Re: [PATCH v2] sendfile.2: Document more return values
From: Michael Kerrisk (man-pages) <hidden>
Date: 2015-12-16 15:13:14
Possibly related (same subject, not in this thread)
- 2015-12-11 · [PATCH v2] sendfile.2: Document more return values · Laurent Georget <hidden>
On 12/11/2015 09:10 PM, Laurent Georget wrote:
As of version 4.3, sendfile(2) can return more error codes than are
documented in sendfile.2. This patch adds some details:
- EINVAL can be returned if count is negative, from function rw_verify_area
in fs/read_write.c, called from do_sendfile, called from sys_sendfile.
- EOVERFLOW can be returned if count is too large, from rw_verify_area,
called from do_sendfile, called from sys_sendfile, or directly from
do_sendfile in one case (pos + count > max size of either in_fd or
out_fd).
- ESPIPE can be returned if offset is not a NULL pointer but the input file
does not support FMODE_PREAD, from do_sendfile, called from sys_sendfile.
Signed-off-by: Laurent Georget <redacted>
---
I removed EPERM from the patch because actually, it cannot be returned in a
vanilla kernel. I had it in my case because of SELinux. There is a call to the
LSM hook security_file_permission inside the function rw_verify_area.
Cheers,Thanks, Laurent. Applied. Cheers, Michael
quoted hunk
man2/sendfile.2 | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)diff --git a/man2/sendfile.2 b/man2/sendfile.2 index 93cf7e1..b56365e 100644 --- a/man2/sendfile.2 +++ b/man2/sendfile.2@@ -136,7 +136,10 @@ Bad address. Descriptor is not valid or locked, or an .BR mmap (2)-like operation is not available for -.IR in_fd . +.IR in_fd , +or +.I count +is negative. .TP .B EINVAL .I out_fd@@ -153,6 +156,16 @@ Unspecified error while reading from .B ENOMEM Insufficient memory to read from .IR in_fd . +.TP +.B EOVERFLOW +.I count +is too large, the operation would result in exceeding the maximum size of either +the input file or the output file. +.TP +.B ESPIPE +.I offset +is not NULL but the input file is not +.BR seek (2)-able. .SH VERSIONS .BR sendfile () first appeared in Linux 2.2.
-- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html