Re: [PATCH 4/7] Ksplice: Add module_data_address (the analogue of module_text_address)

Anders Kaseorg
2009-02-04T20:49:37Z

On Wed, 4 Feb 2009, Rusty Russell wrote:
> Does this mean you really want module_data_address, or you actually want
> a module_address()?

Yeah, that works better.

diff --git a/include/linux/module.h b/include/linux/module.h
index ccbcfa7..42e7c8a 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -363,8 +363,8 @@ static inline int module_is_live(struct module *mod)
/* Is this address in a module? (second is with no locks, for oops) */
struct module *module_text_address(unsigned long addr);
struct module *__module_text_address(unsigned long addr);
-struct module *module_data_address(unsigned long addr);
-struct module *__module_data_address(unsigned long addr);
+struct module *module_address(unsigned long addr);
+struct module *__module_address(unsigned long addr);
int is_module_address(unsigned long addr);

static inline int within_module_core(unsigned long addr, struct module *mod)
diff --git a/kernel/module.c b/kernel/module.c
index b47772d..556112c 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2773,35 +2773,32 @@ struct module *module_text_address(unsigned long addr)
}
EXPORT_SYMBOL_GPL(module_text_address);

-struct module *__module_data_address(unsigned long addr)
+__notrace_funcgraph struct module *__module_address(unsigned long addr)
{
struct module *mod;

if (addr < module_addr_min || addr > module_addr_max)
return NULL;

- list_for_each_entry(mod, &modules, list) {
- if (within(addr, mod->module_core + mod->core_text_size,
- mod->core_size - mod->core_text_size) ||
- within(addr, mod->module_init + mod->init_text_size,
- mod->init_size - mod->init_text_size))
+ list_for_each_entry_rcu(mod, &modules, list)
+ if (within_module_core(addr, mod) ||
+ within_module_init(addr, mod))
return mod;
- }
return NULL;
}
-EXPORT_SYMBOL_GPL(__module_data_address);
+EXPORT_SYMBOL_GPL(__module_address);

-struct module *module_data_address(unsigned long addr)
+struct module *module_address(unsigned long addr)
{
struct module *mod;

preempt_disable();
- mod = __module_data_address(addr);
+ mod = __module_address(addr);
preempt_enable();

return mod;
}
-EXPORT_SYMBOL_GPL(module_data_address);
+EXPORT_SYMBOL_GPL(module_address);

/* Don't grab lock, we're oopsing. */
void print_modules(void)
diff --git a/kernel/ksplice.c b/kernel/ksplice.c
index a3f21a6..0404e46 100644
--- a/kernel/ksplice.c
+++ b/kernel/ksplice.c
@@ -999,8 +999,7 @@ static void *map_writable(void *addr, size_t len)
int nr_pages = 2;
struct page *pages[2];

- if (__module_text_address((unsigned long)addr) == NULL &&
- __module_data_address((unsigned long)addr) == NULL) {
+ if (__module_address((unsigned long)addr) == NULL) {
pages[0] = virt_to_page(addr);
WARN_ON(!PageReserved(pages[0]));
pages[1] = virt_to_page(addr + PAGE_SIZE);
@@ -1412,13 +1411,8 @@ static abort_t try_addr(struct ksplice_pack *pack,
enum run_pre_mode mode)
{
abort_t ret;
- const struct module *run_module;
+ const struct module *run_module = __module_address(run_addr);

- if ((sect->flags & KSPLICE_SECTION_RODATA) != 0 ||
- (sect->flags & KSPLICE_SECTION_DATA) != 0)
- run_module = __module_data_address(run_addr);
- else
- run_module = __module_text_address(run_addr);
if (run_module == pack->primary) {
ksdebug(pack, "run-pre: unexpected address %lx in primary "
"module %s for sect %s\n", run_addr, run_module->name,