svn commit: r341263 - in head/sys: compat/cloudabi32 compat/cloudabi64 compat/freebsd32 kern sys
Brooks Davis
brooks at FreeBSD.org
Thu Nov 29 21:00:58 UTC 2018
Author: brooks
Date: Thu Nov 29 21:00:56 2018
New Revision: 341263
URL: https://svnweb.freebsd.org/changeset/base/341263
Log:
Add helper functions to copy strings into struct image_args.
Given a zeroed struct image_args with an allocated buf member,
exec_args_add_fname() must be called to install a file name (or NULL).
Then zero or more calls to exec_args_add_env() followed by zero or
more calls to exec_args_add_env(). exec_args_adjust_args() may be
called after args and/or env to allow an interpreter to be prepended to
the argument list.
To allow code reuse when adding arg and env variables, begin_envv
should be accessed with the accessor exec_args_get_begin_envv()
which handles the case when no environment entries have been added.
Use these functions to simplify exec_copyin_args() and
freebsd32_exec_copyin_args().
Reviewed by: kib
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15468
Modified:
head/sys/compat/cloudabi32/cloudabi32_module.c
head/sys/compat/cloudabi64/cloudabi64_module.c
head/sys/compat/freebsd32/freebsd32_misc.c
head/sys/kern/imgact_binmisc.c
head/sys/kern/imgact_shell.c
head/sys/kern/kern_exec.c
head/sys/sys/imgact.h
Modified: head/sys/compat/cloudabi32/cloudabi32_module.c
==============================================================================
--- head/sys/compat/cloudabi32/cloudabi32_module.c Thu Nov 29 20:59:18 2018 (r341262)
+++ head/sys/compat/cloudabi32/cloudabi32_module.c Thu Nov 29 21:00:56 2018 (r341263)
@@ -54,7 +54,7 @@ cloudabi32_copyout_strings(struct image_params *imgp)
/* Copy out program arguments. */
args = imgp->args;
- len = args->begin_envv - args->begin_argv;
+ len = exec_args_get_begin_envv(args) - args->begin_argv;
begin = rounddown2(imgp->sysent->sv_usrstack - len, sizeof(register_t));
copyout(args->begin_argv, (void *)begin, len);
return ((register_t *)begin);
@@ -109,7 +109,8 @@ cloudabi32_fixup(register_t **stack_base, struct image
* exec_copyin_data_fds(). Undo this by reducing the length.
*/
args = (Elf32_Auxargs *)imgp->auxargs;
- argdatalen = imgp->args->begin_envv - imgp->args->begin_argv;
+ argdatalen = exec_args_get_begin_envv(imgp->args) -
+ imgp->args->begin_argv;
if (argdatalen > 0)
--argdatalen;
Modified: head/sys/compat/cloudabi64/cloudabi64_module.c
==============================================================================
--- head/sys/compat/cloudabi64/cloudabi64_module.c Thu Nov 29 20:59:18 2018 (r341262)
+++ head/sys/compat/cloudabi64/cloudabi64_module.c Thu Nov 29 21:00:56 2018 (r341263)
@@ -54,7 +54,7 @@ cloudabi64_copyout_strings(struct image_params *imgp)
/* Copy out program arguments. */
args = imgp->args;
- len = args->begin_envv - args->begin_argv;
+ len = exec_args_get_begin_envv(args) - args->begin_argv;
begin = rounddown2(imgp->sysent->sv_usrstack - len, sizeof(register_t));
copyout(args->begin_argv, (void *)begin, len);
return ((register_t *)begin);
@@ -109,7 +109,8 @@ cloudabi64_fixup(register_t **stack_base, struct image
* exec_copyin_data_fds(). Undo this by reducing the length.
*/
args = (Elf64_Auxargs *)imgp->auxargs;
- argdatalen = imgp->args->begin_envv - imgp->args->begin_argv;
+ argdatalen = exec_args_get_begin_envv(imgp->args) -
+ imgp->args->begin_argv;
if (argdatalen > 0)
--argdatalen;
Modified: head/sys/compat/freebsd32/freebsd32_misc.c
==============================================================================
--- head/sys/compat/freebsd32/freebsd32_misc.c Thu Nov 29 20:59:18 2018 (r341262)
+++ head/sys/compat/freebsd32/freebsd32_misc.c Thu Nov 29 21:00:56 2018 (r341263)
@@ -337,7 +337,6 @@ freebsd32_exec_copyin_args(struct image_args *args, co
{
char *argp, *envp;
u_int32_t *p32, arg;
- size_t length;
int error;
bzero(args, sizeof(*args));
@@ -355,20 +354,10 @@ freebsd32_exec_copyin_args(struct image_args *args, co
/*
* Copy the file name.
