From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/fs/binfmt_misc.c | 103 ++++++++++++++++-----------------------------------
1 files changed, 33 insertions(+), 70 deletions(-)
diff --git a/kernel/fs/binfmt_misc.c b/kernel/fs/binfmt_misc.c
index 27a04f4..83b1992 100644
--- a/kernel/fs/binfmt_misc.c
+++ b/kernel/fs/binfmt_misc.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* binfmt_misc.c
*
@@ -22,6 +23,7 @@
#include <linux/pagemap.h>
#include <linux/namei.h>
#include <linux/mount.h>
+#include <linux/fs_context.h>
#include <linux/syscalls.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
@@ -42,10 +44,10 @@
static int enabled = 1;
enum {Enabled, Magic};
-#define MISC_FMT_PRESERVE_ARGV0 (1 << 31)
-#define MISC_FMT_OPEN_BINARY (1 << 30)
-#define MISC_FMT_CREDENTIALS (1 << 29)
-#define MISC_FMT_OPEN_FILE (1 << 28)
+#define MISC_FMT_PRESERVE_ARGV0 (1UL << 31)
+#define MISC_FMT_OPEN_BINARY (1UL << 30)
+#define MISC_FMT_CREDENTIALS (1UL << 29)
+#define MISC_FMT_OPEN_FILE (1UL << 28)
typedef struct {
struct list_head list;
@@ -132,7 +134,6 @@
Node *fmt;
struct file *interp_file = NULL;
int retval;
- int fd_binary = -1;
retval = -ENOEXEC;
if (!enabled)
@@ -158,51 +159,25 @@
goto ret;
}
- if (fmt->flags & MISC_FMT_OPEN_BINARY) {
+ if (fmt->flags & MISC_FMT_OPEN_BINARY)
+ bprm->have_execfd = 1;
- /* if the binary should be opened on behalf of the
- * interpreter than keep it open and assign descriptor
- * to it
- */
- fd_binary = get_unused_fd_flags(0);
- if (fd_binary < 0) {
- retval = fd_binary;
- goto ret;
- }
- fd_install(fd_binary, bprm->file);
-
- /* if the binary is not readable than enforce mm->dumpable=0
- regardless of the interpreter's permissions */
- would_dump(bprm, bprm->file);
-
- allow_write_access(bprm->file);
- bprm->file = NULL;
-
- /* mark the bprm that fd should be passed to interp */
- bprm->interp_flags |= BINPRM_FLAGS_EXECFD;
- bprm->interp_data = fd_binary;
-
- } else {
- allow_write_access(bprm->file);
- fput(bprm->file);
- 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;
+ goto ret;
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;
+ goto ret;
bprm->argc++;
/* Update interp in case binfmt_script needs it. */
retval = bprm_change_interp(fmt->interpreter, bprm);
if (retval < 0)
- goto error;
+ goto ret;
if (fmt->flags & MISC_FMT_OPEN_FILE) {
interp_file = file_clone_open(fmt->interp_file);
@@ -213,38 +188,16 @@
}
retval = PTR_ERR(interp_file);
if (IS_ERR(interp_file))
- goto error;
+ goto ret;
- bprm->file = interp_file;
- if (fmt->flags & MISC_FMT_CREDENTIALS) {
- loff_t pos = 0;
+ bprm->interpreter = interp_file;
+ if (fmt->flags & MISC_FMT_CREDENTIALS)
+ bprm->execfd_creds = 1;
- /*
- * No need to call prepare_binprm(), it's already been
- * done. bprm->buf is stale, update from interp_file.
- */
- memset(bprm->buf, 0, BINPRM_BUF_SIZE);
- retval = kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE,
- &pos);
- } else
- retval = prepare_binprm(bprm);
-
- if (retval < 0)
- goto error;
-
- retval = search_binary_handler(bprm);
- if (retval < 0)
- goto error;
-
+ retval = 0;
ret:
dput(fmt->dentry);
return retval;
-error:
- if (fd_binary > 0)
- ksys_close(fd_binary);
- bprm->interp_flags = 0;
- bprm->interp_data = 0;
- goto ret;
}
/* Command parsers */
@@ -819,7 +772,7 @@
.evict_inode = bm_evict_inode,
};
-static int bm_fill_super(struct super_block *sb, void *data, int silent)
+static int bm_fill_super(struct super_block *sb, struct fs_context *fc)
{
int err;
static const struct tree_descr bm_files[] = {
@@ -834,10 +787,19 @@
return err;
}
-static struct dentry *bm_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static int bm_get_tree(struct fs_context *fc)
{
- return mount_single(fs_type, flags, data, bm_fill_super);
+ return get_tree_single(fc, bm_fill_super);
+}
+
+static const struct fs_context_operations bm_context_ops = {
+ .get_tree = bm_get_tree,
+};
+
+static int bm_init_fs_context(struct fs_context *fc)
+{
+ fc->ops = &bm_context_ops;
+ return 0;
}
static struct linux_binfmt misc_format = {
@@ -848,7 +810,7 @@
static struct file_system_type bm_fs_type = {
.owner = THIS_MODULE,
.name = "binfmt_misc",
- .mount = bm_mount,
+ .init_fs_context = bm_init_fs_context,
.kill_sb = kill_litter_super,
};
MODULE_ALIAS_FS("binfmt_misc");
@@ -870,3 +832,4 @@
core_initcall(init_misc_binfmt);
module_exit(exit_misc_binfmt);
MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
--
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