On Tue, Oct 08, 2019 at 09:18:45AM +0200, Borislav Petkov wrote: > On Mon, Oct 07, 2019 at 09:04:05PM -0700, Sean Christopherson wrote: > > > BIT(30) > > > > This is intentionally open coded so that it can be stringified in asm. > > It stringifies just fine with the BIT() macro too: > > # 187 "arch/x86/kernel/cpu/sgx/encls.h" 1 > 1: .byte 0x0f, 0x01, 0xcf; > 2: > .section .fixup,"ax" > 3: orl $((((1UL))) << (30)),%eax > jmp 2b > .previous > > and the resulting object: > > Disassembly of section .fixup: > > 0000000000000000 <.fixup>: > 0: 0d 00 00 00 40 or $0x40000000,%eax > 5: e9 00 00 00 00 jmpq a <__addressable_sgx_free_page107+0x2>
Hmm, I get assembler errors using gcc 5.4.0 linux/arch/x86/kernel/cpu/sgx/encls.h: Assembler messages: linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: junk `UL)))<<(30))' after expression linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: junk `UL)))<<(30))' after expression linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: missing ')' linux/arch/x86/kernel/cpu/sgx/encls.h:207: Error: junk `UL)))<<(30))' after expression linux/scripts/Makefile.build:265: recipe for target 'arch/x86/kernel/cpu/sgx/encls.o' failed
