Re: [PATCH] kbuild, x86: revert macros in extended asm workarounds
From: Sedat Dilek
Date: Mon Dec 17 2018 - 04:16:55 EST
On Thu, Dec 13, 2018 at 10:19 AM Masahiro Yamada
<yamada.masahiro@xxxxxxxxxxxxx> wrote:
>
> Revert the following commits:
>
> - 5bdcd510c2ac9efaf55c4cbd8d46421d8e2320cd
> ("x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs")
>
> - d5a581d84ae6b8a4a740464b80d8d9cf1e7947b2
> ("x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs")
>
> - 0474d5d9d2f7f3b11262f7bf87d0e7314ead9200.
> ("x86/extable: Macrofy inline assembly code to work around GCC inlining bugs")
>
> - 494b5168f2de009eb80f198f668da374295098dd.
> ("x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops")
>
> - f81f8ad56fd1c7b99b2ed1c314527f7d9ac447c6.
> ("x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs")
>
> - 77f48ec28e4ccff94d2e5f4260a83ac27a7f3099.
> ("x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs")
>
> - 9e1725b410594911cc5981b6c7b4cea4ec054ca8.
> ("x86/refcount: Work around GCC inlining bug")
> (Conflicts: arch/x86/include/asm/refcount.h)
>
> - c06c4d8090513f2974dfdbed2ac98634357ac475.
> ("x86/objtool: Use asm macros to work around GCC inlining bugs")
>
> - 77b0bf55bc675233d22cd5df97605d516d64525e.
> ("kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs")
>
> A few days after those commits applied, discussion started to solve
> the issue more elegantly on the compiler side:
>
> https://lkml.org/lkml/2018/10/7/92
>
> The "asm inline" was implemented by Segher Boessenkool, and now queued
> up for GCC 9. (People were positive even for back-porting it to older
> compilers).
>
> Since the in-kernel workarounds merged, some issues have been reported:
> breakage of building with distcc/icecc, breakage of distro packages for
> module building. (More fundamentally, we cannot build external modules
> after 'make clean')
>
> Patching around the build system would make the code even uglier.
>
> Given that this issue will be solved in a cleaner way sooner or later,
> let's revert the in-kernel workarounds, and wait for GCC 9.
>
> Reported-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> # distcc
> Reported-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> # debian/rpm package
Hi,
I reported the issue with debian package breakage in [1].
I am not subscribed to any involved mailing-list and not following all
the discussions.
I see the situation is not easy as there is especially linux-kbuild
and linux/x86 involved and maybe other interests.
But I am interested in having a fix in v4.20 final and hope this all
still works with LLVM/Clang.
I can offer my help in testing - against Linux v4.20-rc7.
Not sure if all discussed material is in upstream or elsewhere.
What is your suggestion for me as a tester?
Will we have a solution in Linux v4.20 final?
Thanks.
With my best wishes,
- Sedat -
[1] https://marc.info/?t=154212770600037&r=1&w=2
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> Cc: Nadav Amit <namit@xxxxxxxxxx>
> Cc: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx>
> ---
>
> Please consider this for v4.20 release.
> Currently, distro package build is broken.
>
>
> Makefile | 9 +---
> arch/x86/Makefile | 7 ---
> arch/x86/entry/calling.h | 2 +-
> arch/x86/include/asm/alternative-asm.h | 20 +++----
> arch/x86/include/asm/alternative.h | 11 +++-
> arch/x86/include/asm/asm.h | 53 +++++++++++-------
> arch/x86/include/asm/bug.h | 98 +++++++++++++++-------------------
> arch/x86/include/asm/cpufeature.h | 82 ++++++++++++----------------
> arch/x86/include/asm/jump_label.h | 72 ++++++++++++++++++-------
> arch/x86/include/asm/paravirt_types.h | 56 +++++++++----------
> arch/x86/include/asm/refcount.h | 81 ++++++++++++----------------
> arch/x86/kernel/macros.S | 16 ------
> include/asm-generic/bug.h | 8 +--
> include/linux/compiler.h | 56 +++++--------------
> scripts/Kbuild.include | 4 +-
> scripts/mod/Makefile | 2 -
> 16 files changed, 262 insertions(+), 315 deletions(-)
> delete mode 100644 arch/x86/kernel/macros.S
>
> diff --git a/Makefile b/Makefile
> index f2c3423..4cf4c5b 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1081,7 +1081,7 @@ scripts: scripts_basic scripts_dtc asm-generic gcc-plugins $(autoksyms_h)
> # version.h and scripts_basic is processed / created.
