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System call Handling

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# 1  
Old 11-04-2012
System call Handling
In Linux in older versions the user calls were routed to their corresponding system calls through interrupt 80 which was handled by system_call().
I mean say for the user mode function read() there was a corresponding kernel mode function.
The system call index was fed in eax register and was used to index into system call table to find the corresponding kernel mode function.

But in newer linux versions I heard this has changed and interrupts are no more used.
Will anyone let me know what is the new mechanism to handle system calls?
Any good link will help.
# 2  
Old 11-07-2012
You can read with read( . . . ) or with syscall(SYS_READ, . . . ). This allows one to write their own libc clone and add side effects to calls like read(). One app used it to write restart checkpoints.
Last edited by DGPickett; 11-07-2012 at 06:24 PM..
# 3  
Old 11-07-2012
Lots of details here: System call - Wikipedia, the free encyclopedia
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