What is the difference between ioctl (), unlocked_ioctl () and ... - linux
Follows an explanation of the patch that introduced unlocked_ioctl and compat_ioctl into 2.6.11. The removal of the ioctl field happened a lot later, in 2.6.36. Explanation: When ioctl was executed, it took the Big Kernel Lock (BKL), so nothing else could execute at the same time. This is very bad on a multiprocessor machine, so there was a big ...
Usage difference between device files, ioctl, sysfs, netlink
2018年12月16日 · Adding more to confuse :" ioctl : However, ioctl is deprecated in the kernel, and you will find it hard to get any drivers with new uses of ioctl accepted upstream. The kernel maintainers dislike ioctl because it makes kernel code and application code too interdependent, and it is hard to keep both of them in step across kernel versions and ...
Are ioctl calls blocking? - Unix & Linux Stack Exchange
2021年7月1日 · GPIO_V2_LINE_SET_VALUES_IOCTL seems safe enough; it matches the expected use of ioctl, “manipulat[ing] the underlying device parameters of special files”. It is implemented in linereq_set_values , which acquires a lock, but I don’t think that lock can block for an indefinite amount of time (its users are all non-blocking).
Get all ioctl code and which module they map - linux
2019年5月13日 · _IO an ioctl with no parameters _IOW an ioctl with write parameters (copy_from_user) _IOR an ioctl with read parameters (copy_to_user) _IOWR an ioctl with both write and read parameters. But some ioctl definitions are not following this prescription and are not different from usual macros, like in the case of tty driver:
IOCTL() Library for Windows - Unix & Linux Stack Exchange
2016年1月9日 · In Unix, IOCTL (I/O control) is a catch-all system call to ask for random, device-dependent actions. The exact calls supported, what actions can be requested, and so on, are extremely operating system (and device driver) dependent. You'll probably find some "standard" ones agree between Unices, but not across the board. To Windows, just forget it.
echo test | stty -echo -> stty: standard input: Inappropriate ioctl …
stty connects to the terminal on its standard input. You need to run the Perl script with its standard input connected to the terminal that you want to act on.
Set can baudrate with ioctl or similar from C/C++
2020年5月7日 · I'm currently setting the baudrate of my can0 with ip link: /sbin/ip link set can0 up type can bitrate 250000 I'm just wondering how to do the same from within C/C++?
How to I set the permissions necessary to make the ioctl …
2019年7月6日 · The ioctl call is part of the cdda-player app I call as follows: cdda-player -ev /dev/sr0 After taking a look into the sourcecode of libcdio, I found out that this line of code makes trouble: int i_rc = ioctl (p_env->gen.fd, CDROM_SEND_PACKET, &cgc); When I run the code as root (using sudo), everything works fine. Here are the permissions for ...
Is there any difference between #include <linux/ioctl.h> and …
2022年5月3日 · linux/ioctl.h shouldn’t be referenced directly in user code; however that’s what you’d use when writing a Linux driver. Basically, if you see #include <sys/ioctl.h>, you’re looking at program code; if you see #include <linux/ioctl.h>, you’re looking at either kernel (device driver) code, or program code with over-enthusiastic #includes.
FIDEDUPERANGE ioctl doesn't behave as expected on btrfs
2021年1月18日 · remap_file_range() handles the functionality for multiple ioctls adapted from btrfs that were originally designed and implemented separately in btrfs. In the clone ioctls, src_length == 0 means clone to the end of the file. In the dedup ioctl, src_length == 0 means dedup nothing. I forget exactly when, but there was an effort to unify the clone ...