search for: altinstruct

...*/ -#define ALTERNATIVE(oldinstr, newinstr, feature) \ +#define __ALTERNATIVE(section, oldinstr, newinstr, feature) \ 140:; \ oldinstr; \ 141:; \ .skip -(((144f-143f)-(141b-140b)) > 0) * \ ((144f-143f)-(141b-140b)),0x90; \ 142:; \ - .pushsection .altinstructions, "a"; \ + .pushsection section, "a"; \ altinstruction_entry 140b,143f,feature,142b-140b,144f-143f,142b-141b;\ .popsection; \ .pushsection .altinstr_replacement, "ax"; \ @@ -55,6 +55,11 @@ 144:; \ .popsection +#define ARGS(args...)...

...str. ".skip" directive takes care of proper instruction padding * in case @newinstr is longer than @oldinstr. */ -.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: +#define ALTERNATIVE(oldinstr, newinstr, feature) \ +140:; \ + oldinstr; \ +141:; \ + .skip -...

...t_paravirtprobe = .; + *(.paravirtprobe); + *(.paravirtprobe_failsafe); + __stop_paravirtprobe = .; + } + _edata = .; /* End of data section */ . = ALIGN(PAGE_SIZE); @@ -180,14 +187,20 @@ SECTIONS __con_initcall_end = .; SECURITY_INIT . = ALIGN(8); - __alt_instructions = .; .altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) { + __alt_instructions = .; *(.altinstructions) + __alt_instructions_end = .; } - __alt_instructions_end = .; .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) { *(.altinstr_replacement) } + . = ALIGN(8); + .parai...

...t_paravirtprobe = .; + *(.paravirtprobe); + *(.paravirtprobe_failsafe); + __stop_paravirtprobe = .; + } + _edata = .; /* End of data section */ . = ALIGN(PAGE_SIZE); @@ -180,14 +187,20 @@ SECTIONS __con_initcall_end = .; SECURITY_INIT . = ALIGN(8); - __alt_instructions = .; .altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) { + __alt_instructions = .; *(.altinstructions) + __alt_instructions_end = .; } - __alt_instructions_end = .; .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) { *(.altinstr_replacement) } + . = ALIGN(8); + .parai...

Hi Andi, Here's a little batch of cleanups: - re-enable VDSO when PARAVIRT is enabled - make the parainstructions symbols match the other altinstructions naming convention - add kernel command-line options to disable altinstructions for smp and pv_ops Oh, and I'm mailing your noreplacement patch back at you, for no particularly good reason. J --

Hi Andi, Here's a little batch of cleanups: - re-enable VDSO when PARAVIRT is enabled - make the parainstructions symbols match the other altinstructions naming convention - add kernel command-line options to disable altinstructions for smp and pv_ops Oh, and I'm mailing your noreplacement patch back at you, for no particularly good reason. J --

...can be padded with nops as needed. + * + * For non barrier like inlines please define new variants + * without volatile and memory clobber. + */ +#define alternative(oldinstr, newinstr, feature) \ + asm volatile ("661:\n\t" oldinstr "\n662:\n" \ + ".section .altinstructions,\"a\"\n" \ + " .align 4\n" \ + " .long 661b\n" /* label */ \ + " .long 663f\n" /* new instruction */ \ + " .byte %c0\n" /* feature bit */ \ +...

...can be padded with nops as needed. + * + * For non barrier like inlines please define new variants + * without volatile and memory clobber. + */ +#define alternative(oldinstr, newinstr, feature) \ + asm volatile ("661:\n\t" oldinstr "\n662:\n" \ + ".section .altinstructions,\"a\"\n" \ + " .align 4\n" \ + " .long 661b\n" /* label */ \ + " .long 663f\n" /* new instruction */ \ + " .byte %c0\n" /* feature bit */ \ +...

...t;feature=%P[feature] t_yes=%l[t_yes] " - "t_no=%l[t_no] always=%P[always]" + asm_volatile_goto("1: jmp 6f\n" + "2:\n" + ".skip -(((5f-4f) - (2b-1b)) > 0) * " + "((5f-4f) - (2b-1b)),0x90\n" + "3:\n" + ".section .altinstructions,\"a\"\n" + " .long 1b - .\n" /* src offset */ + " .long 4f - .\n" /* repl offset */ + " .word %P[always]\n" /* always replace */ + " .byte 3b - 1b\n" /* src len */ + " .byte 5f - 4f\n" /* repl len */ + " .byt...

Hi all, This is version three of the patches I previously posted here: v1: https://lore.kernel.org/lkml/20191108170120.22331-1-will at kernel.org/ v2: https://lore.kernel.org/r/20200630173734.14057-1-will at kernel.org Changes since v2 include: * Actually add the barrier in READ_ONCE() for Alpha! * Implement Alpha's smp_load_acquire() using __READ_ONCE(), rather than the other

...paravirt: Simplify ____PVOP_CALL() x86/paravirt: Clean up paravirt_types.h x86/asm: Convert ALTERNATIVE*() assembler macros to preprocessor macros x86/alternative: Support indirect call replacement x86/paravirt: Add paravirt alternatives infrastructure objtool: Add support for new .pv_altinstructions section x86/paravirt: Convert natively patched pv ops to use paravirt alternatives arch/x86/entry/entry_32.S | 13 +- arch/x86/entry/entry_64.S | 12 +- arch/x86/entry/entry_64_compat.S | 9 +- arch/x86/entry/vdso/vdso32/system_call.S | 10 +-...

