lsfd: mark XMODE.m on fds monitored by select(2) and pselect6(2)

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index ed23b6109c27cc4226eb5002a3b8ddda7183d711..6d0cd0e41a4f758d2210307e5dab0ae90ca183d4 100644 (file)
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -32,6 +32,7 @@
 #include <ctype.h>
 #include <search.h>
 #include <poll.h>
+#include <sys/select.h>
 
 #include <sys/uio.h>
 #include <linux/sched.h>
@@ -1486,6 +1487,52 @@ static void mark_poll_fds_as_multiplexed(char *buf,
        free (local.iov_base);
 }
 
+static void mark_select_fds_as_multiplexed(char *buf,
+                                          pid_t pid, struct proc *proc)
+{
+       long nfds;
+       long fds[3];
+
+       struct iovec  local[3];
+       fd_set local_set[3];
+       struct iovec  remote[3];
+       ssize_t n;
+       ssize_t expected_n = 0;
+
+       struct list_head *f;
+
+       if (sscanf(buf, "%lx %lx %lx %lx", &nfds, fds + 0, fds + 1, fds + 2) != 4)
+               return;
+
+       if (nfds == 0)
+               return;
+
+       for (int i = 0; i < 3; i++) {
+               /* If the remote address for the fd_set is 0x0, no set is tehre. */
+               remote[i].iov_len = local[i].iov_len = fds[i]? sizeof(local_set[i]): 0;
+               expected_n += (ssize_t)local[i].iov_len;
+               local[i].iov_base = local_set + i;
+               remote[i].iov_base = (void *)(fds[i]);
+       }
+
+       n = process_vm_readv(pid, local, 3, remote, 3, 0);
+       if (n < 0 || n != expected_n)
+                       return;
+
+       list_for_each (f, &proc->files) {
+               struct file *file = list_entry(f, struct file, files);
+               if (is_opened_file(file) && !file->multiplexed) {
+                       int fd = file->association;
+                       if (nfds <= fd)
+                               continue;
+                       if ((fds[0] && FD_ISSET(fd, (fd_set *)local[0].iov_base))
+                           || (fds[1] && FD_ISSET(fd, (fd_set *)local[1].iov_base))
+                           || (fds[2] && FD_ISSET(fd, (fd_set *)local[2].iov_base)))
+                               file->multiplexed = 1;
+               }
+       }
+}
+
 static void parse_proc_syscall(struct lsfd_control *ctl __attribute__((__unused__)),
                               struct path_cxt *pc, pid_t pid, struct proc *proc)
 {
@@ -1519,6 +1566,22 @@ static void parse_proc_syscall(struct lsfd_control *ctl __attribute__((__unused_
                mark_poll_fds_as_multiplexed(ptr, pid, proc);
                break;
 #endif
+
+#ifdef SYS_select
+       case SYS_select:
+               mark_select_fds_as_multiplexed(ptr, pid, proc);
+               break;
+#endif
+#ifdef SYS_pselect6
+       case SYS_pselect6:
+               mark_select_fds_as_multiplexed(ptr, pid, proc);
+               break;
+#endif
+#ifdef         SYS_pselect6_time64
+       case SYS_pselect6_time64:
+               mark_select_fds_as_multiplexed(ptr, pid, proc);
+               break;
+#endif
        }
 }