Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/scripts/coccinelle/api/alloc/alloc_cast.cocci b/scripts/coccinelle/api/alloc/alloc_cast.cocci
index 408ee38..f6f0ccd 100644
--- a/scripts/coccinelle/api/alloc/alloc_cast.cocci
+++ b/scripts/coccinelle/api/alloc/alloc_cast.cocci
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /// Remove casting the values returned by memory allocation functions
 /// like kmalloc, kzalloc, kmem_cache_alloc, kmem_cache_zalloc etc.
 ///
@@ -8,8 +9,8 @@
 //# need some reformatting.
 //
 // Confidence: High
-// Copyright: (C) 2014 Himangi Saraogi GPLv2.
-// Copyright: (C) 2017 Himanshu Jha GPLv2.
+// Copyright: (C) 2014 Himangi Saraogi
+// Copyright: (C) 2017 Himanshu Jha
 // Comments:
 // Options: --no-includes --include-headers
 //
@@ -32,7 +33,7 @@
   (T *)
   \(kmalloc\|kzalloc\|kcalloc\|kmem_cache_alloc\|kmem_cache_zalloc\|
    kmem_cache_alloc_node\|kmalloc_node\|kzalloc_node\|vmalloc\|vzalloc\|
-   dma_alloc_coherent\|dma_zalloc_coherent\|devm_kmalloc\|devm_kzalloc\|
+   dma_alloc_coherent\|devm_kmalloc\|devm_kzalloc\|
    kvmalloc\|kvzalloc\|kvmalloc_node\|kvzalloc_node\|pci_alloc_consistent\|
    pci_zalloc_consistent\|kmem_alloc\|kmem_zalloc\|kmem_zone_alloc\|
    kmem_zone_zalloc\|vmalloc_node\|vzalloc_node\)(...)
@@ -55,7 +56,7 @@
 * (T *)
   \(kmalloc\|kzalloc\|kcalloc\|kmem_cache_alloc\|kmem_cache_zalloc\|
    kmem_cache_alloc_node\|kmalloc_node\|kzalloc_node\|vmalloc\|vzalloc\|
-   dma_alloc_coherent\|dma_zalloc_coherent\|devm_kmalloc\|devm_kzalloc\|
+   dma_alloc_coherent\|devm_kmalloc\|devm_kzalloc\|
    kvmalloc\|kvzalloc\|kvmalloc_node\|kvzalloc_node\|pci_alloc_consistent\|
    pci_zalloc_consistent\|kmem_alloc\|kmem_zalloc\|kmem_zone_alloc\|
    kmem_zone_zalloc\|vmalloc_node\|vzalloc_node\)(...)
@@ -78,7 +79,7 @@
 - (T *)
   \(kmalloc\|kzalloc\|kcalloc\|kmem_cache_alloc\|kmem_cache_zalloc\|
    kmem_cache_alloc_node\|kmalloc_node\|kzalloc_node\|vmalloc\|vzalloc\|
-   dma_alloc_coherent\|dma_zalloc_coherent\|devm_kmalloc\|devm_kzalloc\|
+   dma_alloc_coherent\|devm_kmalloc\|devm_kzalloc\|
    kvmalloc\|kvzalloc\|kvmalloc_node\|kvzalloc_node\|pci_alloc_consistent\|
    pci_zalloc_consistent\|kmem_alloc\|kmem_zalloc\|kmem_zone_alloc\|
    kmem_zone_zalloc\|vmalloc_node\|vzalloc_node\)(...)
