d31563b5f9
Since eventfd's document has clearly stated: A write(2) call adds
the 8-byte integer value supplied in its buffer to the counter.
However, in the current implementation, the following code snippet
did not cause an error:
char str[16] = "hello world";
uint64_t value;
ssize_t size;
int fd;
fd = eventfd(0, 0);
size = write(fd, &str, strlen(str));
printf("eventfd: test writing a string, size=%ld\n", size);
size = read(fd, &value, sizeof(value));
printf("eventfd: test reading as uint64, size=%ld, valus=0x%lX\n",
size, value);
close(fd);
And its output is:
eventfd: test writing a string, size=8
eventfd: test reading as uint64, size=8, valus=0x6F77206F6C6C6568
By checking whether count is equal to sizeof(ucnt), such errors
could be detected. It also follows the requirements of the manual.
Signed-off-by: Wen Yang <wenyang.linux@foxmail.com>
Link: https://lore.kernel.org/r/tencent_10AAA44731FFFA493F9F5501521F07DD4D0A@qq.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Eric Biggers <ebiggers@google.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.