Messages in this thread Patch in this message | | | From | Jarkko Sakkinen <> | Subject | [PATCH v4 7/7] kprobes: Flag out CONFIG_MODULES dependent code | Date | Fri, 17 Jul 2020 06:04:21 +0300 |
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Remove CONFIG_MODULES dependency by flagging out the dependent code. This allows to use kprobes in a kernel without support for loadable modules, which could be useful for a test kernel or perhaps an embedded kernel.
Cc: Andi Kleen <ak@linux.intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> --- arch/Kconfig | 2 +- include/linux/module.h | 14 +++++------ kernel/kprobes.c | 48 +++++++++++++++++++++++-------------- kernel/trace/trace_kprobe.c | 16 +++++++++++-- 4 files changed, 52 insertions(+), 28 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig index 8cc35dc556c7..e3d6b6868ccb 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -61,7 +61,7 @@ config OPROFILE_NMI_TIMER config KPROBES bool "Kprobes" - depends on MODULES + depends on MODULES || ARCH_HAS_TEXT_ALLOC depends on HAVE_KPROBES select KALLSYMS help diff --git a/include/linux/module.h b/include/linux/module.h index 8850b9692b8f..22c646cff6bd 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -290,6 +290,13 @@ extern typeof(name) __mod_##type##__##name##_device_table \ struct notifier_block; +enum module_state { + MODULE_STATE_LIVE, /* Normal state. */ + MODULE_STATE_COMING, /* Full formed, running module_init. */ + MODULE_STATE_GOING, /* Going away. */ + MODULE_STATE_UNFORMED, /* Still setting it up. */ +}; + #ifdef CONFIG_MODULES extern int modules_disabled; /* for sysctl */ @@ -305,13 +312,6 @@ struct module_use { struct module *source, *target; }; -enum module_state { - MODULE_STATE_LIVE, /* Normal state. */ - MODULE_STATE_COMING, /* Full formed, running module_init. */ - MODULE_STATE_GOING, /* Going away. */ - MODULE_STATE_UNFORMED, /* Still setting it up. */ -}; - struct mod_tree_node { struct module *mod; struct latch_tree_node node; diff --git a/kernel/kprobes.c b/kernel/kprobes.c index f73cf71ef47d..6ee7286b1f7e 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1609,6 +1609,7 @@ static int check_kprobe_address_safe(struct kprobe *p, goto out; } +#ifdef CONFIG_MODULES /* * If the module freed .init.text, we couldn't insert * kprobes in there. @@ -1619,6 +1620,7 @@ static int check_kprobe_address_safe(struct kprobe *p, *probed_mod = NULL; ret = -ENOENT; } +#endif } out: preempt_enable(); @@ -2215,24 +2217,6 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end) return 0; } -/* Remove all symbols in given area from kprobe blacklist */ -static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) -{ - struct kprobe_blacklist_entry *ent, *n; - - list_for_each_entry_safe(ent, n, &kprobe_blacklist, list) { - if (ent->start_addr < start || ent->start_addr >= end) - continue; - list_del(&ent->list); - kfree(ent); - } -} - -static void kprobe_remove_ksym_blacklist(unsigned long entry) -{ - kprobe_remove_area_blacklist(entry, entry + 1); -} - int __init __weak arch_populate_kprobe_blacklist(void) { return 0; @@ -2275,6 +2259,25 @@ static int __init populate_kprobe_blacklist(unsigned long *start, return ret ? : arch_populate_kprobe_blacklist(); } +#ifdef CONFIG_MODULES +/* Remove all symbols in given area from kprobe blacklist */ +static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) +{ + struct kprobe_blacklist_entry *ent, *n; + + list_for_each_entry_safe(ent, n, &kprobe_blacklist, list) { + if (ent->start_addr < start || ent->start_addr >= end) + continue; + list_del(&ent->list); + kfree(ent); + } +} + +static void kprobe_remove_ksym_blacklist(unsigned long entry) +{ + kprobe_remove_area_blacklist(entry, entry + 1); +} + static void add_module_kprobe_blacklist(struct module *mod) { unsigned long start, end; @@ -2320,6 +2323,15 @@ static void remove_module_kprobe_blacklist(struct module *mod) kprobe_remove_area_blacklist(start, end); } } +#else +static void add_module_kprobe_blacklist(struct module *mod) +{ +} + +static void remove_module_kprobe_blacklist(struct module *mod) +{ +} +#endif /* CONFIG_MODULES */ /* Module notifier call back, checking kprobes on the module */ static int kprobes_module_callback(struct notifier_block *nb, diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 710ec6a6aa8f..881c998d0162 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -103,8 +103,9 @@ static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) return !!(kprobe_gone(&tk->rp.kp)); } +#ifdef CONFIG_MODULES static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, - struct module *mod) + struct module *mod) { int len = strlen(mod->name); const char *name = trace_kprobe_symbol(tk); @@ -129,6 +130,17 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) return ret; } +#else +static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, + struct module *mod) +{ + return false; +} +static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) +{ + return false; +} +#endif static bool trace_kprobe_is_busy(struct dyn_event *ev) { @@ -688,7 +700,7 @@ static int trace_kprobe_module_callback(struct notifier_block *nb, if (ret) pr_warn("Failed to re-register probe %s on %s: %d\n", trace_probe_name(&tk->tp), - mod->name, ret); + module_name(mod), ret); } } mutex_unlock(&event_mutex); -- 2.25.1
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