mm/slab: make __free(kfree) accept error pointers

jira LE-3587
Rebuild_History Non-Buildable kernel-4.18.0-553.62.1.el8_10
commit-author Dan Carpenter <[email protected]>
commit cd7eb8f
Empty-Commit: Cherry-Pick Conflicts during history rebuild.
Will be included in final tarball splat. Ref for failed cherry-pick at:
ciq/ciq_backports/kernel-4.18.0-553.62.1.el8_10/cd7eb8f8.failed

Currently, if an automatically freed allocation is an error pointer that
will lead to a crash.  An example of this is in wm831x_gpio_dbg_show().

   171	char *label __free(kfree) = gpiochip_dup_line_label(chip, i);
   172	if (IS_ERR(label)) {
   173		dev_err(wm831x->dev, "Failed to duplicate label\n");
   174		continue;
   175  }

The auto clean up function should check for error pointers as well,
otherwise we're going to keep hitting issues like this.

Fixes: 54da6a0 ("locking: Introduce __cleanup() based infrastructure")
	Cc: <[email protected]>
	Signed-off-by: Dan Carpenter <[email protected]>
	Acked-by: David Rientjes <[email protected]>
	Signed-off-by: Vlastimil Babka <[email protected]>
(cherry picked from commit cd7eb8f)
	Signed-off-by: Jonathan Maple <[email protected]>

# Conflicts:
#	include/linux/slab.h

Author: PlaidCat

ciq/ciq_backports/kernel-4.18.0-553.62.1.el8_10/cd7eb8f8.failed

@@ -0,0 +1,75 @@
+mm/slab: make __free(kfree) accept error pointers
+
+jira LE-3587
+Rebuild_History Non-Buildable kernel-4.18.0-553.62.1.el8_10
+commit-author Dan Carpenter <[email protected]>
+commit cd7eb8f83fcf258f71e293f7fc52a70be8ed0128
+Empty-Commit: Cherry-Pick Conflicts during history rebuild.
+Will be included in final tarball splat. Ref for failed cherry-pick at:
+ciq/ciq_backports/kernel-4.18.0-553.62.1.el8_10/cd7eb8f8.failed
+
+Currently, if an automatically freed allocation is an error pointer that
+will lead to a crash.  An example of this is in wm831x_gpio_dbg_show().
+
+   171	char *label __free(kfree) = gpiochip_dup_line_label(chip, i);
+   172	if (IS_ERR(label)) {
+   173		dev_err(wm831x->dev, "Failed to duplicate label\n");
+   174		continue;
+   175  }
+
+The auto clean up function should check for error pointers as well,
+otherwise we're going to keep hitting issues like this.
+
+Fixes: 54da6a092431 ("locking: Introduce __cleanup() based infrastructure")
+	Cc: <[email protected]>
+	Signed-off-by: Dan Carpenter <[email protected]>
+	Acked-by: David Rientjes <[email protected]>
+	Signed-off-by: Vlastimil Babka <[email protected]>
+(cherry picked from commit cd7eb8f83fcf258f71e293f7fc52a70be8ed0128)
+	Signed-off-by: Jonathan Maple <[email protected]>
+
+# Conflicts:
+#	include/linux/slab.h
+diff --cc include/linux/slab.h
+index 7cec7ba2bcd8,739b21262507..000000000000
+--- a/include/linux/slab.h
++++ b/include/linux/slab.h
+@@@ -185,11 -261,12 +185,20 @@@ int kmem_cache_shrink(struct kmem_cach
+  /*
+   * Common kmalloc functions provided by all allocators
+   */
+++<<<<<<< HEAD
+ +void * __must_check __krealloc(const void *, size_t, gfp_t);
+ +void * __must_check krealloc(const void *, size_t, gfp_t);
+ +void kfree(const void *);
+ +void kfree_sensitive(const void *);
+ +size_t __ksize(const void *);
+++=======
++ void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __realloc_size(2);
++ void kfree(const void *objp);
++ void kfree_sensitive(const void *objp);
++ size_t __ksize(const void *objp);
++ 
++ DEFINE_FREE(kfree, void *, if (!IS_ERR_OR_NULL(_T)) kfree(_T))
+++>>>>>>> cd7eb8f83fcf (mm/slab: make __free(kfree) accept error pointers)
+  
+  /**
+   * ksize - Report actual allocation size of associated object
+@@@ -772,9 -789,11 +781,14 @@@ static inline void *kvcalloc(size_t n, 
+  	return kvmalloc_array(n, size, flags | __GFP_ZERO);
+  }
+  
+ -extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
+ -		      __realloc_size(3);
+ +extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize,
+ +		gfp_t flags);
+  extern void kvfree(const void *addr);
+++<<<<<<< HEAD
+++=======
++ DEFINE_FREE(kvfree, void *, if (!IS_ERR_OR_NULL(_T)) kvfree(_T))
++ 
+++>>>>>>> cd7eb8f83fcf (mm/slab: make __free(kfree) accept error pointers)
+  extern void kvfree_sensitive(const void *addr, size_t len);
+  
+  unsigned int kmem_cache_size(struct kmem_cache *s);
+* Unmerged path include/linux/slab.h