>
> # Listed in dependency order
> -PHONY += prepare archprepare macroprepare prepare0 prepare1 prepare2 prepare3
> +PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
>
> # prepare3 is used to check if we are building in a separate output directory,
> # and if so do:
> @@ -1104,9 +1104,7 @@ prepare2: prepare3 outputmakefile asm-generic
> prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h
> $(cmd_crmodverdir)
>
> -macroprepare: prepare1 archmacros
> -
> -archprepare: archheaders archscripts macroprepare scripts_basic
> +archprepare: archheaders archscripts prepare1 scripts_basic
>
> prepare0: archprepare gcc-plugins
> $(Q)$(MAKE) $(build)=.
> @@ -1174,9 +1172,6 @@ archheaders:
> PHONY += archscripts
> archscripts:
>
> -PHONY += archmacros
> -archmacros:
> -
> PHONY += __headers
> __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
> $(Q)$(MAKE) $(build)=scripts build_unifdef
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index 75ef499..85a66c4 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -232,13 +232,6 @@ archscripts: scripts_basic
> archheaders:
> $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
>
> -archmacros:
> - $(Q)$(MAKE) $(build)=arch/x86/kernel arch/x86/kernel/macros.s
> -
> -ASM_MACRO_FLAGS = -Wa,arch/x86/kernel/macros.s
> -export ASM_MACRO_FLAGS
> -KBUILD_CFLAGS += $(ASM_MACRO_FLAGS)
> -
> ###
> # Kernel objects
>
> diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
> index 25e5a6b..20d0885 100644
> --- a/arch/x86/entry/calling.h
> +++ b/arch/x86/entry/calling.h
> @@ -352,7 +352,7 @@ For 32-bit we have the following conventions - kernel is built with
> .macro CALL_enter_from_user_mode
> #ifdef CONFIG_CONTEXT_TRACKING
> #ifdef HAVE_JUMP_LABEL
> - STATIC_BRANCH_JMP l_yes=.Lafter_call_\@, key=context_tracking_enabled, branch=1
> + STATIC_JUMP_IF_FALSE .Lafter_call_\@, context_tracking_enabled, def=0
> #endif
> call enter_from_user_mode
> .Lafter_call_\@:
> diff --git a/arch/x86/include/asm/alternative-asm.h b/arch/x86/include/asm/alternative-asm.h
> index 8e4ea39..31b627b 100644
> --- a/arch/x86/include/asm/alternative-asm.h
> +++ b/arch/x86/include/asm/alternative-asm.h
> @@ -7,24 +7,16 @@
> #include <asm/asm.h>
>
> #ifdef CONFIG_SMP
> -.macro LOCK_PREFIX_HERE
> + .macro LOCK_PREFIX
> +672: lock
> .pushsection .smp_locks,"a"
> .balign 4
> - .long 671f - . # offset
> + .long 672b - .
> .popsection
> -671:
> -.endm
> -
> -.macro LOCK_PREFIX insn:vararg
> - LOCK_PREFIX_HERE
> - lock \insn
> -.endm
> + .endm
> #else
> -.macro LOCK_PREFIX_HERE
> -.endm
> -
> -.macro LOCK_PREFIX insn:vararg
> -.endm
> + .macro LOCK_PREFIX
> + .endm
> #endif
>
> /*
> diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
> index d7faa16..4cd6a3b 100644
> --- a/arch/x86/include/asm/alternative.h
> +++ b/arch/x86/include/asm/alternative.h
> @@ -31,8 +31,15 @@
> */
>
> #ifdef CONFIG_SMP
> -#define LOCK_PREFIX_HERE "LOCK_PREFIX_HERE\n\t"
> -#define LOCK_PREFIX "LOCK_PREFIX "
> +#define LOCK_PREFIX_HERE \
> + ".pushsection .smp_locks,\"a\"\n" \
> + ".balign 4\n" \
> + ".long 671f - .\n" /* offset */ \
> + ".popsection\n" \
> + "671:"
> +
> +#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "
> +
> #else /* ! CONFIG_SMP */
> #define LOCK_PREFIX_HERE ""
> #define LOCK_PREFIX ""
> diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
> index 21b0867..6467757b 100644
> --- a/arch/x86/include/asm/asm.h
> +++ b/arch/x86/include/asm/asm.h
> @@ -120,25 +120,12 @@
> /* Exception table entry */
> #ifdef __ASSEMBLY__
> # define _ASM_EXTABLE_HANDLE(from, to, handler) \
> - ASM_EXTABLE_HANDLE from to handler
> -
> -.macro ASM_EXTABLE_HANDLE from:req to:req handler:req
> - .pushsection "__ex_table","a"
> - .balign 4
> - .long (\from) - .
