From 375074cc736ab1d89a708c0a8d7baa4a70d5d476 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Fri, 24 Oct 2014 15:58:07 -0700 Subject: x86: Clean up cr4 manipulation CR4 manipulation was split, seemingly at random, between direct (write_cr4) and using a helper (set/clear_in_cr4). Unfortunately, the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code, which only a small subset of users actually wanted. This patch replaces all cr4 access in functions that don't leave cr4 exactly the way they found it with new helpers cr4_set_bits, cr4_clear_bits, and cr4_set_bits_and_update_boot. Signed-off-by: Andy Lutomirski Reviewed-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Cc: Andrea Arcangeli Cc: Vince Weaver Cc: "hillf.zj" Cc: Valdis Kletnieks Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Kees Cook Cc: Linus Torvalds Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- drivers/lguest/x86/core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index 922a1acbf652..6adfd7ba4c97 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -47,6 +47,7 @@ #include #include #include +#include #include "../lg.h" static int cpu_had_pge; @@ -452,9 +453,9 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu) static void adjust_pge(void *on) { if (on) - write_cr4(read_cr4() | X86_CR4_PGE); + cr4_set_bits(X86_CR4_PGE); else - write_cr4(read_cr4() & ~X86_CR4_PGE); + cr4_clear_bits(X86_CR4_PGE); } /*H:020 -- cgit v1.2.3