The patch titled Subject: init: allow CONFIG_INIT_FALLBACK=n to disable defaults if init= fails has been removed from the -mm tree. Its filename was init-allow-config_init_fallback=n-to-disable-defaults-if-init=-fails.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Subject: init: allow CONFIG_INIT_FALLBACK=n to disable defaults if init= fails If a user puts init=/whatever on the command line and /whatever can't be run, then the kernel will try a few default options before giving up. If init=/whatever came from a bootloader prompt, then this is unexpected but probably harmless. On the other hand, if it comes from a script (e.g. a tool like virtme or perhaps a future kselftest script), then the fallbacks are likely to exist, but they'll do the wrong thing. For example, they might unexpectedly invoke systemd. This adds a config option CONFIG_INIT_FALLBACK. If unset, then a failure to run the specified init= process be fatal. The tentative plan is to remove CONFIG_INIT_FALLBACK for 3.20. [akpm@xxxxxxxxxxxxxxxxxxxx: coding-style fixes] Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Rob Landley <rob@xxxxxxxxxxx> Cc: Chuck Ebbert <cebbert.lkml@xxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Shuah Khan <shuah.kh@xxxxxxxxxxx> Cc: Frank Rowand <frowand.list@xxxxxxxxx> Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx> Acked-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- init/Kconfig | 16 ++++++++++++++++ init/main.c | 7 ++++++- 2 files changed, 22 insertions(+), 1 deletion(-) diff -puN init/Kconfig~init-allow-config_init_fallback=n-to-disable-defaults-if-init=-fails init/Kconfig --- a/init/Kconfig~init-allow-config_init_fallback=n-to-disable-defaults-if-init=-fails +++ a/init/Kconfig @@ -1280,6 +1280,22 @@ source "usr/Kconfig" endif +config INIT_FALLBACK + bool "Fall back to defaults if init= parameter is bad" + default y + help + If enabled, the kernel will try the default init binaries if an + explicit request from the init= parameter fails. + + This can have unexpected effects. For example, booting + with init=/sbin/kiosk_app will run /sbin/init or even /bin/sh + if /sbin/kiosk_app cannot be executed. + + The default value of Y is consistent with historical behavior. + Selecting N is likely to be more appropriate for most uses, + especially on kiosks and on kernels that are intended to be + run under the control of a script. + config CC_OPTIMIZE_FOR_SIZE bool "Optimize for size" help diff -puN init/main.c~init-allow-config_init_fallback=n-to-disable-defaults-if-init=-fails init/main.c --- a/init/main.c~init-allow-config_init_fallback=n-to-disable-defaults-if-init=-fails +++ a/init/main.c @@ -952,8 +952,13 @@ static int __ref kernel_init(void *unuse ret = run_init_process(execute_command); if (!ret) return 0; +#ifndef CONFIG_INIT_FALLBACK + panic("Requested init %s failed (error %d).", + execute_command, ret); +#else pr_err("Failed to execute %s (error %d). Attempting defaults...\n", - execute_command, ret); + execute_command, ret); +#endif } if (!try_to_run_init_process("/sbin/init") || !try_to_run_init_process("/etc/init") || _ Patches currently in -mm which might be from luto@xxxxxxxxxxxxxx are origin.patch init-remove-config_init_fallback.patch syscalls-implement-execveat-system-call.patch x86-hook-up-execveat-system-call.patch syscalls-add-selftest-for-execveat2.patch linux-next.patch all-arches-signal-move-restart_block-to-struct-task_struct.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html