Commit-ID: aa4ea675528f3fa11e9663e5a32f55a81c34dcac Gitweb: http://git.kernel.org/tip/aa4ea675528f3fa11e9663e5a32f55a81c34dcac Author: Andy Lutomirski <l...@kernel.org> AuthorDate: Wed, 22 Mar 2017 14:32:30 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 23 Mar 2017 08:25:07 +0100
x86/gdt: Fix setup_fixmap_gdt() to use the correct PA __pa() cannot be used on percpu pointers because they may be virtually mapped. Use per_cpu_ptr_to_phys() instead. This fixes a boot crash on a some 32-bit configurations. I assume this is related to which allocation strategy is chosen by the percpu core. Signed-off-by: Andy Lutomirski <l...@kernel.org> Cc: Boris Ostrovsky <boris.ostrov...@oracle.com> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Josh Poimboeuf <jpoim...@redhat.com> Cc: Juergen Gross <jgr...@suse.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Garnier <thgar...@google.com> Cc: Thomas Gleixner <t...@linutronix.de> Fixes: 69218e47994d x86: ("Remap GDT tables in the fixmap section") Link: http://lkml.kernel.org/r/22e0069c29fba31998f193201e359eebfdac4960.1490218061.git.l...@kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/include/asm/desc.h | 6 ++++++ arch/x86/kernel/cpu/common.c | 4 ++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h index ec05f9c..bde1169 100644 --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -98,6 +98,12 @@ static inline unsigned long get_current_gdt_ro_vaddr(void) return (unsigned long)get_current_gdt_ro(); } +/* Provide the physical address of the GDT page. */ +static inline phys_addr_t get_cpu_gdt_paddr(unsigned int cpu) +{ + return per_cpu_ptr_to_phys(get_cpu_gdt_rw(cpu)); +} + #ifdef CONFIG_X86_64 static inline void pack_gate(gate_desc *gate, unsigned type, unsigned long func, diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index f8e22db..f6e20e2 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -461,8 +461,8 @@ pgprot_t pg_fixmap_gdt_flags = PAGE_KERNEL; /* Setup the fixmap mapping only once per-processor */ static inline void setup_fixmap_gdt(int cpu) { - __set_fixmap(get_cpu_gdt_ro_index(cpu), - __pa(get_cpu_gdt_rw(cpu)), pg_fixmap_gdt_flags); + __set_fixmap(get_cpu_gdt_ro_index(cpu), get_cpu_gdt_paddr(cpu), + pg_fixmap_gdt_flags); } /* Load the original GDT from the per-cpu structure */