...paravirt: Simplify ____PVOP_CALL() x86/paravirt: Clean up paravirt_types.h x86/asm: Convert ALTERNATIVE*() assembler macros to preprocessor macros x86/alternative: Support indirect call replacement x86/paravirt: Add paravirt alternatives infrastructure objtool: Add support for new .pv_altinstructions section x86/paravirt: Convert natively patched pv ops to use paravirt alternatives arch/x86/entry/entry_32.S | 13 +- arch/x86/entry/entry_64.S | 12 +- arch/x86/entry/entry_64_compat.S | 9 +- arch/x86/entry/vdso/vdso32/system_call.S | 10 +-...

Hi everyone, This is the long-awaited version two of the patches I previously posted in November last year: https://lore.kernel.org/lkml/20191108170120.22331-1-will at kernel.org/ I ended up parking the series while the READ_ONCE() implementation was being overhauled, but with that merged during the recent merge window and LTO patches being posted again [1], it was time for a refresh. The

Hi everyone, This is the long-awaited version two of the patches I previously posted in November last year: https://lore.kernel.org/lkml/20191108170120.22331-1-will at kernel.org/ I ended up parking the series while the READ_ONCE() implementation was being overhauled, but with that merged during the recent merge window and LTO patches being posted again [1], it was time for a refresh. The

...t;feature=%P[feature] t_yes=%l[t_yes] " - "t_no=%l[t_no] always=%P[always]" + asm_volatile_goto("1: jmp 6f\n" + "2:\n" + ".skip -(((5f-4f) - (2b-1b)) > 0) * " + "((5f-4f) - (2b-1b)),0x90\n" + "3:\n" + ".section .altinstructions,\"a\"\n" + " .long 1b - .\n" /* src offset */ + " .long 4f - .\n" /* repl offset */ + " .word %P[always]\n" /* always replace */ + " .byte 3b - 1b\n" /* src len */ + " .byte 5f - 4f\n" /* repl len */ + " .byt...

...t;feature=%P[feature] t_yes=%l[t_yes] " - "t_no=%l[t_no] always=%P[always]" + asm_volatile_goto("1: jmp 6f\n" + "2:\n" + ".skip -(((5f-4f) - (2b-1b)) > 0) * " + "((5f-4f) - (2b-1b)),0x90\n" + "3:\n" + ".section .altinstructions,\"a\"\n" + " .long 1b - .\n" /* src offset */ + " .long 4f - .\n" /* repl offset */ + " .word %P[always]\n" /* always replace */ + " .byte 3b - 1b\n" /* src len */ + " .byte 5f - 4f\n" /* repl len */ + " .byt...

Is it OK for section .parainstructions to reference exit.text? I'm seeing: WARNING: drivers/net/hamradio/scc.o - Section mismatch: reference to .exit.text: from .parainstructions after '' (at offset 0x0) WARNING: drivers/net/hamradio/scc.o - Section mismatch: reference to .exit.text: from .parainstructions after '' (at offset 0x8) If that's OK, we need a small patch to

Is it OK for section .parainstructions to reference exit.text? I'm seeing: WARNING: drivers/net/hamradio/scc.o - Section mismatch: reference to .exit.text: from .parainstructions after '' (at offset 0x0) WARNING: drivers/net/hamradio/scc.o - Section mismatch: reference to .exit.text: from .parainstructions after '' (at offset 0x8) If that's OK, we need a small patch to

...:9: ./arch/x86/include/asm/mshyperv.h:189:23: [0;1;31merror: invalid operand in inline asm: 聽聽聽聽聽聽'mov $4, %r8999: .pushsection .discard.nospec .long 999b - . .popsection 聽聽聽聽聽聽661: call *$5662:.skip -(((6651f-6641f)-(662b-661b)) > 0) * 聽聽聽聽聽聽((6651f-6641f)-(662b-661b)),0x90663:.pushsection .altinstructions,"a" 聽聽聽聽聽聽.long 661b - . .long 6641f - . .word ( 7*32+12) .byte 663b-661b .byte 聽聽聽聽聽聽6651f-6641f .byte 663b-662b.popsection.pushsection .altinstr_replacement, 聽聽聽聽聽聽"ax"6641: call __x86_indirect_thunk_${5:V}6651: .popsection' 聽聽聽聽聽聽聽聽__asm__ __volatile__("mov %4, %...

I've landed the patch in r324449. Before we merge this into two different Clang release branches and almost immediately release one of them, I would really like someone to confirm that this patch works well with the Linux kernel. David, if you're up for that, it would be great. Alternatively, Guenter or someone else here can help. On Tue, Feb 6, 2018 at 5:59 PM Chandler Carruth