Fix: older kernels (3.2.x) don't undefine TRACE_SYSTEM

[lttng-modules.git] / lttng-syscalls.c

diff --git a/lttng-syscalls.c b/lttng-syscalls.c
index cba0016007d95c190fc4a4987c0f727e8a7cefeb..a4a8ed44cd9c76dbc38d0ce8e319182b9f52392e 100644 (file)
--- a/lttng-syscalls.c
+++ b/lttng-syscalls.c
@@ -91,6 +91,7 @@ struct mmap_arg_struct;
 #define PARAMS(args...)        args
 
 /* Handle unknown syscalls */
+#undef TRACE_SYSTEM
 #define TRACE_SYSTEM syscalls_unknown
 #include "instrumentation/syscalls/headers/syscalls_unknown.h"
 #undef TRACE_SYSTEM
@@ -1036,6 +1037,8 @@ int lttng_syscall_filter_disable(struct lttng_channel *chan,
        WARN_ON_ONCE(!chan->sc_table);
 
        if (!chan->sc_filter) {
+               if (!chan->syscall_all)
+                       return -EEXIST;
                filter = kzalloc(sizeof(struct lttng_syscall_filter),
                                GFP_KERNEL);
                if (!filter)
@@ -1048,6 +1051,14 @@ int lttng_syscall_filter_disable(struct lttng_channel *chan,
        }
 
        if (!name) {
+               /* Fail if all syscalls are already disabled. */
+               if (bitmap_empty(filter->sc, NR_syscalls)
+                       && bitmap_empty(filter->sc_compat,
+                               NR_compat_syscalls)) {
+                       ret = -EEXIST;
+                       goto error;
+               }
+
                /* Disable all system calls */
                bitmap_clear(filter->sc, 0, NR_syscalls);
                bitmap_clear(filter->sc_compat, 0, NR_compat_syscalls);
@@ -1060,18 +1071,18 @@ int lttng_syscall_filter_disable(struct lttng_channel *chan,
                goto error;
        }
        if (syscall_nr >= 0) {
-               if (!test_bit(syscall_nr, chan->sc_filter->sc)) {
+               if (!test_bit(syscall_nr, filter->sc)) {
                        ret = -EEXIST;
                        goto error;
                }
-               bitmap_clear(chan->sc_filter->sc, syscall_nr, 1);
+               bitmap_clear(filter->sc, syscall_nr, 1);
        }
        if (compat_syscall_nr >= 0) {
-               if (!test_bit(compat_syscall_nr, chan->sc_filter->sc_compat)) {
+               if (!test_bit(compat_syscall_nr, filter->sc_compat)) {
                        ret = -EEXIST;
                        goto error;
                }
-               bitmap_clear(chan->sc_filter->sc_compat, compat_syscall_nr, 1);
+               bitmap_clear(filter->sc_compat, compat_syscall_nr, 1);
        }
 apply_filter:
        if (!chan->sc_filter)
@@ -1220,12 +1231,12 @@ long lttng_channel_syscall_mask(struct lttng_channel *channel,
 
        for (bit = 0; bit < ARRAY_SIZE(sc_table); bit++) {
                bt_bitfield_write_be(tmp_mask, char, bit, 1,
-                       test_bit(bit, filter->sc));
+                       filter ? test_bit(bit, filter->sc) : 1);
        }
        for (; bit < sc_tables_len; bit++) {
                bt_bitfield_write_be(tmp_mask, char, bit, 1,
-                       test_bit(bit - ARRAY_SIZE(sc_table),
-                               filter->sc_compat));
+                       filter ? test_bit(bit - ARRAY_SIZE(sc_table),
+                               filter->sc_compat) : 1);
        }
        if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
                ret = -EFAULT;