From 5279631271b32201243c60308a8987bd585e4460 Mon Sep 17 00:00:00 2001 From: Zhou Chengming Date: Fri, 7 Jul 2017 11:15:58 +0800 Subject: module: fix ddebug_remove_module() ddebug_remove_module() use mod->name to find the ddebug_table of the module and remove it. But dynamic_debug_setup() use the first _ddebug->modname to create ddebug_table for the module. It's ok when the _ddebug->modname is the same with the mod->name. But livepatch module is special, it may contain _ddebugs of other modules, the modname of which is different from the name of livepatch module. So ddebug_remove_module() can't use mod->name to find the right ddebug_table and remove it. It can cause kernel crash when we cat the file /dynamic_debug/control. Signed-off-by: Zhou Chengming Signed-off-by: Jessica Yu --- kernel/module.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 40f983cbea81..de66ec825992 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2707,21 +2707,21 @@ static void add_kallsyms(struct module *mod, const struct load_info *info) } #endif /* CONFIG_KALLSYMS */ -static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num) +static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num) { if (!debug) return; #ifdef CONFIG_DYNAMIC_DEBUG - if (ddebug_add_module(debug, num, debug->modname)) + if (ddebug_add_module(debug, num, mod->name)) pr_err("dynamic debug error adding module: %s\n", debug->modname); #endif } -static void dynamic_debug_remove(struct _ddebug *debug) +static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug) { if (debug) - ddebug_remove_module(debug->modname); + ddebug_remove_module(mod->name); } void * __weak module_alloc(unsigned long size) @@ -3715,7 +3715,7 @@ static int load_module(struct load_info *info, const char __user *uargs, goto free_arch_cleanup; } - dynamic_debug_setup(info->debug, info->num_debug); + dynamic_debug_setup(mod, info->debug, info->num_debug); /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */ ftrace_module_init(mod); @@ -3779,7 +3779,7 @@ static int load_module(struct load_info *info, const char __user *uargs, module_disable_nx(mod); ddebug_cleanup: - dynamic_debug_remove(info->debug); + dynamic_debug_remove(mod, info->debug); synchronize_sched(); kfree(mod->args); free_arch_cleanup: -- cgit v1.2.3 From 3e234289f86b12985ef8909cd34525fcb66c4efb Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Fri, 3 Mar 2017 18:00:22 -0500 Subject: ftrace: Allow module init functions to be traced Allow for module init sections to be traced as well as core kernel init sections. Now that filtering modules functions can be stored, for when they are loaded, it makes sense to be able to trace them. Cc: Jessica Yu Cc: Rusty Russell Signed-off-by: Steven Rostedt (VMware) --- kernel/module.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index de66ec825992..58bca427ac3f 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3473,6 +3473,8 @@ static noinline int do_init_module(struct module *mod) if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC)) async_synchronize_full(); + ftrace_free_mem(mod->init_layout.base, mod->init_layout.base + + mod->init_layout.size); mutex_lock(&module_mutex); /* Drop initial reference. */ module_put(mod); -- cgit v1.2.3 From aba4b5c22cbac296f4081a0476d0c55828f135b4 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Fri, 1 Sep 2017 08:35:38 -0400 Subject: ftrace: Save module init functions kallsyms symbols for tracing If function tracing is active when the module init functions are freed, then store them to be referenced by kallsyms. As module init functions can now be traced on module load, they were useless: ># echo ':mod:snd_seq' > set_ftrace_filter ># echo function > current_tracer ># modprobe snd_seq ># cat trace # tracer: function # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | modprobe-2786 [000] .... 3189.037874: 0xffffffffa0860000 <-do_one_initcall modprobe-2786 [000] .... 3189.037876: 0xffffffffa086004d <-0xffffffffa086000f modprobe-2786 [000] .... 3189.037876: 0xffffffffa086010d <-0xffffffffa0860018 modprobe-2786 [000] .... 