From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 13 Jan 2022 00:31:19 +0000 (-0800)
Subject: Merge tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git... 
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=64ad9461521b1a357846ef6cedc4bccd48a046e0;p=linux.git

Merge tag 'x86_core_for_v5.17_rc1' of git://git./linux/kernel/git/tip/tip

Pull x86 core updates from Borislav Petkov:

 - Get rid of all the .fixup sections because this generates
   misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
   LIVEPATCH as the backtrace misses the function which is being fixed
   up.

 - Add Straight Line Speculation mitigation support which uses a new
   compiler switch -mharden-sls= which sticks an INT3 after a RET or an
   indirect branch in order to block speculation after them. Reportedly,
   CPUs do speculate behind such insns.

 - The usual set of cleanups and improvements

* tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  x86/entry_32: Fix segment exceptions
  objtool: Remove .fixup handling
  x86: Remove .fixup section
  x86/word-at-a-time: Remove .fixup usage
  x86/usercopy: Remove .fixup usage
  x86/usercopy_32: Simplify __copy_user_intel_nocache()
  x86/sgx: Remove .fixup usage
  x86/checksum_32: Remove .fixup usage
  x86/vmx: Remove .fixup usage
  x86/kvm: Remove .fixup usage
  x86/segment: Remove .fixup usage
  x86/fpu: Remove .fixup usage
  x86/xen: Remove .fixup usage
  x86/uaccess: Remove .fixup usage
  x86/futex: Remove .fixup usage
  x86/msr: Remove .fixup usage
  x86/extable: Extend extable functionality
  x86/entry_32: Remove .fixup usage
  x86/entry_64: Remove .fixup usage
  x86/copy_mc_64: Remove .fixup usage
  ...
---

64ad9461521b1a357846ef6cedc4bccd48a046e0
diff --cc arch/x86/lib/copy_user_64.S
index a2cbeae4b180d,e6ac38587b40d..8ca5ecf16dc47
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@@ -200,19 -190,16 +190,16 @@@ EXPORT_SYMBOL(copy_user_generic_string
   */
  SYM_FUNC_START(copy_user_enhanced_fast_string)
  	ASM_STAC
 -	cmpl $64,%edx
 -	jb .L_copy_short_string	/* less then 64 bytes, avoid the costly 'rep' */
 +	/* CPUs without FSRM should avoid rep movsb for short copies */
 +	ALTERNATIVE "cmpl $64, %edx; jb .L_copy_short_string", "", X86_FEATURE_FSRM
  	movl %edx,%ecx
- 1:	rep
- 	movsb
+ 1:	rep movsb
  	xorl %eax,%eax
  	ASM_CLAC
- 	ret
+ 	RET
  
- 	.section .fixup,"ax"
  12:	movl %ecx,%edx		/* ecx is zerorest also */
  	jmp .Lcopy_user_handle_tail
- 	.previous
  
  	_ASM_EXTABLE_CPY(1b, 12b)
  SYM_FUNC_END(copy_user_enhanced_fast_string)
@@@ -241,14 -224,14 +228,19 @@@ SYM_CODE_START_LOCAL(.Lcopy_user_handle
  1:	rep movsb
  2:	mov %ecx,%eax
  	ASM_CLAC
- 	ret
+ 	RET
  
 +3:
 +	movl %edx,%eax
 +	ASM_CLAC
 +	RET
 +
  	_ASM_EXTABLE_CPY(1b, 2b)
+ 
+ .Lcopy_user_handle_align:
+ 	addl %ecx,%edx			/* ecx is zerorest also */
+ 	jmp .Lcopy_user_handle_tail
+ 
  SYM_CODE_END(.Lcopy_user_handle_tail)
  
  /*
diff --cc arch/x86/platform/efi/efi_thunk_64.S
index 5b7c6e09954ec,f2a8eec69f8f6..25799d7686240
--- a/arch/x86/platform/efi/efi_thunk_64.S
+++ b/arch/x86/platform/efi/efi_thunk_64.S
@@@ -70,10 -60,10 +70,10 @@@ SYM_CODE_START(__efi64_thunk
  	pushq	%rdi			/* EFI runtime service address */
  	lretq
  
 -1:	movq	24(%rsp), %rsp
 +1:	movq	0x20(%rsp), %rsp
  	pop	%rbx
  	pop	%rbp
- 	retq
+ 	RET
  
  	.code32
  2:	pushl	$__KERNEL_CS