> - .long (\to) - .
> - .long (\handler) - .
> + .pushsection "__ex_table","a" ; \
> + .balign 4 ; \
> + .long (from) - . ; \
> + .long (to) - . ; \
> + .long (handler) - . ; \
> .popsection
> -.endm
> -#else /* __ASSEMBLY__ */
> -
> -# define _ASM_EXTABLE_HANDLE(from, to, handler) \
> - "ASM_EXTABLE_HANDLE from=" #from " to=" #to \
> - " handler=\"" #handler "\"\n\t"
> -
> -/* For C file, we already have NOKPROBE_SYMBOL macro */
> -
> -#endif /* __ASSEMBLY__ */
>
> # define _ASM_EXTABLE(from, to) \
> _ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
> @@ -161,7 +148,6 @@
> _ASM_PTR (entry); \
> .popsection
>
> -#ifdef __ASSEMBLY__
> .macro ALIGN_DESTINATION
> /* check for bad alignment of destination */
> movl %edi,%ecx
> @@ -185,7 +171,34 @@
> _ASM_EXTABLE_UA(100b, 103b)
> _ASM_EXTABLE_UA(101b, 103b)
> .endm
> -#endif /* __ASSEMBLY__ */
> +
> +#else
> +# define _EXPAND_EXTABLE_HANDLE(x) #x
> +# define _ASM_EXTABLE_HANDLE(from, to, handler) \
> + " .pushsection \"__ex_table\",\"a\"\n" \
> + " .balign 4\n" \
> + " .long (" #from ") - .\n" \
> + " .long (" #to ") - .\n" \
> + " .long (" _EXPAND_EXTABLE_HANDLE(handler) ") - .\n" \
> + " .popsection\n"
> +
> +# define _ASM_EXTABLE(from, to) \
> + _ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
> +
> +# define _ASM_EXTABLE_UA(from, to) \
> + _ASM_EXTABLE_HANDLE(from, to, ex_handler_uaccess)
> +
> +# define _ASM_EXTABLE_FAULT(from, to) \
> + _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
> +
> +# define _ASM_EXTABLE_EX(from, to) \
> + _ASM_EXTABLE_HANDLE(from, to, ex_handler_ext)
> +
> +# define _ASM_EXTABLE_REFCOUNT(from, to) \
> + _ASM_EXTABLE_HANDLE(from, to, ex_handler_refcount)
> +
> +/* For C file, we already have NOKPROBE_SYMBOL macro */
> +#endif
>
> #ifndef __ASSEMBLY__
> /*
> diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
> index 5090035..6804d66 100644
> --- a/arch/x86/include/asm/bug.h
> +++ b/arch/x86/include/asm/bug.h
> @@ -4,8 +4,6 @@
>
> #include <linux/stringify.h>
>
> -#ifndef __ASSEMBLY__
> -
> /*
> * Despite that some emulators terminate on UD2, we use it for WARN().
