Hi,
This patch removes copypasted code that prepares args and env in exec
system call.
Index: sys/kern/kern_exec.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_exec.c,v
retrieving revision 1.173
diff -u -p -r1.173 kern_exec.c
--- sys/kern/kern_exec.c 5 Dec 2015 10:11:53 -0000 1.173
+++ sys/kern/kern_exec.c 12 Dec 2015 17:34:43 -0000
@@ -77,6 +77,12 @@ const struct kmem_va_mode kv_exec = {
.kv_map = &exec_map
};
+struct argcontext
+{
+ char *buffer;
+ char *bptr;
+};
+
/*
* Map the shared signal code.
*/
@@ -231,6 +237,58 @@ bad1:
return (error);
}
+void
+copy_fake_args(struct exec_package *pack, struct argcontext *argctx,
+ long *count)
+{
+ char **fake_args_vec = pack->ep_fa;
+
+ while (*fake_args_vec != NULL) {
+ char *arg = *fake_args_vec;
+
+ while (*arg)
+ *argctx->bptr++ = *arg++;
+
+ *argctx->bptr++ = '\0';
+
+ free(*fake_args_vec, M_EXEC, 0);
+
+ fake_args_vec++;
+ (*count)++;
+ }
+
+ free(pack->ep_fa, M_EXEC, 0);
+ pack->ep_flags &= ~EXEC_HASARGL;
+}
+
+int
+copy_strings(char * const *src, struct argcontext *argctx, long *count)
+{
+ int error;
+ size_t len;
+ size_t maxlen = argctx->buffer + ARG_MAX - argctx->bptr;
+ char *sp;
+
+ while (1) {
+ if ((error = copyin(src, &sp, sizeof(sp))) != 0)
+ return error;
+ if (!sp)
+ break;
+ if ((error = copyinstr(sp, argctx->bptr, maxlen, &len)) != 0) {
+ if (error == ENAMETOOLONG)
+ error = E2BIG;
+ return error;
+ }
+
+ maxlen -= len;
+ argctx->bptr += len;
+ src++;
+ (*count)++;
+ }
+
+ return 0;
+}
+
/*
* exec system call
*/
@@ -242,13 +300,13 @@ sys_execve(struct proc *p, void *v, regi
syscallarg(char *const *) argp;
syscallarg(char *const *) envp;
} */ *uap = v;
+ struct argcontext argctx;
int error;
struct exec_package pack;
struct nameidata nid;
struct vattr attr;
struct ucred *cred = p->p_ucred;
- char *argp;
- char * const *cpp, *dp, *sp;
+ char * const *cpp;
#ifdef KTRACE
char *env_start;
#endif
@@ -261,7 +319,6 @@ sys_execve(struct proc *p, void *v, regi
char *stack;
struct ps_strings arginfo;
struct vmspace *vm = pr->ps_vmspace;
- char **tmpfap;
extern struct emul emul_native;
#if NSYSTRACE > 0
int wassugid = ISSET(pr->ps_flags, PS_SUGID | PS_SUGIDEXEC);
@@ -317,38 +374,23 @@ sys_execve(struct proc *p, void *v, regi
pack.ep_flags = 0;
/* see if we can run it. */
- if ((error = check_exec(p, &pack)) != 0) {
+ if ((error = check_exec(p, &pack)) != 0)
goto freehdr;
- }
/* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */
-
+
/* allocate an argument buffer */
- argp = km_alloc(NCARGS, &kv_exec, &kp_pageable, &kd_waitok);
+ argctx.buffer = km_alloc(NCARGS, &kv_exec, &kp_pageable, &kd_waitok);
#ifdef DIAGNOSTIC
- if (argp == NULL)
- panic("execve: argp == NULL");
+ if (argctx.buffer == NULL)
+ panic("execve: argctx.buffer == NULL");
#endif
- dp = argp;
+ argctx.bptr = argctx.buffer;
argc = 0;
/* copy the fake args list, if there's one, freeing it as we go */
- if (pack.ep_flags & EXEC_HASARGL) {
- tmpfap = pack.ep_fa;
- while (*tmpfap != NULL) {
- char *cp;
-
- cp = *tmpfap;
- while (*cp)
- *dp++ = *cp++;
- *dp++ = '\0';
-
- free(*tmpfap, M_EXEC, 0);
- tmpfap++; argc++;
- }
- free(pack.ep_fa, M_EXEC, 0);
- pack.ep_flags &= ~EXEC_HASARGL;
- }
+ if (pack.ep_flags & EXEC_HASARGL)
+ copy_fake_args(&pack, &argctx, &argc);
/* Now get argv & environment */
if (!(cpp = SCARG(uap, argp))) {
@@ -359,21 +401,9 @@ sys_execve(struct proc *p, void *v, regi
