From 68accac392d859d24adcf1be3a90e41f978bd54c Mon Sep 17 00:00:00 2001 From: Krzysztof Mazur <krzysiek@podlesie.net> Date: Fri, 6 Nov 2015 14:18:36 +0100 Subject: [PATCH] x86/setup: Fix low identity map for >= 2GB kernel range The commit f5f3497cad8c extended the low identity mapping. However, if the kernel uses more than 2 GB (VMSPLIT_2G_OPT or VMSPLIT_1G memory split), the normal memory mapping is overwritten by the low identity mapping causing a crash. To avoid overwritting, limit the low identity map to cover only memory before kernel range (PAGE_OFFSET). Fixes: f5f3497cad8c "x86/setup: Extend low identity map to cover whole kernel range Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Matt Fleming <matt.fleming@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1446815916-22105-1-git-send-email-krzysiek@podlesie.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/x86/kernel/setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index a1e4da98c8f0d..29db25f9a745e 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1188,7 +1188,7 @@ void __init setup_arch(char **cmdline_p) */ clone_pgd_range(initial_page_table, swapper_pg_dir + KERNEL_PGD_BOUNDARY, - KERNEL_PGD_PTRS); + min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY)); #endif tboot_probe(); -- GitLab