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// SPDX-License-Identifier: GPL-2.0
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <asm/setup.h>
static char new_command_line[COMMAND_LINE_SIZE];
static int cmdline_proc_show(struct seq_file *m, void *v)
{
seq_puts(m, new_command_line);
seq_putc(m, '\n');
return 0;
}
static int cmdline_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, cmdline_proc_show, NULL);
}
static const struct file_operations cmdline_proc_fops = {
.open = cmdline_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static void patch_flag(char *cmd, const char *flag, const char *val)
{
size_t flag_len, val_len;
char *start, *end;
start = strstr(cmd, flag);
if (!start)
return;
flag_len = strlen(flag);
val_len = strlen(val);
end = start + flag_len + strcspn(start + flag_len, " ");
memmove(start + flag_len + val_len, end, strlen(end) + 1);
memcpy(start + flag_len, val, val_len);
}
static void patch_safetynet_flags(char *cmd)
{
patch_flag(cmd, "androidboot.verifiedbootstate=", "green");
patch_flag(cmd, "androidboot.veritymode=", "enforcing");
patch_flag(cmd, "androidboot.vbmeta.device_state=", "locked");
}
static int __init proc_cmdline_init(void)
{
strcpy(new_command_line, saved_command_line);
/*
* Patch various flags from command line seen by userspace in order to
* pass SafetyNet checks.
*/
patch_safetynet_flags(new_command_line);
proc_create("cmdline", 0, NULL, &cmdline_proc_fops);
return 0;
}
fs_initcall(proc_cmdline_init);
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