*/
- if (fname != NULL) {
- args->fname = args->buf;
- error = (segflg == UIO_SYSSPACE) ?
- copystr(fname, args->fname, PATH_MAX, &length) :
- copyinstr(fname, args->fname, PATH_MAX, &length);
- if (error != 0)
- goto err_exit;
- } else
- length = 0;
+ error = exec_args_add_fname(args, fname, segflg);
+ if (error != 0)
+ goto err_exit;
- args->begin_argv = args->buf + length;
- args->endp = args->begin_argv;
- args->stringspace = ARG_MAX;
-
/*
* extract arguments first
*/
@@ -380,19 +369,11 @@ freebsd32_exec_copyin_args(struct image_args *args, co
if (arg == 0)
break;
argp = PTRIN(arg);
- error = copyinstr(argp, args->endp, args->stringspace, &length);
- if (error) {
- if (error == ENAMETOOLONG)
- error = E2BIG;
+ error = exec_args_add_arg(args, argp, UIO_USERSPACE);
+ if (error != 0)
goto err_exit;
- }
- args->stringspace -= length;
- args->endp += length;
- args->argc++;
}
- args->begin_envv = args->endp;
-
/*
* extract environment strings
*/
@@ -405,16 +386,9 @@ freebsd32_exec_copyin_args(struct image_args *args, co
if (arg == 0)
break;
envp = PTRIN(arg);
- error = copyinstr(envp, args->endp, args->stringspace,
- &length);
- if (error) {
- if (error == ENAMETOOLONG)
- error = E2BIG;
+ error = exec_args_add_env(args, envp, UIO_USERSPACE);
+ if (error != 0)
goto err_exit;
- }
- args->stringspace -= length;
- args->endp += length;
- args->envc++;
}
}
Modified: head/sys/kern/imgact_binmisc.c
==============================================================================
--- head/sys/kern/imgact_binmisc.c Thu Nov 29 20:59:18 2018 (r341262)
+++ head/sys/kern/imgact_binmisc.c Thu Nov 29 21:00:56 2018 (r341263)
@@ -649,21 +649,12 @@ imgact_binmisc_exec(struct image_params *imgp)
s++;
}
- /* Check to make sure we won't overrun the stringspace. */
- if (offset > imgp->args->stringspace) {
+ /* Make room for the interpreter */
+ error = exec_args_adjust_args(imgp->args, 0, offset);
+ if (error != 0) {
sx_sunlock(&interp_list_sx);
- error = E2BIG;
goto done;
}
-
- /* Make room for the interpreter */
- bcopy(imgp->args->begin_argv, imgp->args->begin_argv + offset,
- imgp->args->endp - imgp->args->begin_argv);
-
- /* Adjust everything by the offset. */
- imgp->args->begin_envv += offset;
- imgp->args->endp += offset;
- imgp->args->stringspace -= offset;
/* Add the new argument(s) in the count. */
imgp->args->argc += ibe->ibe_interp_argcnt;
Modified: head/sys/kern/imgact_shell.c
==============================================================================
--- head/sys/kern/imgact_shell.c Thu Nov 29 20:59:18 2018 (r341262)
+++ head/sys/kern/imgact_shell.c Thu Nov 29 21:00:56 2018 (r341263)
@@ -196,19 +196,12 @@ exec_shell_imgact(struct image_params *imgp)
length = (imgp->args->argc == 0) ? 0 :
strlen(imgp->args->begin_argv) + 1; /* bytes to delete */
- if (offset > imgp->args->stringspace + length) {
+ error = exec_args_adjust_args(imgp->args, length, offset);
+ if (error != 0) {
if (sname != NULL)
sbuf_delete(sname);
- return (E2BIG);
+ return (error);
}
-
- bcopy(imgp->args->begin_argv + length, imgp->args->begin_argv + offset,
- imgp->args->endp - (imgp->args->begin_argv + length));
-
- offset -= length; /* calculate actual adjustment */
- imgp->args->begin_envv += offset;
- imgp->args->endp += offset;
- imgp->args->stringspace -= offset;
/*
* If there was no arg[0] when we started, then the interpreter_name
Modified: head/sys/kern/kern_exec.c
==============================================================================
--- head/sys/kern/kern_exec.c Thu Nov 29 20:59:18 2018 (r341262)
+++ head/sys/kern/kern_exec.c Thu Nov 29 21:00:56 2018 (r341263)
@@ -345,9 +345,9 @@ kern_execve(struct thread *td, struct image_args *args
{
AUDIT_ARG_ARGV(args->begin_argv, args->argc,
- args->begin_envv - args->begin_argv);
- AUDIT_ARG_ENVV(args->begin_envv, args->envc,
- args->endp - args->begin_envv);
+ exec_args_get_begin_envv(args) - args->begin_argv);
+ AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc,
+ args->endp - exec_args_get_begin_envv(args));
return (do_execve(td, args, mac_p));
}
@@ -717,7 +717,7 @@ interpret:
/*
* Malloc things before we need locks.
