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authorJessica Yu <jeyu@kernel.org>2019-07-23 15:26:28 +0200
committerJessica Yu <jeyu@kernel.org>2019-07-30 10:35:23 +0200
commit38f054d549a869f22a02224cd276a27bf14b6171 (patch)
tree4318fc573fcb3d013d681c45e7a781f36e8dd13d /kernel
parent5f9e832c137075045d15cd6899ab0505cfb2ca4b (diff)
downloadlinux-38f054d549a869f22a02224cd276a27bf14b6171.tar.bz2
modules: always page-align module section allocations
Some arches (e.g., arm64, x86) have moved towards non-executable module_alloc() allocations for security hardening reasons. That means that the module loader will need to set the text section of a module to executable, regardless of whether or not CONFIG_STRICT_MODULE_RWX is set. When CONFIG_STRICT_MODULE_RWX=y, module section allocations are always page-aligned to handle memory rwx permissions. On some arches with CONFIG_STRICT_MODULE_RWX=n however, when setting the module text to executable, the BUG_ON() in frob_text() gets triggered since module section allocations are not page-aligned when CONFIG_STRICT_MODULE_RWX=n. Since the set_memory_* API works with pages, and since we need to call set_memory_x() regardless of whether CONFIG_STRICT_MODULE_RWX is set, we might as well page-align all module section allocations for ease of managing rwx permissions of module sections (text, rodata, etc). Fixes: 2eef1399a866 ("modules: fix BUG when load module with rodata=n") Reported-by: Martin Kaiser <lists@kaiser.cx> Reported-by: Bartosz Golaszewski <brgl@bgdev.pl> Tested-by: David Lechner <david@lechnology.com> Tested-by: Martin Kaiser <martin@kaiser.cx> Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/module.c7
1 files changed, 1 insertions, 6 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 5933395af9a0..cd8df516666d 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -64,14 +64,9 @@
/*
* Modules' sections will be aligned on page boundaries
- * to ensure complete separation of code and data, but
- * only when CONFIG_STRICT_MODULE_RWX=y
+ * to ensure complete separation of code and data
*/
-#ifdef CONFIG_STRICT_MODULE_RWX
# define debug_align(X) ALIGN(X, PAGE_SIZE)
-#else
-# define debug_align(X) (X)
-#endif
/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))