[tip:core/stacktrace] dma/debug: Simplify stracktrace retrieval

[tip-bot for Thomas Gleixner]

Commit-ID:  746017ed8d4d3c2070bb03aee9536f24da43c778
Gitweb:     https://git.kernel.org/tip/746017ed8d4d3c2070bb03aee9536f24da43c778
Author:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Thu, 25 Apr 2019 11:45:05 +0200
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 29 Apr 2019 12:37:50 +0200

dma/debug: Simplify stracktrace retrieval

Replace the indirection through struct stack_trace with an invocation of
the storage array based interface.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: kasan-dev@xxxxxxxxxxxxxxxx
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Johannes Thumshirn <jthumshirn@xxxxxxx>
Cc: David Sterba <dsterba@xxxxxxxx>
Cc: Chris Mason <clm@xxxxxx>
Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
Cc: linux-btrfs@xxxxxxxxxxxxxxx
Cc: dm-devel@xxxxxxxxxx
Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
Cc: Alasdair Kergon <agk@xxxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Cc: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
Cc: Miroslav Benes <mbenes@xxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20190425094802.248658135@xxxxxxxxxxxxx

---
 kernel/dma/debug.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index a218e43cc382..badd77670d00 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -89,8 +89,8 @@ struct dma_debug_entry {
 	int		 sg_mapped_ents;
 	enum map_err_types  map_err_type;
 #ifdef CONFIG_STACKTRACE
-	struct		 stack_trace stacktrace;
-	unsigned long	 st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
+	unsigned int	stack_len;
+	unsigned long	stack_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
 #endif
 };
 
@@ -174,7 +174,7 @@ static inline void dump_entry_trace(struct dma_debug_entry *entry)
 #ifdef CONFIG_STACKTRACE
 	if (entry) {
 		pr_warning("Mapped at:\n");
-		print_stack_trace(&entry->stacktrace, 0);
+		stack_trace_print(entry->stack_entries, entry->stack_len, 0);
 	}
 #endif
 }
@@ -704,12 +704,10 @@ static struct dma_debug_entry *dma_entry_alloc(void)
 	spin_unlock_irqrestore(&free_entries_lock, flags);
 
 #ifdef CONFIG_STACKTRACE
-	entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
-	entry->stacktrace.entries = entry->st_entries;
-	entry->stacktrace.skip = 1;
-	save_stack_trace(&entry->stacktrace);
+	entry->stack_len = stack_trace_save(entry->stack_entries,
+					    ARRAY_SIZE(entry->stack_entries),
+					    1);
 #endif
-
 	return entry;
 }