dma-debug: only skip one stackframe entry
authorScott Wood <swood@redhat.com>
Wed, 10 Apr 2019 21:59:25 +0000 (16:59 -0500)
committerChristoph Hellwig <hch@lst.de>
Thu, 11 Apr 2019 17:29:50 +0000 (19:29 +0200)
commit8c5165430c0194df92369162d1c7f53f8672baa5
tree739255d87917d08f3da0df4004e9d8d26fd8e139
parent2a29e9f6b9b499f1fc5f4a48220dc3f4428499f9
dma-debug: only skip one stackframe entry

With skip set to 1, I get a traceback like this:

[  106.867637] DMA-API: Mapped at:
[  106.870784]  afu_dma_map_region+0x2cd/0x4f0 [dfl_afu]
[  106.875839]  afu_ioctl+0x258/0x380 [dfl_afu]
[  106.880108]  do_vfs_ioctl+0xa9/0x720
[  106.883688]  ksys_ioctl+0x60/0x90
[  106.887007]  __x64_sys_ioctl+0x16/0x20

With the previous value of 2, afu_dma_map_region was being omitted.  I
suspect that the code paths have simply changed since the value of 2 was
chosen a decade ago, but it's also possible that it varies based on which
mapping function was used, compiler inlining choices, etc.  In any case,
it's best to err on the side of skipping less.

Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
kernel/dma/debug.c