[PATCH 07/32] mm: Bring back vmalloc_exec

[Kent Overstreet <kent.overstreet@linux.dev>]

From: Kent Overstreet <kent.overstreet@gmail.com>

This is needed for bcachefs, which dynamically generates per-btree node
unpack functions.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: linux-mm@kvack.org
---
 include/linux/vmalloc.h |  1 +
 kernel/module/main.c    |  4 +---
 mm/nommu.c              | 18 ++++++++++++++++++
 mm/vmalloc.c            | 21 +++++++++++++++++++++
 4 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 69250efa03..ff147fe115 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -145,6 +145,7 @@ extern void *vzalloc(unsigned long size) __alloc_size(1);
 extern void *vmalloc_user(unsigned long size) __alloc_size(1);
 extern void *vmalloc_node(unsigned long size, int node) __alloc_size(1);
 extern void *vzalloc_node(unsigned long size, int node) __alloc_size(1);
+extern void *vmalloc_exec(unsigned long size, gfp_t gfp_mask) __alloc_size(1);
 extern void *vmalloc_32(unsigned long size) __alloc_size(1);
 extern void *vmalloc_32_user(unsigned long size) __alloc_size(1);
 extern void *__vmalloc(unsigned long size, gfp_t gfp_mask) __alloc_size(1);
diff --git a/kernel/module/main.c b/kernel/module/main.c
index d3be89de70..9eaa89e84c 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1607,9 +1607,7 @@ static void dynamic_debug_remove(struct module *mod, struct _ddebug_info *dyndbg
 
 void * __weak module_alloc(unsigned long size)
 {
-	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
-			GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
-			NUMA_NO_NODE, __builtin_return_address(0));
+	return vmalloc_exec(size, GFP_KERNEL);
 }
 
 bool __weak module_init_section(const char *name)
diff --git a/mm/nommu.c b/mm/nommu.c
index 57ba243c6a..8d9ab19e39 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -280,6 +280,24 @@ void *vzalloc_node(unsigned long size, int node)
 }
 EXPORT_SYMBOL(vzalloc_node);
 
+/**
+ *	vmalloc_exec  -  allocate virtually contiguous, executable memory
+ *	@size:		allocation size
+ *
+ *	Kernel-internal function to allocate enough pages to cover @size
+ *	the page level allocator and map them into contiguous and
+ *	executable kernel virtual space.
+ *
+ *	For tight control over page level allocator and protection flags
+ *	use __vmalloc() instead.
+ */
+
+void *vmalloc_exec(unsigned long size, gfp_t gfp_mask)
+{
+	return __vmalloc(size, gfp_mask);
+}
+EXPORT_SYMBOL_GPL(vmalloc_exec);
+
 /**
  * vmalloc_32  -  allocate virtually contiguous memory (32bit addressable)
  *	@size:		allocation size
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 31ff782d36..2ebb9ea7f0 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3401,6 +3401,27 @@ void *vzalloc_node(unsigned long size, int node)
 }
 EXPORT_SYMBOL(vzalloc_node);
 
+/**
+ * vmalloc_exec - allocate virtually contiguous, executable memory
+ * @size:	  allocation size
+ *
+ * Kernel-internal function to allocate enough pages to cover @size
+ * the page level allocator and map them into contiguous and
+ * executable kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+void *vmalloc_exec(unsigned long size, gfp_t gfp_mask)
+{
+	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
+			gfp_mask, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
+			NUMA_NO_NODE, __builtin_return_address(0));
+}
+EXPORT_SYMBOL_GPL(vmalloc_exec);
+
 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
 #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
-- 
2.40.1