/*
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception-*.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void syscall(struct trapframe *tf) {
int callno;
int32_t retval;
int err;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
off_t pos, new_pos;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t) tf->tf_a0, (userptr_t) tf->tf_a1);
break;
case SYS_open:
err = sys_open((userptr_t) tf->tf_a0, (int) tf->tf_a1,
(int) tf->tf_a2, &retval);
break;
case SYS_read:
err = sys_read((int) tf->tf_a0, (userptr_t) tf->tf_a1,
(int) tf->tf_a2, &retval);
break;
case SYS_write:
err = sys_write((int) tf->tf_a0, (userptr_t) tf->tf_a1,
(int) tf->tf_a2, &retval);
break;
case SYS_lseek:
pos = (((off_t)tf->tf_a2 << 32) | tf->tf_a3);
err = sys_lseek((userptr_t) tf->tf_a0, pos,
(userptr_t)(tf->tf_sp+16), &new_pos);
if (err == 0)
{
retval = (int32_t)(new_pos >> 32);
tf->tf_v1 = (int32_t)(new_pos & 0xFFFFFFFF);
}
break;
case SYS_close:
err = sys_close((userptr_t) tf->tf_a0, &retval);
break;
case SYS_dup2:
err = sys_dup2((userptr_t) tf->tf_a0, (userptr_t) tf->tf_a1, &retval);
break;
case SYS_getpid:
err = sys_getpid(&retval);
break;
case SYS_sbrk:
err = sys_sbrk((userptr_t)tf->tf_a0, &retval);
break;
case SYS_fork:
err = sys_fork(tf, &retval);
break;
case SYS_execv:
err = sys_execv((userptr_t) tf->tf_a0, (userptr_t) tf->tf_a1, &retval);
retval = 0;
break;
case SYS_waitpid:
err = sys_waitpid((userptr_t) tf->tf_a0, (userptr_t) tf->tf_a1,
(userptr_t) tf->tf_a2, &retval);
break;
case SYS__exit:
//kprintf("TEMPPPP:Exit has been called! \n");
err = sys__exit((int) tf->tf_a0);
break;
/* Add stuff here */
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
/*
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void
syscall(struct trapframe *tf)
{
int callno;
int32_t retval;
int err;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1);
break;
/* ASST2: These implementations of read and write only work for
* console I/O (stdin, stdout and stderr file descriptors)
*/
case SYS_read:
err = sys_read(tf->tf_a0, (userptr_t)tf->tf_a1, tf->tf_a2,
&retval);
break;
case SYS_write:
err = sys_write(tf->tf_a0, (userptr_t)tf->tf_a1, tf->tf_a2,
&retval);
break;
/* process calls */
case SYS__exit:
thread_exit(_MKWAIT_EXIT(tf->tf_a0));
panic("Returning from exit\n");
case SYS_fork:
err = sys_fork(tf, &retval);
break;
/* ASST2 - You need to fill in the code for each of these cases */
case SYS_getpid:
err = sys_getpid(&retval);
break;
case SYS_waitpid:
if(sys_waitpid(tf->tf_a0, \
(userptr_t)tf->tf_a1, tf->tf_a2, &retval) == -1)
{
err=retval;
}
else{
err=0;
}
break;
case SYS_kill:
err = sys_kill(tf->tf_a0, tf->tf_a1);
break;
/* Even more system calls will go here */
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
if (err) {
/*
* Return the error code. This gets converted at
* userlevel to a return value of -1 and the error
* code in errno.
*/
tf->tf_v0 = err;
tf->tf_a3 = 1; /* signal an error */
}
else {
/* Success. */
tf->tf_v0 = retval;
tf->tf_a3 = 0; /* signal no error */
}
/*
* Now, advance the program counter, to avoid restarting
* the syscall over and over again.
