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linux/arch/s390/include/asm/nospec-insn.h

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s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_S390_NOSPEC_ASM_H
#define _ASM_S390_NOSPEC_ASM_H
#include <asm/dwarf.h>
#ifdef __ASSEMBLY__
s390: disable asm code expolines if cc does not support it To avoid a mixture of asm code with expolines and c code without them, propagate CC_USING_EXPOLINE to KBUILD_AFLAGS and use it to detect whether asm code should have expolines or not. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-06-15 11:22:18 +03:00
#ifdef CC_USING_EXPOLINE
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
/*
* The expoline macros are used to create thunks in the same format
* as gcc generates them. The 'comdat' section flag makes sure that
* the various thunks are merged into a single copy.
*/
.macro __THUNK_PROLOG_NAME name
s390/nospec: add an option to use thunk-extern Currently with -mindirect-branch=thunk and -mfunction-return=thunk compiler options expoline thunks are put into individual COMDAT group sections. s390 is the only architecture which has group sections and it has implications for kpatch and objtool tools support. Using -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern is an alternative, which comes with a need to generate all required expoline thunks manually. Unfortunately modules area is too far away from the kernel image, and expolines from the kernel image cannon be used. But since all new distributions (except Debian) build kernels for machine generations newer than z10, where "exrl" instruction is available, that leaves only 16 expolines thunks possible. Provide an option to build the kernel with -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern for z10 or newer. This also requires to postlink expoline thunks into all modules explicitly. Currently modules already contain most expolines anyhow. Unfortunately -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern options support is broken in gcc <= 11.2. Additional compile test is required to verify proper gcc support. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Co-developed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-06 22:56:07 +03:00
#ifdef CONFIG_EXPOLINE_EXTERN
.pushsection .text,"ax",@progbits
s390/nospec: align and size extern thunks Kernel has full control over how extern thunks generated by arch/s390/lib/expoline.S look like. Align them to 16 bytes like other symbols. Also set proper symbols size which is important for tooling. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-07 00:30:42 +03:00
.align 16,0x07
s390/nospec: add an option to use thunk-extern Currently with -mindirect-branch=thunk and -mfunction-return=thunk compiler options expoline thunks are put into individual COMDAT group sections. s390 is the only architecture which has group sections and it has implications for kpatch and objtool tools support. Using -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern is an alternative, which comes with a need to generate all required expoline thunks manually. Unfortunately modules area is too far away from the kernel image, and expolines from the kernel image cannon be used. But since all new distributions (except Debian) build kernels for machine generations newer than z10, where "exrl" instruction is available, that leaves only 16 expolines thunks possible. Provide an option to build the kernel with -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern for z10 or newer. This also requires to postlink expoline thunks into all modules explicitly. Currently modules already contain most expolines anyhow. Unfortunately -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern options support is broken in gcc <= 11.2. Additional compile test is required to verify proper gcc support. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Co-developed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-06 22:56:07 +03:00
#else
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.pushsection .text.\name,"axG",@progbits,\name,comdat
s390/nospec: add an option to use thunk-extern Currently with -mindirect-branch=thunk and -mfunction-return=thunk compiler options expoline thunks are put into individual COMDAT group sections. s390 is the only architecture which has group sections and it has implications for kpatch and objtool tools support. Using -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern is an alternative, which comes with a need to generate all required expoline thunks manually. Unfortunately modules area is too far away from the kernel image, and expolines from the kernel image cannon be used. But since all new distributions (except Debian) build kernels for machine generations newer than z10, where "exrl" instruction is available, that leaves only 16 expolines thunks possible. Provide an option to build the kernel with -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern for z10 or newer. This also requires to postlink expoline thunks into all modules explicitly. Currently modules already contain most expolines anyhow. Unfortunately -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern options support is broken in gcc <= 11.2. Additional compile test is required to verify proper gcc support. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Co-developed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-06 22:56:07 +03:00
#endif
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.globl \name
.hidden \name
.type \name,@function
\name:
CFI_STARTPROC
.endm
s390/nospec: align and size extern thunks Kernel has full control over how extern thunks generated by arch/s390/lib/expoline.S look like. Align them to 16 bytes like other symbols. Also set proper symbols size which is important for tooling. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-07 00:30:42 +03:00
.macro __THUNK_EPILOG_NAME name
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
CFI_ENDPROC
s390/nospec: align and size extern thunks Kernel has full control over how extern thunks generated by arch/s390/lib/expoline.S look like. Align them to 16 bytes like other symbols. Also set proper symbols size which is important for tooling. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-07 00:30:42 +03:00
#ifdef CONFIG_EXPOLINE_EXTERN
.size \name, .-\name
#endif
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.popsection
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro __THUNK_PROLOG_BR r1
