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exec: Simplify sv_copyout_strings implementations a bit

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Simplify control flow around handling of the execpath length and signal
trampoline.  Cache the sysentvec pointer in a local variable.

No functional change intended.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33703
This commit is contained in:
Mark Johnston 2021-12-31 12:50:15 -05:00
parent 757089f01e
commit f04a096049
6 changed files with 33 additions and 70 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
sys/amd64/linux/linux_sysvec.c
View File

@ -358,17 +358,12 @@ linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
size_t execpath_len;
struct proc *p;
/* Calculate string base and vector table pointers. */
if (imgp->execpath != NULL && imgp->auxargs != NULL)
execpath_len = strlen(imgp->execpath) + 1;
else
execpath_len = 0;
p = imgp->proc;
arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
destp = (uintptr_t)arginfo;
if (execpath_len != 0) {
if (imgp->execpath != NULL && imgp->auxargs != NULL) {
execpath_len = strlen(imgp->execpath) + 1;
destp -= execpath_len;
destp = rounddown2(destp, sizeof(void *));
imgp->execpathp = (void *)destp;

9
sys/amd64/linux32/linux32_sysvec.c
View File

@ -771,16 +771,11 @@ linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
char canary[LINUX_AT_RANDOM_LEN];
size_t execpath_len;
/* Calculate string base and vector table pointers. */
if (imgp->execpath != NULL && imgp->auxargs != NULL)
execpath_len = strlen(imgp->execpath) + 1;
else
execpath_len = 0;
arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
destp = (uintptr_t)arginfo;
if (execpath_len != 0) {
if (imgp->execpath != NULL && imgp->auxargs != NULL) {
execpath_len = strlen(imgp->execpath) + 1;
destp -= execpath_len;
destp = rounddown2(destp, sizeof(uint32_t));
imgp->execpathp = (void *)destp;

9
sys/arm64/linux/linux_sysvec.c
View File

@ -255,17 +255,12 @@ linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
struct proc *p;
int argc, envc, error;
/* Calculate string base and vector table pointers. */
if (imgp->execpath != NULL && imgp->auxargs != NULL)
execpath_len = strlen(imgp->execpath) + 1;
else
execpath_len = 0;
p = imgp->proc;
arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
destp = (uintptr_t)arginfo;
if (execpath_len != 0) {
if (imgp->execpath != NULL && imgp->auxargs != NULL) {
execpath_len = strlen(imgp->execpath) + 1;
destp -= execpath_len;
destp = rounddown2(destp, sizeof(void *));
imgp->execpathp = (void *)destp;

28
sys/compat/freebsd32/freebsd32_misc.c
View File

@ -3391,6 +3391,7 @@ syscall32_helper_unregister(struct syscall_helper_data *sd)
int
freebsd32_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
{
struct sysentvec *sysent;
int argc, envc, i;
uint32_t *vectp;
char *stringp;
@ -3401,30 +3402,20 @@ freebsd32_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
size_t execpath_len;
int error, szsigcode;
/*
* Calculate string base and vector table pointers.
* Also deal with signal trampoline code for this exec type.
*/
if (imgp->execpath != NULL && imgp->auxargs != NULL)
execpath_len = strlen(imgp->execpath) + 1;
else
execpath_len = 0;
arginfo = (struct freebsd32_ps_strings *)curproc->p_sysent->
sv_psstrings;
sysent = imgp->sysent;
arginfo = (struct freebsd32_ps_strings *)sysent->sv_psstrings;
imgp->ps_strings = arginfo;
if (imgp->proc->p_sysent->sv_sigcode_base == 0)
szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
else
szsigcode = 0;
destp = (uintptr_t)arginfo;
/*
* install sigcode
* Install sigcode.
*/
if (szsigcode != 0) {
if (sysent->sv_sigcode_base == 0) {
szsigcode = *sysent->sv_szsigcode;
destp -= szsigcode;
destp = rounddown2(destp, sizeof(uint32_t));
error = copyout(imgp->proc->p_sysent->sv_sigcode, (void *)destp,
error = copyout(sysent->sv_sigcode, (void *)destp,
szsigcode);
if (error != 0)
return (error);
@ -3433,7 +3424,8 @@ freebsd32_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
/*
* Copy the image path for the rtld.
*/
if (execpath_len != 0) {
if (imgp->execpath != NULL && imgp->auxargs != NULL) {
execpath_len = strlen(imgp->execpath) + 1;
destp -= execpath_len;
imgp->execpathp = (void *)destp;
error = copyout(imgp->execpath, imgp->execpathp, execpath_len);

