svn commit: r337046 - in stable/11/sys: amd64/linux amd64/linux32 compat/freebsd32 i386/linux kern sys
John Baldwin
jhb at FreeBSD.org
Wed Aug 1 17:40:20 UTC 2018
Author: jhb
Date: Wed Aug 1 17:40:17 2018
New Revision: 337046
URL: https://svnweb.freebsd.org/changeset/base/337046
Log:
MFC 332782:
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().
Modified:
stable/11/sys/amd64/linux/linux_sysvec.c
stable/11/sys/amd64/linux32/linux32_sysvec.c
stable/11/sys/compat/freebsd32/freebsd32_misc.c
stable/11/sys/i386/linux/linux_sysvec.c
stable/11/sys/kern/kern_exec.c
stable/11/sys/sys/imgact.h
Directory Properties:
stable/11/ (props changed)
Modified: stable/11/sys/amd64/linux/linux_sysvec.c
==============================================================================
--- stable/11/sys/amd64/linux/linux_sysvec.c Wed Aug 1 15:55:14 2018 (r337045)
+++ stable/11/sys/amd64/linux/linux_sysvec.c Wed Aug 1 17:40:17 2018 (r337046)
@@ -359,31 +359,21 @@ 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: stable/11/sys/amd64/linux32/linux32_sysvec.c
==============================================================================
--- stable/11/sys/amd64/linux32/linux32_sysvec.c Wed Aug 1 15:55:14 2018 (r337045)
+++ stable/11/sys/amd64/linux32/linux32_sysvec.c Wed Aug 1 17:40:17 2018 (r337046)
@@ -854,31 +854,21 @@ 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: stable/11/sys/compat/freebsd32/freebsd32_misc.c
==============================================================================
--- stable/11/sys/compat/freebsd32/freebsd32_misc.c Wed Aug 1 15:55:14 2018 (r337045)
+++ stable/11/sys/compat/freebsd32/freebsd32_misc.c Wed Aug 1 17:40:17 2018 (r337046)
@@ -2885,33 +2885,21 @@ 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: stable/11/sys/i386/linux/linux_sysvec.c
==============================================================================
--- stable/11/sys/i386/linux/linux_sysvec.c Wed Aug 1 15:55:14 2018 (r337045)
+++ stable/11/sys/i386/linux/linux_sysvec.c Wed Aug 1 17:40:17 2018 (r337046)
@@ -336,29 +336,21 @@ 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: stable/11/sys/kern/kern_exec.c
==============================================================================
--- stable/11/sys/kern/kern_exec.c Wed Aug 1 15:55:14 2018 (r337045)
+++ stable/11/sys/kern/kern_exec.c Wed Aug 1 17:40:17 2018 (r337046)
@@ -1533,33 +1533,21 @@ 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: stable/11/sys/sys/imgact.h
==============================================================================
--- stable/11/sys/sys/imgact.h Wed Aug 1 15:55:14 2018 (r337045)
+++ stable/11/sys/sys/imgact.h Wed Aug 1 17:40:17 2018 (r337046)
@@ -73,7 +73,6 @@ 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;
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