if (pack.ep_flags & EXEC_SKIPARG)
cpp++;
- while (1) {
- len = argp + ARG_MAX - dp;
- if ((error = copyin(cpp, &sp, sizeof(sp))) != 0)
- goto bad;
- if (!sp)
- break;
- if ((error = copyinstr(sp, dp, len, &len)) != 0) {
- if (error == ENAMETOOLONG)
- error = E2BIG;
- goto bad;
- }
- dp += len;
- cpp++;
- argc++;
- }
+ /* copy args */
+ if (copy_strings(cpp, &argctx, &argc) != 0)
+ goto bad;
/* must have at least one argument */
if (argc == 0) {
@@ -382,39 +412,31 @@ sys_execve(struct proc *p, void *v, regi
}
#ifdef KTRACE
- if (KTRPOINT(p, KTR_EXECARGS))
- ktrexec(p, KTR_EXECARGS, argp, dp - argp);
+ if (KTRPOINT(p, KTR_EXECARGS)) {
+ ktrexec(p, KTR_EXECARGS, argctx.buffer,
+ argctx.bptr - argctx.buffer);
+ }
#endif
envc = 0;
/* environment does not need to be there */
if ((cpp = SCARG(uap, envp)) != NULL ) {
#ifdef KTRACE
- env_start = dp;
+ env_start = argctx.bptr;
#endif
- while (1) {
- len = argp + ARG_MAX - dp;
- if ((error = copyin(cpp, &sp, sizeof(sp))) != 0)
- goto bad;
- if (!sp)
- break;
- if ((error = copyinstr(sp, dp, len, &len)) != 0) {
- if (error == ENAMETOOLONG)
- error = E2BIG;
- goto bad;
- }
- dp += len;
- cpp++;
- envc++;
- }
-
+ if (copy_strings(cpp, &argctx, &envc) != 0)
+ goto bad;
#ifdef KTRACE
- if (KTRPOINT(p, KTR_EXECENV))
- ktrexec(p, KTR_EXECENV, env_start, dp - env_start);
+ if (KTRPOINT(p, KTR_EXECENV)) {
+ ktrexec(p, KTR_EXECENV, env_start,
+ argctx.bptr - env_start);
+ }
#endif
}
- dp = (char *)(((long)dp + _STACKALIGNBYTES) & ~_STACKALIGNBYTES);
+ argctx.bptr =
+ (char *)(((long)argctx.bptr + _STACKALIGNBYTES) &
+ ~_STACKALIGNBYTES);
sgap = STACKGAPLEN;
@@ -430,7 +452,8 @@ sys_execve(struct proc *p, void *v, regi
/* Now check if args & environ fit into new stack */
len = ((argc + envc + 2 + pack.ep_emul->e_arglen) * sizeof(char *) +
- sizeof(long) + dp + sgap + sizeof(struct ps_strings)) - argp;
+ sizeof(long) + argctx.bptr + sgap + sizeof(struct ps_strings)) -
+ argctx.buffer;
len = (len + _STACKALIGNBYTES) &~ _STACKALIGNBYTES;
@@ -505,7 +528,7 @@ sys_execve(struct proc *p, void *v, regi
stack = (char *)(vm->vm_minsaddr - len);
#endif
/* Now copy argc, args & environ to new stack */
- if (!(*pack.ep_emul->e_copyargs)(&pack, &arginfo, stack, argp))
+ if (!(*pack.ep_emul->e_copyargs)(&pack, &arginfo, stack, argctx.buffer))
goto exec_abort;
/* copy out the process's ps_strings structure */
@@ -672,7 +695,7 @@ sys_execve(struct proc *p, void *v, regi
timespecclear(&p->p_tu.tu_runtime);
p->p_tu.tu_uticks = p->p_tu.tu_sticks = p->p_tu.tu_iticks = 0;
- km_free(argp, NCARGS, &kv_exec, &kp_pageable);
+ km_free(argctx.buffer, NCARGS, &kv_exec, &kp_pageable);
pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf);
vn_close(pack.ep_vp, FREAD, cred, p);
@@ -777,7 +800,7 @@ bad:
/* close and put the exec'd file */
vn_close(pack.ep_vp, FREAD, cred, p);
pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf);
- km_free(argp, NCARGS, &kv_exec, &kp_pageable);
+ km_free(argctx.buffer, NCARGS, &kv_exec, &kp_pageable);
freehdr:
free(pack.ep_hdr, M_EXEC, pack.ep_hdrlen);
@@ -806,7 +829,7 @@ exec_abort:
free(pack.ep_emul_arg, M_TEMP, pack.ep_emul_argsize);
pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf);
vn_close(pack.ep_vp, FREAD, cred, p);
- km_free(argp, NCARGS, &kv_exec, &kp_pageable);
+ km_free(argctx.buffer, NCARGS, &kv_exec, &kp_pageable);
free_pack_abort:
free(pack.ep_hdr, M_EXEC, pack.ep_hdrlen);
