[PATCH 6/7] exec: simplify the copy_strings_kernel calling convention

Christoph Hellwig
2020-04-21T15:42:38Z

copy_strings_kernel is always used with a single argument,
adjust the calling convention to that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/binfmt_em86.c | 6 +++---
fs/binfmt_misc.c | 4 ++--
fs/binfmt_script.c | 6 +++---
fs/exec.c | 13 ++++++-------
include/linux/binfmts.h | 3 +--
5 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/fs/binfmt_em86.c b/fs/binfmt_em86.c
index 466497860c62..f33fa668c91f 100644
--- a/fs/binfmt_em86.c
+++ b/fs/binfmt_em86.c
@@ -68,15 +68,15 @@ static int load_em86(struct linux_binprm *bprm)
* user environment and arguments are stored.
*/
remove_arg_zero(bprm);
- retval = copy_strings_kernel(1, &bprm->filename, bprm);
+ retval = copy_string_kernel(bprm->filename, bprm);
if (retval < 0) return retval;
bprm->argc++;
if (i_arg) {
- retval = copy_strings_kernel(1, &i_arg, bprm);
+ retval = copy_string_kernel(i_arg, bprm);
if (retval < 0) return retval;
bprm->argc++;
}
- retval = copy_strings_kernel(1, &i_name, bprm);
+ retval = copy_string_kernel(i_name, bprm);
if (retval < 0) return retval;
bprm->argc++;

diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index cdb45829354d..b15257d8ff5e 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -190,13 +190,13 @@ static int load_misc_binary(struct linux_binprm *bprm)
bprm->file = NULL;
}
/* make argv[1] be the path to the binary */
- retval = copy_strings_kernel(1, &bprm->interp, bprm);
+ retval = copy_string_kernel(bprm->interp, bprm);
if (retval < 0)
goto error;
bprm->argc++;

/* add the interp as argv[0] */
- retval = copy_strings_kernel(1, &fmt->interpreter, bprm);
+ retval = copy_string_kernel(fmt->interpreter, bprm);
if (retval < 0)
goto error;
bprm->argc++;
diff --git a/fs/binfmt_script.c b/fs/binfmt_script.c
index e9e6a6f4a35f..c4fb7f52a46e 100644
--- a/fs/binfmt_script.c
+++ b/fs/binfmt_script.c
@@ -117,17 +117,17 @@ static int load_script(struct linux_binprm *bprm)
retval = remove_arg_zero(bprm);
if (retval)
return retval;
- retval = copy_strings_kernel(1, &bprm->interp, bprm);
+ retval = copy_string_kernel(bprm->interp, bprm);
if (retval < 0)
return retval;
bprm->argc++;
if (i_arg) {
- retval = copy_strings_kernel(1, &i_arg, bprm);
+ retval = copy_string_kernel(i_arg, bprm);
if (retval < 0)
return retval;
bprm->argc++;
}
- retval = copy_strings_kernel(1, &i_name, bprm);
+ retval = copy_string_kernel(i_name, bprm);
if (retval)
return retval;
bprm->argc++;
diff --git a/fs/exec.c b/fs/exec.c
index 06b4c550af5d..b2a77d5acede 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -588,24 +588,23 @@ static int copy_strings(int argc, struct user_arg_ptr argv,
}

/*
- * Like copy_strings, but get argv and its values from kernel memory.
+ * Copy and argument/environment string from the kernel to the processes stack.
*/
-int copy_strings_kernel(int argc, const char *const *__argv,
- struct linux_binprm *bprm)
+int copy_string_kernel(const char *arg, struct linux_binprm *bprm)
{
int r;
mm_segment_t oldfs = get_fs();
struct user_arg_ptr argv = {
- .ptr.native = (const char __user *const __user *)__argv,
+ .ptr.native = (const char __user *const __user *)&arg,
};

set_fs(KERNEL_DS);
- r = copy_strings(argc, argv, bprm);
+ r = copy_strings(1, argv, bprm);
set_fs(oldfs);

return r;
}
-EXPORT_SYMBOL(copy_strings_kernel);
+EXPORT_SYMBOL(copy_string_kernel);

#ifdef CONFIG_MMU

@@ -1863,7 +1862,7 @@ static int __do_execve_file(int fd, struct filename *filename,
if (retval < 0)
goto out;

- retval = copy_strings_kernel(1, &bprm->filename, bprm);
+ retval = copy_string_kernel(bprm->filename, bprm);
if (retval < 0)
goto out;

diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index a345d9fed3d8..3d3afe094c97 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -144,8 +144,7 @@ extern int setup_arg_pages(struct linux_binprm * bprm,
extern int transfer_args_to_stack(struct linux_binprm *bprm,
unsigned long *sp_location);
extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
-extern int copy_strings_kernel(int argc, const char *const *argv,
- struct linux_binprm *bprm);
+int copy_string_kernel(const char *arg, struct linux_binprm *bprm);
extern void install_exec_creds(struct linux_binprm *bprm);
extern void set_binfmt(struct linux_binfmt *new);
extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t);
--
2.26.1