kernel/linux.git/drivers/misc/genwqe, branch v3.18.76

GenWQE: Fix bad page access during abort of resource allocation

2016-11-24T03:56:30+00:00

[ Upstream commit a7a7aeefbca2982586ba2c9fd7739b96416a6d1d ] When interrupting an application which was allocating DMAable memory, it was possible, that the DMA memory was deallocated twice, leading to the error symptoms below. Thanks to Gerald, who analyzed the problem and provided this patch. I agree with his analysis of the problem: ddcb_cmd_fixups() -> genwqe_alloc_sync_sgl() (fails in f/lpage, but sgl->sgl != NULL and f/lpage maybe also != NULL) -> ddcb_cmd_cleanup() -> genwqe_free_sync_sgl() (double free, because sgl->sgl != NULL and f/lpage maybe also != NULL) In this scenario we would have exactly the kind of double free that would explain the WARNING / Bad page state, and as expected it is caused by broken error handling (cleanup). Using the Ubuntu git source, tag Ubuntu-4.4.0-33.52, he was able to reproduce the "Bad page state" issue, and with the patch on top he could not reproduce it any more. ------------[ cut here ]------------ WARNING: at /build/linux-o03cxz/linux-4.4.0/arch/s390/include/asm/pci_dma.h:141 Modules linked in: qeth_l2 ghash_s390 prng aes_s390 des_s390 des_generic sha512_s390 sha256_s390 sha1_s390 sha_common genwqe_card qeth crc_itu_t qdio ccwgroup vmur dm_multipath dasd_eckd_mod dasd_mod CPU: 2 PID: 3293 Comm: genwqe_gunzip Not tainted 4.4.0-33-generic #52-Ubuntu task: 0000000032c7e270 ti: 00000000324e4000 task.ti: 00000000324e4000 Krnl PSW : 0404c00180000000 0000000000156346 (dma_update_cpu_trans+0x9e/0xa8) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 EA:3 Krnl GPRS: 00000000324e7bcd 0000000000c3c34a 0000000027628298 000000003215b400 0000000000000400 0000000000001fff 0000000000000400 0000000116853000 07000000324e7b1e 0000000000000001 0000000000000001 0000000000000001 0000000000001000 0000000116854000 0000000000156402 00000000324e7a38 Krnl Code: 000000000015633a: 95001000 cli 0(%r1),0 000000000015633e: a774ffc3 brc 7,1562c4 #0000000000156342: a7f40001 brc 15,156344 >0000000000156346: 92011000 mvi 0(%r1),1 000000000015634a: a7f4ffbd brc 15,1562c4 000000000015634e: 0707 bcr 0,%r7 0000000000156350: c00400000000 brcl 0,156350 0000000000156356: eb7ff0500024 stmg %r7,%r15,80(%r15) Call Trace: ([<00000000001563e0>] dma_update_trans+0x90/0x228) [<00000000001565dc>] s390_dma_unmap_pages+0x64/0x160 [<00000000001567c2>] s390_dma_free+0x62/0x98 [<000003ff801310ce>] __genwqe_free_consistent+0x56/0x70 [genwqe_card] [<000003ff801316d0>] genwqe_free_sync_sgl+0xf8/0x160 [genwqe_card] [<000003ff8012bd6e>] ddcb_cmd_cleanup+0x86/0xa8 [genwqe_card] [<000003ff8012c1c0>] do_execute_ddcb+0x110/0x348 [genwqe_card] [<000003ff8012c914>] genwqe_ioctl+0x51c/0xc20 [genwqe_card] [<000000000032513a>] do_vfs_ioctl+0x3b2/0x518 [<0000000000325344>] SyS_ioctl+0xa4/0xb8 [<00000000007b86c6>] system_call+0xd6/0x264 [<000003ff9e8e520a>] 0x3ff9e8e520a Last Breaking-Event-Address: [<0000000000156342>] dma_update_cpu_trans+0x9a/0xa8 ---[ end trace 35996336235145c8 ]--- BUG: Bad page state in process jbd2/dasdb1-8 pfn:3215b page:000003d100c856c0 count:-1 mapcount:0 mapping: (null) index:0x0 flags: 0x3fffc0000000000() page dumped because: nonzero _count Signed-off-by: Gerald Schaefer Signed-off-by: Frank Haverkamp Cc: stable Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

misc: genwqe: check for error from get_user_pages_fast()