*/
tf->tf_epc += 4;
/* Make sure the syscall code didn't forget to lower spl */
KASSERT(curthread->t_curspl == 0);
/* ...or leak any spinlocks */
KASSERT(curthread->t_iplhigh_count == 0);
}
/*
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void
syscall(struct trapframe *tf)
{
//kprintf("Starting syscall\n");
int callno;
int32_t retval;
int err;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1);
break;
#ifdef UW
case SYS_write:
err = sys_write((int)tf->tf_a0,
(userptr_t)tf->tf_a1,
(int)tf->tf_a2,
(int *)(&retval));
break;
case SYS__exit:
sys__exit((int)tf->tf_a0);
/* sys__exit does not return, execution should not get here */
panic("unexpected return from sys__exit");
break;
case SYS_getpid:
err = sys_getpid((pid_t *)&retval);
break;
case SYS_waitpid:
err = sys_waitpid((pid_t)tf->tf_a0,
(userptr_t)tf->tf_a1,
(int)tf->tf_a2,
(pid_t *)&retval);
break;
case SYS_fork:
err = sys_fork(tf, (pid_t *)&retval);
break;
case SYS_execv:
err=sys_execv((char *)tf->tf_a0, (char **) tf->tf_a1);
break;
#endif // UW
/* Add stuff here */
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
if (err) {
/*
* Return the error code. This gets converted at
* userlevel to a return value of -1 and the error
* code in errno.
*/
tf->tf_v0 = err;
tf->tf_a3 = 1; /* signal an error */
}
else {
/* Success. */
tf->tf_v0 = retval;
tf->tf_a3 = 0; /* signal no error */
}
/*
* Now, advance the program counter, to avoid restarting
* the syscall over and over again.
*/
tf->tf_epc += 4;
/* Make sure the syscall code didn't forget to lower spl */
KASSERT(curthread->t_curspl == 0);
/* ...or leak any spinlocks */
KASSERT(curthread->t_iplhigh_count == 0);
}
/**
* SPB & FAR
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void
syscall(struct trapframe *tf)
{
int callno, err;
int32_t retval;
off_t pos = 0;
off_t lsret;
int whence;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0, (userptr_t)tf->tf_a1);
break;
case SYS_open:
err = sys_open((const char*)tf->tf_a0, tf->tf_a1, &retval);
break;
case SYS_read:
err = sys_read((int)tf->tf_a0,(void*)tf->tf_a1,(size_t)tf->tf_a2,&retval);
break;
case SYS_write:
err = sys_write((int)tf->tf_a0,(const void*)tf->tf_a1,(size_t)tf->tf_a2,&retval);
break;
case SYS_close:
err = sys_close((int)tf->tf_a0, &retval);
break;
case SYS_lseek:
pos |= (off_t)tf->tf_a2;
pos <<= 32; //puts a2 and a3 into one var.
pos |= (off_t)tf->tf_a3;
err = copyin((const userptr_t)tf->tf_sp+16, &whence, sizeof(whence));
if (err)
break;
err = sys_lseek((int)tf->tf_a0, pos, (int)whence, &lsret);
if(!err){
retval = lsret>>32;
tf->tf_v1 = lsret;
}
break;
case SYS_dup2:
err = sys_dup2((int)tf->tf_a0 , (int)tf->tf_a1, &retval);
break;
case SYS_chdir:
err = sys_chdir((const char*)tf->tf_a0);
break;
case SYS___getcwd:
err = sys___getcwd((char*)tf->tf_a0, (size_t)tf->tf_a1, &retval);
break;
case SYS_fork:
err = sys_fork(tf, &retval);
break;
case SYS_getpid:
err = sys_getpid(&retval);
break;
case SYS__exit:
err = sys__exit((int)tf->tf_a0, &retval);
break;
case SYS_waitpid:
err = sys_waitpid((int) tf->tf_a0, (int*) tf->tf_a1, tf->tf_a2, &retval);
break;
case SYS_execv:
err = sys_execv((const char*) tf->tf_a0, (char**) tf->tf_a1, &retval);
break;
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
/*
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void
syscall(struct trapframe *tf)
{
int callno;
int32_t retval;
int err;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1);
break;
//F*****G A2
case SYS_write:
err=write(tf->tf_a0,(void*)tf->tf_a1,tf->tf_a2);
break;
/* Add stuff here */
case SYS_open:
break;
case SYS_close:
break;
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
if (err) {
/*
* Return the error code. This gets converted at
* userlevel to a return value of -1 and the error
* code in errno.
*/
tf->tf_v0 = err;
tf->tf_a3 = 1; /* signal an error */
}
else {
/* Success. */
tf->tf_v0 = retval;
tf->tf_a3 = 0; /* signal no error */
}
/*
* Now, advance the program counter, to avoid restarting
* the syscall over and over again.
