diff mbox series

[RFC,05/12] module: Move arch strict rwx support to a separate file

Message ID 20211228213041.1356334-6-atomlin@redhat.com (mailing list archive)
State Superseded
Headers show
Series module: core code clean up | expand

Commit Message

Aaron Tomlin Dec. 28, 2021, 9:30 p.m. UTC 
No functional change.

This patch migrates applicable architecture code
that support strict module rwx from core module code
into kernel/module/arch_strict_rwx.c

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 include/linux/module.h          | 16 +++++++++++
 kernel/module/Makefile          |  1 +
 kernel/module/arch_strict_rwx.c | 44 ++++++++++++++++++++++++++++
 kernel/module/main.c            | 51 ---------------------------------
 4 files changed, 61 insertions(+), 51 deletions(-)
 create mode 100644 kernel/module/arch_strict_rwx.c

Comments

Luis Chamberlain Jan. 12, 2022, 4:13 p.m. UTC | #1 
On Tue, Dec 28, 2021 at 09:30:34PM +0000, Aaron Tomlin wrote:
> diff --git a/kernel/module/Makefile b/kernel/module/Makefile
> index 9d593362156d..95fad95a0549 100644
> --- a/kernel/module/Makefile
> +++ b/kernel/module/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_MODULE_SIG) += signing.o
>  obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
>  obj-$(CONFIG_LIVEPATCH) += livepatch.o
>  obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
> +obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
> diff --git a/kernel/module/arch_strict_rwx.c b/kernel/module/arch_strict_rwx.c
> new file mode 100644
> index 000000000000..68e970671ec5
> --- /dev/null
> +++ b/kernel/module/arch_strict_rwx.c
> @@ -0,0 +1,44 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * kernel/module/arch_strict_rwx.c - module arch strict rwx

No need to repeat the name of the file, a simple:

+ * module arch strict rwx

Would do it.

Please get 0day to test your git tree as you work on it, and before
posting patches ensure they get tested by 0day, so we run into less
issues once merged into modules-next.

  Luis
diff mbox series

Patch

diff --git a/include/linux/module.h b/include/linux/module.h
index 8b4d254a84c0..caa7212cf754 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -338,6 +338,22 @@  struct module_layout {
 #endif
 };
 
+/*
+ * Modules' sections will be aligned on page boundaries
+ * to ensure complete separation of code and data, but
+ * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
+ */
+#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
+# define debug_align(X) ALIGN(X, PAGE_SIZE)
+
+extern void frob_text(const struct module_layout *layout, int (*set_memory)(unsigned long start, int num_pages));
+extern void module_enable_x(const struct module *mod);
+#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+# define debug_align(X) (X)
+
+static void module_enable_x(const struct module *mod) { }
+#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+
 #ifdef CONFIG_MODULES_TREE_LOOKUP
 struct mod_tree_root {
 	struct latch_tree_root root;
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 9d593362156d..95fad95a0549 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -8,3 +8,4 @@  obj-$(CONFIG_MODULE_SIG) += signing.o
 obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
 obj-$(CONFIG_LIVEPATCH) += livepatch.o
 obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
+obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
diff --git a/kernel/module/arch_strict_rwx.c b/kernel/module/arch_strict_rwx.c
new file mode 100644
index 000000000000..68e970671ec5
--- /dev/null
+++ b/kernel/module/arch_strict_rwx.c
@@ -0,0 +1,44 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * kernel/module/arch_strict_rwx.c - module arch strict rwx
+ *
+ * Copyright (C) 2015 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/set_memory.h>
+
+/*
+ * LKM RO/NX protection: protect module's text/ro-data
+ * from modification and any data from execution.
+ *
+ * General layout of module is:
+ *          [text] [read-only-data] [ro-after-init] [writable data]
+ * text_size -----^                ^               ^               ^
+ * ro_size ------------------------|               |               |
+ * ro_after_init_size -----------------------------|               |
+ * size -----------------------------------------------------------|
+ *
+ * These values are always page-aligned (as is base)
+ */
+
+/*
+ * Since some arches are moving towards PAGE_KERNEL module allocations instead
+ * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
+ * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
+ * whether we are strict.
+ */
+void frob_text(const struct module_layout *layout,
+		      int (*set_memory)(unsigned long start, int num_pages))
+{
+	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
+	BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
+	set_memory((unsigned long)layout->base,
+		   layout->text_size >> PAGE_SHIFT);
+}
+
+void module_enable_x(const struct module *mod)
+{
+	frob_text(&mod->core_layout, set_memory_x);
+	frob_text(&mod->init_layout, set_memory_x);
+}
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 692cc520420d..a0619256b343 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -13,7 +13,6 @@ 
 #include <linux/trace_events.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
-#include <linux/buildid.h>
 #include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/sysfs.h>
@@ -63,17 +62,6 @@ 
 #define CREATE_TRACE_POINTS
 #include <trace/events/module.h>
 
-/*
- * Modules' sections will be aligned on page boundaries
- * to ensure complete separation of code and data, but
- * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
- */
-#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
-# define debug_align(X) ALIGN(X, PAGE_SIZE)
-#else
-# define debug_align(X) (X)
-#endif
-
 /*
  * Mutex protects:
  * 1) List of modules (also safely readable with preempt_disable),
@@ -1786,45 +1774,6 @@  static void mod_sysfs_teardown(struct module *mod)
 	mod_sysfs_fini(mod);
 }
 
-/*
- * LKM RO/NX protection: protect module's text/ro-data
- * from modification and any data from execution.
- *
- * General layout of module is:
- *          [text] [read-only-data] [ro-after-init] [writable data]
- * text_size -----^                ^               ^               ^
- * ro_size ------------------------|               |               |
- * ro_after_init_size -----------------------------|               |
- * size -----------------------------------------------------------|
- *
- * These values are always page-aligned (as is base)
- */
-
-/*
- * Since some arches are moving towards PAGE_KERNEL module allocations instead
- * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
- * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
- * whether we are strict.
- */
-#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
-static void frob_text(const struct module_layout *layout,
-		      int (*set_memory)(unsigned long start, int num_pages))
-{
-	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
-	BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
-	set_memory((unsigned long)layout->base,
-		   layout->text_size >> PAGE_SHIFT);
-}
-
-static void module_enable_x(const struct module *mod)
-{
-	frob_text(&mod->core_layout, set_memory_x);
-	frob_text(&mod->init_layout, set_memory_x);
-}
-#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-static void module_enable_x(const struct module *mod) { }
-#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-
 #ifdef CONFIG_STRICT_MODULE_RWX
 static void frob_rodata(const struct module_layout *layout,
 			int (*set_memory)(unsigned long start, int num_pages))