> *
> @@ -22,15 +20,53 @@
>
> #define LEN_UD2 2
>
> +#ifdef CONFIG_GENERIC_BUG
> +
> +#ifdef CONFIG_X86_32
> +# define __BUG_REL(val) ".long " __stringify(val)
> +#else
> +# define __BUG_REL(val) ".long " __stringify(val) " - 2b"
> +#endif
> +
> +#ifdef CONFIG_DEBUG_BUGVERBOSE
> +
> +#define _BUG_FLAGS(ins, flags) \
> +do { \
> + asm volatile("1:\t" ins "\n" \
> + ".pushsection __bug_table,\"aw\"\n" \
> + "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \
> + "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \
> + "\t.word %c1" "\t# bug_entry::line\n" \
> + "\t.word %c2" "\t# bug_entry::flags\n" \
> + "\t.org 2b+%c3\n" \
> + ".popsection" \
> + : : "i" (__FILE__), "i" (__LINE__), \
> + "i" (flags), \
> + "i" (sizeof(struct bug_entry))); \
> +} while (0)
> +
> +#else /* !CONFIG_DEBUG_BUGVERBOSE */
> +
> #define _BUG_FLAGS(ins, flags) \
> do { \
> - asm volatile("ASM_BUG ins=\"" ins "\" file=%c0 line=%c1 " \
> - "flags=%c2 size=%c3" \
> - : : "i" (__FILE__), "i" (__LINE__), \
> - "i" (flags), \
> + asm volatile("1:\t" ins "\n" \
> + ".pushsection __bug_table,\"aw\"\n" \
> + "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \
> + "\t.word %c0" "\t# bug_entry::flags\n" \
> + "\t.org 2b+%c1\n" \
> + ".popsection" \
> + : : "i" (flags), \
> "i" (sizeof(struct bug_entry))); \
> } while (0)
>
> +#endif /* CONFIG_DEBUG_BUGVERBOSE */
> +
> +#else
> +
> +#define _BUG_FLAGS(ins, flags) asm volatile(ins)
> +
> +#endif /* CONFIG_GENERIC_BUG */
> +
> #define HAVE_ARCH_BUG
> #define BUG() \
> do { \
> @@ -46,54 +82,4 @@ do { \
>
> #include <asm-generic/bug.h>
>
> -#else /* __ASSEMBLY__ */
> -
> -#ifdef CONFIG_GENERIC_BUG
> -
> -#ifdef CONFIG_X86_32
> -.macro __BUG_REL val:req
> - .long \val
> -.endm
> -#else
> -.macro __BUG_REL val:req
> - .long \val - 2b
> -.endm
> -#endif
> -
> -#ifdef CONFIG_DEBUG_BUGVERBOSE
> -
> -.macro ASM_BUG ins:req file:req line:req flags:req size:req
> -1: \ins
> - .pushsection __bug_table,"aw"
> -2: __BUG_REL val=1b # bug_entry::bug_addr
> - __BUG_REL val=\file # bug_entry::file
> - .word \line # bug_entry::line
> - .word \flags # bug_entry::flags
> - .org 2b+\size
> - .popsection
> -.endm
> -
> -#else /* !CONFIG_DEBUG_BUGVERBOSE */
> -
> -.macro ASM_BUG ins:req file:req line:req flags:req size:req
> -1: \ins
> - .pushsection __bug_table,"aw"
> -2: __BUG_REL val=1b # bug_entry::bug_addr
> - .word \flags # bug_entry::flags
> - .org 2b+\size
> - .popsection
> -.endm
> -
> -#endif /* CONFIG_DEBUG_BUGVERBOSE */
> -
> -#else /* CONFIG_GENERIC_BUG */
> -
> -.macro ASM_BUG ins:req file:req line:req flags:req size:req
> - \ins
> -.endm
> -
> -#endif /* CONFIG_GENERIC_BUG */
> -
> -#endif /* __ASSEMBLY__ */
> -
> #endif /* _ASM_X86_BUG_H */
> diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
> index 7d44272..aced6c9 100644
> --- a/arch/x86/include/asm/cpufeature.h
> +++ b/arch/x86/include/asm/cpufeature.h
> @@ -2,10 +2,10 @@
> #ifndef _ASM_X86_CPUFEATURE_H
> #define _ASM_X86_CPUFEATURE_H
>
> -#ifdef __KERNEL__
> -#ifndef __ASSEMBLY__
> -