*/
tf->tf_epc += 4;
/* Make sure the syscall code didn't forget to lower spl */
KASSERT(curthread->t_curspl == 0);
/* ...or leak any spinlocks */
KASSERT(curthread->t_iplhigh_count == 0);
}
void
syscall(struct trapframe *tf)
{
int callno;
int32_t retval;
int err;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
uint32_t v0, v1;
off_t pos;
int whence;
//userptr_t *status;
struct stat statbuf;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1); /* the syscall ov*/
break;
case SYS_open:
err = sys_open((const_userptr_t)tf->tf_a0, tf->tf_a1, (mode_t)tf ->tf_a2, &retval);
break;
case SYS_close:
err = sys_close((tf->tf_a0),&retval);
break;
case SYS_read:
err = sys_read(tf->tf_a0, (userptr_t)tf->tf_a1, (size_t)tf -> tf_a2, &retval);
//retval = (int32_t)bytes;
break;
case SYS_write:
err = sys_write(tf->tf_a0, (userptr_t)tf->tf_a1, (size_t)tf -> tf_a2, &retval);
//retval = (int32_t)bytes;
break;
case SYS_lseek:
pos = tf->tf_a2;
pos = pos << 32;
pos += tf -> tf_a3;
err = copyin((const_userptr_t)tf->tf_sp+16,&whence,sizeof(int));
if(err)
{
break;
}
err = sys_lseek(tf->tf_a0, pos, whence, &v0, &v1);
if(err)
{
break;
}
retval = v0;
tf->tf_v1 = v1;
break;
case SYS__exit:
sys__exit(tf->tf_a0);
// We are only here because of one of 2 reasons. We tried to kill the initial thread
// while there was/were (an) immediate child(ren) of it running.
// *NOTE* I'm actually NOT sure if that's a valid reason to be here
// Second reason? Something went horribly, horribly wrong
err = 0;
break;
case SYS_dup2:
err = sys_dup2(tf->tf_a0,tf->tf_a1,&retval);
break;
case SYS_fstat:
err = sys_fstat(tf->tf_a0, &statbuf);
break;
case SYS_fork:
err = sys_fork(tf, &retval);
break;
case SYS_getpid:
err = sys_getpid(&retval);
break;
case SYS_waitpid:
err = sys_waitpid(tf->tf_a0, (int*)tf->tf_a1, (int)tf->tf_a2, &retval);
break;
case SYS___getcwd:
err = sys___getcwd((char*)tf->tf_a0,(size_t)tf->tf_a1,&retval);
break;
case SYS_chdir:
err = sys_chdir((char*)tf->tf_a0,&retval);
break;
case SYS_execv:
err = sys_execv((const char*)tf->tf_a0, (char**)tf->tf_a1);
break;
case SYS_sbrk:
err = sbrk((int)tf->tf_a0,&retval);
break;
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
if (err) {
/*
* Return the error code. This gets converted at
* userlevel to a return value of -1 and the error
* code in errno.
*/
tf->tf_v0 = err;
tf->tf_a3 = 1; /* signal an error */
}
else {
/* Success. */
tf->tf_v0 = retval;
tf->tf_a3 = 0; /* signal no error */
}
/*
* Now, advance the program counter, to avoid restarting
* the syscall over and over again.
*/
tf->tf_epc += 4;
/* Make sure the syscall code didn't forget to lower spl */
KASSERT(curthread->t_curspl == 0);
/* ...or leak any spinlocks */
KASSERT(curthread->t_iplhigh_count == 0);
}
/*
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception-*.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void
syscall(void *trapframe, unsigned long junk)
{
curproc->rt = (curproc->rt == BACKGROUND_U ? BACKGROUND_K : INTERACTIVE_K);
(void)junk;
struct trapframe *tf = (struct trapframe*)trapframe;
if(!curproc->context)
curproc->context = kmalloc(sizeof(struct trapframe));
memcpy(curproc->context, tf, sizeof(struct trapframe));
int callno;
int32_t retval;
int err;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1);
break;
/* Add stuff here */
case SYS__exit:
_exit((int)tf->tf_a0);
break;
case SYS_chdir:
err = chdir((const char*)tf->tf_a0);
break;
case SYS_close:
err = close((int)tf->tf_a0,
&retval);
break;
case SYS_dup2:
err = dup2((int)tf->tf_a0,
(int)tf->tf_a1,
&retval);
break;
case SYS_execv:
err = execv((const char*)tf->tf_a0,
(char **)tf->tf_a1);
break;
case SYS_fork:
err = fork(&retval);
break;
case SYS___getcwd:
err = __getcwd((char*)tf->tf_a0,
(size_t)tf->tf_a1,
&retval);
break;
case SYS_getpid:
err = getpid(&retval);//always return 0
break;
case SYS_lseek:
err = lseek((int)tf->tf_a0,
(off_t)(tf->tf_a1 | tf->tf_a2),
(int)tf->tf_a3,
(off_t*)&retval);
break;
case SYS_open:
err = open((const char*)tf->tf_a0,
(int)tf->tf_a1,
&retval);
break;
case SYS_read:
err = read((int)tf->tf_a0,
(void*)tf->tf_a1,
(size_t)tf->tf_a2,
&retval);
break;
case SYS_waitpid:
err = waitpid((pid_t)tf->tf_a0,
(int *)tf->tf_a1,
(int)tf->tf_a2,
&retval);
break;
case SYS_write:
err = write((int)tf->tf_a0,
(userptr_t)tf->tf_a1,
(size_t)tf->tf_a2,
&retval);
break;
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
if (err) {
/*
* Return the error code. This gets converted at
* userlevel to a return value of -1 and the error
* code in errno.
