[PATCH] dma-mapping: Fix tracing dma_alloc/free with vmalloc'd memory

[Sean Anderson]

Not all virtual addresses have physical addresses, such as if they were
vmalloc'd. Just trace the virtual address instead of trying to trace a
physical address. This aligns with the API, and is good enough to
associate dma_alloc with dma_free.

Fixes: 038eb433dc14 ("dma-mapping: add tracing for dma-mapping API calls")
Reported-by: syzbot+b4bfacdec173efaa8...@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/670ebde5.050a0220.d9b66.0154....@google.com/
Signed-off-by: Sean Anderson <sean.ander...@linux.dev>
---
%p obfuscates virtual addresses when tracing just like with printk.

 include/trace/events/dma.h | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/include/trace/events/dma.h b/include/trace/events/dma.h
index 569f86a44aaa..b0f41265191c 100644
--- a/include/trace/events/dma.h
+++ b/include/trace/events/dma.h
@@ -121,7 +121,7 @@ TRACE_EVENT(dma_alloc,
 
        TP_STRUCT__entry(
                __string(device, dev_name(dev))
-               __field(u64, phys_addr)
+               __field(void *, virt_addr)
                __field(u64, dma_addr)
                __field(size_t, size)
                __field(gfp_t, flags)
@@ -130,18 +130,18 @@ TRACE_EVENT(dma_alloc,
 
        TP_fast_assign(
                __assign_str(device);
-               __entry->phys_addr = virt_to_phys(virt_addr);
+               __entry->virt_addr = virt_addr;
                __entry->dma_addr = dma_addr;
                __entry->size = size;
                __entry->flags = flags;
                __entry->attrs = attrs;
        ),
 
-       TP_printk("%s dma_addr=%llx size=%zu phys_addr=%llx flags=%s attrs=%s",
+       TP_printk("%s dma_addr=%llx size=%zu virt_addr=%p flags=%s attrs=%s",
                __get_str(device),
                __entry->dma_addr,
                __entry->size,
-               __entry->phys_addr,
+               __entry->virt_addr,
                show_gfp_flags(__entry->flags),
                decode_dma_attrs(__entry->attrs))
 );
@@ -153,7 +153,7 @@ TRACE_EVENT(dma_free,
 
        TP_STRUCT__entry(
                __string(device, dev_name(dev))
-               __field(u64, phys_addr)
+               __field(void *, virt_addr)
                __field(u64, dma_addr)
                __field(size_t, size)
                __field(unsigned long, attrs)
@@ -161,17 +161,17 @@ TRACE_EVENT(dma_free,
 
        TP_fast_assign(
                __assign_str(device);
-               __entry->phys_addr = virt_to_phys(virt_addr);
+               __entry->virt_addr = virt_addr;
                __entry->dma_addr = dma_addr;
                __entry->size = size;
                __entry->attrs = attrs;
        ),
 
-       TP_printk("%s dma_addr=%llx size=%zu phys_addr=%llx attrs=%s",
+       TP_printk("%s dma_addr=%llx size=%zu virt_addr=%p attrs=%s",
                __get_str(device),
                __entry->dma_addr,
                __entry->size,
-               __entry->phys_addr,
+               __entry->virt_addr,
                decode_dma_attrs(__entry->attrs))
 );
 
-- 
2.35.1.1320.gc452695387.dirty