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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-13 03:31:19 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-13 03:31:19 +0300 |
commit | 64ad9461521b1a357846ef6cedc4bccd48a046e0 (patch) | |
tree | f134404b6c6df89198a4a2f2be6fef21af133c73 /arch/x86/lib/copy_user_64.S | |
parent | 8e5b0adeea19309c8ce0e3c9119061554973efa9 (diff) | |
parent | 9cdbeec4096804083944d05da96bbaf59a1eb4f9 (diff) | |
download | linux-64ad9461521b1a357846ef6cedc4bccd48a046e0.tar.xz |
Merge tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/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
...
Diffstat (limited to 'arch/x86/lib/copy_user_64.S')
-rw-r--r-- | arch/x86/lib/copy_user_64.S | 42 |
1 files changed, 16 insertions, 26 deletions
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index a2cbeae4b180..8ca5ecf16dc4 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -32,14 +32,10 @@ decl %ecx jnz 100b 102: - .section .fixup,"ax" -103: addl %ecx,%edx /* ecx is zerorest also */ - jmp .Lcopy_user_handle_tail - .previous - _ASM_EXTABLE_CPY(100b, 103b) - _ASM_EXTABLE_CPY(101b, 103b) - .endm + _ASM_EXTABLE_CPY(100b, .Lcopy_user_handle_align) + _ASM_EXTABLE_CPY(101b, .Lcopy_user_handle_align) +.endm /* * copy_user_generic_unrolled - memory copy with exception handling. @@ -105,9 +101,8 @@ SYM_FUNC_START(copy_user_generic_unrolled) jnz 21b 23: xor %eax,%eax ASM_CLAC - ret + RET - .section .fixup,"ax" 30: shll $6,%ecx addl %ecx,%edx jmp 60f @@ -115,7 +110,6 @@ SYM_FUNC_START(copy_user_generic_unrolled) jmp 60f 50: movl %ecx,%edx 60: jmp .Lcopy_user_handle_tail /* ecx is zerorest also */ - .previous _ASM_EXTABLE_CPY(1b, 30b) _ASM_EXTABLE_CPY(2b, 30b) @@ -166,20 +160,16 @@ SYM_FUNC_START(copy_user_generic_string) movl %edx,%ecx shrl $3,%ecx andl $7,%edx -1: rep - movsq +1: rep movsq 2: movl %edx,%ecx -3: rep - movsb +3: rep movsb xorl %eax,%eax ASM_CLAC - ret + RET - .section .fixup,"ax" 11: leal (%rdx,%rcx,8),%ecx 12: movl %ecx,%edx /* ecx is zerorest also */ jmp .Lcopy_user_handle_tail - .previous _ASM_EXTABLE_CPY(1b, 11b) _ASM_EXTABLE_CPY(3b, 12b) @@ -203,16 +193,13 @@ SYM_FUNC_START(copy_user_enhanced_fast_string) /* 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) @@ -241,7 +228,7 @@ SYM_CODE_START_LOCAL(.Lcopy_user_handle_tail) 1: rep movsb 2: mov %ecx,%eax ASM_CLAC - ret + RET 3: movl %edx,%eax @@ -249,6 +236,11 @@ SYM_CODE_START_LOCAL(.Lcopy_user_handle_tail) 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) /* @@ -357,9 +349,8 @@ SYM_FUNC_START(__copy_user_nocache) xorl %eax,%eax ASM_CLAC sfence - ret + RET - .section .fixup,"ax" .L_fixup_4x8b_copy: shll $6,%ecx addl %ecx,%edx @@ -375,7 +366,6 @@ SYM_FUNC_START(__copy_user_nocache) .L_fixup_handle_tail: sfence jmp .Lcopy_user_handle_tail - .previous _ASM_EXTABLE_CPY(1b, .L_fixup_4x8b_copy) _ASM_EXTABLE_CPY(2b, .L_fixup_4x8b_copy) |