time, following messages are shown: kernel BUG at mm/slub.c:3409! invalid opcode: 0000 [#1] SMP Modules linked in: ebtable_nat ebtables xt_CHECKSUM iptable_mangle bridge stp llc ipmi_devintf ipmi_msghandler sunrpc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc vfat fat dm_mirror dm_region_hash dm_log dm_mod vhost_net macvtap macvlan tun uinput iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode pcspkr sg i2c_i801 lpc_ich mfd_core igb i2c_algo_bit i2c_core e1000e ptp pps_core tpm_infineon ioatdma dca sr_mod cdrom sd_mod crc_t10dif usb_storage megaraid_sas lpfc scsi_transport_fc scsi_tgt scsi_mod CPU 0 Pid: 5091, comm: kworker/0:2 Tainted: G W 3.9.0-rc6+ #15 RIP: kfree+0x232/0x240 Process kworker/0:2 (pid: 5091, threadinfo ffff88084678c000, task ffff88083928ca80) Call Trace: __release_region+0xd4/0xe0 __remove_pages+0x52/0x110 arch_remove_memory+0x89/0xd0 remove_memory+0xc4/0x100 acpi_memory_device_remove+0x6d/0xb1 acpi_device_remove+0x89/0xab __device_release_driver+0x7c/0xf0 device_release_driver+0x2f/0x50 acpi_bus_device_detach+0x6c/0x70 acpi_ns_walk_namespace+0x11a/0x250 acpi_walk_namespace+0xee/0x137 acpi_bus_trim+0x33/0x7a acpi_bus_hot_remove_device+0xc4/0x1a1 acpi_os_execute_deferred+0x27/0x34 process_one_work+0x1f7/0x590 worker_thread+0x11a/0x370 kthread+0xee/0x100 ret_from_fork+0x7c/0xb0 RIP [] kfree+0x232/0x240 RSP The reason why the messages are shown is to release a resource structure, allocated by bootmem, by kfree(). So when we release a resource structure, we should check whether it is allocated by bootmem or not. But even if we know a resource structure is allocated by bootmem, we cannot release it since SLxB cannot treat it. So for reusing a resource structure, this patch remembers it by using bootmem_resource as follows: When releasing a resource structure by free_resource(), free_resource() checks whether the resource structure is allocated by bootmem or not. If it is allocated by bootmem, free_resource() adds it to bootmem_resource. If it is not allocated by bootmem, free_resource() release it by kfree(). And when getting a new resource structure by get_resource(), get_resource() checks whether bootmem_resource has released resource structures or not. If there is a released resource structure, get_resource() returns it. If there is not a releaed resource structure, get_resource() returns new resource structure allocated by kzalloc(). [akpm@linux-foundation.org: s/get_resource/alloc_resource/] Signed-off-by: Yasuaki Ishimatsu Reviewed-by: Toshi Kani Cc: Johannes Weiner Cc: Ram Pai Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed