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xen/extras/mini-os/main.c
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Jeremy Fitzhardinge b57bd6d273 mini-os: work around ld bug causing stupid CTOR count
I'm seeing pvgrub crashing when running CTORs.  It appears its because
the magic in the linker script is generating junk.  If I get ld to
output a map, I see:

.ctors          0x0000000000097000       0x18
                0x0000000000097000                __CTOR_LIST__ = .
                0x0000000000097000        0x4 LONG 0x25c04
                (((__CTOR_END__ - __CTOR_LIST__) / 0x4) - 0x2)
 *(.ctors)
 .ctors         0x0000000000097004       0x10
                /home/jeremy/hg/xen/unstable/stubdom/mini-os-x86_32-grub/mini-os.o
                0x0000000000097014        0x4 LONG 0x0
                0x0000000000097018                __CTOR_END__ = .


In other words, somehow ((0x97018-0x97000) / 4) - 2 = 0x25c04

The specific crash is that the ctor loop tries to call the NULL
sentinel.  I'm seeing the same with the DTOR list.

Avoid this by terminating the loop with the NULL sentinel, and get rid
of the CTOR count entirely.

From: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Keir Fraser <keir@xen.org>
2011-08-19 09:57:42 +01:00

191 lines
3.9 KiB
C

/*
* POSIX-compatible main layer
*
* Samuel Thibault <Samuel.Thibault@eu.citrix.net>, October 2007
*/
#ifdef HAVE_LIBC
#include <os.h>
#include <sched.h>
#include <console.h>
#include <netfront.h>
#include <pcifront.h>
#include <time.h>
#include <stdlib.h>
#include <unistd.h>
#include <xenbus.h>
#include <events.h>
extern int main(int argc, char *argv[], char *envp[]);
extern void __libc_init_array(void);
extern void __libc_fini_array(void);
extern unsigned long __CTOR_LIST__[];
extern unsigned long __DTOR_LIST__[];
#if 0
#include <stdio.h>
int main(int argc, char *argv[], char *envp[])
{
printf("Hello, World!\n");
return 1;
}
#endif
void _init(void)
{
}
void _fini(void)
{
}
extern char __app_bss_start, __app_bss_end;
static void call_main(void *p)
{
char *c, quote;
#ifdef CONFIG_QEMU
char *domargs, *msg;
#endif
int argc;
char **argv;
char *envp[] = { NULL };
#ifdef CONFIG_QEMU
char *vm;
char path[128];
int domid;
#endif
int i;
/* Let other parts initialize (including console output) before maybe
* crashing. */
//sleep(1);
#ifndef CONFIG_GRUB
sparse((unsigned long) &__app_bss_start, &__app_bss_end - &__app_bss_start);
#if defined(HAVE_LWIP) && !defined(CONFIG_QEMU)
start_networking();
#endif
#endif
create_thread("pcifront", pcifront_watches, NULL);
#ifdef CONFIG_QEMU
/* Fetch argc, argv from XenStore */
domid = xenbus_read_integer("target");
if (domid == -1) {
printk("Couldn't read target\n");
do_exit();
}
snprintf(path, sizeof(path), "/local/domain/%d/vm", domid);
msg = xenbus_read(XBT_NIL, path, &vm);
if (msg) {
printk("Couldn't read vm path\n");
do_exit();
}
printk("dom vm is at %s\n", vm);
snprintf(path, sizeof(path), "%s/image/dmargs", vm);
free(vm);
msg = xenbus_read(XBT_NIL, path, &domargs);
if (msg) {
printk("Couldn't get stubdom args: %s\n", msg);
domargs = strdup("");
}
#endif
argc = 1;
#define PARSE_ARGS(ARGS,START,QUOTE,END) \
c = ARGS; \
quote = 0; \
while (*c) { \
if (*c != ' ') { \
START; \
while (*c) { \
if (quote) { \
if (*c == quote) { \
quote = 0; \
QUOTE; \
continue; \
} \
} else if (*c == ' ') \
break; \
if (*c == '"' || *c == '\'') { \
quote = *c; \
QUOTE; \
continue; \
} \
c++; \
} \
} else { \
END; \
while (*c == ' ') \
c++; \
} \
} \
if (quote) {\
printk("Warning: unterminated quotation %c\n", quote); \
quote = 0; \
}
#define PARSE_ARGS_COUNT(ARGS) PARSE_ARGS(ARGS, argc++, c++, )
#define PARSE_ARGS_STORE(ARGS) PARSE_ARGS(ARGS, argv[argc++] = c, memmove(c, c + 1, strlen(c + 1) + 1), *c++ = 0)
PARSE_ARGS_COUNT((char*)start_info.cmd_line);
#ifdef CONFIG_QEMU
PARSE_ARGS_COUNT(domargs);
#endif
argv = alloca((argc + 1) * sizeof(char *));
argv[0] = "main";
argc = 1;
PARSE_ARGS_STORE((char*)start_info.cmd_line)
#ifdef CONFIG_QEMU
PARSE_ARGS_STORE(domargs)
#endif
argv[argc] = NULL;
for (i = 0; i < argc; i++)
printf("\"%s\" ", argv[i]);
printf("\n");
__libc_init_array();
environ = envp;
for (i = 0; __CTOR_LIST__[i] != 0; i++)
((void((*)(void)))__CTOR_LIST__[i]) ();
tzset();
exit(main(argc, argv, envp));
}
void _exit(int ret)
{
int i;
for (i = 0; __DTOR_LIST__[i] != 0; i++)
((void((*)(void)))__DTOR_LIST__[i]) ();
close_all_files();
__libc_fini_array();
printk("main returned %d\n", ret);
#ifdef HAVE_LWIP
stop_networking();
#endif
stop_kernel();
if (!ret) {
/* No problem, just shutdown. */
struct sched_shutdown sched_shutdown = { .reason = SHUTDOWN_poweroff };
HYPERVISOR_sched_op(SCHEDOP_shutdown, &sched_shutdown);
}
do_exit();
}
int app_main(start_info_t *si)
{
printk("Dummy main: start_info=%p\n", si);
main_thread = create_thread("main", call_main, si);
return 0;
}
#endif