3.2.51-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Russ Anderson <rja@xxxxxxx>
commit 21ea9f5ace3a7317cc3ba1fbc749758021a83136 upstream.
"cat /sys/devices/system/memory/memory*/removable" crashed the system.
The problem is that show_mem_removable() is passing a
bad pfn to is_mem_section_removable(), which causes
if (!node_online(page_to_nid(page)))
to blow up. Why is it passing in a bad pfn?
The reason is that show_mem_removable() will loop sections_per_block
times. sections_per_block is 16, but mem->section_count is 8,
indicating holes in this memory block. Checking that the memory section
is present before checking to see if the memory section is removable
fixes the problem.
harp5-sys:~ # cat /sys/devices/system/memory/memory*/removable
0
1
1
1
1
1
1
1
1
1
1
1
1
1
BUG: unable to handle kernel paging request at ffffea00c3200000
IP: [<ffffffff81117ed1>] is_pageblock_removable_nolock+0x1/0x90
PGD 83ffd4067 PUD 37bdfce067 PMD 0
Oops: 0000 [#1] SMP
Modules linked in: autofs4 binfmt_misc rdma_ucm rdma_cm iw_cm ib_addr ib_srp scsi_transport_srp scsi_tgt ib_ipoib ib_cm ib_uverbs ib_umad iw_cxgb3 cxgb3 mdio mlx4_en mlx4_ib ib_sa mlx4_core ib_mthca ib_mad ib_core fuse nls_iso8859_1 nls_cp437 vfat fat joydev loop hid_generic usbhid hid hwperf(O) numatools(O) dm_mod iTCO_wdt ipv6 iTCO_vendor_support igb i2c_i801 ioatdma i2c_algo_bit ehci_pci pcspkr lpc_ich i2c_core ehci_hcd ptp sg mfd_core dca rtc_cmos pps_core mperf button xhci_hcd sd_mod crc_t10dif usbcore usb_common scsi_dh_emc scsi_dh_hp_sw scsi_dh_alua scsi_dh_rdac scsi_dh gru(O) xvma(O) xfs crc32c libcrc32c thermal sata_nv processor piix mptsas mptscsih scsi_transport_sas mptbase megaraid_sas fan thermal_sys hwmon ext3 jbd ata_piix ahci libahci libata scsi_mod
CPU: 4 PID: 5991 Comm: cat Tainted: G O 3.11.0-rc5-rja-uv+ #10
Hardware name: SGI UV2000/ROMLEY, BIOS SGI UV 2000/3000 series BIOS 01/15/2013
task: ffff88081f034580 ti: ffff880820022000 task.ti: ffff880820022000
RIP: 0010:[<ffffffff81117ed1>] [<ffffffff81117ed1>] is_pageblock_removable_nolock+0x1/0x90
RSP: 0018:ffff880820023df8 EFLAGS: 00010287
RAX: 0000000000040000 RBX: ffffea00c3200000 RCX: 0000000000000004
RDX: ffffea00c30b0000 RSI: 00000000001c0000 RDI: ffffea00c3200000
RBP: ffff880820023e38 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: ffffea00c33c0000
R13: 0000160000000000 R14: 6db6db6db6db6db7 R15: 0000000000000001
FS: 00007ffff7fb2700(0000) GS:ffff88083fc80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffea00c3200000 CR3: 000000081b954000 CR4: 00000000000407e0
Call Trace:
show_mem_removable+0x41/0x70
dev_attr_show+0x2a/0x60
sysfs_read_file+0xf7/0x1c0
vfs_read+0xc8/0x130
SyS_read+0x5d/0xa0
system_call_fastpath+0x16/0x1b
Signed-off-by: Russ Anderson <rja@xxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/base/memory.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -172,6 +172,8 @@ static ssize_t show_mem_removable(struct
container_of(dev, struct memory_block, sysdev);
for (i = 0; i < sections_per_block; i++) {
+ if (!present_section_nr(mem->start_section_nr + i))
+ continue;
pfn = section_nr_to_pfn(mem->start_section_nr + i);
ret &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
}
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