Date: Wed, 19 Mar 2014 12:35:04 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r263349 - in head/sys: compat/freebsd32 kern Message-ID: <201403191235.s2JCZ4vv028522@svn.freebsd.org>
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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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