[gcc(refs/users/marxin/heads/lto-plugin-get_symbols_v3-v4)] lto-plugin: make claim_file_handler thread-safe

[Martin Liska <marxin@gcc.gnu.org>]

https://gcc.gnu.org/g:9770238db77eab4243696e3f0b71df11777a715a

commit 9770238db77eab4243696e3f0b71df11777a715a
Author: Martin Liska <mliska@suse.cz>
Date:   Mon May 16 14:18:41 2022 +0200

    lto-plugin: make claim_file_handler thread-safe
    
    lto-plugin/ChangeLog:
    
            * lto-plugin.c (plugin_lock): New lock.
            (claim_file_handler): Use mutex for critical section.
            (onload): Initialize mutex.

Diff:
---
 lto-plugin/lto-plugin.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/lto-plugin/lto-plugin.c b/lto-plugin/lto-plugin.c
index 00b760636dc..13118c4983c 100644
--- a/lto-plugin/lto-plugin.c
+++ b/lto-plugin/lto-plugin.c
@@ -55,6 +55,7 @@ along with this program; see the file COPYING3.  If not see
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/types.h>
+#include <pthread.h>
 #ifdef HAVE_SYS_WAIT_H
 #include <sys/wait.h>
 #endif
@@ -157,6 +158,9 @@ enum symbol_style
   ss_uscore,	/* Underscore prefix all symbols.  */
 };
 
+/* Plug-in mutex.  */
+static pthread_mutex_t plugin_lock;
+
 static char *arguments_file_name;
 static ld_plugin_register_claim_file register_claim_file;
 static ld_plugin_register_all_symbols_read register_all_symbols_read;
@@ -1262,15 +1266,18 @@ claim_file_handler (const struct ld_plugin_input_file *file, int *claimed)
 			      lto_file.symtab.syms);
       check (status == LDPS_OK, LDPL_FATAL, "could not add symbols");
 
+      pthread_mutex_lock (&plugin_lock);
       num_claimed_files++;
       claimed_files =
 	xrealloc (claimed_files,
 		  num_claimed_files * sizeof (struct plugin_file_info));
       claimed_files[num_claimed_files - 1] = lto_file;
+      pthread_mutex_unlock (&plugin_lock);
 
       *claimed = 1;
     }
 
+  pthread_mutex_lock (&plugin_lock);
   if (offload_files == NULL)
     {
       /* Add dummy item to the start of the list.  */
@@ -1333,11 +1340,12 @@ claim_file_handler (const struct ld_plugin_input_file *file, int *claimed)
 	offload_files_last_lto = ofld;
       num_offload_files++;
     }
+  pthread_mutex_unlock (&plugin_lock);
 
   goto cleanup;
 
  err:
-  non_claimed_files++;
+  __atomic_fetch_add (&non_claimed_files, 1, __ATOMIC_RELAXED);
   free (lto_file.name);
 
  cleanup:
@@ -1415,6 +1423,12 @@ onload (struct ld_plugin_tv *tv)
   struct ld_plugin_tv *p;
   enum ld_plugin_status status;
 
+  if (pthread_mutex_init (&plugin_lock, NULL) != 0)
+    {
+      fprintf (stderr, "mutex init failed\n");
+      abort ();
+    }
+
   p = tv;
   while (p->tv_tag)
     {