*/
- i = imgp->args->begin_envv - imgp->args->begin_argv;
+ i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv;
/* Cache arguments if they fit inside our allowance */
if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
newargs = pargs_alloc(i);
@@ -1171,9 +1171,8 @@ int
exec_copyin_args(struct image_args *args, const char *fname,
enum uio_seg segflg, char **argv, char **envv)
{
- u_long argp, envp;
+ u_long arg, env;
int error;
- size_t length;
bzero(args, sizeof(*args));
if (argv == NULL)
@@ -1190,67 +1189,43 @@ exec_copyin_args(struct image_args *args, const char *
/*
* Copy the file name.
*/
- if (fname != NULL) {
- args->fname = args->buf;
- error = (segflg == UIO_SYSSPACE) ?
- copystr(fname, args->fname, PATH_MAX, &length) :
- copyinstr(fname, args->fname, PATH_MAX, &length);
- if (error != 0)
- goto err_exit;
- } else
- length = 0;
+ error = exec_args_add_fname(args, fname, segflg);
+ if (error != 0)
+ goto err_exit;
- args->begin_argv = args->buf + length;
- args->endp = args->begin_argv;
- args->stringspace = ARG_MAX;
-
/*
* extract arguments first
*/
for (;;) {
- error = fueword(argv++, &argp);
+ error = fueword(argv++, &arg);
if (error == -1) {
error = EFAULT;
goto err_exit;
}
- if (argp == 0)
+ if (arg == 0)
break;
- error = copyinstr((void *)(uintptr_t)argp, args->endp,
- args->stringspace, &length);
- if (error != 0) {
- if (error == ENAMETOOLONG)
- error = E2BIG;
+ error = exec_args_add_arg(args, (char *)(uintptr_t)arg,
+ UIO_USERSPACE);
+ if (error != 0)
goto err_exit;
- }
- args->stringspace -= length;
- args->endp += length;
- args->argc++;
}
- args->begin_envv = args->endp;
-
/*
* extract environment strings
*/
if (envv) {
for (;;) {
- error = fueword(envv++, &envp);
+ error = fueword(envv++, &env);
if (error == -1) {
error = EFAULT;
goto err_exit;
}
- if (envp == 0)
+ if (env == 0)
break;
- error = copyinstr((void *)(uintptr_t)envp,
- args->endp, args->stringspace, &length);
- if (error != 0) {
- if (error == ENAMETOOLONG)
- error = E2BIG;
+ error = exec_args_add_env(args,
+ (char *)(uintptr_t)env, UIO_USERSPACE);
+ if (error != 0)
goto err_exit;
- }
- args->stringspace -= length;
- args->endp += length;
- args->envc++;
}
}
@@ -1305,8 +1280,6 @@ exec_copyin_data_fds(struct thread *td, struct image_a
/* No argument buffer provided. */
args->endp = args->begin_argv;
}
- /* There are no environment variables. */
- args->begin_envv = args->endp;
/* Create new file descriptor table. */
kfds = malloc(fdslen * sizeof(int), M_TEMP, M_WAITOK);
@@ -1460,6 +1433,126 @@ exec_free_args(struct image_args *args)
}
if (args->fdp != NULL)
fdescfree_remapped(args->fdp);
+}
+
+/*
+ * A set to functions to fill struct image args.
+ *
+ * NOTE: exec_args_add_fname() must be called (possibly with a NULL
+ * fname) before the other functions. All exec_args_add_arg() calls must
+ * be made before any exec_args_add_env() calls. exec_args_adjust_args()
+ * may be called any time after exec_args_add_fname().
+ *
+ * exec_args_add_fname() - install path to be executed
+ * exec_args_add_arg() - append an argument string
+ * exec_args_add_env() - append an env string
+ * exec_args_adjust_args() - adjust location of the argument list to
+ * allow new arguments to be prepended
+ */
+int
+exec_args_add_fname(struct image_args *args, const char *fname,
+ enum uio_seg segflg)
+{
+ int error;
+ size_t length;
+
+ KASSERT(args->fname == NULL, ("fname already appended"));
+ KASSERT(args->endp == NULL, ("already appending to args"));
+
+ if (fname != NULL) {
+ args->fname = args->buf;
+ error = segflg == UIO_SYSSPACE ?
