4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Andi Kleen <a...@linux.intel.com> commit 0c2a3913d6f50503f7c59d83a6219e39508cc898 upstream. With a followon patch we want to make clearcpuid affect the XSAVE configuration. But xsave is currently initialized before arguments are parsed. Move the clearcpuid= parsing into the special early xsave argument parsing code. Since clearcpuid= contains a = we need to keep the old __setup around as a dummy, otherwise it would end up as a environment variable in init's environment. Signed-off-by: Andi Kleen <a...@linux.intel.com> Reviewed-by: Thomas Gleixner <t...@linutronix.de> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Link: http://lkml.kernel.org/r/20171013215645.23166-4-a...@firstfloor.org Signed-off-by: Ingo Molnar <mi...@kernel.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- arch/x86/kernel/cpu/common.c | 16 +++++++--------- arch/x86/kernel/fpu/init.c | 11 +++++++++++ 2 files changed, 18 insertions(+), 9 deletions(-) --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1301,18 +1301,16 @@ void print_cpu_info(struct cpuinfo_x86 * pr_cont(")\n"); } -static __init int setup_disablecpuid(char *arg) +/* + * clearcpuid= was already parsed in fpu__init_parse_early_param. + * But we need to keep a dummy __setup around otherwise it would + * show up as an environment variable for init. + */ +static __init int setup_clearcpuid(char *arg) { - int bit; - - if (get_option(&arg, &bit) && bit >= 0 && bit < NCAPINTS * 32) - setup_clear_cpu_cap(bit); - else - return 0; - return 1; } -__setup("clearcpuid=", setup_disablecpuid); +__setup("clearcpuid=", setup_clearcpuid); #ifdef CONFIG_X86_64 DEFINE_PER_CPU_FIRST(union irq_stack_union, --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -249,6 +249,10 @@ static void __init fpu__init_system_ctx_ */ static void __init fpu__init_parse_early_param(void) { + char arg[32]; + char *argptr = arg; + int bit; + if (cmdline_find_option_bool(boot_command_line, "no387")) setup_clear_cpu_cap(X86_FEATURE_FPU); @@ -266,6 +270,13 @@ static void __init fpu__init_parse_early if (cmdline_find_option_bool(boot_command_line, "noxsaves")) setup_clear_cpu_cap(X86_FEATURE_XSAVES); + + if (cmdline_find_option(boot_command_line, "clearcpuid", arg, + sizeof(arg)) && + get_option(&argptr, &bit) && + bit >= 0 && + bit < NCAPINTS * 32) + setup_clear_cpu_cap(bit); } /*