*/
tf->tf_v0 = err;
tf->tf_a3 = 1; /* signal an error */
}
else {
/* Success. */
tf->tf_v0 = retval;
tf->tf_a3 = 0; /* signal no error */
}
/*
* Now, advance the program counter, to avoid restarting
* the syscall over and over again.
*/
tf->tf_epc += 4;
/* Make sure the syscall code didn't forget to lower spl */
KASSERT(curthread->t_curspl == 0);
/* ...or leak any spinlocks */
KASSERT(curthread->t_iplhigh_count == 0);
curproc->rt = (curproc->rt == BACKGROUND_K ? BACKGROUND_U : INTERACTIVE_U);
}
/*
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void
syscall(struct trapframe *tf)
{
int callno;
int32_t retval;
int err;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
/* note the casts to userptr_t */
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1);
break;
/* process calls */
case SYS_fork:
err = sys_fork(tf, &retval);
break;
case SYS_execv:
err = sys_execv(
(userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1);
break;
case SYS__exit:
sys__exit(tf->tf_a0);
panic("Returning from exit\n");
case SYS_waitpid:
err = sys_waitpid(
tf->tf_a0,
(userptr_t)tf->tf_a1,
tf->tf_a2,
&retval);
break;
case SYS_getpid:
err = sys_getpid(&retval);
break;
/* file calls */
case SYS_open:
err = sys_open(
(userptr_t)tf->tf_a0,
tf->tf_a1,
tf->tf_a2,
&retval);
break;
case SYS_dup2:
err = sys_dup2(
tf->tf_a0,
tf->tf_a1,
&retval);
break;
case SYS_close:
err = sys_close(tf->tf_a0);
break;
case SYS_read:
err = sys_read(
tf->tf_a0,
(userptr_t)tf->tf_a1,
tf->tf_a2,
&retval);
break;
case SYS_write:
err = sys_write(
tf->tf_a0,
(userptr_t)tf->tf_a1,
tf->tf_a2,
&retval);
break;
case SYS_lseek:
{
/*
* Because the position argument is 64 bits wide,
* it goes in the a2/a3 registers and we have to
* get "whence" from the stack. Furthermore, the
* return value is 64 bits wide, so the extra
* part of it goes in the v1 register.
*
* This is a trifle messy.
*/
uint64_t offset;
int whence;
off_t retval64;
join32to64(tf->tf_a2, tf->tf_a3, &offset);
err = copyin((userptr_t)tf->tf_sp + 16,
&whence, sizeof(int));
if (err) {
break;
}
err = sys_lseek(tf->tf_a0, offset, whence, &retval64);
if (err) {
break;
}
split64to32(retval64, &tf->tf_v0, &tf->tf_v1);
retval = tf->tf_v0;
}
break;
case SYS_chdir:
err = sys_chdir((userptr_t)tf->tf_a0);
break;
case SYS___getcwd:
err = sys___getcwd(
(userptr_t)tf->tf_a0,
tf->tf_a1,
&retval);
break;
/* Even more system calls will go here */
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
if (err) {
/*
* Return the error code. This gets converted at
* userlevel to a return value of -1 and the error
* code in errno.
*/
tf->tf_v0 = err;
tf->tf_a3 = 1; /* signal an error */
}
else {
/* Success. */
tf->tf_v0 = retval;
tf->tf_a3 = 0; /* signal no error */
}
/*
* Now, advance the program counter, to avoid restarting
* the syscall over and over again.
