diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 6d59c8e77..e7edc9e4c 100755 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -194,10 +194,17 @@ static unsigned long __recover_probed_insn(kprobe_opcode_t *buf, unsigned long addr) { struct kprobe *kp; - bool faddr; + unsigned long faddr; kp = get_kprobe((void *)addr); - faddr = ftrace_location(addr) == addr; + faddr = ftrace_location(addr); + /* + * Addresses inside the ftrace location are refused by + * arch_check_ftrace_location(). Something went terribly wrong + * if such an address is checked here. + */ + if (WARN_ON(faddr && faddr != addr)) + return 0UL; /* * Use the current code if it is not modified by Kprobe * and it cannot be modified by ftrace. diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 57f653a6a..3988776e1 100755 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -89,6 +89,18 @@ out: return tr; } +static int is_ftrace_location(void *ip) +{ + long addr; + + addr = ftrace_location((long)ip); + if (!addr) + return 0; + if (WARN_ON_ONCE(addr != (long)ip)) + return -EFAULT; + return 1; +} + static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr) { void *ip = tr->func.addr; @@ -117,12 +129,12 @@ static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_ad static int register_fentry(struct bpf_trampoline *tr, void *new_addr) { void *ip = tr->func.addr; - unsigned long faddr; int ret; - faddr = ftrace_location((unsigned long)ip); - if (faddr) - tr->func.ftrace_managed = true; + ret = is_ftrace_location(ip); + if (ret < 0) + return ret; + tr->func.ftrace_managed = ret; if (tr->func.ftrace_managed) ret = register_ftrace_direct((long)ip, (long)new_addr); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 9bd02fa78..ef0d23344 100755 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1611,10 +1611,14 @@ static inline int check_kprobe_rereg(struct kprobe *p) int __weak arch_check_ftrace_location(struct kprobe *p) { - unsigned long addr = (unsigned long)p->addr; + unsigned long ftrace_addr; - if (ftrace_location(addr) == addr) { + ftrace_addr = ftrace_location((unsigned long)p->addr); + if (ftrace_addr) { #ifdef CONFIG_KPROBES_ON_FTRACE + /* Given address is not on the instruction boundary */ + if ((unsigned long)p->addr != ftrace_addr) + return -EILSEQ; p->flags |= KPROBE_FLAG_FTRACE; #else /* !CONFIG_KPROBES_ON_FTRACE */ return -EINVAL; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index a781733b2..31fec924b 100755 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1575,34 +1575,17 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end) } /** - * ftrace_location - return the ftrace location + * ftrace_location - return true if the ip giving is a traced location * @ip: the instruction pointer to check * - * If @ip matches the ftrace location, return @ip. - * If @ip matches sym+0, return sym's ftrace location. - * Otherwise, return 0. + * Returns rec->ip if @ip given is a pointer to a ftrace location. + * That is, the instruction that is either a NOP or call to + * the function tracer. It checks the ftrace internal tables to + * determine if the address belongs or not. */ unsigned long ftrace_location(unsigned long ip) { - struct dyn_ftrace *rec; - unsigned long offset; - unsigned long size; - - rec = lookup_rec(ip, ip); - if (!rec) { - if (!kallsyms_lookup_size_offset(ip, &size, &offset)) - goto out; - - /* map sym+0 to __fentry__ */ - if (!offset) - rec = lookup_rec(ip, ip + size - 1); - } - - if (rec) - return rec->ip; - -out: - return 0; + return ftrace_location_range(ip, ip); } /** @@ -4965,8 +4948,7 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) { struct ftrace_func_entry *entry; - ip = ftrace_location(ip); - if (!ip) + if (!ftrace_location(ip)) return -EINVAL; if (remove) { @@ -5114,16 +5096,11 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr) struct ftrace_func_entry *entry; struct ftrace_hash *free_hash = NULL; struct dyn_ftrace *rec; - int ret = -ENODEV; + int ret = -EBUSY; mutex_lock(&direct_mutex); - ip = ftrace_location(ip); - if (!ip) - goto out_unlock; - /* See if there's a direct function at @ip already */ - ret = -EBUSY; if (ftrace_find_rec_direct(ip)) goto out_unlock; @@ -5252,10 +5229,6 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr) mutex_lock(&direct_mutex); - ip = ftrace_location(ip); - if (!ip) - goto out_unlock; - entry = find_direct_entry(&ip, NULL); if (!entry) goto out_unlock; @@ -5387,11 +5360,6 @@ int modify_ftrace_direct(unsigned long ip, mutex_lock(&direct_mutex); mutex_lock(&ftrace_lock); - - ip = ftrace_location(ip); - if (!ip) - goto out_unlock; - entry = find_direct_entry(&ip, &rec); if (!entry) goto out_unlock;