Bill Wendling 552bc7f3ec x86/paravirt: add extra clobbers with ZERO_CALL_USED_REGS enabled ... [ Upstream commit 8c86f29bfb ] The ZERO_CALL_USED_REGS feature may zero out caller-saved registers before returning. In spurious_kernel_fault(), the "pte_offset_kernel()" call results in this assembly code: .Ltmp151: #APP # ALT: oldnstr .Ltmp152: .Ltmp153: .Ltmp154: .section .discard.retpoline_safe,"",@progbits .quad .Ltmp154 .text callq *pv_ops+536(%rip) .Ltmp155: .section .parainstructions,"a",@progbits .p2align 3, 0x0 .quad .Ltmp153 .byte 67 .byte .Ltmp155-.Ltmp153 .short 1 .text .Ltmp156: # ALT: padding .zero (-(((.Ltmp157-.Ltmp158)-(.Ltmp156-.Ltmp152))>0))*((.Ltmp157-.Ltmp158)-(.Ltmp156-.Ltmp152)),144 .Ltmp159: .section .altinstructions,"a",@progbits .Ltmp160: .long .Ltmp152-.Ltmp160 .Ltmp161: .long .Ltmp158-.Ltmp161 .short 33040 .byte .Ltmp159-.Ltmp152 .byte .Ltmp157-.Ltmp158 .text .section .altinstr_replacement,"ax",@progbits # ALT: replacement 1 .Ltmp158: movq %rdi, %rax .Ltmp157: .text #NO_APP .Ltmp162: testb $-128, %dil The "testb" here is using %dil, but the %rdi register was cleared before returning from "callq *pv_ops+536(%rip)". Adding the proper constraints results in the use of a different register: movq %r11, %rdi # Similar to above. testb $-128, %r11b Link: https://github.com/KSPP/linux/issues/192 Signed-off-by: Bill Wendling <morbo@google.com> Reported-and-tested-by: Nathan Chancellor <nathan@kernel.org> Fixes: 035f7f87b7 ("randstruct: Enable Clang support") Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/lkml/fa6df43b-8a1a-8ad1-0236-94d2a0b588fa@suse.com/ Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220902213750.1124421-3-morbo@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-10-21 12:38:01 +02:00
..
boot	x86/boot: Don't propagate uninitialized boot_params->cc_blob_address	2022-08-24 09:03:04 +02:00
coco	x86/tdx: Handle load_unaligned_zeropad() page-cross to a shared page	2022-06-17 15:37:33 -07:00
configs	xen: branch for v6.0-rc3	2022-08-27 15:38:00 -07:00
crypto	SPDX changes for 6.0-rc1	2022-08-04 12:12:54 -07:00
entry	x86/entry: Fix entry_INT80_compat for Xen PV guests	2022-08-16 10:02:52 +02:00
events	PCI interpretation compile fixes	2022-09-01 19:21:27 -04:00
hyperv	ARM:	2022-08-04 14:59:54 -07:00
ia32	x86: Remove a.out support	2022-04-11 18:04:27 +02:00
include	x86/paravirt: add extra clobbers with ZERO_CALL_USED_REGS enabled	2022-10-21 12:38:01 +02:00
kernel	- Add the respective UP last level cache mask accessors in order not to	2022-10-02 09:30:35 -07:00
kvm	KVM: VMX: Drop bits 31:16 when shoving exception error code into VMCS	2022-10-21 12:37:55 +02:00
lib	x86/uaccess: avoid check_object_size() in copy_from_user_nmi()	2022-09-26 12:14:35 -07:00
math-emu	x86/32: Remove lazy GS macros	2022-04-14 14:09:43 +02:00
mm	x86/mm: disable instrumentations of mm/pgprot.c	2022-09-11 16:22:30 -07:00
net	Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next	2022-07-22 16:55:44 -07:00
pci	x86/PCI: Revert "x86/PCI: Clip only host bridge windows for E820 regions"	2022-06-17 14:24:14 -05:00
platform	Bitmap patches for v6.0-rc1	2022-08-07 17:52:35 -07:00
power	x86/cpu: Load microcode during restore_processor_state()	2022-04-19 19:37:05 +02:00
purgatory	x86/purgatory: Omit use of bin2c	2022-07-25 10:32:32 +02:00
ras
realmode	Intel Trust Domain Extensions	2022-05-23 17:51:12 -07:00
tools
um	arch: um: Mark the stack non-executable to fix a binutils warning	2022-09-21 09:11:42 +02:00
video
virt/vmx/tdx	x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers	2022-04-07 08:27:50 -07:00
xen	x86/xen: Add support for HVMOP_set_evtchn_upcall_vector	2022-08-12 11:28:21 +02:00
.gitignore	x86/purgatory: Omit use of bin2c	2022-07-25 10:32:32 +02:00
Kbuild
Kconfig	- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe	2022-08-05 16:32:45 -07:00
Kconfig.assembler
Kconfig.cpu
Kconfig.debug	arch: make TRACE_IRQFLAGS_NMI_SUPPORT generic	2022-06-23 15:39:21 +01:00
Makefile	asm goto: eradicate CC_HAS_ASM_GOTO	2022-08-21 10:06:28 -07:00
Makefile.um
Makefile_32.cpu