[PATCH RESEND 05/10] via-cuda: Fix re-initialization of reply_ptr and reading_reply

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From	Finn Thain <fthain@telegraphics.com.au>
Newsgroups	linux.kernel
Subject	[PATCH RESEND 05/10] via-cuda: Fix re-initialization of reply_ptr and reading_reply
Date	Sun, 01 Jan 2017 02:00:01 +0100
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When reading_reply is set, reply_ptr points into an adb_request struct.
Conversely, when reply_ptr instead points into the global cuda_rbuf,
reading_reply must be false.

Unfortunately, this rule can be violated because re-initialization
of reply_ptr and reading_reply presently depends on the TREQ input.

Fix this by re-initializing reply_ptr and reading_reply as soon as they
are known to be invalid.

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
 drivers/macintosh/via-cuda.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/macintosh/via-cuda.c b/drivers/macintosh/via-cuda.c
index 1cf1467..ae3da6b 100644
--- a/drivers/macintosh/via-cuda.c
+++ b/drivers/macintosh/via-cuda.c
@@ -592,6 +592,7 @@ cuda_interrupt(int irq, void *arg)
 	    }
 	    current_req = req->next;
 	    complete = 1;
+	    reading_reply = 0;
 	} else {
 	    /* This is tricky. We must break the spinlock to call
 	     * cuda_input. However, doing so means we might get
@@ -603,11 +604,10 @@ cuda_interrupt(int irq, void *arg)
 	    ibuf_len = reply_ptr - cuda_rbuf;
 	    memcpy(ibuf, cuda_rbuf, ibuf_len);
 	}
+	reply_ptr = cuda_rbuf;
 	if (TREQ_asserted(status)) {
 	    assert_TIP();
 	    cuda_state = reading;
-	    reply_ptr = cuda_rbuf;
-	    reading_reply = 0;
 	} else {
 	    cuda_state = idle;
 	    cuda_start();
-- 
2.10.2

Thread

[PATCH RESEND 00/10] Replace via-maciisi with via-cuda driver Finn Thain <fthain@telegraphics.com.au> - 2017-01-01 02:00 +0100
  [PATCH RESEND 04/10] via-cuda: Prevent read buffer overflow Finn Thain <fthain@telegraphics.com.au> - 2017-01-01 02:00 +0100
  [PATCH RESEND 10/10] m68k/mac: Replace via-maciisi driver with  via-cuda driver Finn Thain <fthain@telegraphics.com.au> - 2017-01-01 02:00 +0100
    Re: [PATCH RESEND 10/10] m68k/mac: Replace via-maciisi driver with  via-cuda driver Geert Uytterhoeven <geert@linux-m68k.org> - 2017-01-02 11:30 +0100
      Re: [PATCH RESEND 10/10] m68k/mac: Replace via-maciisi driver with  via-cuda driver Finn Thain <fthain@telegraphics.com.au> - 2017-01-03 01:40 +0100
  [PATCH RESEND 05/10] via-cuda: Fix re-initialization of reply_ptr and  reading_reply Finn Thain <fthain@telegraphics.com.au> - 2017-01-01 02:00 +0100
  [PATCH RESEND 08/10] via-cuda: Initialize data_index early and  increment consistently Finn Thain <fthain@telegraphics.com.au> - 2017-01-01 02:00 +0100
  [PATCH RESEND 02/10] via-cuda: Remove redundant temporary variable Finn Thain <fthain@telegraphics.com.au> - 2017-01-01 02:00 +0100
  [PATCH RESEND 01/10] via-cuda: Cleanup printk calls Finn Thain <fthain@telegraphics.com.au> - 2017-01-01 02:00 +0100
  [PATCH RESEND 09/10] via-cuda: Add support for Egret system  controller Finn Thain <fthain@telegraphics.com.au> - 2017-01-01 02:00 +0100
  [PATCH RESEND 03/10] via-cuda: Add TREQ, TIP and TACK signal helpers Finn Thain <fthain@telegraphics.com.au> - 2017-01-01 02:00 +0100
  [PATCH RESEND 07/10] via-cuda: Use spinlock_irq_save/restore instead  of enable/disable_irq Finn Thain <fthain@telegraphics.com.au> - 2017-01-01 02:00 +0100

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