Author: jhb Date: Thu Apr 19 16:00:34 2018 New Revision: 332782 URL: https://svnweb.freebsd.org/changeset/base/332782
Log: Simplify the code to allocate stack for auxv, argv[], and environment vectors. Remove auxarg_size as it was only used once right after a confusing assignment in each of the variants of exec_copyout_strings(). Reviewed by: emaste MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D15123 Modified: head/sys/amd64/linux/linux_sysvec.c head/sys/amd64/linux32/linux32_sysvec.c head/sys/compat/freebsd32/freebsd32_misc.c head/sys/i386/linux/linux_sysvec.c head/sys/kern/kern_exec.c head/sys/sys/imgact.h Modified: head/sys/amd64/linux/linux_sysvec.c ============================================================================== --- head/sys/amd64/linux/linux_sysvec.c Thu Apr 19 15:52:45 2018 (r332781) +++ head/sys/amd64/linux/linux_sysvec.c Thu Apr 19 16:00:34 2018 (r332782) @@ -331,31 +331,21 @@ linux_copyout_strings(struct image_params *imgp) roundup(sizeof(canary), sizeof(char *)); copyout(canary, (void *)imgp->canary, sizeof(canary)); - /* If we have a valid auxargs ptr, prepare some room on the stack. */ + vectp = (char **)destp; if (imgp->auxargs) { /* - * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for - * lower compatibility. + * Allocate room on the stack for the ELF auxargs + * array. It has LINUX_AT_COUNT entries. */ - imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size : - (LINUX_AT_COUNT * 2); - - /* - * The '+ 2' is for the null pointers at the end of each of - * the arg and env vector sets,and imgp->auxarg_size is room - * for argument of Runtime loader. - */ - vectp = (char **)(destp - (imgp->args->argc + - imgp->args->envc + 2 + imgp->auxarg_size) * sizeof(char *)); - - } else { - /* - * 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 -= howmany(LINUX_AT_COUNT * sizeof(Elf64_Auxinfo), + sizeof(*vectp)); } + + /* + * Allocate room for the argv[] and env vectors including the + * terminating NULL pointers. + */ + vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; /* vectp also becomes our initial stack base. */ stack_base = (register_t *)vectp; Modified: head/sys/amd64/linux32/linux32_sysvec.c ============================================================================== --- head/sys/amd64/linux32/linux32_sysvec.c Thu Apr 19 15:52:45 2018 (r332781) +++ head/sys/amd64/linux32/linux32_sysvec.c Thu Apr 19 16:00:34 2018 (r332782) @@ -793,31 +793,21 @@ linux_copyout_strings(struct image_params *imgp) roundup(sizeof(canary), sizeof(char *)); copyout(canary, (void *)imgp->canary, sizeof(canary)); - /* If we have a valid auxargs ptr, prepare some room on the stack. */ + vectp = (uint32_t *)destp; if (imgp->auxargs) { /* - * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for - * lower compatibility. + * Allocate room on the stack for the ELF auxargs + * array. It has LINUX_AT_COUNT entries. */ - imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size : - (LINUX_AT_COUNT * 2); - /* - * The '+ 2' is for the null pointers at the end of each of - * the arg and env vector sets,and imgp->auxarg_size is room - * for argument of Runtime loader. - */ - vectp = (u_int32_t *) (destp - (imgp->args->argc + - imgp->args->envc + 2 + imgp->auxarg_size) * - sizeof(u_int32_t)); - - } 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 -= howmany(LINUX_AT_COUNT * sizeof(Elf32_Auxinfo), + sizeof(*vectp)); } + + /* + * Allocate room for the argv[] and env vectors including the + * terminating NULL pointers. + */ + vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; /* vectp also becomes our initial stack base. */ stack_base = vectp; Modified: head/sys/compat/freebsd32/freebsd32_misc.c ============================================================================== --- head/sys/compat/freebsd32/freebsd32_misc.c Thu Apr 19 15:52:45 2018 (r332781) +++ head/sys/compat/freebsd32/freebsd32_misc.c Thu Apr 19 16:00:34 2018 (r332782) @@ -3180,33 +3180,21 @@ freebsd32_copyout_strings(struct image_params *imgp) 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. - */ + vectp = (uint32_t *)destp; if (imgp->auxargs) { /* - * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for - * lower compatibility. + * Allocate room on the stack for the ELF auxargs + * array. It has up to AT_COUNT entries. */ - imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size - : (AT_COUNT * 2); - /* - * The '+ 2' is for the null pointers at the end of each of - * the arg and env vector sets,and imgp->auxarg_size is room - * for argument of Runtime loader. - */ - vectp = (u_int32_t *) (destp - (imgp->args->argc + - imgp->args->envc + 2 + imgp->auxarg_size + execpath_len) * - sizeof(u_int32_t)); - } 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 -= howmany(AT_COUNT * sizeof(Elf32_Auxinfo), + sizeof(*vectp)); } + + /* + * Allocate room for the argv[] and env vectors including the + * terminating NULL pointers. + */ + vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; /* * vectp also becomes our initial stack base Modified: head/sys/i386/linux/linux_sysvec.c ============================================================================== --- head/sys/i386/linux/linux_sysvec.c Thu Apr 19 15:52:45 2018 (r332781) +++ head/sys/i386/linux/linux_sysvec.c Thu Apr 19 16:00:34 2018 (r332782) @@ -309,29 +309,21 @@ linux_copyout_strings(struct image_params *imgp) roundup(sizeof(canary), sizeof(char *)); copyout(canary, (void *)imgp->canary, sizeof(canary)); - /* If we have a valid auxargs ptr, prepare some room on the stack. */ + vectp = (char **)destp; if (imgp->auxargs) { /* - * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for - * lower compatibility. + * Allocate room on the stack for the ELF auxargs + * array. It has LINUX_AT_COUNT entries. */ - imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size : - (LINUX_AT_COUNT * 2); - /* - * The '+ 2' is for the null pointers at the end of each of - * the arg and env vector sets,and imgp->auxarg_size is room - * for argument of Runtime loader. - */ - vectp = (char **)(destp - (imgp->args->argc + - imgp->args->envc + 2 + imgp->auxarg_size) * sizeof(char *)); - } else { - /* - * 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 -= howmany(LINUX_AT_COUNT * sizeof(Elf32_Auxinfo), + sizeof(*vectp)); } + + /* + * Allocate room for the argv[] and env vectors including the + * terminating NULL pointers. + */ + vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; /* vectp also becomes our initial stack base. */ stack_base = (register_t *)vectp; Modified: head/sys/kern/kern_exec.c ============================================================================== --- head/sys/kern/kern_exec.c Thu Apr 19 15:52:45 2018 (r332781) +++ head/sys/kern/kern_exec.c Thu Apr 19 16:00:34 2018 (r332782) @@ -1537,33 +1537,21 @@ exec_copyout_strings(struct image_params *imgp) destp -= ARG_MAX - imgp->args->stringspace; destp = rounddown2(destp, sizeof(void *)); - /* - * If we have a valid auxargs ptr, prepare some room - * on the stack. - */ + vectp = (char **)destp; if (imgp->auxargs) { /* - * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for - * lower compatibility. + * Allocate room on the stack for the ELF auxargs + * array. It has up to AT_COUNT entries. */ - imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size : - (AT_COUNT * 2); - /* - * The '+ 2' is for the null pointers at the end of each of - * the arg and env vector sets,and imgp->auxarg_size is room - * for argument of Runtime loader. - */ - vectp = (char **)(destp - (imgp->args->argc + - imgp->args->envc + 2 + imgp->auxarg_size) - * sizeof(char *)); - } else { - /* - * 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 -= howmany(AT_COUNT * sizeof(Elf_Auxinfo), + sizeof(*vectp)); } + + /* + * Allocate room for the argv[] and env vectors including the + * terminating NULL pointers. + */ + vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; /* * vectp also becomes our initial stack base Modified: head/sys/sys/imgact.h ============================================================================== --- head/sys/sys/imgact.h Thu Apr 19 15:52:45 2018 (r332781) +++ head/sys/sys/imgact.h Thu Apr 19 16:00:34 2018 (r332782) @@ -75,7 +75,6 @@ struct image_params { void *auxargs; /* ELF Auxinfo structure pointer */ struct sf_buf *firstpage; /* first page that we mapped */ unsigned long ps_strings; /* PS_STRINGS for BSD/OS binaries */ - size_t auxarg_size; struct image_args *args; /* system call arguments */ struct sysentvec *sysent; /* system entry vector */ char *execpath; _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