> #include <asm/processor.h>
> +
> +#if defined(__KERNEL__) && !defined(__ASSEMBLY__)
> +
> #include <asm/asm.h>
> #include <linux/bitops.h>
>
> @@ -161,10 +161,37 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
> */
> static __always_inline __pure bool _static_cpu_has(u16 bit)
> {
> - asm_volatile_goto("STATIC_CPU_HAS bitnum=%[bitnum] "
> - "cap_byte=\"%[cap_byte]\" "
> - "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 */
> + " .byte 3b - 2b\n" /* pad len */
> + ".previous\n"
> + ".section .altinstr_replacement,\"ax\"\n"
> + "4: jmp %l[t_no]\n"
> + "5:\n"
> + ".previous\n"
> + ".section .altinstructions,\"a\"\n"
> + " .long 1b - .\n" /* src offset */
> + " .long 0\n" /* no replacement */
> + " .word %P[feature]\n" /* feature bit */
> + " .byte 3b - 1b\n" /* src len */
> + " .byte 0\n" /* repl len */
> + " .byte 0\n" /* pad len */
> + ".previous\n"
> + ".section .altinstr_aux,\"ax\"\n"
> + "6:\n"
> + " testb %[bitnum],%[cap_byte]\n"
> + " jnz %l[t_yes]\n"
> + " jmp %l[t_no]\n"
> + ".previous\n"
> : : [feature] "i" (bit),
> [always] "i" (X86_FEATURE_ALWAYS),
> [bitnum] "i" (1 << (bit & 7)),
> @@ -199,44 +226,5 @@ static __always_inline __pure bool _static_cpu_has(u16 bit)
> #define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
> boot_cpu_data.x86_model
>
> -#else /* __ASSEMBLY__ */
> -
> -.macro STATIC_CPU_HAS bitnum:req cap_byte:req feature:req t_yes:req t_no:req always:req
> -1:
> - jmp 6f
> -2:
> - .skip -(((5f-4f) - (2b-1b)) > 0) * ((5f-4f) - (2b-1b)),0x90
> -3:
> - .section .altinstructions,"a"
> - .long 1b - . /* src offset */
> - .long 4f - . /* repl offset */
> - .word \always /* always replace */
> - .byte 3b - 1b /* src len */
> - .byte 5f - 4f /* repl len */
> - .byte 3b - 2b /* pad len */
> - .previous
> - .section .altinstr_replacement,"ax"
> -4:
> - jmp \t_no
> -5:
> - .previous
> - .section .altinstructions,"a"
> - .long 1b - . /* src offset */
> - .long 0 /* no replacement */
> - .word \feature /* feature bit */
> - .byte 3b - 1b /* src len */
> - .byte 0 /* repl len */
> - .byte 0 /* pad len */
> - .previous
> - .section .altinstr_aux,"ax"
> -6:
> - testb \bitnum,\cap_byte
> - jnz \t_yes
> - jmp \t_no
> - .previous
> -.endm
> -
> -#endif /* __ASSEMBLY__ */
> -
> -#endif /* __KERNEL__ */
> +#endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */
> #endif /* _ASM_X86_CPUFEATURE_H */
> diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h
> index a5fb34f..21efc9d 100644
> --- a/arch/x86/include/asm/jump_label.h
> +++ b/arch/x86/include/asm/jump_label.h
> @@ -2,6 +2,19 @@
> #ifndef _ASM_X86_JUMP_LABEL_H
> #define _ASM_X86_JUMP_LABEL_H
>
> +#ifndef HAVE_JUMP_LABEL
> +/*
> + * For better or for worse, if jump labels (the gcc extension) are missing,
> + * then the entire static branch patching infrastructure is compiled out.
> + * If that happens, the code in here will malfunction. Raise a compiler
> + * error instead.
> + *
> + * In theory, jump labels and the static branch patching infrastructure
> + * could be decoupled to fix this.