@@ -95,7 +96,7 @@
  (T@p *)
   \(kmalloc\|kzalloc\|kcalloc\|kmem_cache_alloc\|kmem_cache_zalloc\|
    kmem_cache_alloc_node\|kmalloc_node\|kzalloc_node\|vmalloc\|vzalloc\|
-   dma_alloc_coherent\|dma_zalloc_coherent\|devm_kmalloc\|devm_kzalloc\|
+   dma_alloc_coherent\|devm_kmalloc\|devm_kzalloc\|
    kvmalloc\|kvzalloc\|kvmalloc_node\|kvzalloc_node\|pci_alloc_consistent\|
    pci_zalloc_consistent\|kmem_alloc\|kmem_zalloc\|kmem_zone_alloc\|
    kmem_zone_zalloc\|vmalloc_node\|vzalloc_node\)(...)
diff --git a/scripts/coccinelle/api/alloc/pool_zalloc-simple.cocci b/scripts/coccinelle/api/alloc/pool_zalloc-simple.cocci
index 9b7eb32..9c61a23 100644
--- a/scripts/coccinelle/api/alloc/pool_zalloc-simple.cocci
+++ b/scripts/coccinelle/api/alloc/pool_zalloc-simple.cocci
@@ -1,7 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 ///
 /// Use *_pool_zalloc rather than *_pool_alloc followed by memset with 0
 ///
-// Copyright: (C) 2015 Intel Corp.  GPLv2.
+// Copyright: (C) 2015 Intel Corp.
 // Options: --no-includes --include-headers
 //
 // Keywords: dma_pool_zalloc, pci_pool_zalloc
diff --git a/scripts/coccinelle/api/alloc/zalloc-simple.cocci b/scripts/coccinelle/api/alloc/zalloc-simple.cocci
index d819275..26cda3f 100644
--- a/scripts/coccinelle/api/alloc/zalloc-simple.cocci
+++ b/scripts/coccinelle/api/alloc/zalloc-simple.cocci
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 ///
 /// Use zeroing allocator rather than allocator followed by memset with 0
 ///
@@ -6,9 +7,9 @@
 /// matched code has to be contiguous
 ///
 // Confidence: High
-// Copyright: (C) 2009-2010 Julia Lawall, Nicolas Palix, DIKU.  GPLv2.
-// Copyright: (C) 2009-2010 Gilles Muller, INRIA/LiP6.  GPLv2.
-// Copyright: (C) 2017 Himanshu Jha GPLv2.
+// Copyright: (C) 2009-2010 Julia Lawall, Nicolas Palix, DIKU.
+// Copyright: (C) 2009-2010 Gilles Muller, INRIA/LiP6.
+// Copyright: (C) 2017 Himanshu Jha
 // URL: http://coccinelle.lip6.fr/rules/kzalloc.html
 // Options: --no-includes --include-headers
 //
@@ -69,15 +70,6 @@
 - x = (T)vmalloc(E1);
 + x = (T)vzalloc(E1);
 |
-- x = dma_alloc_coherent(E2,E1,E3,E4);
-+ x = dma_zalloc_coherent(E2,E1,E3,E4);
-|
-- x = (T *)dma_alloc_coherent(E2,E1,E3,E4);
-+ x = dma_zalloc_coherent(E2,E1,E3,E4);
-|
-- x = (T)dma_alloc_coherent(E2,E1,E3,E4);
-+ x = (T)dma_zalloc_coherent(E2,E1,E3,E4);
-|
 - x = kmalloc_node(E1,E2,E3);
 + x = kzalloc_node(E1,E2,E3);
 |
@@ -225,7 +217,7 @@
 x << r2.x;
 @@
 
-msg="WARNING: dma_zalloc_coherent should be used for %s, instead of dma_alloc_coherent/memset" % (x)
+msg="WARNING: dma_alloc_coherent use in %s already zeroes out memory,  so memset is not needed" % (x)
 coccilib.report.print_report(p[0], msg)
 
 //-----------------------------------------------------------------
diff --git a/scripts/coccinelle/api/atomic_as_refcounter.cocci b/scripts/coccinelle/api/atomic_as_refcounter.cocci
index 988120e..0f78d94 100644
--- a/scripts/coccinelle/api/atomic_as_refcounter.cocci
+++ b/scripts/coccinelle/api/atomic_as_refcounter.cocci
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 // Check if refcount_t type and API should be used
 // instead of atomic_t type when dealing with refcounters
 //
diff --git a/scripts/coccinelle/api/check_bq27xxx_data.cocci b/scripts/coccinelle/api/check_bq27xxx_data.cocci
index 9212b85..fae539e 100644
--- a/scripts/coccinelle/api/check_bq27xxx_data.cocci
+++ b/scripts/coccinelle/api/check_bq27xxx_data.cocci
@@ -1,10 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /// Detect BQ27XXX_DATA structures with identical registers, dm registers or
 /// properties.
