diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 7a13e6ac6327..88589d74a892 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2423,7 +2423,7 @@ kprobe_multi_link_handler(struct fprobe *fp, unsigned long entry_ip, kprobe_multi_link_prog_run(link, entry_ip, regs); } -static int symbols_cmp(const void *a, const void *b) +static int symbols_cmp_r(const void *a, const void *b, const void *priv) { const char **str_a = (const char **) a; const char **str_b = (const char **) b; @@ -2431,6 +2431,28 @@ static int symbols_cmp(const void *a, const void *b) return strcmp(*str_a, *str_b); } +struct multi_symbols_sort { + const char **funcs; + u64 *cookies; +}; + +static void symbols_swap_r(void *a, void *b, int size, const void *priv) +{ + const struct multi_symbols_sort *data = priv; + const char **name_a = a, **name_b = b; + + swap(*name_a, *name_b); + + /* If defined, swap also related cookies. */ + if (data->cookies) { + u64 *cookie_a, *cookie_b; + + cookie_a = data->cookies + (name_a - data->funcs); + cookie_b = data->cookies + (name_b - data->funcs); + swap(*cookie_a, *cookie_b); + } +} + int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { struct bpf_kprobe_multi_link *link = NULL; @@ -2468,25 +2490,6 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr if (!addrs) return -ENOMEM; - if (uaddrs) { - if (copy_from_user(addrs, uaddrs, size)) { - err = -EFAULT; - goto error; - } - } else { - struct user_syms us; - - err = copy_user_syms(&us, usyms, cnt); - if (err) - goto error; - - sort(us.syms, cnt, sizeof(*us.syms), symbols_cmp, NULL); - err = ftrace_lookup_symbols(us.syms, cnt, addrs); - free_user_syms(&us); - if (err) - goto error; - } - ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); if (ucookies) { cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); @@ -2500,6 +2503,33 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr } } + if (uaddrs) { + if (copy_from_user(addrs, uaddrs, size)) { + err = -EFAULT; + goto error; + } + } else { + struct multi_symbols_sort data = { + .cookies = cookies, + }; + struct user_syms us; + + err = copy_user_syms(&us, usyms, cnt); + if (err) + goto error; + + if (cookies) + data.funcs = us.syms; + + sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, + symbols_swap_r, &data); + + err = ftrace_lookup_symbols(us.syms, cnt, addrs); + free_user_syms(&us); + if (err) + goto error; + } + link = kzalloc(sizeof(*link), GFP_KERNEL); if (!link) { err = -ENOMEM;