From: Jessica Yu jeyu@kernel.org
stable inclusion from stable-v5.10.118 commit 56642f6af2ab3f9a4c77cc5e97ba61b9b46aa92d category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L686
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 055f23b74b20f2824ce33047b4cf2e2aa856bf3b upstream.
Previously, when CONFIG_MODULE_UNLOAD=n, the module loader just does not attempt to load exit sections since it never expects that any code in those sections will ever execute. However, dynamic code patching (alternatives, jump_label and static_call) can have sites in __exit code, even if __exit is never executed. Therefore __exit must be present at runtime, at least for as long as __init code is.
Commit 33121347fb1c ("module: treat exit sections the same as init sections when !CONFIG_MODULE_UNLOAD") solves the requirements of jump_labels and static_calls by putting the exit sections in the init region of the module so that they are at least present at init, and discarded afterwards. It does this by including a check for exit sections in module_init_section(), so that it also returns true for exit sections, and the module loader will automatically sort them in the init region of the module.
However, the solution there was not completely arch-independent. ARM is a special case where it supplies its own module_{init, exit}_section() functions. Instead of pushing the exit section checks into module_init_section(), just implement the exit section check in layout_sections(), so that we don't have to touch arch-dependent code.
Fixes: 33121347fb1c ("module: treat exit sections the same as init sections when !CONFIG_MODULE_UNLOAD") Reviewed-by: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: Jessica Yu jeyu@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- kernel/module.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c index de90f989c558..3934ecaf19f7 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2292,6 +2292,15 @@ void *__symbol_get(const char *symbol) } EXPORT_SYMBOL_GPL(__symbol_get);
+static bool module_init_layout_section(const char *sname) +{ +#ifndef CONFIG_MODULE_UNLOAD + if (module_exit_section(sname)) + return true; +#endif + return module_init_section(sname); +} + /* * Ensure that an exported symbol [global namespace] does not already exist * in the kernel or in some other module's exported symbol table. @@ -2501,7 +2510,7 @@ static void layout_sections(struct module *mod, struct load_info *info) if ((s->sh_flags & masks[m][0]) != masks[m][0] || (s->sh_flags & masks[m][1]) || s->sh_entsize != ~0UL - || module_init_section(sname)) + || module_init_layout_section(sname)) continue; s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i); pr_debug("\t%s\n", sname); @@ -2534,7 +2543,7 @@ static void layout_sections(struct module *mod, struct load_info *info) if ((s->sh_flags & masks[m][0]) != masks[m][0] || (s->sh_flags & masks[m][1]) || s->sh_entsize != ~0UL - || !module_init_section(sname)) + || !module_init_layout_section(sname)) continue; s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i) | INIT_OFFSET_MASK); @@ -2873,11 +2882,7 @@ void * __weak module_alloc(unsigned long size)
bool __weak module_init_section(const char *name) { -#ifndef CONFIG_MODULE_UNLOAD - return strstarts(name, ".init") || module_exit_section(name); -#else return strstarts(name, ".init"); -#endif }
bool __weak module_exit_section(const char *name)