 //# Doesn't unfold macros used in register or property fields.
 //# Requires OCaml scripting
 ///
 // Confidence: High
-// Copyright: (C) 2017 Julia Lawall, Inria/LIP6, GPLv2.
+// Copyright: (C) 2017 Julia Lawall, Inria/LIP6,
 // URL: http://coccinelle.lip6.fr/
 // Requires: 1.0.7
 // Keywords: BQ27XXX_DATA
diff --git a/scripts/coccinelle/api/drm-get-put.cocci b/scripts/coccinelle/api/drm-get-put.cocci
deleted file mode 100644
index 3a09c97..0000000
--- a/scripts/coccinelle/api/drm-get-put.cocci
+++ /dev/null
@@ -1,78 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-///
-/// Use drm_*_get() and drm_*_put() helpers instead of drm_*_reference() and
-/// drm_*_unreference() helpers.
-///
-// Confidence: High
-// Copyright: (C) 2017 NVIDIA Corporation
-// Options: --no-includes --include-headers
-//
-
-virtual patch
-virtual report
-
-@depends on patch@
-expression object;
-@@
-
-(
-- drm_connector_reference(object)
-+ drm_connector_get(object)
-|
-- drm_connector_unreference(object)
-+ drm_connector_put(object)
-|
-- drm_framebuffer_reference(object)
-+ drm_framebuffer_get(object)
-|
-- drm_framebuffer_unreference(object)
-+ drm_framebuffer_put(object)
-|
-- drm_gem_object_reference(object)
-+ drm_gem_object_get(object)
-|
-- drm_gem_object_unreference(object)
-+ drm_gem_object_put(object)
-|
-- __drm_gem_object_unreference(object)
-+ __drm_gem_object_put(object)
-|
-- drm_gem_object_unreference_unlocked(object)
-+ drm_gem_object_put_unlocked(object)
-|
-- drm_dev_unref(object)
-+ drm_dev_put(object)
-)
-
-@r depends on report@
-expression object;
-position p;
-@@
-
-(
-drm_connector_unreference@p(object)
-|
-drm_connector_reference@p(object)
-|
-drm_framebuffer_unreference@p(object)
-|
-drm_framebuffer_reference@p(object)
-|
-drm_gem_object_unreference@p(object)
-|
-drm_gem_object_reference@p(object)
-|
-__drm_gem_object_unreference(object)
-|
-drm_gem_object_unreference_unlocked(object)
-|
-drm_dev_unref@p(object)
-)
-
-@script:python depends on report@
-object << r.object;
-p << r.p;
-@@
-
-msg="WARNING: use get/put helpers to reference and dereference %s" % (object)
-coccilib.report.print_report(p[0], msg)
diff --git a/scripts/coccinelle/api/err_cast.cocci b/scripts/coccinelle/api/err_cast.cocci
index 2ce1150..0e661c8 100644
--- a/scripts/coccinelle/api/err_cast.cocci
+++ b/scripts/coccinelle/api/err_cast.cocci
@@ -1,10 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0-only
 ///
 /// Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...))
 ///
 // Confidence: High
-// Copyright: (C) 2009, 2010 Nicolas Palix, DIKU.  GPLv2.
-// Copyright: (C) 2009, 2010 Julia Lawall, DIKU.  GPLv2.
