Author: kib
Date: Wed Mar 19 12:35:04 2014
New Revision: 263349
URL: http://svnweb.freebsd.org/changeset/base/263349
Log:
Make the array pointed to by AT_PAGESIZES auxv properly aligned.
Also, remove the expression which calculated the location of the
strings for a new image and grown over the time to be
non-comprehensible. Instead, calculate the offsets by steps, which
also makes fixing the alignments much cleaner.
Reported and reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Modified:
head/sys/compat/freebsd32/freebsd32_misc.c
head/sys/kern/kern_exec.c
Modified: head/sys/compat/freebsd32/freebsd32_misc.c
==============================================================================
--- head/sys/compat/freebsd32/freebsd32_misc.c Wed Mar 19 12:32:50 2014
(r263348)
+++ head/sys/compat/freebsd32/freebsd32_misc.c Wed Mar 19 12:35:04 2014
(r263349)
@@ -2822,7 +2822,8 @@ freebsd32_copyout_strings(struct image_p
{
int argc, envc, i;
u_int32_t *vectp;
- char *stringp, *destp;
+ char *stringp;
+ uintptr_t destp;
u_int32_t *stack_base;
struct freebsd32_ps_strings *arginfo;
char canary[sizeof(long) * 8];
@@ -2844,35 +2845,34 @@ freebsd32_copyout_strings(struct image_p
szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
else
szsigcode = 0;
- destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
- roundup(execpath_len, sizeof(char *)) -
- roundup(sizeof(canary), sizeof(char *)) -
- roundup(sizeof(pagesizes32), sizeof(char *)) -
- roundup((ARG_MAX - imgp->args->stringspace), sizeof(char *));
+ destp = (uintptr_t)arginfo;
/*
* install sigcode
*/
- if (szsigcode != 0)
- copyout(imgp->proc->p_sysent->sv_sigcode,
- ((caddr_t)arginfo - szsigcode), szsigcode);
+ if (szsigcode != 0) {
+ destp -= szsigcode;
+ destp = rounddown2(destp, sizeof(uint32_t));
+ copyout(imgp->proc->p_sysent->sv_sigcode, (void *)destp,
+ szsigcode);
+ }
/*
* Copy the image path for the rtld.
*/
if (execpath_len != 0) {
- imgp->execpathp = (uintptr_t)arginfo - szsigcode - execpath_len;
- copyout(imgp->execpath, (void *)imgp->execpathp,
- execpath_len);
+ destp -= execpath_len;
+ imgp->execpathp = destp;
+ copyout(imgp->execpath, (void *)destp, execpath_len);
}
/*
* Prepare the canary for SSP.
*/
arc4rand(canary, sizeof(canary), 0);
- imgp->canary = (uintptr_t)arginfo - szsigcode - execpath_len -
- sizeof(canary);
- copyout(canary, (void *)imgp->canary, sizeof(canary));
+ destp -= sizeof(canary);
+ imgp->canary = destp;
+ copyout(canary, (void *)destp, sizeof(canary));
imgp->canarylen = sizeof(canary);
/*
@@ -2880,11 +2880,15 @@ freebsd32_copyout_strings(struct image_p
*/
for (i = 0; i < MAXPAGESIZES; i++)
pagesizes32[i] = (uint32_t)pagesizes[i];
- imgp->pagesizes = (uintptr_t)arginfo - szsigcode - execpath_len -
- roundup(sizeof(canary), sizeof(char *)) - sizeof(pagesizes32);
- copyout(pagesizes32, (void *)imgp->pagesizes, sizeof(pagesizes32));
+ destp -= sizeof(pagesizes32);
+ destp = rounddown2(destp, sizeof(uint32_t));
+ imgp->pagesizes = destp;
+ copyout(pagesizes32, (void *)destp, sizeof(pagesizes32));
imgp->pagesizeslen = sizeof(pagesizes32);
+ destp -= ARG_MAX - imgp->args->stringspace;
+ destp = rounddown2(destp, sizeof(uint32_t));
+
/*
* If we have a valid auxargs ptr, prepare some room
* on the stack.