*/
tf->tf_epc += 4;
/* Make sure the syscall code didn't forget to lower spl */
KASSERT(curthread->t_curspl == 0);
/* ...or leak any spinlocks */
KASSERT(curthread->t_iplhigh_count == 0);
}
/*
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception-*.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void
syscall(struct trapframe *tf)
{
int callno;
int32_t retval;
int err;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
int whence = 0;
off_t position = 0;
int32_t retval2 = 0;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1);
break;
/* Add stuff here */
case SYS_write:
err = sys_write((int)tf->tf_a0,(const void *)tf->tf_a1,(size_t)tf->tf_a2, &retval);
break;
case SYS_read:
err = sys_read(tf->tf_a0, (void *) tf->tf_a1, (size_t) tf->tf_a2, &retval);
break;
case SYS_open:
err = sys_open((char *)tf->tf_a0, tf->tf_a1, (mode_t)tf->tf_a2, &retval);
break;
case SYS_close:
err = sys_close(tf->tf_a0);
break;
case SYS_dup2:
err = sys_dup2(tf->tf_a0, tf->tf_a1, &retval);
break;
case SYS_lseek:
position |= (off_t)tf->tf_a2;
position <<= 32;
position |= (off_t)tf->tf_a3;
err = copyin((const userptr_t)tf->tf_sp+16, &whence, sizeof(whence));
if (err)
break;
err = sys_lseek((int)tf->tf_a0, position, (int)whence, &retval, &retval2);
if(!err)
tf->tf_v1 = retval2;
break;
case SYS_fork:
err = sys_fork(tf,&retval);
break;
case SYS_getpid:
err = sys_getpid((pid_t *)&retval);
break;
case SYS_waitpid:
err = sys_waitpid((pid_t)tf->tf_a0, (userptr_t)tf->tf_a1, (int)tf->tf_a2, (pid_t *)&retval);
break;
case SYS__exit:
sys__exit((int)tf->tf_a0);
err = -1;
//will never come here as it doesnt return
break;
case SYS_execv:
err=sys_execv((const char *)tf->tf_a0,(char **)tf->tf_a1);
break;
case SYS_sbrk:
err=(int)sys_sbrk((intptr_t)tf->tf_a0, (vaddr_t *)&retval);
break;
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
if (err) {
/*
* Return the error code. This gets converted at
* userlevel to a return value of -1 and the error
* code in errno.
*/
tf->tf_v0 = err;
tf->tf_a3 = 1; /* signal an error */
}
else {
/* Success. */
tf->tf_v0 = retval;
tf->tf_a3 = 0; /* signal no error */
}
/*
* Now, advance the program counter, to avoid restarting
* the syscall over and over again.
*/
tf->tf_epc += 4;
/* Make sure the syscall code didn't forget to lower spl */
KASSERT(curthread->t_curspl == 0);
/* ...or leak any spinlocks */
KASSERT(curthread->t_iplhigh_count == 0);
}
/*
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void
syscall(struct trapframe *tf)
{
int callno;
int32_t retval;
int err = 0;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1);
break;
/* Add stuff here */
case SYS_read:
err = sys_read((int)tf->tf_a0, // filehandle
(void*)tf->tf_a1, // buffer
(size_t)tf->tf_a2, // size
&retval); // return value
break;
case SYS_write:
err = sys_write((int)tf->tf_a0, // filehandle
(const void*)tf->tf_a1, // buffer
(size_t)tf->tf_a2, // size
&retval); // return value
break;
case SYS_open:
err = sys_open((const char*)tf->tf_a0, // filename
(int)tf->tf_a1, // flags
&retval); // return value
break;
case SYS_close:
err = sys_close((int)tf->tf_a0); // filehandle
break;
case SYS_dup2:
err = sys_dup2((int)tf->tf_a0, // old_filehandle
(int)tf->tf_a1, // new_filehandle
&retval); // return value
break;
case SYS__exit:
sys_exit((int)tf->tf_a0); // exitcode
break;
case SYS_getpid:
retval = sys_getpid(); // exitcode
break;
case SYS_waitpid:
err = sys_waitpid((pid_t)tf->tf_a0, (int*)tf->tf_a1, tf->tf_a2, &retval);
break;
case SYS_fork:
err = sys_fork(tf, &retval);
break;
case SYS_execv:
err = sys_execv((userptr_t)tf->tf_a0, (userptr_t)tf->tf_a1);
break;
case SYS_sbrk:
