System may crash in ahci_hw_interrupt() or ahci_thread_fn() when accessing
the interrupt status in a port's private_data if the port is actually a
DUMMY port.
# lspci | grep ATA
00:1f.2 SATA controller: Intel Corporation 82801JI (ICH10 Family) SATA AHCI Controller
# systemctl status kdump (to ensure kdump service is running)
# echo c > /proc/sysrq-trigger
<snip console output for linux-3.15-rc1>
[ 9.352080] ahci 0000:00:1f.2: AHCI 0001.0200 32 slots 6 ports 3 Gbps 0x1 impl SATA mode
[ 9.352084] ahci 0000:00:1f.2: flags: 64bit ncq sntf pm led clo pio slum part ccc
[ 9.368155] Console: switching to colour frame buffer device 128x48
[ 9.439759] mgag200 0000:11:00.0: fb0: mgadrmfb frame buffer device
[ 9.446765] mgag200 0000:11:00.0: registered panic notifier
[ 9.470166] scsi1 : ahci
[ 9.479166] scsi2 : ahci
[ 9.488172] scsi3 : ahci
[ 9.497174] scsi4 : ahci
[ 9.506175] scsi5 : ahci
[ 9.515174] scsi6 : ahci
[ 9.518181] ata1: SATA max UDMA/133 abar m2048@0x95c00000 port 0x95c00100 irq 91
[ 9.526448] ata2: DUMMY
[ 9.529182] ata3: DUMMY
[ 9.531916] ata4: DUMMY
[ 9.534650] ata5: DUMMY
[ 9.537382] ata6: DUMMY
[ 9.576196] [drm] Initialized mgag200 1.0.0 20110418 for 0000:11:00.0 on minor 0
[ 9.845257] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 9.865161] ata1.00: ATAPI: Optiarc DVD RW AD-7580S, FX04, max UDMA/100
[ 9.891407] ata1.00: configured for UDMA/100
[ 9.900525] scsi 1:0:0:0: CD-ROM Optiarc DVD RW AD-7580S FX04 PQ: 0 ANSI: 5
[ 10.247399] iTCO_vendor_support: vendor-support=0
[ 10.261572] iTCO_wdt: Intel TCO WatchDog Timer Driver v1.11
[ 10.269764] iTCO_wdt: unable to reset NO_REBOOT flag, device disabled by hardware/BIOS
[ 10.301932] sd 0:2:0:0: [sda] 570310656 512-byte logical blocks: (291 GB/271 GiB)
[ 10.317085] sd 0:2:0:0: [sda] Write Protect is off
[ 10.328326] sd 0:2:0:0: [sda] Write cache: disabled, read cache: disabled, supports DPO and FUA
[ 10.375452] BUG: unable to handle kernel NULL pointer dereference at 000000000000003c
[ 10.384217] IP: [<ffffffffa0133df0>] ahci_hw_interrupt+0x100/0x130 [libahci]
[ 10.392101] PGD 0
[ 10.394353] Oops: 0000 [#1] SMP
[ 10.397978] Modules linked in: sr_mod(+) cdrom sd_mod iTCO_wdt crc_t10dif iTCO_vendor_support crct10dif_common ahci libahci libata lpc_ich mfd_core mgag200 syscopyarea sysfillrect sysimgblt i2c_algo_bit drm_kms_helper ttm drm i2c_core megaraid_sas dm_mirror dm_region_hash
dm_log dm_mod
[ 10.426499] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.15.0-rc1 #1
[ 10.433495] Hardware name: QCI QSSC-S4R/QSSC-S4R, BIOS QSSC-S4R.QCI.01.00.S013.032920111005 03/29/2011
[ 10.443886] task: ffffffff81906460 ti: ffffffff818f0000 task.ti: ffffffff818f0000
[ 10.452239] RIP: 0010:[<ffffffffa0133df0>] [<ffffffffa0133df0>] ahci_hw_interrupt+0x100/0x130 [libahci]
[ 10.462838] RSP: 0018:ffff880033c03d98 EFLAGS: 00010046
[ 10.468767] RAX: 0000000000a400a4 RBX: ffff880029a6bc18 RCX: 00000000fffffffa
[ 10.476731] RDX: 00000000000000a4 RSI: ffff880029bb0000 RDI: ffff880029a6bc18
[ 10.484696] RBP: ffff880033c03dc8 R08: 0000000000000000 R09: ffff88002f800490
[ 10.492661] R10: 0000000000000000 R11: 0000000000000005 R12: 0000000000000000
[ 10.500625] R13: ffff880029a6bd98 R14: 0000000000000000 R15: ffffc90000194000
[ 10.508590] FS: 0000000000000000(0000) GS:ffff880033c00000(0000) knlGS:0000000000000000
