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pstore: Remove needless lock during console writes
authorKees Cook <keescook@chromium.org>
Thu, 1 Nov 2018 21:08:07 +0000 (14:08 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 11 Jun 2019 10:20:52 +0000 (12:20 +0200)
commit b77fa617a2ff4d6beccad3d3d4b3a1f2d10368aa upstream.

Since the console writer does not use the preallocated crash dump buffer
any more, there is no reason to perform locking around it.

Fixes: 70ad35db3321 ("pstore: Convert console write to use ->write_buf")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/pstore/platform.c

index b821054..805283b 100644 (file)
@@ -476,31 +476,14 @@ static void pstore_unregister_kmsg(void)
 #ifdef CONFIG_PSTORE_CONSOLE
 static void pstore_console_write(struct console *con, const char *s, unsigned c)
 {
-       const char *e = s + c;
+       struct pstore_record record;
 
-       while (s < e) {
-               struct pstore_record record;
-               unsigned long flags;
-
-               pstore_record_init(&record, psinfo);
-               record.type = PSTORE_TYPE_CONSOLE;
-
-               if (c > psinfo->bufsize)
-                       c = psinfo->bufsize;
+       pstore_record_init(&record, psinfo);
+       record.type = PSTORE_TYPE_CONSOLE;
 
-               if (oops_in_progress) {
-                       if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
-                               break;
-               } else {
-                       spin_lock_irqsave(&psinfo->buf_lock, flags);
-               }
-               record.buf = (char *)s;
-               record.size = c;
-               psinfo->write(&record);
-               spin_unlock_irqrestore(&psinfo->buf_lock, flags);
-               s += c;
-               c = e - s;
-       }
+       record.buf = (char *)s;
+       record.size = c;
+       psinfo->write(&record);
 }
 
 static struct console pstore_console = {