-// Copyright: (C) 2009, 2010 Gilles Muller, INRIA/LiP6.  GPLv2.
+// Copyright: (C) 2009, 2010 Nicolas Palix, DIKU.
+// Copyright: (C) 2009, 2010 Julia Lawall, DIKU.
+// Copyright: (C) 2009, 2010 Gilles Muller, INRIA/LiP6.
 // URL: http://coccinelle.lip6.fr/
 // Options:
 //
diff --git a/scripts/coccinelle/api/kstrdup.cocci b/scripts/coccinelle/api/kstrdup.cocci
index 09cba54..19f2645 100644
--- a/scripts/coccinelle/api/kstrdup.cocci
+++ b/scripts/coccinelle/api/kstrdup.cocci
@@ -1,9 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /// Use kstrdup rather than duplicating its implementation
 ///
 // Confidence: High
-// Copyright: (C) 2010-2012 Nicolas Palix.  GPLv2.
-// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.  GPLv2.
-// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.  GPLv2.
+// Copyright: (C) 2010-2012 Nicolas Palix.
+// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.
+// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.
 // URL: http://coccinelle.lip6.fr/
 // Comments:
 // Options: --no-includes --include-headers
@@ -76,7 +77,7 @@
 p2 << r1.p2;
 @@
 
-cocci.print_main("WARNING opportunity for kstrdep",p1)
+cocci.print_main("WARNING opportunity for kstrdup",p1)
 cocci.print_secs("strcpy",p2)
 
 @script:python depends on org@
@@ -84,7 +85,7 @@
 p2 << r2.p2;
 @@
 
-cocci.print_main("WARNING opportunity for kstrdep",p1)
+cocci.print_main("WARNING opportunity for kstrdup",p1)
 cocci.print_secs("memcpy",p2)
 
 @script:python depends on report@
@@ -92,7 +93,7 @@
 p2 << r1.p2;
 @@
 
-msg = "WARNING opportunity for kstrdep (strcpy on line %s)" % (p2[0].line)
+msg = "WARNING opportunity for kstrdup (strcpy on line %s)" % (p2[0].line)
 coccilib.report.print_report(p1[0], msg)
 
 @script:python depends on report@
@@ -100,5 +101,5 @@
 p2 << r2.p2;
 @@
 
-msg = "WARNING opportunity for kstrdep (memcpy on line %s)" % (p2[0].line)
+msg = "WARNING opportunity for kstrdup (memcpy on line %s)" % (p2[0].line)
 coccilib.report.print_report(p1[0], msg)
diff --git a/scripts/coccinelle/api/memdup.cocci b/scripts/coccinelle/api/memdup.cocci
index 8fd6437..30b15df 100644
--- a/scripts/coccinelle/api/memdup.cocci
+++ b/scripts/coccinelle/api/memdup.cocci
@@ -1,9 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /// Use kmemdup rather than duplicating its implementation
 ///
 // Confidence: High
-// Copyright: (C) 2010-2012 Nicolas Palix.  GPLv2.
-// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.  GPLv2.
-// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.  GPLv2.
+// Copyright: (C) 2010-2012 Nicolas Palix.
+// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.
+// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.
 // URL: http://coccinelle.lip6.fr/
 // Comments:
 // Options: --no-includes --include-headers
diff --git a/scripts/coccinelle/api/memdup_user.cocci b/scripts/coccinelle/api/memdup_user.cocci
index 2a5aea8..c809ab1 100644
--- a/scripts/coccinelle/api/memdup_user.cocci
+++ b/scripts/coccinelle/api/memdup_user.cocci
@@ -1,10 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /// Use memdup_user rather than duplicating its implementation
 /// This is a little bit restricted to reduce false positives
 ///
 // Confidence: High
-// Copyright: (C) 2010-2012 Nicolas Palix.  GPLv2.
-// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.  GPLv2.
-// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.  GPLv2.
