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Put a system call not present checking wrapper around the call to

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__getcwd().  I've got this libc code running on one of my machines
at the moment without the __getcwd() syscall being present.
This commit is contained in:
peter 1997-09-16 06:00:50 +00:00
parent 93105e4a32
commit d96eb92b4f
1 changed files with 36 additions and 10 deletions
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46
lib/libc/gen/getcwd.c
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@ -45,11 +45,14 @@ static char sccsid[] = "@(#)getcwd.c 8.5 (Berkeley) 2/7/95";
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#define ISDOT(dp) \
(dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
(dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
static int have__getcwd = 1; /* 0 = no, 1 = perhaps, 2 = yes */
char *
getcwd(pt, size)
char *pt;
@ -89,17 +92,40 @@ getcwd(pt, size)
return (NULL);
ept = pt + ptsize;
}
if (!__getcwd(pt, ept - pt)) {
if (*pt != '/') {
bpt = pt;
ept = pt + strlen(pt) - 1;
while (bpt < ept) {
c = *bpt;
*bpt++ = *ept;
*ept-- = c;
}
if (have__getcwd) {
struct sigaction sa, osa;
int sigsys_installed = 0;
int ret;
if (have__getcwd == 1) { /* unsure? */
bzero(&sa, sizeof(sa));
sa.sa_handler = SIG_IGN;
if (sigaction(SIGSYS, &sa, &osa) >= 0)
sigsys_installed = 1;
}
ret = __getcwd(pt, ept - pt);
if (sigsys_installed == 1) {
int oerrno = errno;
sigaction(SIGSYS, &osa, NULL);
errno = oerrno;
}
/* XXX a bogus syscall seems to return EINVAL(!) */
if (ret < 0 && (errno == ENOSYS || errno == EINVAL))
have__getcwd = 0;
else if (have__getcwd == 1)
have__getcwd = 2; /* yep, remember we have it */
if (ret == 0) {
if (*pt != '/') {
bpt = pt;
ept = pt + strlen(pt) - 1;
while (bpt < ept) {
c = *bpt;
*bpt++ = *ept;
*ept-- = c;
}
}
return (pt);
}
return (pt);
}
bpt = ept - 1;
*bpt = '\0';