+ copystr(fname, args->fname, PATH_MAX, &length) :
+ copyinstr(fname, args->fname, PATH_MAX, &length);
+ if (error != 0)
+ return (error == ENAMETOOLONG ? E2BIG : error);
+ } else
+ length = 0;
+
+ /* Set up for _arg_*()/_env_*() */
+ args->endp = args->buf + length;
+ /* begin_argv must be set and kept updated */
+ args->begin_argv = args->endp;
+ KASSERT(exec_map_entry_size - length >= ARG_MAX,
+ ("too little space remaining for arguments %zu < %zu",
+ exec_map_entry_size - length, (size_t)ARG_MAX));
+ args->stringspace = ARG_MAX;
+
+ return (0);
+}
+
+static int
+exec_args_add_str(struct image_args *args, const char *str,
+ enum uio_seg segflg, int *countp)
+{
+ int error;
+ size_t length;
+
+ KASSERT(args->endp != NULL, ("endp not initialized"));
+ KASSERT(args->begin_argv != NULL, ("begin_argp not initialized"));
+
+ error = (segflg == UIO_SYSSPACE) ?
+ copystr(str, args->endp, args->stringspace, &length) :
+ copyinstr(str, args->endp, args->stringspace, &length);
+ if (error != 0)
+ return (error == ENAMETOOLONG ? E2BIG : error);
+ args->stringspace -= length;
+ args->endp += length;
+ (*countp)++;
+
+ return (0);
+}
+
+int
+exec_args_add_arg(struct image_args *args, const char *argp,
+ enum uio_seg segflg)
+{
+
+ KASSERT(args->envc == 0, ("appending args after env"));
+
+ return (exec_args_add_str(args, argp, segflg, &args->argc));
+}
+
+int
+exec_args_add_env(struct image_args *args, const char *envp,
+ enum uio_seg segflg)
+{
+
+ if (args->envc == 0)
+ args->begin_envv = args->endp;
+
+ return (exec_args_add_str(args, envp, segflg, &args->envc));
+}
+
+int
+exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend)
+{
+ ssize_t offset;
+
+ KASSERT(args->endp != NULL, ("endp not initialized"));
+ KASSERT(args->begin_argv != NULL, ("begin_argp not initialized"));
+
+ offset = extend - consume;
+ if (args->stringspace < offset)
+ return (E2BIG);
+ memmove(args->begin_argv + extend, args->begin_argv + consume,
+ args->endp - args->begin_argv + consume);
+ if (args->envc > 0)
+ args->begin_envv += offset;
+ args->endp += offset;
+ args->stringspace -= offset;
+ return (0);
+}
+
+char *
+exec_args_get_begin_envv(struct image_args *args)
+{
+
+ KASSERT(args->endp != NULL, ("endp not initialized"));
+
+ if (args->envc > 0)
+ return (args->begin_envv);
+ return (args->endp);
}
/*
Modified: head/sys/sys/imgact.h
==============================================================================
--- head/sys/sys/imgact.h Thu Nov 29 20:59:18 2018 (r341262)
+++ head/sys/sys/imgact.h Thu Nov 29 21:00:56 2018 (r341263)
@@ -46,7 +46,8 @@ struct image_args {
char *buf; /* pointer to string buffer */
void *bufkva; /* cookie for string buffer KVA */
char *begin_argv; /* beginning of argv in buf */
- char *begin_envv; /* beginning of envv in buf */
+ char *begin_envv; /* (interal use only) beginning of envv in buf,
+ * access with exec_args_get_begin_envv(). */
char *endp; /* current `end' pointer of arg & env strings */
char *fname; /* pointer to filename of executable (system space) */
char *fname_buf; /* pointer to optional malloc(M_TEMP) buffer */
@@ -96,6 +97,15 @@ struct thread;
struct vmspace;
int exec_alloc_args(struct image_args *);
+int exec_args_add_arg(struct image_args *args, const char *argp,
+ enum uio_seg segflg);
+int exec_args_add_env(struct image_args *args, const char *envp,
+ enum uio_seg segflg);
+int exec_args_add_fname(struct image_args *args, const char *fname,
+ enum uio_seg segflg);
+int exec_args_adjust_args(struct image_args *args, size_t consume,
+ ssize_t extend);
+char *exec_args_get_begin_envv(struct image_args *args);
int exec_check_permissions(struct image_params *);
register_t *exec_copyout_strings(struct image_params *);
void exec_free_args(struct image_args *);
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