This is a note to let you know that I've just added the patch titled
x86/entry/64: Merge SAVE_C_REGS and SAVE_EXTRA_REGS, remove unused extensions
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-entry-64-merge-save_c_regs-and-save_extra_regs-remove-unused-extensions.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2e3f0098bc45f710a2f4cbcc94b80a1fae7a99a1 Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
Date: Sun, 11 Feb 2018 11:49:42 +0100
Subject: x86/entry/64: Merge SAVE_C_REGS and SAVE_EXTRA_REGS, remove unused extensions
From: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
commit 2e3f0098bc45f710a2f4cbcc94b80a1fae7a99a1 upstream.
All current code paths call SAVE_C_REGS and then immediately
SAVE_EXTRA_REGS. Therefore, merge these two macros and order the MOV
sequeneces properly.
While at it, remove the macros to save all except specific registers,
as these macros have been unused for a long time.
Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: dan.j.williams@xxxxxxxxx
Link: http://lkml.kernel.org/r/20180211104949.12992-2-linux@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/entry/calling.h | 57 ++++++++++++----------------------------------
arch/x86/entry/entry_64.S | 12 +++------
2 files changed, 19 insertions(+), 50 deletions(-)
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -101,49 +101,22 @@ For 32-bit we have the following convent
addq $-(15*8), %rsp
.endm
- .macro SAVE_C_REGS_HELPER offset=0 rax=1 rcx=1 r8910=1 r11=1
- .if \r11
- movq %r11, 6*8+\offset(%rsp)
- .endif
- .if \r8910
- movq %r10, 7*8+\offset(%rsp)
- movq %r9, 8*8+\offset(%rsp)
- movq %r8, 9*8+\offset(%rsp)
- .endif
- .if \rax
- movq %rax, 10*8+\offset(%rsp)
- .endif
- .if \rcx
- movq %rcx, 11*8+\offset(%rsp)
- .endif
- movq %rdx, 12*8+\offset(%rsp)
- movq %rsi, 13*8+\offset(%rsp)
+ .macro SAVE_REGS offset=0
movq %rdi, 14*8+\offset(%rsp)
- UNWIND_HINT_REGS offset=\offset extra=0
- .endm
- .macro SAVE_C_REGS offset=0
- SAVE_C_REGS_HELPER \offset, 1, 1, 1, 1
- .endm
- .macro SAVE_C_REGS_EXCEPT_RAX_RCX offset=0
- SAVE_C_REGS_HELPER \offset, 0, 0, 1, 1
- .endm
- .macro SAVE_C_REGS_EXCEPT_R891011
- SAVE_C_REGS_HELPER 0, 1, 1, 0, 0
- .endm
- .macro SAVE_C_REGS_EXCEPT_RCX_R891011
- SAVE_C_REGS_HELPER 0, 1, 0, 0, 0
- .endm
- .macro SAVE_C_REGS_EXCEPT_RAX_RCX_R11
- SAVE_C_REGS_HELPER 0, 0, 0, 1, 0
- .endm
-
- .macro SAVE_EXTRA_REGS offset=0
- movq %r15, 0*8+\offset(%rsp)
- movq %r14, 1*8+\offset(%rsp)
- movq %r13, 2*8+\offset(%rsp)
- movq %r12, 3*8+\offset(%rsp)
- movq %rbp, 4*8+\offset(%rsp)
+ movq %rsi, 13*8+\offset(%rsp)
+ movq %rdx, 12*8+\offset(%rsp)
+ movq %rcx, 11*8+\offset(%rsp)
+ movq %rax, 10*8+\offset(%rsp)
+ movq %r8, 9*8+\offset(%rsp)
+ movq %r9, 8*8+\offset(%rsp)
+ movq %r10, 7*8+\offset(%rsp)
+ movq %r11, 6*8+\offset(%rsp)
movq %rbx, 5*8+\offset(%rsp)
+ movq %rbp, 4*8+\offset(%rsp)
+ movq %r12, 3*8+\offset(%rsp)
+ movq %r13, 2*8+\offset(%rsp)
+ movq %r14, 1*8+\offset(%rsp)
+ movq %r15, 0*8+\offset(%rsp)
UNWIND_HINT_REGS offset=\offset
.endm
@@ -197,7 +170,7 @@ For 32-bit we have the following convent
* is just setting the LSB, which makes it an invalid stack address and is also
* a signal to the unwinder that it's a pt_regs pointer in disguise.
