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linux/arch/x86/include/asm/alternative-asm.h

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x86, alternative: Add header guards to <asm/alternative-asm.h> Add header guards to protect <asm/alternative-asm.h> against multiple inclusion. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1348256595-29119-6-git-send-email-hpa@linux.intel.com
2012-09-21 19:43:09 +00:00
#ifndef _ASM_X86_ALTERNATIVE_ASM_H
#define _ASM_X86_ALTERNATIVE_ASM_H
x86: rename .i assembler includes to .h .i is an ending used for preprocessed stuff. This patch therefore renames assembler include files to .h and guards the contents with an #ifdef __ASSEMBLY__. [ tglx: arch/x86 adaptation ] Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-17 16:04:38 +00:00
#ifdef __ASSEMBLY__
x86/alternatives: No need for alternatives-asm.h to re-invent stuff already in asm.h This at once also gets the alignment specification right for x86-64. Signed-off-by: Jan Beulich <jbeulich@novell.com> LKML-Reference: <4B0FF8F80200007800022708@vpn.id2.novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-27 15:06:16 +00:00
#include <asm/asm.h>
x86: rename .i assembler includes to .h .i is an ending used for preprocessed stuff. This patch therefore renames assembler include files to .h and guards the contents with an #ifdef __ASSEMBLY__. [ tglx: arch/x86 adaptation ] Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-17 16:04:38 +00:00
#ifdef CONFIG_SMP
.macro LOCK_PREFIX
x86: Fix atomic64_xxx_cx8() functions It appears about all functions in arch/x86/lib/atomic64_cx8_32.S are wrong in case cmpxchg8b must be restarted, because LOCK_PREFIX macro defines a label "1" clashing with other local labels : 1: some_instructions LOCK_PREFIX cmpxchg8b (%ebp) jne 1b / jumps to beginning of LOCK_PREFIX ! A possible fix is to use a magic label "672" in LOCK_PREFIX asm definition, similar to the "671" one we defined in LOCK_PREFIX_HERE. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Jan Beulich <JBeulich@suse.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1325608540.2320.103.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-03 16:35:40 +00:00
672: lock
x86, alternative: Use .pushsection/.popsection .section/.previous doesn't nest. Use .pushsection/.popsection in <asm/alternative.h> so that they can be properly nested. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1348256595-29119-5-git-send-email-hpa@linux.intel.com
2012-09-21 19:43:08 +00:00
.pushsection .smp_locks,"a"
x86-64: Reduce SMP locks table size Reduce the SMP locks table size by using relative pointers instead of absolute ones, thus cutting the table size by half. Signed-off-by: Jan Beulich <jbeulich@novell.com> LKML-Reference: <4BCF30FE020000780003B3B6@vpn.id2.novell.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-04-21 15:08:14 +00:00
.balign 4
x86: Fix atomic64_xxx_cx8() functions It appears about all functions in arch/x86/lib/atomic64_cx8_32.S are wrong in case cmpxchg8b must be restarted, because LOCK_PREFIX macro defines a label "1" clashing with other local labels : 1: some_instructions LOCK_PREFIX cmpxchg8b (%ebp) jne 1b / jumps to beginning of LOCK_PREFIX ! A possible fix is to use a magic label "672" in LOCK_PREFIX asm definition, similar to the "671" one we defined in LOCK_PREFIX_HERE. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Jan Beulich <JBeulich@suse.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1325608540.2320.103.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-03 16:35:40 +00:00
.long 672b - .