> + */
> +#error asm/jump_label.h included on a non-jump-label kernel
> +#endif
> +
> #define JUMP_LABEL_NOP_SIZE 5
>
> #ifdef CONFIG_X86_64
> @@ -20,9 +33,15 @@
>
> static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
> {
> - asm_volatile_goto("STATIC_BRANCH_NOP l_yes=\"%l[l_yes]\" key=\"%c0\" "
> - "branch=\"%c1\""
> - : : "i" (key), "i" (branch) : : l_yes);
> + asm_volatile_goto("1:"
> + ".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
> + ".pushsection __jump_table, \"aw\" \n\t"
> + _ASM_ALIGN "\n\t"
> + ".long 1b - ., %l[l_yes] - . \n\t"
> + _ASM_PTR "%c0 + %c1 - .\n\t"
> + ".popsection \n\t"
> + : : "i" (key), "i" (branch) : : l_yes);
> +
> return false;
> l_yes:
> return true;
> @@ -30,8 +49,14 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran
>
> static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
> {
> - asm_volatile_goto("STATIC_BRANCH_JMP l_yes=\"%l[l_yes]\" key=\"%c0\" "
> - "branch=\"%c1\""
> + asm_volatile_goto("1:"
> + ".byte 0xe9\n\t .long %l[l_yes] - 2f\n\t"
> + "2:\n\t"
> + ".pushsection __jump_table, \"aw\" \n\t"
> + _ASM_ALIGN "\n\t"
> + ".long 1b - ., %l[l_yes] - . \n\t"
> + _ASM_PTR "%c0 + %c1 - .\n\t"
> + ".popsection \n\t"
> : : "i" (key), "i" (branch) : : l_yes);
>
> return false;
> @@ -41,26 +66,37 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool
>
> #else /* __ASSEMBLY__ */
>
> -.macro STATIC_BRANCH_NOP l_yes:req key:req branch:req
> -.Lstatic_branch_nop_\@:
> - .byte STATIC_KEY_INIT_NOP
> -.Lstatic_branch_no_after_\@:
> +.macro STATIC_JUMP_IF_TRUE target, key, def
> +.Lstatic_jump_\@:
> + .if \def
> + /* Equivalent to "jmp.d32 \target" */
> + .byte 0xe9
> + .long \target - .Lstatic_jump_after_\@
> +.Lstatic_jump_after_\@:
> + .else
> + .byte STATIC_KEY_INIT_NOP
> + .endif
> .pushsection __jump_table, "aw"
> _ASM_ALIGN
> - .long .Lstatic_branch_nop_\@ - ., \l_yes - .
> - _ASM_PTR \key + \branch - .
> + .long .Lstatic_jump_\@ - ., \target - .
> + _ASM_PTR \key - .
> .popsection
> .endm
>
> -.macro STATIC_BRANCH_JMP l_yes:req key:req branch:req
> -.Lstatic_branch_jmp_\@:
> - .byte 0xe9
> - .long \l_yes - .Lstatic_branch_jmp_after_\@
> -.Lstatic_branch_jmp_after_\@:
> +.macro STATIC_JUMP_IF_FALSE target, key, def
> +.Lstatic_jump_\@:
> + .if \def
> + .byte STATIC_KEY_INIT_NOP
> + .else
> + /* Equivalent to "jmp.d32 \target" */
> + .byte 0xe9
> + .long \target - .Lstatic_jump_after_\@
> +.Lstatic_jump_after_\@:
> + .endif
> .pushsection __jump_table, "aw"
> _ASM_ALIGN
> - .long .Lstatic_branch_jmp_\@ - ., \l_yes - .
> - _ASM_PTR \key + \branch - .
> + .long .Lstatic_jump_\@ - ., \target - .
> + _ASM_PTR \key + 1 - .
> .popsection
> .endm
>
> diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
> index 26942ad..488c596 100644
> --- a/arch/x86/include/asm/paravirt_types.h
> +++ b/arch/x86/include/asm/paravirt_types.h
> @@ -348,11 +348,23 @@ extern struct paravirt_patch_template pv_ops;
> #define paravirt_clobber(clobber) \
> [paravirt_clobber] "i" (clobber)
>
> +/*
> + * Generate some code, and mark it as patchable by the
> + * apply_paravirt() alternate instruction patcher.
> + */
> +#define _paravirt_alt(insn_string, type, clobber) \
> + "771:\n\t" insn_string "\n" "772:\n" \
> + ".pushsection .parainstructions,\"a\"\n" \
> + _ASM_ALIGN "\n" \
> + _ASM_PTR " 771b\n" \
> + " .byte " type "\n" \
> + " .byte 772b-771b\n" \
> + " .short " clobber "\n" \
> + ".popsection\n"
> +
> /* Generate patchable code, with the default asm parameters. */
> -#define paravirt_call \
> - "PARAVIRT_CALL type=\"%c[paravirt_typenum]\"" \
> - " clobber=\"%c[paravirt_clobber]\"" \
> - " pv_opptr=\"%c[paravirt_opptr]\";"
> +#define paravirt_alt(insn_string) \
> + _paravirt_alt(insn_string, "%c[paravirt_typenum]", "%c[paravirt_clobber]")
>
> /* Simple instruction patching code. */
> #define NATIVE_LABEL(a,x,b) "\n\t.globl " a #x "_" #b "\n" a #x "_" #b ":\n\t"
> @@ -373,6 +385,16 @@ unsigned native_patch(u8 type, void *ibuf, unsigned long addr, unsigned len);
> int paravirt_disable_iospace(void);
>
> /*
> + * This generates an indirect call based on the operation type number.
