From 8c5165430c0194df92369162d1c7f53f8672baa5 Mon Sep 17 00:00:00 2001 From: Scott Wood Date: Wed, 10 Apr 2019 16:59:25 -0500 Subject: [PATCH] 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 Signed-off-by: Christoph Hellwig --- kernel/dma/debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 45d51e8e26f6..a218e43cc382 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -706,7 +706,7 @@ static struct dma_debug_entry *dma_entry_alloc(void) #ifdef CONFIG_STACKTRACE entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES; entry->stacktrace.entries = entry->st_entries; - entry->stacktrace.skip = 2; + entry->stacktrace.skip = 1; save_stack_trace(&entry->stacktrace); #endif