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From b7d6f44a0fa716a82969725516dc0b16bc7cd514 Mon Sep 17 00:00:00 2001 |
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From: John David Anglin <dave.anglin@bell.net> |
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Date: Wed, 26 Jan 2022 20:39:05 +0000 |
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Subject: parisc: Fix data TLB miss in sba_unmap_sg |
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From: John David Anglin <dave.anglin@bell.net> |
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|
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commit b7d6f44a0fa716a82969725516dc0b16bc7cd514 upstream. |
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|
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Rolf Eike Beer reported the following bug: |
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|
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[1274934.746891] Bad Address (null pointer deref?): Code=15 (Data TLB miss fault) at addr 0000004140000018 |
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[1274934.746891] CPU: 3 PID: 5549 Comm: cmake Not tainted 5.15.4-gentoo-parisc64 #4 |
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[1274934.746891] Hardware name: 9000/785/C8000 |
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[1274934.746891] |
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[1274934.746891] YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI |
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[1274934.746891] PSW: 00001000000001001111111000001110 Not tainted |
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[1274934.746891] r00-03 000000ff0804fe0e 0000000040bc9bc0 00000000406760e4 0000004140000000 |
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[1274934.746891] r04-07 0000000040b693c0 0000004140000000 000000004a2b08b0 0000000000000001 |
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[1274934.746891] r08-11 0000000041f98810 0000000000000000 000000004a0a7000 0000000000000001 |
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[1274934.746891] r12-15 0000000040bddbc0 0000000040c0cbc0 0000000040bddbc0 0000000040bddbc0 |
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[1274934.746891] r16-19 0000000040bde3c0 0000000040bddbc0 0000000040bde3c0 0000000000000007 |
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[1274934.746891] r20-23 0000000000000006 000000004a368950 0000000000000000 0000000000000001 |
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[1274934.746891] r24-27 0000000000001fff 000000000800000e 000000004a1710f0 0000000040b693c0 |
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[1274934.746891] r28-31 0000000000000001 0000000041f988b0 0000000041f98840 000000004a171118 |
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[1274934.746891] sr00-03 00000000066e5800 0000000000000000 0000000000000000 00000000066e5800 |
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[1274934.746891] sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000 |
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[1274934.746891] |
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[1274934.746891] IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000406760e8 00000000406760ec |
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[1274934.746891] IIR: 48780030 ISR: 0000000000000000 IOR: 0000004140000018 |
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[1274934.746891] CPU: 3 CR30: 00000040e3a9c000 CR31: ffffffffffffffff |
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[1274934.746891] ORIG_R28: 0000000040acdd58 |
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[1274934.746891] IAOQ[0]: sba_unmap_sg+0xb0/0x118 |
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[1274934.746891] IAOQ[1]: sba_unmap_sg+0xb4/0x118 |
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[1274934.746891] RP(r2): sba_unmap_sg+0xac/0x118 |
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[1274934.746891] Backtrace: |
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[1274934.746891] [<00000000402740cc>] dma_unmap_sg_attrs+0x6c/0x70 |
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[1274934.746891] [<000000004074d6bc>] scsi_dma_unmap+0x54/0x60 |
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[1274934.746891] [<00000000407a3488>] mptscsih_io_done+0x150/0xd70 |
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[1274934.746891] [<0000000040798600>] mpt_interrupt+0x168/0xa68 |
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[1274934.746891] [<0000000040255a48>] __handle_irq_event_percpu+0xc8/0x278 |
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[1274934.746891] [<0000000040255c34>] handle_irq_event_percpu+0x3c/0xd8 |
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[1274934.746891] [<000000004025ecb4>] handle_percpu_irq+0xb4/0xf0 |
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[1274934.746891] [<00000000402548e0>] generic_handle_irq+0x50/0x70 |
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[1274934.746891] [<000000004019a254>] call_on_stack+0x18/0x24 |
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[1274934.746891] |
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[1274934.746891] Kernel panic - not syncing: Bad Address (null pointer deref?) |
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|
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The bug is caused by overrunning the sglist and incorrectly testing |
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sg_dma_len(sglist) before nents. Normally this doesn't cause a crash, |
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but in this case sglist crossed a page boundary. This occurs in the |
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following code: |
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|
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while (sg_dma_len(sglist) && nents--) { |
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The fix is simply to test nents first and move the decrement of nents |
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into the loop. |
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|
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Reported-by: Rolf Eike Beer <eike-kernel@sf-tec.de> |
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Signed-off-by: John David Anglin <dave.anglin@bell.net> |
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Cc: stable@vger.kernel.org |
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Signed-off-by: Helge Deller <deller@gmx.de> |
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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--- |
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drivers/parisc/sba_iommu.c | 3 ++- |
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1 file changed, 2 insertions(+), 1 deletion(-) |
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|
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--- a/drivers/parisc/sba_iommu.c |
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+++ b/drivers/parisc/sba_iommu.c |
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@@ -1047,7 +1047,7 @@ sba_unmap_sg(struct device *dev, struct |
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spin_unlock_irqrestore(&ioc->res_lock, flags); |
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#endif |
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|
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- while (sg_dma_len(sglist) && nents--) { |
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+ while (nents && sg_dma_len(sglist)) { |
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|
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sba_unmap_page(dev, sg_dma_address(sglist), sg_dma_len(sglist), |
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direction, 0); |
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@@ -1056,6 +1056,7 @@ sba_unmap_sg(struct device *dev, struct |
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ioc->usingle_calls--; /* kluge since call is unmap_sg() */ |
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#endif |
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++sglist; |
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+ nents--; |
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} |
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|
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DBG_RUN_SG("%s() DONE (nents %d)\n", __func__, nents); |
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