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Remove code to support the top of the stack layout for FreeBSD 1.x/2.x

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kernel, but keep explanation of the old ps_strings structure to make
it clear what sanity check tries to accomplish.

Noted by:	Oliver Pinter <oliver.pinter@hardenedbsd.org>
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
This commit is contained in:
Konstantin Belousov 2015-04-20 09:07:12 +00:00
parent 19b5b56d7f
commit a22fc06636
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=281763
1 changed files with 36 additions and 37 deletions
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73
lib/libc/gen/setproctitle.c
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@ -42,9 +42,10 @@ __FBSDID("$FreeBSD$");
* 1: old_ps_strings at the very top of the stack.
* 2: old_ps_strings at SPARE_USRSPACE below the top of the stack.
* 3: ps_strings at the very top of the stack.
* This attempts to support a kernel built in the #2 and #3 era.
*/
* We only support a kernel providing #3 style ps_strings.
*
* For historical purposes, a definition of the old ps_strings structure
* and location is preserved below:
struct old_ps_strings {
char *old_ps_argvstr;
int old_ps_nargvstr;
@ -53,6 +54,7 @@ struct old_ps_strings {
};
#define OLD_PS_STRINGS ((struct old_ps_strings *) \
(USRSTACK - SPARE_USRSPACE - sizeof(struct old_ps_strings)))
*/
#include <stdarg.h>
@ -136,41 +138,38 @@ setproctitle(const char *fmt, ...)
ps_strings = (struct ps_strings *)ul_ps_strings;
}
/* PS_STRINGS points to zeroed memory on a style #2 kernel */
if (ps_strings->ps_argvstr) {
/* style #3 */
if (oargc == -1) {
/* Record our original args */
oargc = ps_strings->ps_nargvstr;
oargv = ps_strings->ps_argvstr;
for (i = len = 0; i < oargc; i++) {
/*
* The program may have scribbled into its
* argv array, e.g., to remove some arguments.
* If that has happened, break out before
* trying to call strlen on a NULL pointer.
*/
if (oargv[i] == NULL) {
oargc = i;
break;
}
snprintf(obuf + len, SPT_BUFSIZE - len, "%s%s",
len ? " " : "", oargv[i]);
if (len)
len++;
len += strlen(oargv[i]);
if (len >= SPT_BUFSIZE)
break;
/*
* PS_STRINGS points to zeroed memory on a style #2 kernel.
* Should not happen.
*/
if (ps_strings->ps_argvstr == NULL)
return;
/* style #3 */
if (oargc == -1) {
/* Record our original args */
oargc = ps_strings->ps_nargvstr;
oargv = ps_strings->ps_argvstr;
for (i = len = 0; i < oargc; i++) {
/*
* The program may have scribbled into its
* argv array, e.g., to remove some arguments.
* If that has happened, break out before
* trying to call strlen on a NULL pointer.
*/
if (oargv[i] == NULL) {
oargc = i;
break;
}
snprintf(obuf + len, SPT_BUFSIZE - len, "%s%s",
len != 0 ? " " : "", oargv[i]);
if (len != 0)
len++;
len += strlen(oargv[i]);
if (len >= SPT_BUFSIZE)
break;
}
ps_strings->ps_nargvstr = nargc;
ps_strings->ps_argvstr = nargvp;
} else {
/* style #2 - we can only restore our first arg :-( */
if (*obuf == '\0')
strncpy(obuf, OLD_PS_STRINGS->old_ps_argvstr,
SPT_BUFSIZE - 1);
OLD_PS_STRINGS->old_ps_nargvstr = 1;
OLD_PS_STRINGS->old_ps_argvstr = nargvp[0];
}
ps_strings->ps_nargvstr = nargc;
ps_strings->ps_argvstr = nargvp;
}