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authorChristophe Leroy <christophe.leroy@csgroup.eu>2022-02-23 10:01:00 +0100
committerLuis Chamberlain <mcgrof@kernel.org>2022-04-05 08:43:04 -0700
commitef505058dc5524488a84423b4d5e8a7598a23a2e (patch)
tree335a6a86daae4db2d7bf305df6439fa4bf53dbb6 /kernel/module/strict_rwx.c
parent32a08c17d8096f0fd2c6600bc5fe8464aaf68ea7 (diff)
downloadlinux-ef505058dc5524488a84423b4d5e8a7598a23a2e.tar.bz2
module: Rework layout alignment to avoid BUG_ON()s
Perform layout alignment verification up front and WARN_ON() and fail module loading instead of crashing the machine. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Diffstat (limited to 'kernel/module/strict_rwx.c')
-rw-r--r--kernel/module/strict_rwx.c27
1 files changed, 18 insertions, 9 deletions
diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c
index 43332b4416b0..f36ea54c1dac 100644
--- a/kernel/module/strict_rwx.c
+++ b/kernel/module/strict_rwx.c
@@ -42,9 +42,6 @@ static void frob_text(const struct module_layout *layout,
static void frob_rodata(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
{
- BUG_ON(!PAGE_ALIGNED(layout->base));
- BUG_ON(!PAGE_ALIGNED(layout->text_size));
- BUG_ON(!PAGE_ALIGNED(layout->ro_size));
set_memory((unsigned long)layout->base + layout->text_size,
(layout->ro_size - layout->text_size) >> PAGE_SHIFT);
}
@@ -52,9 +49,6 @@ static void frob_rodata(const struct module_layout *layout,
static void frob_ro_after_init(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
{
- BUG_ON(!PAGE_ALIGNED(layout->base));
- BUG_ON(!PAGE_ALIGNED(layout->ro_size));
- BUG_ON(!PAGE_ALIGNED(layout->ro_after_init_size));
set_memory((unsigned long)layout->base + layout->ro_size,
(layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
}
@@ -62,13 +56,28 @@ static void frob_ro_after_init(const struct module_layout *layout,
static void frob_writable_data(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
{
- BUG_ON(!PAGE_ALIGNED(layout->base));
- BUG_ON(!PAGE_ALIGNED(layout->ro_after_init_size));
- BUG_ON(!PAGE_ALIGNED(layout->size));
set_memory((unsigned long)layout->base + layout->ro_after_init_size,
(layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
}
+static bool layout_check_misalignment(const struct module_layout *layout)
+{
+ return WARN_ON(!PAGE_ALIGNED(layout->base)) ||
+ WARN_ON(!PAGE_ALIGNED(layout->text_size)) ||
+ WARN_ON(!PAGE_ALIGNED(layout->ro_size)) ||
+ WARN_ON(!PAGE_ALIGNED(layout->ro_after_init_size)) ||
+ WARN_ON(!PAGE_ALIGNED(layout->size));
+}
+
+bool module_check_misalignment(const struct module *mod)
+{
+ if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
+ return false;
+
+ return layout_check_misalignment(&mod->core_layout) ||
+ layout_check_misalignment(&mod->init_layout);
+}
+
void module_enable_x(const struct module *mod)
{
if (!PAGE_ALIGNED(mod->core_layout.base) ||