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Make the array pointed to by AT_PAGESIZES auxv properly aligned.

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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
This commit is contained in:
Konstantin Belousov 2014-03-19 12:35:04 +00:00
parent 8d08c1118c
commit 88b124cede
2 changed files with 51 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
sys/compat/freebsd32/freebsd32_misc.c
View File

@ -2822,7 +2822,8 @@ freebsd32_copyout_strings(struct image_params *imgp)
{
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_params *imgp)
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_params *imgp)
*/
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_params *imgp)
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_params *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.

45
sys/kern/kern_exec.c
View File

@ -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.