+// Copyright: (C) 2010-2012 Nicolas Palix.
+// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.
+// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.
 // URL: http://coccinelle.lip6.fr/
 // Comments:
 // Options: --no-includes --include-headers
diff --git a/scripts/coccinelle/api/platform_get_irq.cocci b/scripts/coccinelle/api/platform_get_irq.cocci
new file mode 100644
index 0000000..06b6a95
--- /dev/null
+++ b/scripts/coccinelle/api/platform_get_irq.cocci
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+/// Remove dev_err() messages after platform_get_irq*() failures
+//
+// Confidence: Medium
+// Options: --include-headers
+
+virtual patch
+virtual context
+virtual org
+virtual report
+
+@depends on context@
+expression ret;
+struct platform_device *E;
+@@
+
+ret =
+(
+platform_get_irq
+|
+platform_get_irq_byname
+)(E, ...);
+
+if ( \( ret < 0 \| ret <= 0 \) )
+{
+(
+if (ret != -EPROBE_DEFER)
+{ ...
+*dev_err(...);
+... }
+|
+...
+*dev_err(...);
+)
+...
+}
+
+@depends on patch@
+expression ret;
+struct platform_device *E;
+@@
+
+ret =
+(
+platform_get_irq
+|
+platform_get_irq_byname
+)(E, ...);
+
+if ( \( ret < 0 \| ret <= 0 \) )
+{
+(
+-if (ret != -EPROBE_DEFER)
+-{ ...
+-dev_err(...);
+-... }
+|
+...
+-dev_err(...);
+)
+...
+}
+
+@r depends on org || report@
+position p1;
+expression ret;
+struct platform_device *E;
+@@
+
+ret =
+(
+platform_get_irq
+|
+platform_get_irq_byname
+)(E, ...);
+
+if ( \( ret < 0 \| ret <= 0 \) )
+{
+(
+if (ret != -EPROBE_DEFER)
+{ ...
+dev_err@p1(...);
+... }
+|
+...
+dev_err@p1(...);
+)
+...
+}
+
+@script:python depends on org@
+p1 << r.p1;
+@@
+
+cocci.print_main(p1)
+
+@script:python depends on report@
+p1 << r.p1;
+@@
+
+msg = "line %s is redundant because platform_get_irq() already prints an error" % (p1[0].line)
+coccilib.report.print_report(p1[0],msg)
diff --git a/scripts/coccinelle/api/platform_no_drv_owner.cocci b/scripts/coccinelle/api/platform_no_drv_owner.cocci
index c5e3f73..8fa050e 100644
--- a/scripts/coccinelle/api/platform_no_drv_owner.cocci
+++ b/scripts/coccinelle/api/platform_no_drv_owner.cocci
@@ -1,7 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /// Remove .owner field if calls are used which set it automatically
 ///
 // Confidence: High
-// Copyright: (C) 2014 Wolfram Sang. GPL v2.
+// Copyright: (C) 2014 Wolfram Sang.
 
 virtual patch
 virtual context
diff --git a/scripts/coccinelle/api/pm_runtime.cocci b/scripts/coccinelle/api/pm_runtime.cocci
index d67ccf5..1ccce3f 100644
--- a/scripts/coccinelle/api/pm_runtime.cocci
+++ b/scripts/coccinelle/api/pm_runtime.cocci
@@ -1,8 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /// Make sure pm_runtime_* calls does not use unnecessary IS_ERR_VALUE
 ///
 // Keywords: pm_runtime
 // Confidence: Medium
-// Copyright (C) 2013 Texas Instruments Incorporated - GPLv2.
