1 files changed, 114 insertions, 0 deletions

diff --git a/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.24/0038-memory-hotplug-fix-invalid-memory-access-caused-by-s.patch b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.24/0038-memory-hotplug-fix-invalid-memory-access-caused-by-s.patch
new file mode 100644
index 00000000..5d3cef24
--- /dev/null
+++ b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.24/0038-memory-hotplug-fix-invalid-memory-access-caused-by-s.patch
@@ -0,0 +1,114 @@
+From c9a4beeb70f62ec5976dcbb9086683fda56d6aec Mon Sep 17 00:00:00 2001
+From: Jiang Liu <jiang.liu@huawei.com>
+Date: Wed, 11 Jul 2012 14:01:52 -0700
+Subject: [PATCH 038/109] memory hotplug: fix invalid memory access caused by
+ stale kswapd pointer
+
+commit d8adde17e5f858427504725218c56aef90e90fc7 upstream.
+
+kswapd_stop() is called to destroy the kswapd work thread when all memory
+of a NUMA node has been offlined.  But kswapd_stop() only terminates the
+work thread without resetting NODE_DATA(nid)->kswapd to NULL.  The stale
+pointer will prevent kswapd_run() from creating a new work thread when
+adding memory to the memory-less NUMA node again.  Eventually the stale
+pointer may cause invalid memory access.
+
+An example stack dump as below. It's reproduced with 2.6.32, but latest
+kernel has the same issue.
+
+  BUG: unable to handle kernel NULL pointer dereference at (null)
+  IP: [<ffffffff81051a94>] exit_creds+0x12/0x78
+  PGD 0
+  Oops: 0000 [#1] SMP
+  last sysfs file: /sys/devices/system/memory/memory391/state
+  CPU 11
+  Modules linked in: cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq microcode fuse loop dm_mod tpm_tis rtc_cmos i2c_i801 rtc_core tpm serio_raw pcspkr sg tpm_bios igb i2c_core iTCO_wdt rtc_lib mptctl iTCO_vendor_support button dca bnx2 usbhid hid uhci_hcd ehci_hcd usbcore sd_mod crc_t10dif edd ext3 mbcache jbd fan ide_pci_generic ide_core ata_generic ata_piix libata thermal processor thermal_sys hwmon mptsas mptscsih mptbase scsi_transport_sas scsi_mod
+  Pid: 7949, comm: sh Not tainted 2.6.32.12-qiuxishi-5-default #92 Tecal RH2285
+  RIP: 0010:exit_creds+0x12/0x78
+  RSP: 0018:ffff8806044f1d78  EFLAGS: 00010202
+  RAX: 0000000000000000 RBX: ffff880604f22140 RCX: 0000000000019502
+  RDX: 0000000000000000 RSI: 0000000000000202 RDI: 0000000000000000
+  RBP: ffff880604f22150 R08: 0000000000000000 R09: ffffffff81a4dc10
+  R10: 00000000000032a0 R11: ffff880006202500 R12: 0000000000000000
+  R13: 0000000000c40000 R14: 0000000000008000 R15: 0000000000000001
+  FS:  00007fbc03d066f0(0000) GS:ffff8800282e0000(0000) knlGS:0000000000000000
+  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
+  CR2: 0000000000000000 CR3: 000000060f029000 CR4: 00000000000006e0
+  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
+  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
+  Process sh (pid: 7949, threadinfo ffff8806044f0000, task ffff880603d7c600)
+  Stack:
+   ffff880604f22140 ffffffff8103aac5 ffff880604f22140 ffffffff8104d21e
+   ffff880006202500 0000000000008000 0000000000c38000 ffffffff810bd5b1
+   0000000000000000 ffff880603d7c600 00000000ffffdd29 0000000000000003
+  Call Trace:
+    __put_task_struct+0x5d/0x97
+    kthread_stop+0x50/0x58
+    offline_pages+0x324/0x3da
+    memory_block_change_state+0x179/0x1db
+    store_mem_state+0x9e/0xbb
+    sysfs_write_file+0xd0/0x107
+    vfs_write+0xad/0x169
+    sys_write+0x45/0x6e
+    system_call_fastpath+0x16/0x1b
+  Code: ff 4d 00 0f 94 c0 84 c0 74 08 48 89 ef e8 1f fd ff ff 5b 5d 31 c0 41 5c c3 53 48 8b 87 20 06 00 00 48 89 fb 48 8b bf 18 06 00 00 <8b> 00 48 c7 83 18 06 00 00 00 00 00 00 f0 ff 0f 0f 94 c0 84 c0
+  RIP  exit_creds+0x12/0x78
+   RSP <ffff8806044f1d78>
+  CR2: 0000000000000000
+
+[akpm@linux-foundation.org: add pglist_data.kswapd locking comments]
+Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
+Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
+Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
+Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
+Acked-by: Mel Gorman <mgorman@suse.de>
+Acked-by: David Rientjes <rientjes@google.com>
+Reviewed-by: Minchan Kim <minchan@kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
+---
+ include/linux/mmzone.h |    2 +-
+ mm/vmscan.c            |    7 +++++--
+ 2 files changed, 6 insertions(+), 3 deletions(-)
+
+diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
+index 188cb2f..905b1e1 100644
+--- a/include/linux/mmzone.h
++++ b/include/linux/mmzone.h
+@@ -652,7 +652,7 @@ typedef struct pglist_data {
+                                             range, including holes */
+        int node_id;
+        wait_queue_head_t kswapd_wait;
+-       struct task_struct *kswapd;
++       struct task_struct *kswapd;     /* Protected by lock_memory_hotplug() */
+        int kswapd_max_order;
+        enum zone_type classzone_idx;
+ } pg_data_t;
+diff --git a/mm/vmscan.c b/mm/vmscan.c
+index fbe2d2c..72cf498 100644
+--- a/mm/vmscan.c
++++ b/mm/vmscan.c
+@@ -3090,14 +3090,17 @@ int kswapd_run(int nid)
+ }
+ 
+ /*
+- * Called by memory hotplug when all memory in a node is offlined.
++ * Called by memory hotplug when all memory in a node is offlined.  Caller must
++ * hold lock_memory_hotplug().
+  */
+ void kswapd_stop(int nid)
+ {
+        struct task_struct *kswapd = NODE_DATA(nid)->kswapd;
+ 
+-       if (kswapd)
++       if (kswapd) {
+                kthread_stop(kswapd);
++               NODE_DATA(nid)->kswapd = NULL;
++       }
+ }
+ 
+ static int __init kswapd_init(void)
+-- 
+1.7.7.6
+