Revision 8cf66504210d308a35cca35fe9c310b1241f9fa7 authored by Qian Cai on 11 July 2019, 16:17:45 UTC, committed by Linus Torvalds on 21 July 2019, 16:57:13 UTC
The commit b3aa14f02254 ("iommu: remove the mapping_error dma_map_ops method") incorrectly changed the checking from dma_ops_alloc_iova() in map_sg() causes a crash under memory pressure as dma_ops_alloc_iova() never return DMA_MAPPING_ERROR on failure but 0, so the error handling is all wrong. kernel BUG at drivers/iommu/iova.c:801! Workqueue: kblockd blk_mq_run_work_fn RIP: 0010:iova_magazine_free_pfns+0x7d/0xc0 Call Trace: free_cpu_cached_iovas+0xbd/0x150 alloc_iova_fast+0x8c/0xba dma_ops_alloc_iova.isra.6+0x65/0xa0 map_sg+0x8c/0x2a0 scsi_dma_map+0xc6/0x160 pqi_aio_submit_io+0x1f6/0x440 [smartpqi] pqi_scsi_queue_command+0x90c/0xdd0 [smartpqi] scsi_queue_rq+0x79c/0x1200 blk_mq_dispatch_rq_list+0x4dc/0xb70 blk_mq_sched_dispatch_requests+0x249/0x310 __blk_mq_run_hw_queue+0x128/0x200 blk_mq_run_work_fn+0x27/0x30 process_one_work+0x522/0xa10 worker_thread+0x63/0x5b0 kthread+0x1d2/0x1f0 ret_from_fork+0x22/0x40 Fixes: b3aa14f02254 ("iommu: remove the mapping_error dma_map_ops method") Signed-off-by: Qian Cai <cai@lca.pw> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 618381f
clz_ctz.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* lib/clz_ctz.c
*
* Copyright (C) 2013 Chanho Min <chanho.min@lge.com>
*
* The functions in this file aren't called directly, but are required by
* GCC builtins such as __builtin_ctz, and therefore they can't be removed
* despite appearing unreferenced in kernel source.
*
* __c[lt]z[sd]i2 can be overridden by linking arch-specific versions.
*/
#include <linux/export.h>
#include <linux/kernel.h>
int __weak __ctzsi2(int val);
int __weak __ctzsi2(int val)
{
return __ffs(val);
}
EXPORT_SYMBOL(__ctzsi2);
int __weak __clzsi2(int val);
int __weak __clzsi2(int val)
{
return 32 - fls(val);
}
EXPORT_SYMBOL(__clzsi2);
int __weak __clzdi2(long val);
int __weak __ctzdi2(long val);
#if BITS_PER_LONG == 32
int __weak __clzdi2(long val)
{
return 32 - fls((int)val);
}
EXPORT_SYMBOL(__clzdi2);
int __weak __ctzdi2(long val)
{
return __ffs((u32)val);
}
EXPORT_SYMBOL(__ctzdi2);
#elif BITS_PER_LONG == 64
int __weak __clzdi2(long val)
{
return 64 - fls64((u64)val);
}
EXPORT_SYMBOL(__clzdi2);
int __weak __ctzdi2(long val)
{
return __ffs64((u64)val);
}
EXPORT_SYMBOL(__ctzdi2);
#else
#error BITS_PER_LONG not 32 or 64
#endif
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