From 6415813bae75feba10b8ca3ed6634a72c2a4d313 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Sun, 12 Feb 2017 22:12:08 +0100 Subject: x86/cpu: Drop wp_works_ok member of struct cpuinfo_x86 Remove the wp_works_ok member of struct cpuinfo_x86. It's an optimization back from Linux v0.99 times where we had no fixup support yet and did the CR0.WP test via special code in the page fault handler. The < 0 test was an optimization to not do the special casing for each NULL ptr access violation but just for the first one doing the WP test. Today it serves no real purpose as the test no longer needs special code in the page fault handler and the only call side -- mem_init() -- calls it just once, anyway. However, Xen pre-initializes it to 1, to skip the test. Doing the test again for Xen should be no issue at all, as even the commit introducing skipping the test (commit d560bc61575e ("x86, xen: Suppress WP test on Xen")) mentioned it being ban aid only. And, in fact, testing the patch on Xen showed nothing breaks. The pre-fixup times are long gone and with the removal of the fallback handling code in commit a5c2a893dbd4 ("x86, 386 removal: Remove CONFIG_X86_WP_WORKS_OK") the kernel requires a working CR0.WP anyway. So just get rid of the "optimization" and do the test unconditionally. Signed-off-by: Mathias Krause Acked-by: Borislav Petkov Cc: Jesper Nilsson Cc: Jeremy Fitzhardinge Cc: Arnd Hannemann Cc: Mikael Starvik Cc: Geert Uytterhoeven Cc: Andrew Morton Cc: "David S. Miller" Link: http://lkml.kernel.org/r/1486933932-585-3-git-send-email-minipli@googlemail.com Signed-off-by: Thomas Gleixner --- arch/x86/kernel/setup.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'arch/x86/kernel/setup.c') diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 4bf0c8926a1c..7cd7bbefd418 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -173,14 +173,11 @@ static struct resource bss_resource = { #ifdef CONFIG_X86_32 -/* cpu data as detected by the assembly code in head.S */ -struct cpuinfo_x86 new_cpu_data = { - .wp_works_ok = -1, -}; +/* cpu data as detected by the assembly code in head_32.S */ +struct cpuinfo_x86 new_cpu_data; + /* common cpu data for all cpus */ -struct cpuinfo_x86 boot_cpu_data __read_mostly = { - .wp_works_ok = -1, -}; +struct cpuinfo_x86 boot_cpu_data __read_mostly; EXPORT_SYMBOL(boot_cpu_data); unsigned int def_to_bigsmp; -- cgit v1.2.3-59-g8ed1b