From 70ad35db3321a6d129245979de4ac9d06eed897c Mon Sep 17 00:00:00 2001
From: Namhyung Kim <namhyung@kernel.org>
Date: Wed, 19 Oct 2016 10:23:41 +0900
Subject: [PATCH] pstore: Convert console write to use ->write_buf
Maybe I'm missing something, but I don't know why it needs to copy the
input buffer to psinfo->buf and then write. Instead we can write the
input buffer directly. The only implementation that supports console
message (i.e. ramoops) already does it for ftrace messages.
For the upcoming virtio backend driver, it needs to protect psinfo->buf
overwritten from console messages. If it could use ->write_buf method
instead of ->write, the problem will be solved easily.
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
fs/pstore/platform.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 60e6db6f5da2b..729677e18e364 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -585,8 +585,8 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c)
} else {
spin_lock_irqsave(&psinfo->buf_lock, flags);
}
- memcpy(psinfo->buf, s, c);
- psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, 0, c, psinfo);
+ psinfo->write_buf(PSTORE_TYPE_CONSOLE, 0, &id, 0,
+ s, 0, c, psinfo);
spin_unlock_irqrestore(&psinfo->buf_lock, flags);
s += c;
c = e - s;
--
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