Questions tagged [os-userspace]
9 questions
3
votes
1 answer
What's the relationship between kernel space and kernel stack?
I know kernel space is the memory section where the core of operating system executes and provides its services, and the user space is one where user programs run. Also I know that a process has its own stack, heap, data, and text section in its…
Mengfan Ma
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How are operating system containers different from virtual machines?
Everywhere I can see is how Docker can be different from virtual machine but nowhere there is a answer on how basic OS containers are different from virtual machine.
If we consider the basics, it looks like both are same i.e. an operating system is…
Nikhil Agrawal
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vote
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How to access qseecom driver from java code in user space
I want to write security APIs for my Qualcomm device with snapdragon 410c, for that purpose I want to use qseecom driver, can someone point me how can I access qseecom driver from my java code in userspace.
harshalkwagh
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0
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1 answer
Why can User call a system call directly?
Before I ask the question, the following is what I know.
The system call is in the kernel area.
The kernel area cannot be used (accessed) directly by the user.
There are two ways to call a system call.
direct call
wrapping function (API) that…
grower
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0
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1 answer
Converting Jiffies to Microseconds
I want to convert the jiffies time that is extracted from /proc/pid/stat stats, I can convert it to seconds but I am looking for resolution in microseconds or nanoseconds if possible.
I have already looked at Converting jiffies to milli seconds but…
0
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0 answers
linux-xlnx kernel updating from 3.17.0 to 5.15.0, get_fs(), set_fs() macros
I am new to kernel driver development and I am trying update kernel version of a legacy project.
Example code is below
#include
struct file *file_open(const char *path, int flags, int rights)
{
struct file *filptr = NULL;
…
selim
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0
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1 answer
can kernel identify which userapp got killed/closed, among few apps it is serving
I'm writing a linux kernel driver, which creates a char device file "/dev/my_file".
Multiple userspace applications do open() of this file and use the ioctl cmd provided to register app specific data. IOCTL also provides for deregister cmd, which…
Sheetal T
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2 answers
Is there any method of reading and writing more than 1 DW from the user-space of PCI device?
Is there any method of reading and writing more than 1 DW from the user-space of PCI device?
I am currently using https://github.com/numato-viya/pcimem this code for accessing the data from the user space of the PCI device but the limitation of this…
Hamayoun Ahmad
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-1
votes
1 answer
How to find how much userspace memory available to use in Linux environment?
I am using CONFIG_VMSPLIT_1G config in my 32-bit Linux image. so 3GB of virtual address space is allocated to kernel and 1GB of virtual address space to userspace. Now if i run stressapptest in userspace with 80% of the available memory shown using…
Kavin A
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