err = sys_sbrk((intptr_t)tf->tf_a0, &retval);
break;
case SYS_lseek: {
off_t offset = tf->tf_a2;
offset = offset<<32;
offset = offset|tf->tf_a3;
int whence;
int err_copyin = copyin((userptr_t)tf->tf_sp+16,&whence,sizeof(whence));
if (err_copyin) {
break;
}
off_t retoffset;
err = sys_lseek((int)tf->tf_a0, // filehandle
offset, // desired offset
whence,
&retoffset); // return value
if (!err) {
retval = retoffset>>32;
tf->tf_v1 = retoffset;
}
break;
} break;
case SYS___getcwd:
err = sys___getcwd((char*)tf->tf_a0, // buffer
(size_t)tf->tf_a1, // size
&retval); // return value
break;
case SYS_chdir:
err = sys_chdir((char*)tf->tf_a0); // path
break;
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
/*
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception-*.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void
syscall(struct trapframe *tf)
{
int callno;
int32_t retval;
int32_t retval1;
int err;
off_t pos;
int whence;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1);
break;
/* Start of process system calls */
case SYS_fork:
err = sys_fork(tf, &retval);
break;
case SYS_execv:
err = sys_execv((const char*)tf->tf_a0,(char **) tf->tf_a1);
break;
case SYS__exit:
sys__exit(tf->tf_a0);
break;
case SYS_waitpid:
err = sys_waitpid((pid_t)tf->tf_a0, (int *)tf->tf_a1, tf->tf_a2, &retval);
break;
case SYS_getpid:
err = sys_getpid(&retval);
break;
/* End of process system calls */
case SYS_open:
err = sys_open((char *)tf->tf_a0,tf->tf_a1,(mode_t)tf->tf_a2,&retval);
break;
case SYS_close :
err = sys_close(tf->tf_a0, &retval);
break;
case SYS_write :
err = sys_write(tf->tf_a0,(void *) tf->tf_a1,(size_t)tf->tf_a2, &retval);
break;
case SYS_read:
err = sys_read(tf->tf_a0,(void *) tf->tf_a1,(size_t)tf->tf_a2, &retval);
break;
case SYS_lseek:
pos = ( (off_t)tf->tf_a2 << 32 | tf->tf_a3);
if (copyin((const_userptr_t) tf->tf_sp+16, &whence, sizeof(int)) ) {
err = EINVAL ; // definitely an error
break;
}
err = sys_lseek(tf->tf_a0, pos,whence, &retval, &retval1);
if (err == 0) { // if call has passed, then we need to copy retval1 to tf->tf_v1 (low32)
tf->tf_v1 = retval1;
}
break;
case SYS___getcwd:
//char *buf, size_t buflen, int *retval
err = sys__getcwd((char *)tf->tf_a0, (size_t) tf->tf_a1, &retval);
break;
case SYS_dup2:
err = sys_dup2(tf->tf_a0, tf->tf_a1, &retval);
break;
case SYS_chdir:
err = sys_chdir((const char *)tf->tf_a0,&retval);
break;
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
if (err) {
/*
* Return the error code. This gets converted at
* userlevel to a return value of -1 and the error
* code in errno.
*/
tf->tf_v0 = err;
tf->tf_a3 = 1; /* signal an error */
}
else {
/* Success. */
tf->tf_v0 = retval;
tf->tf_a3 = 0; /* signal no error */
}
/*
* Now, advance the program counter, to avoid restarting
* the syscall over and over again.
*/
tf->tf_epc += 4;
/* Make sure the syscall code didn't forget to lower spl */
KASSERT(curthread->t_curspl == 0);
/* ...or leak any spinlocks */
KASSERT(curthread->t_iplhigh_count == 0);
}
/*
* System call dispatcher.
*
* A pointer to the trapframe created during exception entry (in
* exception-*.S) is passed in.
*
* The calling conventions for syscalls are as follows: Like ordinary
* function calls, the first 4 32-bit arguments are passed in the 4
* argument registers a0-a3. 64-bit arguments are passed in *aligned*
* pairs of registers, that is, either a0/a1 or a2/a3. This means that
* if the first argument is 32-bit and the second is 64-bit, a1 is
* unused.
*
* This much is the same as the calling conventions for ordinary
* function calls. In addition, the system call number is passed in
* the v0 register.
