On Sat, Jul 18, 2026 at 02:58:48PM +0200, Martin Kaiser wrote:
> The fsl edma events store a pointer to a struct fsl_edma_engine in the
> ringbuffer and dereference it when a log entry is printed. At this time,
> the pointer may no longer be valid.
>
> Event injection can be used to trigger a crash:
>
> $ cd /sys/kernel/tracing
> $ echo 'value = 0' > events/fsl_edma/edma_writeb/inject
> $ cat trace
>
> The log output needs only edma->membase. Add a membase field at the end
> of the event and use the new field for log output. Keep the existing
> fields for backward compatibility.
>
> Fixes: 11102d0c343b ("dmaengine: fsl-edma: add trace event support")
> Cc: [email protected]
> Reviewed-by: Steven Rostedt <[email protected]>
> Signed-off-by: Martin Kaiser <[email protected]>
> ---Reviewed-by: Frank Li <[email protected]> > v2: > - dmaengine prefix in the subject line > - Cc stable > - Steven's Reviewed tag > > drivers/dma/fsl-edma-trace.h | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/dma/fsl-edma-trace.h b/drivers/dma/fsl-edma-trace.h > index d3541301a247..45d964a3726d 100644 > --- a/drivers/dma/fsl-edma-trace.h > +++ b/drivers/dma/fsl-edma-trace.h > @@ -19,14 +19,16 @@ DECLARE_EVENT_CLASS(edma_log_io, > __field(struct fsl_edma_engine *, edma) > __field(void __iomem *, addr) > __field(u32, value) > + __field(void __iomem *, membase) > ), > TP_fast_assign( > __entry->edma = edma; > __entry->addr = addr; > __entry->value = value; > + __entry->membase = edma->membase; > ), > TP_printk("offset %08x: value %08x", > - (u32)(__entry->addr - __entry->edma->membase), __entry->value) > + (u32)(__entry->addr - __entry->membase), __entry->value) > ); > > DEFINE_EVENT(edma_log_io, edma_readl, > -- > 2.43.7 >
