>From http://kernelnewbies.org/FAQ/asmlinkage :
What is asmlinkage? The asmlinkage tag is one other thing that we should observe about this simple function. This is a #define for some gcc magic that tells the compiler that the function should not expect to find any of its arguments in registers (a common optimization), but only on the CPU's stack. Recall our earlier assertion that system_call consumes its first argument, the system call number, and allows up to four more arguments that are passed along to the real system call. system_call achieves this feat simply by leaving its other arguments (which were passed to it in registers) on the stack. All system calls are marked with the asmlinkage tag, so they all look to the stack for arguments. Of course, in sys_ni_syscall's case, this doesn't make any difference, because sys_ni_syscall doesn't take any arguments, but it's an issue for most other system calls. And, because you'll be seeing asmlinkage in front of many other functions, I thought you should know what it was about. On 07/22/2010 02:00 PM, Smital Desai wrote: > Hi, > > I was just going through some kernel init sequence where a saw something like > this – > > asmlinkage void __init start_kernel(void) > > What does this asmlinkage modifier/ qualifier do ? > > help is greatly appreciated .... > > Thanks and Regards > Smital Desai > > This Email may contain confidential or privileged information for the > intended recipient (s) If you are not the intended recipient, please do not > use or disseminate the information, notify the sender and delete it from your > system. > > ______________________________________________________________________ > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to [email protected] > Please read the FAQ at http://kernelnewbies.org/FAQ > >