3189.037877: 0xffffffffa086011a <-0xffffffffa0860021 modprobe-2786 [000] .... 3189.037877: 0xffffffffa0860080 <-0xffffffffa086002a modprobe-2786 [000] .... 3189.039523: 0xffffffffa0860400 <-0xffffffffa0860033 modprobe-2786 [000] .... 3189.039523: 0xffffffffa086038a <-0xffffffffa086041c modprobe-2786 [000] .... 3189.039591: 0xffffffffa086038a <-0xffffffffa0860436 modprobe-2786 [000] .... 3189.039657: 0xffffffffa086038a <-0xffffffffa0860450 modprobe-2786 [000] .... 3189.039719: 0xffffffffa0860127 <-0xffffffffa086003c modprobe-2786 [000] .... 3189.039742: snd_seq_create_kernel_client <-0xffffffffa08601f6 When the output is shown, the kallsyms for the module init functions have already been freed, and the output of the trace can not convert them to their function names. Now this looks like this: # tracer: function # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | modprobe-2463 [002] .... 174.243237: alsa_seq_init <-do_one_initcall modprobe-2463 [002] .... 174.243239: client_init_data <-alsa_seq_init modprobe-2463 [002] .... 174.243240: snd_sequencer_memory_init <-alsa_seq_init modprobe-2463 [002] .... 174.243240: snd_seq_queues_init <-alsa_seq_init modprobe-2463 [002] .... 174.243240: snd_sequencer_device_init <-alsa_seq_init modprobe-2463 [002] .... 174.244860: snd_seq_info_init <-alsa_seq_init modprobe-2463 [002] .... 174.244861: create_info_entry <-snd_seq_info_init modprobe-2463 [002] .... 174.244936: create_info_entry <-snd_seq_info_init modprobe-2463 [002] .... 174.245003: create_info_entry <-snd_seq_info_init modprobe-2463 [002] .... 174.245072: snd_seq_system_client_init <-alsa_seq_init modprobe-2463 [002] .... 174.245094: snd_seq_create_kernel_client <-snd_seq_system_client_init Signed-off-by: Steven Rostedt (VMware) --- kernel/module.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 58bca427ac3f..279a469dc375 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3473,7 +3473,7 @@ static noinline int do_init_module(struct module *mod) if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC)) async_synchronize_full(); - ftrace_free_mem(mod->init_layout.base, mod->init_layout.base + + ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base + mod->init_layout.size); mutex_lock(&module_mutex); /* Drop initial reference. */ -- cgit v1.2.3 From 9ad0457423af877ad1b76c105a57130da028ccad Mon Sep 17 00:00:00 2001 From: Markus Elfring Date: Fri, 6 Oct 2017 16:27:26 +0200 Subject: kernel/module: Delete an error message for a failed memory allocation in add_module_usage() Omit an extra message for a memory allocation failure in this function. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring Signed-off-by: Jessica Yu --- kernel/module.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index de66ec825992..07ef44767245 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -837,10 +837,8 @@ static int add_module_usage(struct module *a, struct module *b) pr_debug("Allocating new usage for %s.\n", a->name); use = kmalloc(sizeof(*use), GFP_ATOMIC); - if (!use) { - pr_warn("%s: out of memory loading\n", a->name); + if (!use) return -ENOMEM; - } use->source = a; use->target = b; -- cgit v1.2.3 From fda784e50aace694ec2e4e16e2de07b91a938563 Mon Sep 17 00:00:00 2001 From: "Bruno E. O. Meneguele" Date: Tue, 24 Oct 2017 15:37:00 -0200 Subject: module: export module signature enforcement status A static variable sig_enforce is used as status var to indicate the real value of CONFIG_MODULE_SIG_FORCE, once this one is set the var will hold true, but if the CONFIG is not set the status var will hold whatever value is present in the module.sig_enforce kernel cmdline param: true when =1 and false when =0 or not present. Considering this cmdline param take place over the CONFIG value when it's not set, other places in the kernel could misbehave since they would have only the CONFIG_MODULE_SIG_FORCE value to rely on. Exporting this status var allows the kernel to rely in the effective value of module signature enforcement, being it from CONFIG value or cmdline param. Signed-off-by: Bruno E. O. Meneguele Signed-off-by: Mimi Zohar --- kernel/module.