mm/execmem, arch: convert remaining overrides of module_alloc to execmem

Extend execmem parameters to accommodate more complex overrides of
module_alloc() by architectures.

This includes specification of a fallback range required by arm, arm64
and powerpc, EXECMEM_MODULE_DATA type required by powerpc, support for
allocation of KASAN shadow required by s390 and x86 and support for
late initialization of execmem required by arm64.

The core implementation of execmem_alloc() takes care of suppressing
warnings when the initial allocation fails but there is a fallback range
defined.

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Tested-by: Liviu Dudau <liviu@dudau.co.uk>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

1 files changed, 29 insertions, 1 deletions

diff --git a/include/linux/execmem.h b/include/linux/execmem.h
index 96fc59258467..32cef1144117 100644
--- a/include/linux/execmem.h
+++ b/include/linux/execmem.h
@@ -5,6 +5,14 @@
 #include <linux/types.h>
 #include <linux/moduleloader.h>
 
+#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
+		!defined(CONFIG_KASAN_VMALLOC)
+#include <linux/kasan.h>
+#define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
+#else
+#define MODULE_ALIGN PAGE_SIZE
+#endif
+
 /**
  * enum execmem_type - types of executable memory ranges
  *
@@ -22,6 +30,7 @@
  * @EXECMEM_KPROBES: parameters for kprobes
  * @EXECMEM_FTRACE: parameters for ftrace
  * @EXECMEM_BPF: parameters for BPF
+ * @EXECMEM_MODULE_DATA: parameters for module data sections
  * @EXECMEM_TYPE_MAX:
  */
 enum execmem_type {
@@ -30,22 +39,38 @@ enum execmem_type {
 	EXECMEM_KPROBES,
 	EXECMEM_FTRACE,
 	EXECMEM_BPF,
+	EXECMEM_MODULE_DATA,
 	EXECMEM_TYPE_MAX,
 };
 
 /**
+ * enum execmem_range_flags - options for executable memory allocations
+ * @EXECMEM_KASAN_SHADOW:	allocate kasan shadow
+ */
+enum execmem_range_flags {
+	EXECMEM_KASAN_SHADOW	= (1 << 0),
+};
+
+/**
  * struct execmem_range - definition of an address space suitable for code and
  *			  related data allocations
  * @start:	address space start
  * @end:	address space end (inclusive)
+ * @fallback_start: start of the secondary address space range for fallback
+ *                  allocations on architectures that require it
+ * @fallback_end:   start of the secondary address space (inclusive)
  * @pgprot:	permissions for memory in this address space
  * @alignment:	alignment required for text allocations
+ * @flags:	options for memory allocations for this range
  */
 struct execmem_range {
 	unsigned long   start;
 	unsigned long   end;
+	unsigned long   fallback_start;
+	unsigned long   fallback_end;
 	pgprot_t        pgprot;
 	unsigned int	alignment;
+	enum execmem_range_flags flags;
 };
 
 /**
@@ -82,6 +107,9 @@ struct execmem_info *execmem_arch_setup(void);
  * Allocates memory that will contain executable code, either generated or
  * loaded from kernel modules.
  *
+ * Allocates memory that will contain data coupled with executable code,
+ * like data sections in kernel modules.
+ *
  * The memory will have protections defined by architecture for executable
  * region of the @type.
  *
@@ -95,7 +123,7 @@ void *execmem_alloc(enum execmem_type type, size_t size);
  */
 void execmem_free(void *ptr);
 
-#ifdef CONFIG_EXECMEM
+#if defined(CONFIG_EXECMEM) && !defined(CONFIG_ARCH_WANTS_EXECMEM_LATE)
 void execmem_init(void);
 #else
 static inline void execmem_init(void) {}