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From: Johannes Berg <johannes@sipsolutions.net>
To: Anton Ivanov <anton.ivanov@cambridgegreys.com>,
	rrs@researchut.com, linux-um@lists.infradead.org
Subject: Re: uml segfault during I/O
Date: Fri, 18 Oct 2019 10:57:15 +0200	[thread overview]
Message-ID: <7a2c14d38873a5c19f395cc7861fd9811589ca79.camel@sipsolutions.net> (raw)
In-Reply-To: <b742bf38-9cf5-e62f-55df-915929fd526f@cambridgegreys.com>

On Fri, 2019-10-18 at 08:35 +0100, Anton Ivanov wrote:
> 
> Still happening with 5.2.21, albeit a bit more difficult to reproduce.

Just randomly reviewing the code, isn't there a bug in io_thread()?

--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -1602,7 +1602,8 @@ int io_thread(void *arg)
                written = 0;
 
                do {
-                       res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written, n);
+                       res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written,
+                                           n - written);
                        if (res >= 0) {
                                written += res;
                        }

johannes


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  reply	other threads:[~2019-10-18  8:57 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-17 11:37 uml segfault during I/O Ritesh Raj Sarraf
     [not found] ` <1ccf27d8-6b6a-7d08-acef-93077f07511b@cambridgegreys.com>
2019-10-17 13:30   ` Ritesh Raj Sarraf
2019-10-17 13:33     ` Anton Ivanov
2019-10-17 15:03       ` Anton Ivanov
2019-10-17 16:29         ` Anton Ivanov
2019-10-18  7:35           ` Anton Ivanov
2019-10-18  8:57             ` Johannes Berg [this message]
2019-10-18  9:13               ` Anton Ivanov
2019-10-18  9:49                 ` Anton Ivanov
2019-10-18  9:55             ` Anton Ivanov
2019-10-18 10:51               ` Anton Ivanov
2019-10-28 16:51                 ` Anton Ivanov

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