Some blackpoints are only valid for specific architectures. To let each architecture specify its own blackpoints the list has been split in two lists: common and arch. The common list is kept in kernel/kprobes.c and the arch list is kept in the arch/ directory.
Cc: Masami Hiramatsu <[email protected]> Cc: David S. Miller <[email protected]> Cc: [email protected] Signed-off-by: Oskar Andero <[email protected]> --- kernel/kprobes.c | 88 +++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 59 insertions(+), 29 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index c8c2281..2458ae1 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -68,7 +68,6 @@ #endif static int kprobes_initialized; -static bool kprobe_blacklist_initialized; static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; @@ -94,31 +93,64 @@ static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) * * For such cases, we now have a blacklist */ -static struct kprobe_blackpoint kprobe_blacklist[] = { - {"preempt_schedule",}, - {"native_get_debugreg",}, - {"irq_entries_start",}, - {"common_interrupt",}, - {"mcount",}, /* mcount can be called from everywhere */ - {NULL} /* Terminator */ +static const char * const common_kprobes_blacksyms[] = { + "preempt_schedule", + "native_get_debugreg", + "irq_entries_start", + "common_interrupt", + "mcount", /* mcount can be called from everywhere */ }; +static const size_t common_kprobes_blacksyms_size = + ARRAY_SIZE(common_kprobes_blacksyms); + +/* + * These weak symbols can be overridden from the arch/ directory for + * architecure specific blackpoints. + */ +const char * const __weak arch_kprobes_blacksyms[] = {}; +const size_t __weak arch_kprobes_blacksyms_size; + +static struct kprobe_blackpoint *kprobe_blacklist; +static size_t kprobe_blacklist_size; + +static void init_kprobe_blacklist_entry(struct kprobe_blackpoint *kb, + const char * const name) +{ + const char *symbol_name; + char *modname, namebuf[128]; + void *addr; + unsigned long offset = 0, size = 0; + + kb->name = name; + kprobe_lookup_name(kb->name, addr); + if (!addr) + return; + + kb->start_addr = (unsigned long)addr; + symbol_name = kallsyms_lookup(kb->start_addr, + &size, &offset, &modname, namebuf); + if (!symbol_name) + kb->range = 0; + else + kb->range = size; +} /* it can take some time ( > 100ms ) to initialise the * blacklist so we delay this until we actually need it */ static void init_kprobe_blacklist(void) { - int i; - unsigned long offset = 0, size = 0; - char *modname, namebuf[128]; - const char *symbol_name; - void *addr; + int i, j = 0; struct kprobe_blackpoint *kb; mutex_lock(&kprobe_mutex); - if (kprobe_blacklist_initialized) + if (kprobe_blacklist) goto out; + kprobe_blacklist_size = common_kprobes_blacksyms_size + + arch_kprobes_blacksyms_size; + kb = kzalloc(sizeof(*kb) * kprobe_blacklist_size, GFP_KERNEL); + /* * Lookup and populate the kprobe_blacklist. * @@ -127,18 +159,14 @@ static void init_kprobe_blacklist(void) * since a kprobe need not necessarily be at the beginning * of a function. */ - for (kb = kprobe_blacklist; kb->name != NULL; kb++) { - kprobe_lookup_name(kb->name, addr); - if (!addr) - continue; + for (i = 0; i < common_kprobes_blacksyms_size; i++, j++) { + init_kprobe_blacklist_entry(&kb[j], + common_kprobes_blacksyms[i]); + } - kb->start_addr = (unsigned long)addr; - symbol_name = kallsyms_lookup(kb->start_addr, - &size, &offset, &modname, namebuf); - if (!symbol_name) - kb->range = 0; - else - kb->range = size; + for (i = 0; i < arch_kprobes_blacksyms_size; i++, j++) { + init_kprobe_blacklist_entry(&kb[j], + arch_kprobes_blacksyms[i]); } if (kretprobe_blacklist_size) { @@ -153,7 +181,7 @@ static void init_kprobe_blacklist(void) } smp_wmb(); - kprobe_blacklist_initialized = true; + kprobe_blacklist = kb; out: mutex_unlock(&kprobe_mutex); @@ -1384,18 +1412,20 @@ out: static int __kprobes in_kprobes_functions(unsigned long addr) { struct kprobe_blackpoint *kb; + int i; if (addr >= (unsigned long)__kprobes_text_start && addr < (unsigned long)__kprobes_text_end) return -EINVAL; - if (unlikely(!kprobe_blacklist_initialized)) + if (unlikely(!kprobe_blacklist)) init_kprobe_blacklist(); /* * If there exists a kprobe_blacklist, verify and * fail any probe registration in the prohibited area */ - for (kb = kprobe_blacklist; kb->name != NULL; kb++) { + for (i = 0; i < kprobe_blacklist_size; i++) { + kb = &kprobe_blacklist[i]; if (kb->start_addr) { if (addr >= kb->start_addr && addr < (kb->start_addr + kb->range)) @@ -1876,7 +1906,7 @@ int __kprobes register_kretprobe(struct kretprobe *rp) void *addr; if (kretprobe_blacklist_size) { - if (unlikely(!kprobe_blacklist_initialized)) + if (unlikely(!kprobe_blacklist)) init_kprobe_blacklist(); addr = kprobe_addr(&rp->kp); if (IS_ERR(addr)) -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
