x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly

[cascardo/linux.git] / arch / x86 / kernel / setup.c

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index bf780e0..95c8c9c 100644 (file)
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1131,6 +1131,16 @@ void __init setup_arch(char **cmdline_p)
 
        early_trap_pf_init();
 
+       /*
+        * Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)
+        * with the current CR4 value.  This may not be necessary, but
+        * auditing all the early-boot CR4 manipulation would be needed to
+        * rule it out.
+        */
+       if (boot_cpu_data.cpuid_level >= 0)
+               /* A CPU has %cr4 if and only if it has CPUID. */
+               mmu_cr4_features = __read_cr4();
+
        setup_real_mode();
 
        memblock_set_current_limit(get_max_mapped());
@@ -1180,13 +1190,6 @@ void __init setup_arch(char **cmdline_p)
 
        kasan_init();
 
-       if (boot_cpu_data.cpuid_level >= 0) {
-               /* A CPU has %cr4 if and only if it has CPUID */
-               mmu_cr4_features = __read_cr4();
-               if (trampoline_cr4_features)
-                       *trampoline_cr4_features = mmu_cr4_features;
-       }
-
 #ifdef CONFIG_X86_32
        /* sync back kernel address range */
        clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,