*
* On successful return, the return value is passed back in the v0
* register, or v0 and v1 if 64-bit. This is also like an ordinary
* function call, and additionally the a3 register is also set to 0 to
* indicate success.
*
* On an error return, the error code is passed back in the v0
* register, and the a3 register is set to 1 to indicate failure.
* (Userlevel code takes care of storing the error code in errno and
* returning the value -1 from the actual userlevel syscall function.
* See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
*
* Upon syscall return the program counter stored in the trapframe
* must be incremented by one instruction; otherwise the exception
* return code will restart the "syscall" instruction and the system
* call will repeat forever.
*
* If you run out of registers (which happens quickly with 64-bit
* values) further arguments must be fetched from the user-level
* stack, starting at sp+16 to skip over the slots for the
* registerized values, with copyin().
*/
void
syscall(struct trapframe *tf)
{
int callno;
int32_t retval;
int err;
KASSERT(curthread != NULL);
KASSERT(curthread->t_curspl == 0);
KASSERT(curthread->t_iplhigh_count == 0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
case SYS_open:
{
err = sys_open((const_userptr_t)tf->tf_a0, tf->tf_a1, tf->tf_a2, &retval);
break;
}
case SYS_close:
{
err = sys_close(tf->tf_a0);
break;
}
case SYS_read:
{
err = sys_read(tf->tf_a0, (userptr_t)tf->tf_a1, tf->tf_a2, &retval);
break;
}
case SYS_write:
{
err = sys_write(tf->tf_a0, (const userptr_t)tf->tf_a1, tf->tf_a2, &retval);
break;
}
case SYS_lseek:
{
// a little tricky, one of the inputs and the return value are 64 bits long.
int fd = tf->tf_a0;
off_t pos_left32 = tf->tf_a2;
off_t pos_right32 = tf->tf_a3;
//pos_left32 <<= 32; // pos_right32 is changing after this line . WTF !!! .. FOLLOW UP !!
off_t left = pos_left32 << 32;
//off_t pos = pos_left32 | pos_right32;
off_t pos = left | pos_right32;
int whence;
err = copyin((const userptr_t)tf->tf_sp+16, (void*)&whence, sizeof(int));
if(err)
break;
off_t lseek_retval;
err = sys_lseek(fd, pos, whence, &lseek_retval);
if(err)
break;
// check this. how does the value get copied
retval = lseek_retval >> 32;
off_t lseek_right32 = lseek_retval;
lseek_right32 = lseek_right32 << 32;
lseek_right32 = lseek_right32 >> 32;
tf->tf_v1 = lseek_right32;
break;
}
case SYS_dup2:
{
err = sys_dup2(tf->tf_a0, tf->tf_a1, &retval);
break;
}
case SYS_chdir:
{
err = sys_chdir((const userptr_t)tf->tf_a0);
break;
}
case SYS___getcwd:
{
err = sys_getcwd((userptr_t)tf->tf_a0, tf->tf_a1);
break;
}
case SYS___time:
err = sys___time((userptr_t)tf->tf_a0,
(userptr_t)tf->tf_a1);
break;
/* Add stuff here */
case SYS_fork:
err = sys_fork(tf, &retval);
break;
case SYS_getpid:
err = sys_getpid(&retval);
break;
case SYS__exit:
err = sys__exit(tf->tf_a0);
break;
case SYS_waitpid:
err = sys_waitpid(tf->tf_a0, (userptr_t)tf->tf_a1, tf->tf_a2, &retval);
break;
case SYS_execv:
err = sys_execv((userptr_t)tf->tf_a0, (userptr_t *)tf->tf_a1);
break;
case SYS_sbrk:
err = sys_sbrk((intptr_t)tf->tf_a0, &retval);
break;
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
if (err) {
/*
* Return the error code. This gets converted at
* userlevel to a return value of -1 and the error
* code in errno.
*/
tf->tf_v0 = err;
tf->tf_a3 = 1; /* signal an error */
}
else {
/* Success. */
tf->tf_v0 = retval;
tf->tf_a3 = 0; /* signal no error */
}
/*
* Now, advance the program counter, to avoid restarting
* the syscall over and over again.
*/
tf->tf_epc += 4;
/* Make sure the syscall code didn't forget to lower spl */
KASSERT(curthread->t_curspl == 0);
/* ...or leak any spinlocks */
KASSERT(curthread->t_iplhigh_count == 0);
}