2015-01-16T14:59:50+00:00

commit cf35d6e0475982667b0d2d318fb27be4b8849827 upstream. `genwqe_user_vmap()` calls `get_user_pages_fast()` and if the return value is less than the number of pages requested, it frees the pages and returns an error (`-EFAULT`). However, it fails to consider a negative error return value from `get_user_pages_fast()`. In that case, the test `if (rc < m->nr_pages)` will be false (due to promotion of `rc` to a large `unsigned int`) and the code will continue on to call `genwqe_map_pages()` with an invalid list of page pointers. Fix it by bailing out if `get_user_pages_fast()` returns a negative error value. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman

GenWQE: Support blocking when DDCB queue is busy

2014-09-24T06:15:47+00:00

When the GenWQE hardware queue was busy, the driver returned simply -EBUSY. This caused polling by applications which increased the load on the already busy system. This change implements the possiblity to sleep on a waitqueue instead when the DDCB queue is busy. The requestor is woken up when there is free space on the queue again. The old way to get -EBUSY is still available if the device is openend with O_NONBLOCKING. The default is now blocking behavior. Signed-off-by: Frank Haverkamp Signed-off-by: Greg Kroah-Hartman

GenWQE: Fix problem when reading HSI and Retc

2014-09-24T06:15:47+00:00

This patch fixes a problem we found during debug on PPC64 when reading HSI status and Retc. Signed-off-by: Eberhard S. Amann Signed-off-by: Frank Haverkamp Signed-off-by: Greg Kroah-Hartman

GenWQE: Fix checkpatch complaints

2014-09-24T06:15:47+00:00

The checkpatch.pl script got improved. I ran it on the latest GenWQE sources and fixed what it complained about. Signed-off-by: Frank Haverkamp Signed-off-by: Greg Kroah-Hartman

GenWQE: Check return code of pci_sriov_enable

2014-09-24T06:15:46+00:00

Forgetting to check this, can lead to problems on systems which do not support SRIOV. Signed-off-by: Frank Haverkamp Signed-off-by: Greg Kroah-Hartman

GenWQE: Do not modify return code of genwqe_set_interrupt_capability

2014-09-24T06:15:46+00:00

Follow up patch to the one from Sebastian Ott. There is no need to change the return code once it fails. And Sebastians version is tested now and works nicely on our test-system. Signed-off-by: Frank Haverkamp Signed-off-by: Greg Kroah-Hartman

GenWQE: Update author information

2014-09-24T06:15:46+00:00

Updated email address of co-author. Signed-off-by: Frank Haverkamp Signed-off-by: Michael Jung Signed-off-by: Greg Kroah-Hartman

GenWQE: Remove sysfs entry for driver version

2014-09-24T06:15:46+00:00

A special sysfs entry to display the driver version is not needed. We left the driver version and adjusted it to the naming a lot of other drivers use. The information can be retrieved by using modinfo genwqe_card. modinfo genwqe_card will provide the same information. Signed-off-by: Frank Haverkamp Signed-off-by: Greg Kroah-Hartman

GenWQE: Check pci_get_totalvfs return code

2014-09-24T06:15:46+00:00

Currently the driver is using the pci_get_totalvfs() return code directly in a loop. To avoid problems with potentially negative returns in case of errors, we are adding some more sanity checking code. Signed-off-by: Frank Haverkamp Signed-off-by: Greg Kroah-Hartman