> + * The type number, computed in PARAVIRT_PATCH, is derived from the
> + * offset into the paravirt_patch_template structure, and can therefore be
> + * freely converted back into a structure offset.
> + */
> +#define PARAVIRT_CALL \
> + ANNOTATE_RETPOLINE_SAFE \
> + "call *%c[paravirt_opptr];"
> +
> +/*
> * These macros are intended to wrap calls through one of the paravirt
> * ops structs, so that they can be later identified and patched at
> * runtime.
> @@ -509,7 +531,7 @@ int paravirt_disable_iospace(void);
> /* since this condition will never hold */ \
> if (sizeof(rettype) > sizeof(unsigned long)) { \
> asm volatile(pre \
> - paravirt_call \
> + paravirt_alt(PARAVIRT_CALL) \
> post \
> : call_clbr, ASM_CALL_CONSTRAINT \
> : paravirt_type(op), \
> @@ -519,7 +541,7 @@ int paravirt_disable_iospace(void);
> __ret = (rettype)((((u64)__edx) << 32) | __eax); \
> } else { \
> asm volatile(pre \
> - paravirt_call \
> + paravirt_alt(PARAVIRT_CALL) \
> post \
> : call_clbr, ASM_CALL_CONSTRAINT \
> : paravirt_type(op), \
> @@ -546,7 +568,7 @@ int paravirt_disable_iospace(void);
> PVOP_VCALL_ARGS; \
> PVOP_TEST_NULL(op); \
> asm volatile(pre \
> - paravirt_call \
> + paravirt_alt(PARAVIRT_CALL) \
> post \
> : call_clbr, ASM_CALL_CONSTRAINT \
> : paravirt_type(op), \
> @@ -664,26 +686,6 @@ struct paravirt_patch_site {
> extern struct paravirt_patch_site __parainstructions[],
> __parainstructions_end[];
>
> -#else /* __ASSEMBLY__ */
> -
> -/*
> - * This generates an indirect call based on the operation type number.
> - * The type number, computed in PARAVIRT_PATCH, is derived from the
> - * offset into the paravirt_patch_template structure, and can therefore be
> - * freely converted back into a structure offset.
> - */
> -.macro PARAVIRT_CALL type:req clobber:req pv_opptr:req
> -771: ANNOTATE_RETPOLINE_SAFE
> - call *\pv_opptr
> -772: .pushsection .parainstructions,"a"
> - _ASM_ALIGN
> - _ASM_PTR 771b
> - .byte \type
> - .byte 772b-771b
> - .short \clobber
> - .popsection
> -.endm
> -
> #endif /* __ASSEMBLY__ */
>
> #endif /* _ASM_X86_PARAVIRT_TYPES_H */
> diff --git a/arch/x86/include/asm/refcount.h b/arch/x86/include/asm/refcount.h
> index a8b5e1e..dbaed55 100644
> --- a/arch/x86/include/asm/refcount.h
> +++ b/arch/x86/include/asm/refcount.h
> @@ -4,41 +4,6 @@
> * x86-specific implementation of refcount_t. Based on PAX_REFCOUNT from
> * PaX/grsecurity.
> */
> -
> -#ifdef __ASSEMBLY__
> -
> -#include <asm/asm.h>
> -#include <asm/bug.h>
> -
> -.macro REFCOUNT_EXCEPTION counter:req
> - .pushsection .text..refcount
> -111: lea \counter, %_ASM_CX
> -112: ud2
> - ASM_UNREACHABLE
> - .popsection
> -113: _ASM_EXTABLE_REFCOUNT(112b, 113b)
> -.endm
> -
> -/* Trigger refcount exception if refcount result is negative. */
> -.macro REFCOUNT_CHECK_LT_ZERO counter:req
> - js 111f
> - REFCOUNT_EXCEPTION counter="\counter"
> -.endm
> -
> -/* Trigger refcount exception if refcount result is zero or negative. */
> -.macro REFCOUNT_CHECK_LE_ZERO counter:req
> - jz 111f
> - REFCOUNT_CHECK_LT_ZERO counter="\counter"
> -.endm
> -
> -/* Trigger refcount exception unconditionally. */
> -.macro REFCOUNT_ERROR counter:req
> - jmp 111f
> - REFCOUNT_EXCEPTION counter="\counter"
> -.endm
> -
> -#else /* __ASSEMBLY__ */
> -
> #include <linux/refcount.h>
> #include <asm/bug.h>
>
> @@ -50,12 +15,35 @@
> * central refcount exception. The fixup address for the exception points
> * back to the regular execution flow in .text.