*
- * NOTE: This macro must be used *after* SAVE_EXTRA_REGS because it corrupts
+ * NOTE: This macro must be used *after* SAVE_REGS because it corrupts
* the original rbp.
*/
.macro ENCODE_FRAME_POINTER ptregs_offset=0
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -569,8 +569,7 @@ END(irq_entries_start)
1:
ALLOC_PT_GPREGS_ON_STACK
- SAVE_C_REGS
- SAVE_EXTRA_REGS
+ SAVE_REGS
CLEAR_REGS_NOSPEC
ENCODE_FRAME_POINTER
@@ -1126,8 +1125,7 @@ ENTRY(xen_failsafe_callback)
UNWIND_HINT_IRET_REGS
pushq $-1 /* orig_ax = -1 => not a system call */
ALLOC_PT_GPREGS_ON_STACK
- SAVE_C_REGS
- SAVE_EXTRA_REGS
+ SAVE_REGS
CLEAR_REGS_NOSPEC
ENCODE_FRAME_POINTER
jmp error_exit
@@ -1172,8 +1170,7 @@ idtentry machine_check do_mce has_err
ENTRY(paranoid_entry)
UNWIND_HINT_FUNC
cld
- SAVE_C_REGS 8
- SAVE_EXTRA_REGS 8
+ SAVE_REGS 8
CLEAR_REGS_NOSPEC
ENCODE_FRAME_POINTER 8
movl $1, %ebx
@@ -1225,8 +1222,7 @@ END(paranoid_exit)
ENTRY(error_entry)
UNWIND_HINT_FUNC
cld
- SAVE_C_REGS 8
- SAVE_EXTRA_REGS 8
+ SAVE_REGS 8
CLEAR_REGS_NOSPEC
ENCODE_FRAME_POINTER 8
testb $3, CS+8(%rsp)
Patches currently in stable-queue which might be from linux@xxxxxxxxxxxxxxxxxxxx are
queue-4.14/x86-entry-64-interleave-xor-register-clearing-with-push-instructions.patch
queue-4.14/x86-entry-64-merge-the-pop_c_regs-and-pop_extra_regs-macros-into-a-single-pop_regs-macro.patch
queue-4.14/x86-entry-64-remove-the-unused-icebp-macro.patch
queue-4.14/x86-entry-64-use-push_and_clean_regs-in-more-cases.patch
queue-4.14/selftests-x86-disable-tests-requiring-32-bit-support-on-pure-64-bit-systems.patch
queue-4.14/x86-entry-64-fix-paranoid_entry-frame-pointer-warning.patch
queue-4.14/x86-entry-64-merge-save_c_regs-and-save_extra_regs-remove-unused-extensions.patch
queue-4.14/selftests-x86-do-not-rely-on-int-0x80-in-single_step_syscall.c.patch
queue-4.14/selftests-x86-fix-vdso-selftest-segfault-for-vsyscall-none.patch
queue-4.14/x86-entry-64-indent-push_and_clear_regs-and-pop_regs-properly.patch
queue-4.14/selftests-x86-clean-up-and-document-sscanf-usage.patch
queue-4.14/selftests-x86-do-not-rely-on-int-0x80-in-test_mremap_vdso.c.patch
queue-4.14/x86-entry-64-get-rid-of-the-alloc_pt_gpregs_on_stack-and-save_and_clear_regs-macros.patch
queue-4.14/x86-entry-64-introduce-the-push_and_clean_regs-macro.patch