drm: Simplify stacktrace handling

Replace the indirection through struct stack_trace by using the storage
array based interfaces.

The original code in all printing functions is really wrong. It allocates a
storage array on stack which is unused because depot_fetch_stack() does not
store anything in it. It overwrites the entries pointer in the stack_trace
struct so it points to the depot storage.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org
Cc: dm-devel@redhat.com
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: linux-arch@vger.kernel.org
Link: https://lkml.kernel.org/r/20190425094802.622094226@linutronix.de

diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index 6955277..8b4cd31 100644 (file)
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -106,22 +106,19 @@
 static noinline void save_stack(struct drm_mm_node *node)
 {
        unsigned long entries[STACKDEPTH];
-       struct stack_trace trace = {
-               .entries = entries,
-               .max_entries = STACKDEPTH,
-               .skip = 1
-       };
+       unsigned int n;
 
-       save_stack_trace(&trace);
+       n = stack_trace_save(entries, ARRAY_SIZE(entries), 1);
 
        /* May be called under spinlock, so avoid sleeping */
-       node->stack = depot_save_stack(&trace, GFP_NOWAIT);
+       node->stack = stack_depot_save(entries, n, GFP_NOWAIT);
 }
 
 static void show_leaks(struct drm_mm *mm)
 {
        struct drm_mm_node *node;
-       unsigned long entries[STACKDEPTH];
+       unsigned long *entries;
+       unsigned int nr_entries;
        char *buf;
 
        buf = kmalloc(BUFSZ, GFP_KERNEL);
@@ -129,19 +126,14 @@ static void show_leaks(struct drm_mm *mm)
                return;
 
        list_for_each_entry(node, drm_mm_nodes(mm), node_list) {
-               struct stack_trace trace = {
-                       .entries = entries,
-                       .max_entries = STACKDEPTH
-               };
-
                if (!node->stack) {
                        DRM_ERROR("node [%08llx + %08llx]: unknown owner\n",
                                  node->start, node->size);
                        continue;
                }
 
-               depot_fetch_stack(node->stack, &trace);
-               snprint_stack_trace(buf, BUFSZ, &trace, 0);
+               nr_entries = stack_depot_fetch(node->stack, &entries);
+               stack_trace_snprint(buf, BUFSZ, entries, nr_entries, 0);
                DRM_ERROR("node [%08llx + %08llx]: inserted at\n%s",
                          node->start, node->size, buf);
        }

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index b713bed..41b5bcb 100644 (file)
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -36,11 +36,8 @@
 
 static void vma_print_allocator(struct i915_vma *vma, const char *reason)
 {
-       unsigned long entries[12];
-       struct stack_trace trace = {
-               .entries = entries,
-               .max_entries = ARRAY_SIZE(entries),
-       };
+       unsigned long *entries;
+       unsigned int nr_entries;
        char buf[512];
 
        if (!vma->node.stack) {
@@ -49,8 +46,8 @@ static void vma_print_allocator(struct i915_vma *vma, const char *reason)
                return;
        }
 
-       depot_fetch_stack(vma->node.stack, &trace);
-       snprint_stack_trace(buf, sizeof(buf), &trace, 0);
+       nr_entries = stack_depot_fetch(vma->node.stack, &entries);
+       stack_trace_snprint(buf, sizeof(buf), entries, nr_entries, 0);
        DRM_DEBUG_DRIVER("vma.node [%08llx + %08llx] %s: inserted at %s\n",
                         vma->node.start, vma->node.size, reason, buf);
 }

diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 1f8acbb..20c4434 100644 (file)
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -60,27 +60,20 @@
 static noinline depot_stack_handle_t __save_depot_stack(void)
 {
        unsigned long entries[STACKDEPTH];
-       struct stack_trace trace = {
-               .entries = entries,
-               .max_entries = ARRAY_SIZE(entries),
-               .skip = 1,
-       };
+       unsigned int n;
 
-       save_stack_trace(&trace);
-       return depot_save_stack(&trace, GFP_NOWAIT | __GFP_NOWARN);
+       n = stack_trace_save(entries, ARRAY_SIZE(entries), 1);
+       return stack_depot_save(entries, n, GFP_NOWAIT | __GFP_NOWARN);
 }
 
 static void __print_depot_stack(depot_stack_handle_t stack,
                                char *buf, int sz, int indent)
 {
-       unsigned long entries[STACKDEPTH];
-       struct stack_trace trace = {
-               .entries = entries,
-               .max_entries = ARRAY_SIZE(entries),
-       };
+       unsigned long *entries;
+       unsigned int nr_entries;
 
-       depot_fetch_stack(stack, &trace);
-       snprint_stack_trace(buf, sz, &trace, indent);
+       nr_entries = stack_depot_fetch(stack, &entries);
+       stack_trace_snprint(buf, sz, entries, nr_entries, indent);
 }
 
 static void init_intel_runtime_pm_wakeref(struct drm_i915_private *i915)