+// Copyright (C) 2013 Texas Instruments Incorporated -
 // URL: http://coccinelle.lip6.fr/
 // Options: --include-headers
 
diff --git a/scripts/coccinelle/api/ptr_ret.cocci b/scripts/coccinelle/api/ptr_ret.cocci
index dd58dab..e76cd5d 100644
--- a/scripts/coccinelle/api/ptr_ret.cocci
+++ b/scripts/coccinelle/api/ptr_ret.cocci
@@ -1,9 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 ///
 /// Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR
 ///
 // Confidence: High
-// Copyright: (C) 2012 Julia Lawall, INRIA/LIP6.  GPLv2.
-// Copyright: (C) 2012 Gilles Muller, INRIA/LiP6.  GPLv2.
+// Copyright: (C) 2012 Julia Lawall, INRIA/LIP6.
+// Copyright: (C) 2012 Gilles Muller, INRIA/LiP6.
 // URL: http://coccinelle.lip6.fr/
 // Options: --no-includes --include-headers
 //
diff --git a/scripts/coccinelle/api/resource_size.cocci b/scripts/coccinelle/api/resource_size.cocci
index 1935a58..a9a571a 100644
--- a/scripts/coccinelle/api/resource_size.cocci
+++ b/scripts/coccinelle/api/resource_size.cocci
@@ -1,11 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0-only
 ///
 /// Use resource_size function on resource object
 /// instead of explicit computation.
 ///
 //  Confidence: High
-//  Copyright: (C) 2009, 2010 Nicolas Palix, DIKU.  GPLv2.
-//  Copyright: (C) 2009, 2010 Julia Lawall, DIKU.  GPLv2.
-//  Copyright: (C) 2009, 2010 Gilles Muller, INRIA/LiP6.  GPLv2.
+//  Copyright: (C) 2009, 2010 Nicolas Palix, DIKU.
+//  Copyright: (C) 2009, 2010 Julia Lawall, DIKU.
+//  Copyright: (C) 2009, 2010 Gilles Muller, INRIA/LiP6.
 //  URL: http://coccinelle.lip6.fr/
 //  Options:
 //
diff --git a/scripts/coccinelle/api/stream_open.cocci b/scripts/coccinelle/api/stream_open.cocci
new file mode 100644
index 0000000..df00d66
--- /dev/null
+++ b/scripts/coccinelle/api/stream_open.cocci
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0
+// Author: Kirill Smelkov (kirr@nexedi.com)
+//
+// Search for stream-like files that are using nonseekable_open and convert
+// them to stream_open. A stream-like file is a file that does not use ppos in
+// its read and write. Rationale for the conversion is to avoid deadlock in
+// between read and write.
+
+virtual report
+virtual patch
+virtual explain  // explain decisions in the patch (SPFLAGS="-D explain")
+
+// stream-like reader & writer - ones that do not depend on f_pos.
+@ stream_reader @
+identifier readstream, ppos;
+identifier f, buf, len;
+type loff_t;
+@@
+  ssize_t readstream(struct file *f, char *buf, size_t len, loff_t *ppos)
+  {
+    ... when != ppos
+  }
+
+@ stream_writer @
+identifier writestream, ppos;
+identifier f, buf, len;
+type loff_t;
+@@
+  ssize_t writestream(struct file *f, const char *buf, size_t len, loff_t *ppos)
+  {
+    ... when != ppos
+  }
+
+
+// a function that blocks
+@ blocks @
+identifier block_f;
+identifier wait =~ "^wait_.*";
+@@
+  block_f(...) {
+    ... when exists
+    wait(...)
+    ... when exists
+  }
+
+// stream_reader that can block inside.
+//
+// XXX wait_* can be called not directly from current function (e.g. func -> f -> g -> wait())
+// XXX currently reader_blocks supports only direct and 1-level indirect cases.
+@ reader_blocks_direct @
+identifier stream_reader.readstream;
+identifier wait =~ "^wait_.*";
+@@
+  readstream(...)
+  {
+    ... when exists
+    wait(...)
+    ... when exists
+  }
+
+@ reader_blocks_1 @
+identifier stream_reader.readstream;
+identifier blocks.block_f;
+@@
+  readstream(...)