x86, alternative: Use .pushsection/.popsection .section/.previous doesn't nest. Use .pushsection/.popsection in <asm/alternative.h> so that they can be properly nested. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1348256595-29119-5-git-send-email-hpa@linux.intel.com
2012-09-21 19:43:08 +00:00
.popsection
x86: rename .i assembler includes to .h .i is an ending used for preprocessed stuff. This patch therefore renames assembler include files to .h and guards the contents with an #ifdef __ASSEMBLY__. [ tglx: arch/x86 adaptation ] Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-17 16:04:38 +00:00
.endm
#else
.macro LOCK_PREFIX
.endm
#endif
x86/alternatives: Add instruction padding Up until now we have always paid attention to make sure the length of the new instruction replacing the old one is at least less or equal to the length of the old instruction. If the new instruction is longer, at the time it replaces the old instruction it will overwrite the beginning of the next instruction in the kernel image and cause your pants to catch fire. So instead of having to pay attention, teach the alternatives framework to pad shorter old instructions with NOPs at buildtime - but only in the case when len(old instruction(s)) < len(new instruction(s)) and add nothing in the >= case. (In that case we do add_nops() when patching). This way the alternatives user shouldn't have to care about instruction sizes and simply use the macros. Add asm ALTERNATIVE* flavor macros too, while at it. Also, we need to save the pad length in a separate struct alt_instr member for NOP optimization and the way to do that reliably is to carry the pad length instead of trying to detect whether we're looking at single-byte NOPs or at pathological instruction offsets like e9 90 90 90 90, for example, which is a valid instruction. Thanks to Michael Matz for the great help with toolchain questions. Signed-off-by: Borislav Petkov <bp@suse.de>
2014-12-27 09:41:52 +00:00
.macro altinstruction_entry orig alt feature orig_len alt_len pad_len
x86: Make alternative instruction pointers relative This save a few bytes on x86-64 and means that future patches can apply alternatives to unrelocated code. Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/ff64a6b9a1a3860ca4a7b8b6dc7b4754f9491cd7.1310563276.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-07-13 13:24:10 +00:00
.long \orig - .
.long \alt - .
x86, alternative: Add altinstruction_entry macro Add altinstruction_entry macro to generate .altinstructions section entries from assembly code. This should be less failure-prone than open-coding. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Link: http://lkml.kernel.org/r/1305671358-14478-5-git-send-email-fenghua.yu@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-17 22:29:13 +00:00
.word \feature
.byte \orig_len
.byte \alt_len
x86/alternatives: Add instruction padding Up until now we have always paid attention to make sure the length of the new instruction replacing the old one is at least less or equal to the length of the old instruction. If the new instruction is longer, at the time it replaces the old instruction it will overwrite the beginning of the next instruction in the kernel image and cause your pants to catch fire. So instead of having to pay attention, teach the alternatives framework to pad shorter old instructions with NOPs at buildtime - but only in the case when len(old instruction(s)) < len(new instruction(s)) and add nothing in the >= case. (In that case we do add_nops() when patching). This way the alternatives user shouldn't have to care about instruction sizes and simply use the macros. Add asm ALTERNATIVE* flavor macros too, while at it. Also, we need to save the pad length in a separate struct alt_instr member for NOP optimization and the way to do that reliably is to carry the pad length instead of trying to detect whether we're looking at single-byte NOPs or at pathological instruction offsets like e9 90 90 90 90, for example, which is a valid instruction. Thanks to Michael Matz for the great help with toolchain questions. Signed-off-by: Borislav Petkov <bp@suse.de>
2014-12-27 09:41:52 +00:00
.byte \pad_len
.endm
.macro ALTERNATIVE oldinstr, newinstr, feature
140:
\oldinstr
141:
.skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90
142:
.pushsection .altinstructions,"a"
altinstruction_entry 140b,143f,\feature,142b-140b,144f-143f,142b-141b
.popsection
.pushsection .altinstr_replacement,"ax"
143:
\newinstr
144:
.popsection
.endm
.macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2
140:
\oldinstr
141:
.skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90
.skip -(((145f-144f)-(144f-143f)-(141b-140b)) > 0) * ((145f-144f)-(144f-143f)-(141b-140b)),0x90
142:
.pushsection .altinstructions,"a"
altinstruction_entry 140b,143f,\feature1,142b-140b,144f-143f,142b-141b
altinstruction_entry 140b,144f,\feature2,142b-140b,145f-144f,142b-141b
.popsection
.pushsection .altinstr_replacement,"ax"
143:
\newinstr1
144:
\newinstr2
145:
.popsection
x86, alternative: Add altinstruction_entry macro Add altinstruction_entry macro to generate .altinstructions section entries from assembly code. This should be less failure-prone than open-coding. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Link: http://lkml.kernel.org/r/1305671358-14478-5-git-send-email-fenghua.yu@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-17 22:29:13 +00:00
.endm
x86: rename .i assembler includes to .h .i is an ending used for preprocessed stuff. This patch therefore renames assembler include files to .h and guards the contents with an #ifdef __ASSEMBLY__. [ tglx: arch/x86 adaptation ] Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-17 16:04:38 +00:00
#endif /* __ASSEMBLY__ */
x86, alternative: Add header guards to <asm/alternative-asm.h> Add header guards to protect <asm/alternative-asm.h> against multiple inclusion. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1348256595-29119-6-git-send-email-hpa@linux.intel.com
2012-09-21 19:43:09 +00:00
#endif /* _ASM_X86_ALTERNATIVE_ASM_H */
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