Fix: in_x32_syscall was introduced in v4.7.0

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

diff --git a/src/lttng-syscalls.c b/src/lttng-syscalls.c
index bd836c001d658257e5bf529d61a3cbeabc84a168..03c521a1f76acc1fd0b67731d09e398c28bc4013 100644 (file)
--- a/src/lttng-syscalls.c
+++ b/src/lttng-syscalls.c
@@ -28,9 +28,11 @@
 #include <wrapper/file.h>
 #include <wrapper/rcu.h>
 #include <wrapper/syscall.h>
+#include <wrapper/limits.h>
 #include <lttng/events.h>
 #include <lttng/events-internal.h>
 #include <lttng/utils.h>
+#include <lttng/kernel-version.h>
 
 #include "lttng-syscalls.h"
 
@@ -42,7 +44,14 @@
 
 /* in_compat_syscall appears in kernel 4.6. */
 #ifndef in_compat_syscall
- #define in_compat_syscall()   is_compat_task()
+# define in_compat_syscall()   is_compat_task()
+#endif
+
+/* in_x32_syscall appears in kernel 4.7. */
+#if (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(4,7,0))
+# ifdef CONFIG_X86_X32_ABI
+#  define in_x32_syscall()     is_x32_task()
+# endif
 #endif
 
 enum sc_type {
@@ -135,6 +144,15 @@ struct lttng_syscall_filter {
        DECLARE_BITMAP(sc_exit, NR_syscalls);
        DECLARE_BITMAP(sc_compat_entry, NR_compat_syscalls);
        DECLARE_BITMAP(sc_compat_exit, NR_compat_syscalls);
+
+       /*
+        * Reference counters keeping track of number of events enabled
+        * for each bit.
+        */
+       u32 sc_entry_refcount_map[NR_syscalls];
+       u32 sc_exit_refcount_map[NR_syscalls];
+       u32 sc_compat_entry_refcount_map[NR_compat_syscalls];
+       u32 sc_compat_exit_refcount_map[NR_compat_syscalls];
 };
 
 static void syscall_entry_event_unknown(struct hlist_head *unknown_action_list_head,
@@ -261,6 +279,12 @@ void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id)
        const struct trace_syscall_entry *table, *entry;
        size_t table_len;
 
+#ifdef CONFIG_X86_X32_ABI
+       if (in_x32_syscall()) {
+               /* x32 system calls are not supported. */
+               return;
+       }
+#endif
        if (unlikely(in_compat_syscall())) {
                struct lttng_syscall_filter *filter = chan->priv->parent.sc_filter;
 
@@ -498,6 +522,12 @@ void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret)
        size_t table_len;
        long id;
 
+#ifdef CONFIG_X86_X32_ABI
+       if (in_x32_syscall()) {
+               /* x32 system calls are not supported. */
+               return;
+       }
+#endif
        id = syscall_get_nr(current, regs);
 
        if (unlikely(in_compat_syscall())) {
@@ -1367,6 +1397,7 @@ int lttng_syscall_filter_enable(
 {
        const char *syscall_name;
        unsigned long *bitmap;
+       u32 *refcount_map;
        int syscall_nr;
 
        syscall_name = get_syscall_name(desc_name, abi, entryexit);
@@ -1389,9 +1420,11 @@ int lttng_syscall_filter_enable(
                switch (abi) {
                case LTTNG_SYSCALL_ABI_NATIVE:
                        bitmap = filter->sc_entry;
+                       refcount_map = filter->sc_entry_refcount_map;
                        break;
                case LTTNG_SYSCALL_ABI_COMPAT:
                        bitmap = filter->sc_compat_entry;
+                       refcount_map = filter->sc_compat_entry_refcount_map;
                        break;
                default:
                        return -EINVAL;
@@ -1401,9 +1434,11 @@ int lttng_syscall_filter_enable(
                switch (abi) {
                case LTTNG_SYSCALL_ABI_NATIVE:
                        bitmap = filter->sc_exit;
+                       refcount_map = filter->sc_exit_refcount_map;
                        break;
                case LTTNG_SYSCALL_ABI_COMPAT:
                        bitmap = filter->sc_compat_exit;
+                       refcount_map = filter->sc_compat_exit_refcount_map;
                        break;
                default:
                        return -EINVAL;
@@ -1412,9 +1447,10 @@ int lttng_syscall_filter_enable(
        default:
                return -EINVAL;
        }
-       if (test_bit(syscall_nr, bitmap))
-               return -EEXIST;
-       bitmap_set(bitmap, syscall_nr, 1);
+       if (refcount_map[syscall_nr] == U32_MAX)
+               return -EOVERFLOW;
+       if (refcount_map[syscall_nr]++ == 0)
+               bitmap_set(bitmap, syscall_nr, 1);
        return 0;
 }
 
@@ -1428,13 +1464,16 @@ int lttng_syscall_filter_enable_event_notifier(
 
        WARN_ON_ONCE(event_notifier->priv->parent.instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
 
