hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7W46D
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Livepatch allows users to call hook functions to perform some customized operations when insmod the .ko. During the test, it is found that in the ARM64 architecture, if accesses the global variables defined by other ko in hook functions, a crash occurs.
Since relocation is performed during the livepatch insertion, instructions in the icache should be invalid. If the instructions in the icache are directly obtained, incorrect addresses may be obtained, caseing crash. Therefore, flush the icache before calling the hook functions.
Signed-off-by: Ye Weihua yeweihua4@huawei.com Signed-off-by: Zheng Yejian zhengyejian1@huawei.com --- include/linux/moduleloader.h | 2 ++ kernel/livepatch/core.c | 1 + kernel/module/main.c | 2 +- 3 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h index 5b28855880d0..ead55b77a10d 100644 --- a/include/linux/moduleloader.h +++ b/include/linux/moduleloader.h @@ -116,6 +116,8 @@ void module_arch_cleanup(struct module *mod); /* Any cleanup before freeing mod->module_init */ void module_arch_freeing_init(struct module *mod);
+void flush_module_icache(const struct module *mod); + #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \ !defined(CONFIG_KASAN_VMALLOC) #include <linux/kasan.h> diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 34b15dc37f07..18df34068ba0 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -1061,6 +1061,7 @@ static int klp_init_patch(struct klp_patch *patch) }
#ifdef CONFIG_LIVEPATCH_WO_FTRACE + flush_module_icache(patch->mod); set_mod_klp_rel_state(patch->mod, MODULE_KLP_REL_DONE); ret = jump_label_register(patch->mod); if (ret) { diff --git a/kernel/module/main.c b/kernel/module/main.c index a403003d393c..2519d900e591 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -2316,7 +2316,7 @@ static int check_export_symbol_versions(struct module *mod) return 0; }
-static void flush_module_icache(const struct module *mod) +void flush_module_icache(const struct module *mod) { /* * Flush the instruction cache, since we've played with text.