generic: add CONFIG_MANGLE_BOOTARGS and disable it by default

[openwrt/openwrt.git] / target / linux / generic / patches-3.18 / 995-mangle_bootargs.patch

diff --git a/target/linux/generic/patches-3.18/995-mangle_bootargs.patch b/target/linux/generic/patches-3.18/995-mangle_bootargs.patch
new file mode 100644 (file)
index 0000000..5d56cf4
--- /dev/null
+++ b/target/linux/generic/patches-3.18/995-mangle_bootargs.patch
@@ -0,0 +1,55 @@
+--- a/init/main.c
++++ b/init/main.c
+@@ -379,6 +379,26 @@ static void __init setup_command_line(ch
+       strcpy(static_command_line, command_line);
+ }
+ 
++#ifdef CONFIG_MANGLE_BOOTARGS
++static void __init mangle_bootargs(char *command_line)
++{
++      char *rootdev;
++      char *rootfs;
++
++      rootdev = strstr(command_line, "root=/dev/mtdblock");
++      strncpy(rootdev, "mangled_rootblock=", 18);
++
++      rootfs = strstr(command_line, "rootfstype");
++      strncpy(rootfs, "mangled_fs", 10);
++
++}
++#else
++static void __init mangle_bootargs(char *command_line)
++{
++}
++#endif
++
++
+ /*
+  * We need to finalize in a non-__init function or else race conditions
+  * between the root thread and the init thread may cause start_kernel to
+@@ -530,6 +550,7 @@ asmlinkage __visible void __init start_k
+       pr_notice("%s", linux_banner);
+       setup_arch(&command_line);
+       mm_init_cpumask(&init_mm);
++      mangle_bootargs(command_line);
+       setup_command_line(command_line);
+       setup_nr_cpu_ids();
+       setup_per_cpu_areas();
+--- a/init/Kconfig
++++ b/init/Kconfig
+@@ -1597,6 +1597,15 @@ config EMBEDDED
+         an embedded system so certain expert options are available
+         for configuration.
+ 
++config MANGLE_BOOTARGS
++      bool "Rename offending bootargs"
++      depends on EXPERT
++      help
++        Sometimes the bootloader passed bogus root= and rootfstype=
++        parameters to the kernel, and while you want to ignore them,
++        you need to know the values f.e. to support dual firmware
++        layouts on the flash.
++
+ config HAVE_PERF_EVENTS
+       bool
+       help