+       /* Skip unknown syscall */
+       if (syscall_id == -1U)
+               return 0;
+
        ret = lttng_syscall_filter_enable(group->sc_filter,
                event_notifier->priv->parent.desc->event_name,
                event_notifier->priv->parent.u.syscall.abi,
                event_notifier->priv->parent.u.syscall.entryexit);
-       if (ret) {
-               goto end;
-       }
+       if (ret)
+               return ret;
 
        switch (event_notifier->priv->parent.u.syscall.entryexit) {
        case LTTNG_SYSCALL_ENTRY:
@@ -1471,15 +1510,21 @@ int lttng_syscall_filter_enable_event_notifier(
        hlist_add_head_rcu(&event_notifier->priv->parent.u.syscall.node, dispatch_list);
 
 end:
-       return ret ;
+       return ret;
 }
 
 int lttng_syscall_filter_enable_event(
                struct lttng_kernel_channel_buffer *channel,
                struct lttng_kernel_event_recorder *event_recorder)
 {
+       unsigned int syscall_id = event_recorder->priv->parent.u.syscall.syscall_id;
+
        WARN_ON_ONCE(event_recorder->priv->parent.instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
 
+       /* Skip unknown syscall */
+       if (syscall_id == -1U)
+               return 0;
+
        return lttng_syscall_filter_enable(channel->priv->parent.sc_filter,
                event_recorder->priv->parent.desc->event_name,
                event_recorder->priv->parent.u.syscall.abi,
@@ -1494,6 +1539,7 @@ int lttng_syscall_filter_disable(
 {
        const char *syscall_name;
        unsigned long *bitmap;
+       u32 *refcount_map;
        int syscall_nr;
 
        syscall_name = get_syscall_name(desc_name, abi, entryexit);
@@ -1516,9 +1562,11 @@ int lttng_syscall_filter_disable(
                switch (abi) {
                case LTTNG_SYSCALL_ABI_NATIVE:
                        bitmap = filter->sc_entry;
+                       refcount_map = filter->sc_entry_refcount_map;
                        break;
                case LTTNG_SYSCALL_ABI_COMPAT:
                        bitmap = filter->sc_compat_entry;
+                       refcount_map = filter->sc_compat_entry_refcount_map;
                        break;
                default:
                        return -EINVAL;
@@ -1528,9 +1576,11 @@ int lttng_syscall_filter_disable(
                switch (abi) {
                case LTTNG_SYSCALL_ABI_NATIVE:
                        bitmap = filter->sc_exit;
+                       refcount_map = filter->sc_exit_refcount_map;
                        break;
                case LTTNG_SYSCALL_ABI_COMPAT:
                        bitmap = filter->sc_compat_exit;
+                       refcount_map = filter->sc_compat_exit_refcount_map;
                        break;
                default:
                        return -EINVAL;
@@ -1539,10 +1589,10 @@ int lttng_syscall_filter_disable(
        default:
                return -EINVAL;
        }
-       if (!test_bit(syscall_nr, bitmap))
-               return -EEXIST;
-       bitmap_clear(bitmap, syscall_nr, 1);
-
+       if (refcount_map[syscall_nr] == 0)
+               return -ENOENT;
+       if (--refcount_map[syscall_nr] == 0)
+               bitmap_clear(bitmap, syscall_nr, 1);
        return 0;
 }
 
@@ -1550,15 +1600,21 @@ int lttng_syscall_filter_disable_event_notifier(
                struct lttng_kernel_event_notifier *event_notifier)
 {
        struct lttng_event_notifier_group *group = event_notifier->priv->group;
+       unsigned int syscall_id = event_notifier->priv->parent.u.syscall.syscall_id;
        int ret;
 
        WARN_ON_ONCE(event_notifier->priv->parent.instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
 
+       /* Skip unknown syscall */
+       if (syscall_id == -1U)
+               return 0;
+
        ret = lttng_syscall_filter_disable(group->sc_filter,
                event_notifier->priv->parent.desc->event_name,
                event_notifier->priv->parent.u.syscall.abi,
                event_notifier->priv->parent.u.syscall.entryexit);
-       WARN_ON_ONCE(ret != 0);
+       if (ret)
+               return ret;
 
        hlist_del_rcu(&event_notifier->priv->parent.u.syscall.node);
        return 0;
@@ -1568,6 +1624,12 @@ int lttng_syscall_filter_disable_event(
                struct lttng_kernel_channel_buffer *channel,
                struct lttng_kernel_event_recorder *event_recorder)
 {
+       unsigned int syscall_id = event_recorder->priv->parent.u.syscall.syscall_id;
+
+       /* Skip unknown syscall */
+       if (syscall_id == -1U)
+               return 0;
+
        return lttng_syscall_filter_disable(channel->priv->parent.sc_filter,
                event_recorder->priv->parent.desc->event_name,
                event_recorder->priv->parent.u.syscall.abi,