Files
codezero/tasks/libposix/write.c
Bahadir Balban 9992d100d7 Few fixes in libposix error checking.
size_t is a non-negative type and negative error checking didn't work. Now fixed.
Fixed various issues with reading file pages in the sys_read() path.
2008-04-20 02:12:53 +01:00

54 lines
1.1 KiB
C

/*
* l4/posix glue for write()
*
* Copyright (C) 2007 Bahadir Balban
*/
#include <errno.h>
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <l4lib/arch/syscalls.h>
#include <l4lib/arch/syslib.h>
#include <l4lib/ipcdefs.h>
static inline int l4_write(int fd, const void *buf, size_t count)
{
int wrcnt;
write_mr(L4SYS_ARG0, fd);
write_mr(L4SYS_ARG1, (const unsigned long)buf);
write_mr(L4SYS_ARG2, count);
/* Call pager with write() request. Check ipc error. */
if ((wrcnt = l4_sendrecv(PAGER_TID, PAGER_TID, L4_IPC_TAG_WRITE)) < 0) {
printf("%s: L4 IPC Error: %d.\n", __FUNCTION__, wrcnt);
return wrcnt;
}
/* Check if syscall itself was successful */
if ((wrcnt = l4_get_retval()) < 0) {
printf("%s: WRITE Error: %d.\n", __FUNCTION__, (int)wrcnt);
return wrcnt;
}
return wrcnt;
}
ssize_t write(int fd, const void *buf, size_t count)
{
int ret;
if (!count)
return 0;
ret = l4_write(fd, buf, count);
/* If error, return positive error code */
if (ret < 0) {
errno = -ret;
return -1;
}
/* else return value */
return ret;
}