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authorYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>2013-04-29 15:08:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-04-29 15:54:40 -0700
commitebff7d8f270d045338d9f4796014f4db429a17f9 (patch)
treee9270cfd75a045565faee702f167db0efcaf5c76 /kernel/resource.c
parent9ca24e2e19325edc3ed0b437657d26219b7a768a (diff)
downloadlinux-ebff7d8f270d045338d9f4796014f4db429a17f9.tar.bz2
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 [<ffffffff811c41d2>] kfree+0x232/0x240 RSP <ffff88084678d968> 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 <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Ram Pai <linuxram@us.ibm.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/resource.c')
-rw-r--r--kernel/resource.c68
1 files changed, 55 insertions, 13 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index 4aef8867fd4b..d7386986e10e 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -21,6 +21,7 @@
#include <linux/seq_file.h>
#include <linux/device.h>
#include <linux/pfn.h>
+#include <linux/mm.h>
#include <asm/io.h>
@@ -50,6 +51,14 @@ struct resource_constraint {
static DEFINE_RWLOCK(resource_lock);
+/*
+ * For memory hotplug, there is no way to free resource entries allocated
+ * by boot mem after the system is up. So for reusing the resource entry
+ * we need to remember the resource.
+ */
+static struct resource *bootmem_resource_free;
+static DEFINE_SPINLOCK(bootmem_resource_lock);
+
static void *r_next(struct seq_file *m, void *v, loff_t *pos)
{
struct resource *p = v;
@@ -151,6 +160,40 @@ __initcall(ioresources_init);
#endif /* CONFIG_PROC_FS */
+static void free_resource(struct resource *res)
+{
+ if (!res)
+ return;
+
+ if (!PageSlab(virt_to_head_page(res))) {
+ spin_lock(&bootmem_resource_lock);
+ res->sibling = bootmem_resource_free;
+ bootmem_resource_free = res;
+ spin_unlock(&bootmem_resource_lock);
+ } else {
+ kfree(res);
+ }
+}
+
+static struct resource *alloc_resource(gfp_t flags)
+{
+ struct resource *res = NULL;
+
+ spin_lock(&bootmem_resource_lock);
+ if (bootmem_resource_free) {
+ res = bootmem_resource_free;
+ bootmem_resource_free = res->sibling;
+ }
+ spin_unlock(&bootmem_resource_lock);
+
+ if (res)
+ memset(res, 0, sizeof(struct resource));
+ else
+ res = kzalloc(sizeof(struct resource), flags);
+
+ return res;
+}
+
/* Return the conflict entry if you can't request it */
static struct resource * __request_resource(struct resource *root, struct resource *new)
{
@@ -771,7 +814,7 @@ static void __init __reserve_region_with_split(struct resource *root,
{
struct resource *parent = root;
struct resource *conflict;
- struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
+ struct resource *res = alloc_resource(GFP_ATOMIC);
struct resource *next_res = NULL;
if (!res)
@@ -796,7 +839,7 @@ static void __init __reserve_region_with_split(struct resource *root,
/* conflict covered whole area */
if (conflict->start <= res->start &&
conflict->end >= res->end) {
- kfree(res);
+ free_resource(res);
WARN_ON(next_res);
break;
}
@@ -806,10 +849,9 @@ static void __init __reserve_region_with_split(struct resource *root,
end = res->end;
res->end = conflict->start - 1;
if (conflict->end < end) {
- next_res = kzalloc(sizeof(*next_res),
- GFP_ATOMIC);
+ next_res = alloc_resource(GFP_ATOMIC);
if (!next_res) {
- kfree(res);
+ free_resource(res);
break;
}
next_res->name = name;
@@ -899,7 +941,7 @@ struct resource * __request_region(struct resource *parent,
const char *name, int flags)
{
DECLARE_WAITQUEUE(wait, current);
- struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
+ struct resource *res = alloc_resource(GFP_KERNEL);
if (!res)
return NULL;
@@ -933,7 +975,7 @@ struct resource * __request_region(struct resource *parent,
continue;
}
/* Uhhuh, that didn't work out.. */
- kfree(res);
+ free_resource(res);
res = NULL;
break;
}
@@ -967,7 +1009,7 @@ int __check_region(struct resource *parent, resource_size_t start,
return -EBUSY;
release_resource(res);
- kfree(res);
+ free_resource(res);
return 0;
}
EXPORT_SYMBOL(__check_region);
@@ -1007,7 +1049,7 @@ void __release_region(struct resource *parent, resource_size_t start,
write_unlock(&resource_lock);
if (res->flags & IORESOURCE_MUXED)
wake_up(&muxed_resource_wait);
- kfree(res);
+ free_resource(res);
return;
}
p = &res->sibling;
@@ -1055,8 +1097,8 @@ int release_mem_region_adjustable(struct resource *parent,
if ((start < parent->start) || (end > parent->end))
return ret;
- /* The kzalloc() result gets checked later */
- new_res = kzalloc(sizeof(struct resource), GFP_KERNEL);
+ /* The alloc_resource() result gets checked later */
+ new_res = alloc_resource(GFP_KERNEL);
p = &parent->child;
write_lock(&resource_lock);
@@ -1083,7 +1125,7 @@ int release_mem_region_adjustable(struct resource *parent,
if (res->start == start && res->end == end) {
/* free the whole entry */
*p = res->sibling;
- kfree(res);
+ free_resource(res);
ret = 0;
} else if (res->start == start && res->end != end) {
/* adjust the start */
@@ -1119,7 +1161,7 @@ int release_mem_region_adjustable(struct resource *parent,
}
write_unlock(&resource_lock);
- kfree(new_res);
+ free_resource(new_res);
return ret;
}
#endif /* CONFIG_MEMORY_HOTREMOVE */