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index de66ec825992..d1c194b057a2 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -278,6 +278,16 @@ static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); module_param(sig_enforce, bool_enable_only, 0644); #endif /* !CONFIG_MODULE_SIG_FORCE */ +/* + * Export sig_enforce kernel cmdline parameter to allow other subsystems rely + * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. + */ +bool is_module_sig_enforced(void) +{ + return sig_enforce; +} +EXPORT_SYMBOL(is_module_sig_enforced); + /* Block module loading/unloading? */ int modules_disabled = 0; core_param(nomodule, modules_disabled, bint, 0); -- cgit v1.2.3 From 277642dcca765a1955d4c753a5a315ff7f2eb09d Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 12 Nov 2017 17:00:53 -0800 Subject: modules: make sysfs attribute files readable by owner only This code goes back to the historical bitkeeper tree commit 3f7b0672086 ("Module section offsets in /sys/module"), where Jonathan Corbet wanted to show people how to debug loadable modules. See https://lwn.net/Articles/88052/ from June 2004. To expose the required load address information, Jonathan added the sections subdirectory for every module in /sys/modules, and made them S_IRUGO - readable by everybody. It was a more innocent time, plus those S_IRxxx macro names are a lot more confusing than the octal numbers are, so maybe it wasn't even intentional. But here we are, thirteen years later, and I'll just change it to S_IRUSR instead. Let's see if anybody even notices. Cc: Jonathan Corbet Signed-off-by: Linus Torvalds --- kernel/module.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index de66ec825992..fdb3a6aca363 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1516,7 +1516,7 @@ static void add_sect_attrs(struct module *mod, const struct load_info *info) sattr->mattr.show = module_sect_show; sattr->mattr.store = NULL; sattr->mattr.attr.name = sattr->name; - sattr->mattr.attr.mode = S_IRUGO; + sattr->mattr.attr.mode = S_IRUSR; *(gattr++) = &(sattr++)->mattr.attr; } *gattr = NULL; -- cgit v1.2.3 From 516fb7f2e73dcc303fb97fc3593209fcacf2d982 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 12 Nov 2017 18:44:23 -0800 Subject: /proc/module: use the same logic as /proc/kallsyms for address exposure The (alleged) users of the module addresses are the same: kernel profiling. So just expose the same helper and format macros, and unify the logic. Signed-off-by: Linus Torvalds --- kernel/module.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index fdb3a6aca363..0122747ba150 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -4147,6 +4147,7 @@ static int m_show(struct seq_file *m, void *p) { struct module *mod = list_entry(p, struct module, list); char buf[MODULE_FLAGS_BUF_SIZE]; + unsigned long value; /* We always ignore unformed modules. */ if (mod->state == MODULE_STATE_UNFORMED) @@ -4162,7 +4163,8 @@ static int m_show(struct seq_file *m, void *p) mod->state == MODULE_STATE_COMING ? "Loading" : "Live"); /* Used by oprofile and other similar tools. */ - seq_printf(m, " 0x%pK", mod->core_layout.base); + value = m->private ? 0 : (unsigned long)mod->core_layout.base; + seq_printf(m, " 0x" KALLSYM_FMT, value); /* Taints info */ if (mod->taints) @@ -4184,9 +4186,23 @@ static const struct seq_operations modules_op = { .show = m_show }; +/* + * This also sets the "private" pointer to non-NULL if the + * kernel pointers should be hidden (so you can just test + * "m->private" to see if you should keep the values private). + * + * We use the same logic as for /proc/kallsyms. + */ static int modules_open(struct inode *inode, struct file *file) { - return seq_open(file, &modules_op); + int err = seq_open(file, &modules_op); + + if (!err) { + struct seq_file *m = file->private_data; + m->private = kallsyms_show_value() ? NULL : (void *)8ul; + } + + return 0; } static const struct file_operations proc_modules_operations = { -- cgit v1.2.3