+++ Miroslav Benes [16/12/15 13:02 +0100]:
On Mon, 30 Nov 2015, Jessica Yu wrote:Livepatch needs to utilize the symbol information contained in the mod_arch_specific struct in order to be able to call the s390 apply_relocate_add() function to apply relocations. Remove the redundant vfree() in module_finalize() since module_arch_freeing_init() (which also frees said structures) is called in do_init_module(). Keep a reference to syminfo if the module is a livepatch module and free the structures in module_arch_cleanup(). If the module isn't a livepatch module, we free the structures in module_arch_freeing_init() as usual. Signed-off-by: Jessica Yu <jeyu@xxxxxxxxxx> --- arch/s390/kernel/module.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c index 0c1a679..17a1979 100644 --- a/arch/s390/kernel/module.c +++ b/arch/s390/kernel/module.c @@ -51,6 +51,9 @@ void *module_alloc(unsigned long size) void module_arch_freeing_init(struct module *mod) { + if (mod->klp) + return; + vfree(mod->arch.syminfo); mod->arch.syminfo = NULL; }Hm, this is problematic. module_arch_freeing_init() is called from module_deallocate() and this is called in the error path in load_module(). So if there was an error during load_module() of livepatch module which led to free_modinfo label or behind mod->arch.syminfo would not be freed at all. module_arch_cleanup() is called earlier under free_arch_cleanup.
Gah. Good catch. How about we add an additional check to see if mod->state is MODULE_STATE_LIVE? If so, we can return. This means we're coming from do_init_module(). If module_arch_freeing_init() was called and the module was in a state other than MODULE_STATE_LIVE (UNFORMED, GOING, COMING), we know we need to free. Think that would work? Jessica -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
