Hi, There are two things a little different. 1) hijack a syscall 2) add a syscall 1 and 2 in kernel module!! no compile kernel.... if you want 1. You have only replace the entry on sys_call_table for your function. Look at http://kernelnewbies.org/code/intercept for example. 2) you have to replace a entry on sys_call_table that isnīt used. Like up the 222, syscall_table[224]. Replace for your syscall. Like hijack a syscall. For the program call your syscall, do it. #include <asm/unistd.h> // _syscallX macro #define __NR_my_newsyscall 224 // the number of your syscall on sys_call_table _syscall1(int,my_newsyscall,int,x) //example, depend how many arg ok after it, is only call the syscall like: main(){ int i; i=my_newsyscall(100); } The only difference beteween add and hijack is how the program will call your syscall. case 2, you have to inform the user program which entry on sys_call_table is your syscall. Case 1.... If I forgot some detail, anyone.... []īs Thobias -- Watch your mouth, kid, or you'll find yourself floating home. -- Han Solo ---- Thobias Salazar Trevisan <thobias@cos.ufrj.br> Home Page - http://www.cos.ufrj.br/~thobias Parallel Computing Laboratory / COPPE Federal University of Rio de Janeiro Brazil __________________________ | | | Against - HTML Mail | | | -------------------------- > > I use kernel 2.4.2. At this stage, my code: > #include <linux/unistd.h> > ...... > /* generate syscall stub */ > _syscall4(int, foo, struct result *, &result, > const char *, filename, int, flags, int, mode); > /*line143 */ > > /* invoke system call */ > m_errno = foo(&result, "mytest", O_RDONLY, 0444); > ...... > > gives me error: observer.c:143: `__res' undeclared (first use in this > function) > > as I compile my above userland code as follow: > #gcc -c -Wall -O2 observer.c > > my module code is: > asmlinkage int sys_foo(struct result *res, const char *filename, int > flags, int mode) > { > ... > } > > I would like to look at your code. You may send it to me directly at > honghsu@bellatlantic.net > > Many thanks, > -Hong > > > > - > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > IRC Channel: irc.openprojects.net / #kernelnewbies > Web Page: http://www.kernelnewbies.org/ > - Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ IRC Channel: irc.openprojects.net / #kernelnewbies Web Page: http://www.kernelnewbies.org/
