Bug 40012

There is an error in function con_set_unimap (file: linux-3.0/drivers/tty/vt/consolemap.c)

During the copying of the map variable l=<current unicode value> does not increment properly.
> for (i = 0, l = 0; i < 32; i++)
>                if ((p1 = p->uni_pgdir[i]))
>           ...
else (if p1 == NULL) its value will be left unchanged instead of += ...

Steps to reproduce:

1. fbdev driver should be used
2. Switch to virtual console 1 (Alt+F1)
3. Compile and run test1.c
4. Switch to virtual console 2 (Alt+F2)
5. Run test1.c
6. Compile and run test2.c

You will get something like

Current Unicode-to-font map
0x123   U+0001 // Should be U+0041
0x134   U+0042

----- test1.c -----
#define _GNU_SOURCE

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <linux/kd.h>

int main(int argc, char *argv[])
{
struct unipair up = {0x0041, 0x0123};
struct unimapdesc ud = {1, &up};
int fd;
	
	fd = open("/dev/tty0", O_RDWR);
	if (fd < 0)
		err(1, "open");
	
	if (ioctl(fd, PIO_UNIMAPCLR, &ud) < 0)
		err(1, "ioctl(PIO_UNIMAPCLR)");
	
	if (ioctl(fd, PIO_UNIMAP, &ud) < 0)
		err(1, "ioctl(PIO_UNIMAP)");
	
	int i, ct;

	ud.entry_ct = 0;
	ud.entries = 0;
	if (ioctl(fd, GIO_UNIMAP, &ud) < 0 && errno != ENOMEM)
		err(1, "ioctl(GIO_UNIMAP)");
	
	ct = ud.entry_ct;
	ud.entries = (struct unipair *) malloc(ct * sizeof(struct unipair));
	if (ud.entries == NULL) { return -1; }
	
	if (ioctl(fd, GIO_UNIMAP, &ud) < 0)
		err(1, "ioctl(GIO_UNIMAP)");
	
	printf("Current Unicode-to-font map\n");
	for (i = 0; i < ud.entry_ct; i++)
		printf("0x%02x\tU+%04x\n", ud.entries[i].fontpos,
		                           ud.entries[i].unicode);
	
	close(fd);	
	
	return EXIT_SUCCESS;
}
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----- test2.c -----
#define _GNU_SOURCE

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <linux/kd.h>

int main(int argc, char *argv[])
{
struct unipair up = {0x0042, 0x0134};
struct unimapdesc ud = {1, &up};
int fd;
	
	fd = open("/dev/tty0", O_RDWR);
	if (fd < 0)
		err(1, "open");
	
	if (ioctl(fd, PIO_UNIMAP, &ud) < 0)
		err(1, "ioctl(PIO_UNIMAP)");
	
	int i, ct;

	ud.entry_ct = 0;
	ud.entries = 0;
	if (ioctl(fd, GIO_UNIMAP, &ud) < 0 && errno != ENOMEM)
		err(1, "ioctl(GIO_UNIMAP)");
	
	ct = ud.entry_ct;
	ud.entries = (struct unipair *) malloc(ct * sizeof(struct unipair));
	if (ud.entries == NULL) { return -1; }
	
	if (ioctl(fd, GIO_UNIMAP, &ud) < 0)
		err(1, "ioctl(GIO_UNIMAP)");
	
	printf("Current Unicode-to-font map\n");
	for (i = 0; i < ud.entry_ct; i++)
		printf("0x%02x\tU+%04x\n", ud.entries[i].fontpos,
		                           ud.entries[i].unicode);
	
	close(fd);	
	
	return EXIT_SUCCESS;
}
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