On Sat, Dec 16, 2017 at 3:35 PM, kbuild test robot
<fengguang...@intel.com> wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
> WIP.x86/pti-upstream
> head: 78e4da51f7c77587cc6f419af4f63a21b289bdb7
> commit: 7e482cfe4a23ead21215423c4566c8516ba21025 [38/50] x86/pti: Put the LDT
> in its own PGD if PTI is on
> config: i386-randconfig-h0-12170619 (attached as .config)
> compiler: gcc-6 (Debian 6.4.0-9) 6.4.0 20171026
> reproduce:
> git checkout 7e482cfe4a23ead21215423c4566c8516ba21025
> # save the attached .config to linux build tree
> make ARCH=i386
>
> All errors (new ones prefixed by >>):
>
> In file included from arch/x86//kernel/apic/ipi.c:16:0:
> arch/x86/include/asm/mmu_context.h: In function 'ldt_slot_va':
>>> arch/x86/include/asm/mmu_context.h:73:18: error: 'LDT_BASE_ADDR' undeclared
>>> (first use in this function)
> return (void *)(LDT_BASE_ADDR + LDT_SLOT_STRIDE * slot);
> ^~~~~~~~~~~~~
> arch/x86/include/asm/mmu_context.h:73:18: note: each undeclared identifier
> is reported only once for each function it appears in
> --
> In file included from arch/x86//kernel/cpu/common.c:22:0:
> arch/x86/include/asm/mmu_context.h: In function 'ldt_slot_va':
>>> arch/x86/include/asm/mmu_context.h:73:18: error: 'LDT_BASE_ADDR' undeclared
>>> (first use in this function)
> return (void *)(LDT_BASE_ADDR + LDT_SLOT_STRIDE * slot);
> ^~~~~~~~~~~~~
> arch/x86/include/asm/mmu_context.h:73:18: note: each undeclared identifier
> is reported only once for each function it appears in
> In file included from arch/x86//kernel/cpu/common.c:22:0:
> arch/x86/include/asm/mmu_context.h:74:1: warning: control reaches end of
> non-void function [-Wreturn-type]
> }
> ^
>
> vim +/LDT_BASE_ADDR +73 arch/x86/include/asm/mmu_context.h
>
> 70
> 71 static inline void *ldt_slot_va(int slot)
> 72 {
> > 73 return (void *)(LDT_BASE_ADDR + LDT_SLOT_STRIDE * slot);
> 74 }
> 75
>
I would fix this like this:
index b7ffd45b22f7..3c7042877e63 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -70,7 +70,11 @@ struct ldt_struct {
static inline void *ldt_slot_va(int slot)
{
+#ifdef CONFIG_X86_64
return (void *)(LDT_BASE_ADDR + LDT_SLOT_STRIDE * slot);
+#else
+ BUG();
+#endif
}
Ingo or Thomas, want to do that manually? It's probably easier than
folding in a patch.