+  {
+    ... when exists
+    block_f(...)
+    ... when exists
+  }
+
+@ reader_blocks depends on reader_blocks_direct || reader_blocks_1 @
+identifier stream_reader.readstream;
+@@
+  readstream(...) {
+    ...
+  }
+
+
+// file_operations + whether they have _any_ .read, .write, .llseek ... at all.
+//
+// XXX add support for file_operations xxx[N] = ...	(sound/core/pcm_native.c)
+@ fops0 @
+identifier fops;
+@@
+  struct file_operations fops = {
+    ...
+  };
+
+@ has_read @
+identifier fops0.fops;
+identifier read_f;
+@@
+  struct file_operations fops = {
+    .read = read_f,
+  };
+
+@ has_read_iter @
+identifier fops0.fops;
+identifier read_iter_f;
+@@
+  struct file_operations fops = {
+    .read_iter = read_iter_f,
+  };
+
+@ has_write @
+identifier fops0.fops;
+identifier write_f;
+@@
+  struct file_operations fops = {
+    .write = write_f,
+  };
+
+@ has_write_iter @
+identifier fops0.fops;
+identifier write_iter_f;
+@@
+  struct file_operations fops = {
+    .write_iter = write_iter_f,
+  };
+
+@ has_llseek @
+identifier fops0.fops;
+identifier llseek_f;
+@@
+  struct file_operations fops = {
+    .llseek = llseek_f,
+  };
+
+@ has_no_llseek @
+identifier fops0.fops;
+@@
+  struct file_operations fops = {
+    .llseek = no_llseek,
+  };
+
+@ has_noop_llseek @
+identifier fops0.fops;
+@@
+  struct file_operations fops = {
+    .llseek = noop_llseek,
+  };
+
+@ has_mmap @
+identifier fops0.fops;
+identifier mmap_f;
+@@
+  struct file_operations fops = {
+    .mmap = mmap_f,
+  };
+
+@ has_copy_file_range @
+identifier fops0.fops;
+identifier copy_file_range_f;
+@@
+  struct file_operations fops = {
+    .copy_file_range = copy_file_range_f,
+  };
+
+@ has_remap_file_range @
+identifier fops0.fops;
+identifier remap_file_range_f;
+@@
+  struct file_operations fops = {
+    .remap_file_range = remap_file_range_f,
+  };
+
+@ has_splice_read @
+identifier fops0.fops;
+identifier splice_read_f;
+@@
+  struct file_operations fops = {
+    .splice_read = splice_read_f,
+  };
+
+@ has_splice_write @
+identifier fops0.fops;
+identifier splice_write_f;
+@@
+  struct file_operations fops = {
+    .splice_write = splice_write_f,
+  };
+
+
+// file_operations that is candidate for stream_open conversion - it does not
+// use mmap and other methods that assume @offset access to file.
+//
+// XXX for simplicity require no .{read/write}_iter and no .splice_{read/write} for now.
+// XXX maybe_steam.fops cannot be used in other rules - it gives "bad rule maybe_stream or bad variable fops".
+@ maybe_stream depends on (!has_llseek || has_no_llseek || has_noop_llseek) && !has_mmap && !has_copy_file_range && !has_remap_file_range && !has_read_iter && !has_write_iter && !has_splice_read && !has_splice_write @
+identifier fops0.fops;
+@@
+  struct file_operations fops = {
+  };
+
+
+// ---- conversions ----
+
+// XXX .open = nonseekable_open -> .open = stream_open
+// XXX .open = func -> openfunc -> nonseekable_open
+
+// read & write
+//
+// if both are used in the same file_operations together with an opener -
+// under that conditions we can use stream_open instead of nonseekable_open.
