• Dan Williams's avatar
    init: initialize jump labels before command line option parsing · 2b46b985
    Dan Williams authored
    [ Upstream commit 6041186a32585fc7a1d0f6cfe2f138b05fdc3c82 ]
    
    When a module option, or core kernel argument, toggles a static-key it
    requires jump labels to be initialized early.  While x86, PowerPC, and
    ARM64 arrange for jump_label_init() to be called before parse_args(),
    ARM does not.
    
      Kernel command line: rdinit=/sbin/init page_alloc.shuffle=1 panic=-1 console=ttyAMA0,115200 page_alloc.shuffle=1
      ------------[ cut here ]------------
      WARNING: CPU: 0 PID: 0 at ./include/linux/jump_label.h:303
      page_alloc_shuffle+0x12c/0x1ac
      static_key_enable(): static key 'page_alloc_shuffle_key+0x0/0x4' used
      before call to jump_label_init()
      Modules linked in:
      CPU: 0 PID: 0 Comm: swapper Not tainted
      5.1.0-rc4-next-20190410-00003-g3367c36ce744 #1
      Hardware name: ARM Integrator/CP (Device Tree)
      [<c0011c68>] (unwind_backtrace) from [<c000ec48>] (show_stack+0x10/0x18)
      [<c000ec48>] (show_stack) from [<c07e9710>] (dump_stack+0x18/0x24)
      [<c07e9710>] (dump_stack) from [<c001bb1c>] (__warn+0xe0/0x108)
      [<c001bb1c>] (__warn) from [<c001bb88>] (warn_slowpath_fmt+0x44/0x6c)
      [<c001bb88>] (warn_slowpath_fmt) from [<c0b0c4a8>]
      (page_alloc_shuffle+0x12c/0x1ac)
      [<c0b0c4a8>] (page_alloc_shuffle) from [<c0b0c550>] (shuffle_store+0x28/0x48)
      [<c0b0c550>] (shuffle_store) from [<c003e6a0>] (parse_args+0x1f4/0x350)
      [<c003e6a0>] (parse_args) from [<c0ac3c00>] (start_kernel+0x1c0/0x488)
    
    Move the fallback call to jump_label_init() to occur before
    parse_args().
    
    The redundant calls to jump_label_init() in other archs are left intact
    in case they have static key toggling use cases that are even earlier
    than option parsing.
    
    Link: http://lkml.kernel.org/r/155544804466.1032396.13418949511615676665.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: default avatarDan Williams <dan.j.williams@intel.com>
    Reported-by: default avatarGuenter Roeck <groeck@google.com>
    Reviewed-by: default avatarKees Cook <keescook@chromium.org>
    Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Mike Rapoport <rppt@linux.ibm.com>
    Cc: Russell King <rmk@armlinux.org.uk>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
    2b46b985
Name
Last commit
Last update
..
Kconfig Loading commit data...
Makefile Loading commit data...
calibrate.c Loading commit data...
do_mounts.c Loading commit data...
do_mounts.h Loading commit data...
do_mounts_initrd.c Loading commit data...
do_mounts_md.c Loading commit data...
do_mounts_rd.c Loading commit data...
init_task.c Loading commit data...
initramfs.c Loading commit data...
main.c Loading commit data...
noinitramfs.c Loading commit data...
version.c Loading commit data...