s390/nospec: generate single register thunks if possible Currently assembler generated expoline thunks are always in a form __s390_indirect_jump_rXuse_rX even when exrl instruction is available and no additional register is utilized. Generate __s390_indirect_jump_rX versions using a single register if the kernel is built for z10 or newer machine, which have exrl instruction available. Thunks generated are identical to the ones generated by the compiler. This helps to reduce the number of thunks for newer machines generations. Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-28 15:15:59 +03:00
__THUNK_PROLOG_NAME __s390_indirect_jump_r\r1
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro __THUNK_EPILOG_BR r1
s390/nospec: align and size extern thunks Kernel has full control over how extern thunks generated by arch/s390/lib/expoline.S look like. Align them to 16 bytes like other symbols. Also set proper symbols size which is important for tooling. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-07 00:30:42 +03:00
__THUNK_EPILOG_NAME __s390_indirect_jump_r\r1
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro __THUNK_BR r1
s390/nospec: generate single register thunks if possible Currently assembler generated expoline thunks are always in a form __s390_indirect_jump_rXuse_rX even when exrl instruction is available and no additional register is utilized. Generate __s390_indirect_jump_rX versions using a single register if the kernel is built for z10 or newer machine, which have exrl instruction available. Thunks generated are identical to the ones generated by the compiler. This helps to reduce the number of thunks for newer machines generations. Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-28 15:15:59 +03:00
jg __s390_indirect_jump_r\r1
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro __THUNK_BRASL r1,r2
s390/nospec: generate single register thunks if possible Currently assembler generated expoline thunks are always in a form __s390_indirect_jump_rXuse_rX even when exrl instruction is available and no additional register is utilized. Generate __s390_indirect_jump_rX versions using a single register if the kernel is built for z10 or newer machine, which have exrl instruction available. Thunks generated are identical to the ones generated by the compiler. This helps to reduce the number of thunks for newer machines generations. Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-28 15:15:59 +03:00
brasl \r1,__s390_indirect_jump_r\r2
.endm
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro __DECODE_R expand,reg
s390/nospec: prefer local labels in .set directives Use local labels in .set directives to avoid potential compile errors with LTO + clang. See commit 334865b2915c ("x86/extable: Prefer local labels in .set directives") for further details. Since s390 doesn't support LTO currently this doesn't fix a real bug for now, but helps to avoid problems as soon as required pieces have been added to llvm. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-01 21:55:05 +03:00
.set .L__decode_fail,1
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.irp r1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
.ifc \reg,%r\r1
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
\expand \r1
s390/nospec: prefer local labels in .set directives Use local labels in .set directives to avoid potential compile errors with LTO + clang. See commit 334865b2915c ("x86/extable: Prefer local labels in .set directives") for further details. Since s390 doesn't support LTO currently this doesn't fix a real bug for now, but helps to avoid problems as soon as required pieces have been added to llvm. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-01 21:55:05 +03:00
.set .L__decode_fail,0
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.endif
.endr
s390/nospec: prefer local labels in .set directives Use local labels in .set directives to avoid potential compile errors with LTO + clang. See commit 334865b2915c ("x86/extable: Prefer local labels in .set directives") for further details. Since s390 doesn't support LTO currently this doesn't fix a real bug for now, but helps to avoid problems as soon as required pieces have been added to llvm. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-01 21:55:05 +03:00
.if .L__decode_fail == 1
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.error "__DECODE_R failed"
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.endif
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro __DECODE_RR expand,rsave,rtarget
s390/nospec: prefer local labels in .set directives Use local labels in .set directives to avoid potential compile errors with LTO + clang. See commit 334865b2915c ("x86/extable: Prefer local labels in .set directives") for further details. Since s390 doesn't support LTO currently this doesn't fix a real bug for now, but helps to avoid problems as soon as required pieces have been added to llvm. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-01 21:55:05 +03:00
.set .L__decode_fail,1
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.irp r1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
.ifc \rsave,%r\r1
.irp r2,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
.ifc \rtarget,%r\r2
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
\expand \r1,\r2
s390/nospec: prefer local labels in .set directives Use local labels in .set directives to avoid potential compile errors with LTO + clang. See commit 334865b2915c ("x86/extable: Prefer local labels in .set directives") for further details. Since s390 doesn't support LTO currently this doesn't fix a real bug for now, but helps to avoid problems as soon as required pieces have been added to llvm. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-01 21:55:05 +03:00
.set .L__decode_fail,0
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.endif
.endr
.endif
.endr
s390/nospec: prefer local labels in .set directives Use local labels in .set directives to avoid potential compile errors with LTO + clang. See commit 334865b2915c ("x86/extable: Prefer local labels in .set directives") for further details. Since s390 doesn't support LTO currently this doesn't fix a real bug for now, but helps to avoid problems as soon as required pieces have been added to llvm. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-01 21:55:05 +03:00
.if .L__decode_fail == 1
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.error "__DECODE_RR failed"
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.endif
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro __THUNK_EX_BR reg
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
exrl 0,555f
j .
