Commit 4faa0e5d authored by Julian Stecklina's avatar Julian Stecklina Committed by Ingo Molnar
Browse files

x86/boot: Move kernel cmdline setup earlier in the boot process (again) 



When split_lock_detect=off (or similar) is specified in
CONFIG_CMDLINE, its effect is lost. The flow is currently this:

	setup_arch():
	  -> early_cpu_init()
	    -> early_identify_cpu()
	      -> sld_setup()
		-> sld_state_setup()
		  -> Looks for split_lock_detect in boot_command_line

	  -> e820__memory_setup()

	  -> Assemble final command line:
	     boot_command_line = builtin_cmdline + boot_cmdline

	  -> parse_early_param()

There were earlier attempts at fixing this in:

  8d48bf82 ("x86/boot: Pull up cmdline preparation and early param parsing")

later reverted in:

  fbe61839 ("Revert "x86/boot: Pull up cmdline preparation and early param parsing"")

... because parse_early_param() can't be called before
e820__memory_setup().

In this patch, we just move the command line concatenation to the
beginning of early_cpu_init(). This should fix sld_state_setup(), while
not running in the same issues as the earlier attempt.

The order is now:

	setup_arch():
	  -> Assemble final command line:
	     boot_command_line = builtin_cmdline + boot_cmdline

	  -> early_cpu_init()
	    -> early_identify_cpu()
	      -> sld_setup()
		-> sld_state_setup()
		  -> Looks for split_lock_detect in boot_command_line

	  -> e820__memory_setup()

	  -> parse_early_param()

Signed-off-by: default avatarJulian Stecklina <julian.stecklina@cyberus-technology.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: linux-kernel@vger.kernel.org
parent 17608373

arch/x86/kernel/setup.c

+16 −16
Original line number Diff line number Diff line
@@ -753,6 +753,22 @@ void __init setup_arch(char **cmdline_p) 
	boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;

#endif



#ifdef CONFIG_CMDLINE_BOOL

#ifdef CONFIG_CMDLINE_OVERRIDE

	strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);

#else

	if (builtin_cmdline[0]) {

		/* append boot loader cmdline to builtin */

		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);

		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);

		strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);

	}

#endif

#endif



	strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE);

	*cmdline_p = command_line;



	/*

	 * If we have OLPC OFW, we might end up relocating the fixmap due to

	 * reserve_top(), so do this before touching the ioremap area.
@@ -832,22 +848,6 @@ void __init setup_arch(char **cmdline_p) 
	bss_resource.start = __pa_symbol(__bss_start);

	bss_resource.end = __pa_symbol(__bss_stop)-1;



#ifdef CONFIG_CMDLINE_BOOL

#ifdef CONFIG_CMDLINE_OVERRIDE

	strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);

#else

	if (builtin_cmdline[0]) {

		/* append boot loader cmdline to builtin */

		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);

		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);

		strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);

	}

#endif

#endif



	strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE);

	*cmdline_p = command_line;



	/*

	 * x86_configure_nx() is called before parse_early_param() to detect

	 * whether hardware doesn't support NX (so that the early EHCI debug