plan9fox/sys/src/cmd/upas/fs/bos.c
2017-03-12 17:15:03 +01:00

41 lines
798 B
C

#include <u.h>
#include <libc.h>
#include <bio.h>
/*
* assume:
* - the stack segment can't be resized
* - stacks may not be segattached (by name Stack, anyway)
* - no thread library
*/
uintptr
absbos(void)
{
char buf[64], *f[10], *s, *r;
int n;
uintptr p, q;
Biobuf *b;
p = 0xd0000000; /* guess pc kernel */
snprint(buf, sizeof buf, "/proc/%ud/segment", getpid());
b = Bopen(buf, OREAD);
if(b == nil)
return p;
for(; s = Brdstr(b, '\n', 1); free(s)){
if((n = tokenize(s, f, nelem(f))) < 3)
continue;
if(strcmp(f[0], "Stack") != 0)
continue;
/*
* addressing from end because segment
* flags could become discontiguous if
* additional flags are added
*/
q = strtoull(f[n - 3], &r, 16);
if(*r == 0 && (char*)q > end)
p = q;
}
Bterm(b);
return p;
}