8
sys/i386/linux/linux_sysvec.c
View File

@ -289,16 +289,12 @@ linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
size_t execpath_len;
struct proc *p;
/* Calculate string base and vector table pointers. */
p = imgp->proc;
if (imgp->execpath != NULL && imgp->auxargs != NULL)
execpath_len = strlen(imgp->execpath) + 1;
else
execpath_len = 0;
arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
destp = (uintptr_t)arginfo;
if (execpath_len != 0) {
if (imgp->execpath != NULL && imgp->auxargs != NULL) {
execpath_len = strlen(imgp->execpath) + 1;
destp -= execpath_len;
destp = rounddown2(destp, sizeof(void *));
imgp->execpathp = (void *)destp;

40
sys/kern/kern_exec.c
View File

@ -1616,37 +1616,26 @@ exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
uintptr_t destp, ustringp;
struct ps_strings *arginfo;
struct proc *p;
struct sysentvec *sysent;
size_t execpath_len;
int error, szsigcode, szps;
int error, szsigcode;
char canary[sizeof(long) * 8];
szps = sizeof(pagesizes[0]) * MAXPAGESIZES;
/*
* Calculate string base and vector table pointers.
* Also deal with signal trampoline code for this exec type.
*/
if (imgp->execpath != NULL && imgp->auxargs != NULL)
execpath_len = strlen(imgp->execpath) + 1;
else
execpath_len = 0;
p = imgp->proc;
szsigcode = 0;
arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
imgp->ps_strings = arginfo;
if (p->p_sysent->sv_sigcode_base == 0) {
if (p->p_sysent->sv_szsigcode != NULL)
szsigcode = *(p->p_sysent->sv_szsigcode);
}
sysent = p->p_sysent;
arginfo = (struct ps_strings *)sysent->sv_psstrings;
destp = (uintptr_t)arginfo;
imgp->ps_strings = arginfo;
/*
* install sigcode
* Install sigcode.
*/
if (szsigcode != 0) {
if (sysent->sv_sigcode_base == 0 && sysent->sv_szsigcode != NULL) {
szsigcode = *(sysent->sv_szsigcode);
destp -= szsigcode;
destp = rounddown2(destp, sizeof(void *));
error = copyout(p->p_sysent->sv_sigcode, (void *)destp,
szsigcode);
error = copyout(sysent->sv_sigcode, (void *)destp, szsigcode);
if (error != 0)
return (error);
}
@ -1654,7 +1643,8 @@ exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
/*
* Copy the image path for the rtld.
*/
if (execpath_len != 0) {
if (imgp->execpath != NULL && imgp->auxargs != NULL) {
execpath_len = strlen(imgp->execpath) + 1;
destp -= execpath_len;
destp = rounddown2(destp, sizeof(void *));
imgp->execpathp = (void *)destp;
@ -1677,13 +1667,13 @@ exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
/*
* Prepare the pagesizes array.
*/
destp -= szps;
imgp->pagesizeslen = sizeof(pagesizes[0]) * MAXPAGESIZES;
destp -= imgp->pagesizeslen;
destp = rounddown2(destp, sizeof(void *));
imgp->pagesizes = (void *)destp;
error = copyout(pagesizes, imgp->pagesizes, szps);
error = copyout(pagesizes, imgp->pagesizes, imgp->pagesizeslen);
if (error != 0)
return (error);
imgp->pagesizeslen = szps;
/*
* Allocate room for the argument and environment strings.