@@ -2904,13 +2908,14 @@ freebsd32_copyout_strings(struct image_p
vectp = (u_int32_t *) (destp - (imgp->args->argc +
imgp->args->envc + 2 + imgp->auxarg_size + execpath_len) *
sizeof(u_int32_t));
- } else
+ } else {
/*
* The '+ 2' is for the null pointers at the end of each of
* the arg and env vector sets
*/
- vectp = (u_int32_t *)
- (destp - (imgp->args->argc + imgp->args->envc + 2) *
sizeof(u_int32_t));
+ vectp = (u_int32_t *)(destp - (imgp->args->argc +
+ imgp->args->envc + 2) * sizeof(u_int32_t));
+ }
/*
* vectp also becomes our initial stack base
@@ -2923,7 +2928,7 @@ freebsd32_copyout_strings(struct image_p
/*
* Copy out strings - arguments and environment.
*/
- copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
+ copyout(stringp, (void *)destp, ARG_MAX - imgp->args->stringspace);
/*
* Fill in "ps_strings" struct for ps, w, etc.
Modified: head/sys/kern/kern_exec.c
==============================================================================
--- head/sys/kern/kern_exec.c Wed Mar 19 12:32:50 2014 (r263348)
+++ head/sys/kern/kern_exec.c Wed Mar 19 12:35:04 2014 (r263349)
@@ -1231,7 +1231,8 @@ exec_copyout_strings(imgp)
{
int argc, envc;
char **vectp;
- char *stringp, *destp;
+ char *stringp;
+ uintptr_t destp;
register_t *stack_base;
struct ps_strings *arginfo;
struct proc *p;
@@ -1255,45 +1256,47 @@ exec_copyout_strings(imgp)
if (p->p_sysent->sv_szsigcode != NULL)
szsigcode = *(p->p_sysent->sv_szsigcode);
}
- destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
- roundup(execpath_len, sizeof(char *)) -
- roundup(sizeof(canary), sizeof(char *)) -
- roundup(szps, sizeof(char *)) -
- roundup((ARG_MAX - imgp->args->stringspace), sizeof(char *));
+ destp = (uintptr_t)arginfo;
/*
* install sigcode
*/
- if (szsigcode != 0)
- copyout(p->p_sysent->sv_sigcode, ((caddr_t)arginfo -
- szsigcode), szsigcode);
+ if (szsigcode != 0) {
+ destp -= szsigcode;
+ destp = rounddown2(destp, sizeof(void *));
+ copyout(p->p_sysent->sv_sigcode, (void *)destp, szsigcode);
+ }
/*
* Copy the image path for the rtld.
*/
if (execpath_len != 0) {
- imgp->execpathp = (uintptr_t)arginfo - szsigcode - execpath_len;
- copyout(imgp->execpath, (void *)imgp->execpathp,
- execpath_len);
+ destp -= execpath_len;
+ imgp->execpathp = destp;
+ copyout(imgp->execpath, (void *)destp, execpath_len);
}
/*
* Prepare the canary for SSP.
*/
arc4rand(canary, sizeof(canary), 0);
- imgp->canary = (uintptr_t)arginfo - szsigcode - execpath_len -
- sizeof(canary);
- copyout(canary, (void *)imgp->canary, sizeof(canary));
+ destp -= sizeof(canary);
+ imgp->canary = destp;
+ copyout(canary, (void *)destp, sizeof(canary));
imgp->canarylen = sizeof(canary);
/*
* Prepare the pagesizes array.
*/
- imgp->pagesizes = (uintptr_t)arginfo - szsigcode - execpath_len -
- roundup(sizeof(canary), sizeof(char *)) - szps;
- copyout(pagesizes, (void *)imgp->pagesizes, szps);
+ destp -= szps;
+ destp = rounddown2(destp, sizeof(void *));
+ imgp->pagesizes = destp;
+ copyout(pagesizes, (void *)destp, szps);
imgp->pagesizeslen = szps;
+ destp -= ARG_MAX - imgp->args->stringspace;
+ destp = rounddown2(destp, sizeof(void *));
+
/*
* If we have a valid auxargs ptr, prepare some room
* on the stack.
@@ -1318,8 +1321,8 @@ exec_copyout_strings(imgp)
* The '+ 2' is for the null pointers at the end of each of
* the arg and env vector sets
*/
- vectp = (char **)(destp - (imgp->args->argc + imgp->args->envc
+ 2) *
- sizeof(char *));
+ vectp = (char **)(destp - (imgp->args->argc + imgp->args->envc
+ + 2) * sizeof(char *));
}
/*
@@ -1334,7 +1337,7 @@ exec_copyout_strings(imgp)
/*
* Copy out strings - arguments and environment.
*/
- copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
+ copyout(stringp, (void *)destp, ARG_MAX - imgp->args->stringspace);
/*
* Fill in "ps_strings" struct for ps, w, etc.
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