fix: file: Rename fcheck lookup_fd_rcu (v5.11)

See upstream commit:

  commit 460b4f812a9d473d4b39d87d37844f9fc30a9eb3
  Author: Eric W. Biederman <ebiederm@xmission.com>
  Date:   Fri Nov 20 17:14:27 2020 -0600

    file: Rename fcheck lookup_fd_rcu

    Also remove the confusing comment about checking if a fd exists.  I
    could not find one instance in the entire kernel that still matches
    the description or the reason for the name fcheck.

    The need for better names became apparent in the last round of
    discussion of this set of changes[1].

    [1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Iccdab43e94c62dadd3faa52c66b410f1955674fd

diff --git a/probes/lttng-uprobes.c b/probes/lttng-uprobes.c
index bda1d9b46cbce41a5e4a06c2c3b3124e634fbfe3..acb2627af029b83337556c9150f6f1133a2f4d00 100644 (file)
--- a/probes/lttng-uprobes.c
+++ b/probes/lttng-uprobes.c
@@ -9,7 +9,7 @@
  *
  */
 
-#include <linux/fdtable.h>
+#include <wrapper/fdtable.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/namei.h>
@@ -126,7 +126,7 @@ static struct inode *get_inode_from_fd(int fd)
         * Returns the file backing the given fd. Needs to be done inside an RCU
         * critical section.
         */
-       file = fcheck(fd);
+       file = lttng_lookup_fd_rcu(fd);
        if (file == NULL) {
                printk(KERN_WARNING "Cannot access file backing the fd(%d)\n", fd);
                inode = NULL;

diff --git a/wrapper/fdtable.h b/wrapper/fdtable.h
index 8f73559796a0655cdd36e770c674c60e23ba4a46..ccd57e0b0ec7c00b887d160d7ae613f2b9a11709 100644 (file)
--- a/wrapper/fdtable.h
+++ b/wrapper/fdtable.h
@@ -11,6 +11,20 @@
 #include <linux/version.h>
 #include <linux/fdtable.h>
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,11,0))
+static inline
+struct file *lttng_lookup_fd_rcu(unsigned int fd)
+{
+       return lookup_fd_rcu(fd);
+}
+#else
+static inline
+struct file *lttng_lookup_fd_rcu(unsigned int fd)
+{
+       return fcheck(fd);
+}
+#endif
+
 #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,7,0))
 
 int lttng_iterate_fd(struct files_struct *files,