555: br \reg
.endm
s390/nospec: add an option to use thunk-extern Currently with -mindirect-branch=thunk and -mfunction-return=thunk compiler options expoline thunks are put into individual COMDAT group sections. s390 is the only architecture which has group sections and it has implications for kpatch and objtool tools support. Using -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern is an alternative, which comes with a need to generate all required expoline thunks manually. Unfortunately modules area is too far away from the kernel image, and expolines from the kernel image cannon be used. But since all new distributions (except Debian) build kernels for machine generations newer than z10, where "exrl" instruction is available, that leaves only 16 expolines thunks possible. Provide an option to build the kernel with -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern for z10 or newer. This also requires to postlink expoline thunks into all modules explicitly. Currently modules already contain most expolines anyhow. Unfortunately -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern options support is broken in gcc <= 11.2. Additional compile test is required to verify proper gcc support. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Co-developed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-06 22:56:07 +03:00
#ifdef CONFIG_EXPOLINE_EXTERN
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro GEN_BR_THUNK reg
s390/nospec: add an option to use thunk-extern Currently with -mindirect-branch=thunk and -mfunction-return=thunk compiler options expoline thunks are put into individual COMDAT group sections. s390 is the only architecture which has group sections and it has implications for kpatch and objtool tools support. Using -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern is an alternative, which comes with a need to generate all required expoline thunks manually. Unfortunately modules area is too far away from the kernel image, and expolines from the kernel image cannon be used. But since all new distributions (except Debian) build kernels for machine generations newer than z10, where "exrl" instruction is available, that leaves only 16 expolines thunks possible. Provide an option to build the kernel with -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern for z10 or newer. This also requires to postlink expoline thunks into all modules explicitly. Currently modules already contain most expolines anyhow. Unfortunately -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern options support is broken in gcc <= 11.2. Additional compile test is required to verify proper gcc support. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Co-developed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-06 22:56:07 +03:00
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro GEN_BR_THUNK_EXTERN reg
s390/nospec: add an option to use thunk-extern Currently with -mindirect-branch=thunk and -mfunction-return=thunk compiler options expoline thunks are put into individual COMDAT group sections. s390 is the only architecture which has group sections and it has implications for kpatch and objtool tools support. Using -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern is an alternative, which comes with a need to generate all required expoline thunks manually. Unfortunately modules area is too far away from the kernel image, and expolines from the kernel image cannon be used. But since all new distributions (except Debian) build kernels for machine generations newer than z10, where "exrl" instruction is available, that leaves only 16 expolines thunks possible. Provide an option to build the kernel with -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern for z10 or newer. This also requires to postlink expoline thunks into all modules explicitly. Currently modules already contain most expolines anyhow. Unfortunately -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern options support is broken in gcc <= 11.2. Additional compile test is required to verify proper gcc support. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Co-developed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-06 22:56:07 +03:00
#else
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro GEN_BR_THUNK reg
s390/nospec: add an option to use thunk-extern Currently with -mindirect-branch=thunk and -mfunction-return=thunk compiler options expoline thunks are put into individual COMDAT group sections. s390 is the only architecture which has group sections and it has implications for kpatch and objtool tools support. Using -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern is an alternative, which comes with a need to generate all required expoline thunks manually. Unfortunately modules area is too far away from the kernel image, and expolines from the kernel image cannon be used. But since all new distributions (except Debian) build kernels for machine generations newer than z10, where "exrl" instruction is available, that leaves only 16 expolines thunks possible. Provide an option to build the kernel with -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern for z10 or newer. This also requires to postlink expoline thunks into all modules explicitly. Currently modules already contain most expolines anyhow. Unfortunately -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern options support is broken in gcc <= 11.2. Additional compile test is required to verify proper gcc support. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Co-developed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-06 22:56:07 +03:00
#endif
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
__DECODE_R __THUNK_PROLOG_BR,\reg
__THUNK_EX_BR \reg
__DECODE_R __THUNK_EPILOG_BR,\reg
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro BR_EX reg
557: __DECODE_R __THUNK_BR,\reg
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.pushsection .s390_indirect_branches,"a",@progbits
.long 557b-.
.popsection
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro BASR_EX rsave,rtarget
559: __DECODE_RR __THUNK_BRASL,\rsave,\rtarget
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.pushsection .s390_indirect_branches,"a",@progbits
.long 559b-.
.popsection
.endm
#else
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro GEN_BR_THUNK reg
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro BR_EX reg
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
br \reg
.endm
s390/nospec: move to single register thunks Assembler generated expoline thunks were in a form __s390_indirect_jump_rXuse_rX when exrl instruction has not been available. Now with z10 as minimum supported machine generation there is no need for 2 register thunks, always generate __s390_indirect_jump_rX versions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-02-25 12:18:14 +03:00
.macro BASR_EX rsave,rtarget
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
basr \rsave,\rtarget
.endm
s390: disable asm code expolines if cc does not support it To avoid a mixture of asm code with expolines and c code without them, propagate CC_USING_EXPOLINE to KBUILD_AFLAGS and use it to detect whether asm code should have expolines or not. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-06-15 11:22:18 +03:00
#endif /* CC_USING_EXPOLINE */
s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-20 17:49:46 +03:00
#endif /* __ASSEMBLY__ */
#endif /* _ASM_S390_NOSPEC_ASM_H */
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