bpf: factor out a bpf_trace_copy_string helper

[linux-2.6-microblaze.git] / kernel / trace / bpf_trace.c

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 3744372..60e82c7 100644 (file)
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -159,7 +159,7 @@ const struct bpf_func_proto bpf_probe_read_user_proto = {
 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
           const void __user *, unsafe_ptr)
 {
-       int ret = strncpy_from_unsafe_user(dst, unsafe_ptr, size);
+       int ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
 
        if (unlikely(ret < 0))
                memset(dst, 0, size);
@@ -240,7 +240,7 @@ bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr,
         * is returned that can be used for bpf_perf_event_output() et al.
         */
        ret = compat ? strncpy_from_unsafe(dst, unsafe_ptr, size) :
-             strncpy_from_unsafe_strict(dst, unsafe_ptr, size);
+             strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
        if (unlikely(ret < 0))
 out:
                memset(dst, 0, size);
@@ -324,6 +324,28 @@ static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
        return &bpf_probe_write_user_proto;
 }
 
+static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
+               size_t bufsz)
+{
+       void __user *user_ptr = (__force void __user *)unsafe_ptr;
+
+       buf[0] = 0;
+
+       switch (fmt_ptype) {
+       case 's':
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+               strncpy_from_unsafe(buf, unsafe_ptr, bufsz);
+               break;
+#endif
+       case 'k':
+               strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
+               break;
+       case 'u':
+               strncpy_from_user_nofault(buf, user_ptr, bufsz);
+               break;
+       }
+}
+
 /*
  * Only limited trace_printk() conversion specifiers allowed:
  * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pks %pus %s
@@ -406,24 +428,8 @@ fmt_str:
                                break;
                        }
 
-                       buf[0] = 0;
-                       switch (fmt_ptype) {
-                       case 's':
-#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
-                               strncpy_from_unsafe(buf, unsafe_ptr,
-                                                   sizeof(buf));
-                               break;
-#endif
-                       case 'k':
-                               strncpy_from_unsafe_strict(buf, unsafe_ptr,
-                                                          sizeof(buf));
-                               break;
-                       case 'u':
-                               strncpy_from_unsafe_user(buf,
-                                       (__force void __user *)unsafe_ptr,
-                                                        sizeof(buf));
-                               break;
-                       }
+                       bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
+                                       sizeof(buf));
                        goto fmt_next;
                }