+@ fops_rw depends on maybe_stream @
+identifier fops0.fops, openfunc;
+identifier stream_reader.readstream;
+identifier stream_writer.writestream;
+@@
+  struct file_operations fops = {
+      .open  = openfunc,
+      .read  = readstream,
+      .write = writestream,
+  };
+
+@ report_rw depends on report @
+identifier fops_rw.openfunc;
+position p1;
+@@
+  openfunc(...) {
+    <...
+     nonseekable_open@p1
+    ...>
+  }
+
+@ script:python depends on report && reader_blocks @
+fops << fops0.fops;
+p << report_rw.p1;
+@@
+coccilib.report.print_report(p[0],
+  "ERROR: %s: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix." % (fops,))
+
+@ script:python depends on report && !reader_blocks @
+fops << fops0.fops;
+p << report_rw.p1;
+@@
+coccilib.report.print_report(p[0],
+  "WARNING: %s: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open." % (fops,))
+
+
+@ explain_rw_deadlocked depends on explain && reader_blocks @
+identifier fops_rw.openfunc;
+@@
+  openfunc(...) {
+    <...
+-    nonseekable_open
++    nonseekable_open /* read & write (was deadlock) */
+    ...>
+  }
+
+
+@ explain_rw_nodeadlock depends on explain && !reader_blocks @
+identifier fops_rw.openfunc;
+@@
+  openfunc(...) {
+    <...
+-    nonseekable_open
++    nonseekable_open /* read & write (no direct deadlock) */
+    ...>
+  }
+
+@ patch_rw depends on patch @
+identifier fops_rw.openfunc;
+@@
+  openfunc(...) {
+    <...
+-   nonseekable_open
++   stream_open
+    ...>
+  }
+
+
+// read, but not write
+@ fops_r depends on maybe_stream && !has_write @
+identifier fops0.fops, openfunc;
+identifier stream_reader.readstream;
+@@
+  struct file_operations fops = {
+      .open  = openfunc,
+      .read  = readstream,
+  };
+
+@ report_r depends on report @
+identifier fops_r.openfunc;
+position p1;
+@@
+  openfunc(...) {
+    <...
+    nonseekable_open@p1
+    ...>
+  }
+
+@ script:python depends on report @
+fops << fops0.fops;
+p << report_r.p1;
+@@
+coccilib.report.print_report(p[0],
+  "WARNING: %s: .read() has stream semantic; safe to change nonseekable_open -> stream_open." % (fops,))
+
+@ explain_r depends on explain @
+identifier fops_r.openfunc;
+@@
+  openfunc(...) {
+    <...
+-   nonseekable_open
++   nonseekable_open /* read only */
+    ...>
+  }
+
+@ patch_r depends on patch @
+identifier fops_r.openfunc;
+@@
+  openfunc(...) {
+    <...
+-   nonseekable_open
++   stream_open
+    ...>
+  }
+
+
+// write, but not read
+@ fops_w depends on maybe_stream && !has_read @
+identifier fops0.fops, openfunc;
+identifier stream_writer.writestream;
+@@
+  struct file_operations fops = {
+      .open  = openfunc,
+      .write = writestream,
+  };
+
+@ report_w depends on report @
+identifier fops_w.openfunc;
+position p1;
+@@
+  openfunc(...) {
+    <...
+    nonseekable_open@p1
+    ...>
+  }
+
+@ script:python depends on report @
+fops << fops0.fops;
+p << report_w.p1;
+@@
+coccilib.report.print_report(p[0],
+  "WARNING: %s: .write() has stream semantic; safe to change nonseekable_open -> stream_open." % (fops,))
+
+@ explain_w depends on explain @
+identifier fops_w.openfunc;
+@@
+  openfunc(...) {
+    <...
+-   nonseekable_open
++   nonseekable_open /* write only */
+    ...>
+  }
+
+@ patch_w depends on patch @
+identifier fops_w.openfunc;
+@@
+  openfunc(...) {
+    <...
+-   nonseekable_open
++   stream_open
+    ...>
+  }
+
+
+// no read, no write - don't change anything