[ 10.517623] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 10.524035] CR2: 000000000000003c CR3: 00000000328ff000 CR4: 00000000000007b0
[ 10.531999] Stack:
[ 10.534241] 0000000000000017 ffff880031ba7d00 000000000000005c ffff880031ba7d00
[ 10.542535] 0000000000000000 000000000000005c ffff880033c03e10 ffffffff810c2a1e
[ 10.550827] ffff880031ae2900 000000008108fb4f ffff880031ae2900 ffff880031ae2984
[ 10.559121] Call Trace:
[ 10.561849] <IRQ>
[ 10.563994] [<ffffffff810c2a1e>] handle_irq_event_percpu+0x3e/0x1a0
[ 10.571309] [<ffffffff810c2bbd>] handle_irq_event+0x3d/0x60
[ 10.577631] [<ffffffff810c4fdd>] try_one_irq.isra.6+0x8d/0xf0
[ 10.584142] [<ffffffff810c5313>] note_interrupt+0x173/0x1f0
[ 10.590460] [<ffffffff810c2a8e>] handle_irq_event_percpu+0xae/0x1a0
[ 10.597554] [<ffffffff810c2bbd>] handle_irq_event+0x3d/0x60
[ 10.603872] [<ffffffff810c5727>] handle_edge_irq+0x77/0x130
[ 10.610199] [<ffffffff81014b8f>] handle_irq+0xbf/0x150
[ 10.616040] [<ffffffff8109ff4e>] ? vtime_account_idle+0xe/0x50
[ 10.622654] [<ffffffff815fca1a>] ? atomic_notifier_call_chain+0x1a/0x20
[ 10.630140] [<ffffffff816038cf>] do_IRQ+0x4f/0xf0
[ 10.635490] [<ffffffff815f8aed>] common_interrupt+0x6d/0x6d
[ 10.641805] <EOI>
[ 10.643950] [<ffffffff8149ca9f>] ? cpuidle_enter_state+0x4f/0xc0
[ 10.650972] [<ffffffff8149ca98>] ? cpuidle_enter_state+0x48/0xc0
[ 10.657775] [<ffffffff8149cb47>] cpuidle_enter+0x17/0x20
[ 10.663807] [<ffffffff810b0070>] cpu_startup_entry+0x2c0/0x3d0
[ 10.670423] [<ffffffff815dfcc7>] rest_init+0x77/0x80
[ 10.676065] [<ffffffff81a60f47>] start_kernel+0x40f/0x41a
[ 10.682190] [<ffffffff81a60941>] ? repair_env_string+0x5c/0x5c
[ 10.688799] [<ffffffff81a60120>] ? early_idt_handlers+0x120/0x120
[ 10.695699] [<ffffffff81a605ee>] x86_64_start_reservations+0x2a/0x2c
[ 10.702889] [<ffffffff81a60733>] x86_64_start_kernel+0x143/0x152
[ 10.709689] Code: a0 fc ff 85 c0 8b 4d d4 74 c3 48 8b 7b 08 89 ca 48 c7 c6 60 66 13 a0 31 c0 e8 9d 70 28 e1 8b 4d d4 eb aa 0f 1f 84 00 00 00 00 00 <45> 8b 64 24 3c 48 89 df e8 23 47 4c e1 41 83 fc 01 19 c0 48 83
[ 10.731470] RIP [<ffffffffa0133df0>] ahci_hw_interrupt+0x100/0x130 [libahci]
[ 10.739441] RSP <ffff880033c03d98>
[ 10.743333] CR2: 000000000000003c
[ 10.747032] ---[ end trace b6e82636970e2690 ]---
[ 10.760190] Kernel panic - not syncing: Fatal exception in interrupt
[ 10.767291] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff)
Signed-off-by: David Milburn <dmilburn@xxxxxxxxxx>
---
drivers/ata/libahci.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 6bd4f66..401924e 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1791,9 +1791,14 @@ irqreturn_t ahci_thread_fn(int irq, void *dev_instance)
u32 status;
spin_lock_irqsave(&ap->host->lock, flags);
- status = pp->intr_status;
- if (status)
- pp->intr_status = 0;
+ if (!ata_port_is_dummy(ap)) {
+ status = pp->intr_status;
+ if (status)
+ pp->intr_status = 0;
+ } else {
+ spin_unlock_irqrestore(&ap->host->lock, flags);
+ return IRQ_HANDLED;
+ }
spin_unlock_irqrestore(&ap->host->lock, flags);
spin_lock_bh(ap->lock);
@@ -1833,8 +1838,11 @@ irqreturn_t ahci_hw_interrupt(int irq, void *dev_instance)
irq_stat = readl(mmio + HOST_IRQ_STAT);
if (!irq_stat) {
- u32 status = pp->intr_status;
+ u32 status = 0;
+ if (!ata_port_is_dummy(ap_this))
+ status = pp->intr_status;
+
spin_unlock(&host->lock);
VPRINTK("EXIT\n");
--
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