> */
> +#define _REFCOUNT_EXCEPTION \
> + ".pushsection .text..refcount\n" \
> + "111:\tlea %[var], %%" _ASM_CX "\n" \
> + "112:\t" ASM_UD2 "\n" \
> + ASM_UNREACHABLE \
> + ".popsection\n" \
> + "113:\n" \
> + _ASM_EXTABLE_REFCOUNT(112b, 113b)
> +
> +/* Trigger refcount exception if refcount result is negative. */
> +#define REFCOUNT_CHECK_LT_ZERO \
> + "js 111f\n\t" \
> + _REFCOUNT_EXCEPTION
> +
> +/* Trigger refcount exception if refcount result is zero or negative. */
> +#define REFCOUNT_CHECK_LE_ZERO \
> + "jz 111f\n\t" \
> + REFCOUNT_CHECK_LT_ZERO
> +
> +/* Trigger refcount exception unconditionally. */
> +#define REFCOUNT_ERROR \
> + "jmp 111f\n\t" \
> + _REFCOUNT_EXCEPTION
>
> static __always_inline void refcount_add(unsigned int i, refcount_t *r)
> {
> asm volatile(LOCK_PREFIX "addl %1,%0\n\t"
> - "REFCOUNT_CHECK_LT_ZERO counter=\"%[counter]\""
> - : [counter] "+m" (r->refs.counter)
> + REFCOUNT_CHECK_LT_ZERO
> + : [var] "+m" (r->refs.counter)
> : "ir" (i)
> : "cc", "cx");
> }
> @@ -63,32 +51,31 @@ static __always_inline void refcount_add(unsigned int i, refcount_t *r)
> static __always_inline void refcount_inc(refcount_t *r)
> {
> asm volatile(LOCK_PREFIX "incl %0\n\t"
> - "REFCOUNT_CHECK_LT_ZERO counter=\"%[counter]\""
> - : [counter] "+m" (r->refs.counter)
> + REFCOUNT_CHECK_LT_ZERO
> + : [var] "+m" (r->refs.counter)
> : : "cc", "cx");
> }
>
> static __always_inline void refcount_dec(refcount_t *r)
> {
> asm volatile(LOCK_PREFIX "decl %0\n\t"
> - "REFCOUNT_CHECK_LE_ZERO counter=\"%[counter]\""
> - : [counter] "+m" (r->refs.counter)
> + REFCOUNT_CHECK_LE_ZERO
> + : [var] "+m" (r->refs.counter)
> : : "cc", "cx");
> }
>
> static __always_inline __must_check
> bool refcount_sub_and_test(unsigned int i, refcount_t *r)
> {
> -
> return GEN_BINARY_SUFFIXED_RMWcc(LOCK_PREFIX "subl",
> - "REFCOUNT_CHECK_LT_ZERO counter=\"%[var]\"",
> + REFCOUNT_CHECK_LT_ZERO,
> r->refs.counter, e, "er", i, "cx");
> }
>
> static __always_inline __must_check bool refcount_dec_and_test(refcount_t *r)
> {
> return GEN_UNARY_SUFFIXED_RMWcc(LOCK_PREFIX "decl",
> - "REFCOUNT_CHECK_LT_ZERO counter=\"%[var]\"",
> + REFCOUNT_CHECK_LT_ZERO,
> r->refs.counter, e, "cx");
> }
>
> @@ -106,8 +93,8 @@ bool refcount_add_not_zero(unsigned int i, refcount_t *r)
>
> /* Did we try to increment from/to an undesirable state? */
> if (unlikely(c < 0 || c == INT_MAX || result < c)) {
> - asm volatile("REFCOUNT_ERROR counter=\"%[counter]\""
> - : : [counter] "m" (r->refs.counter)
> + asm volatile(REFCOUNT_ERROR
> + : : [var] "m" (r->refs.counter)
> : "cc", "cx");
> break;
> }
> @@ -122,6 +109,4 @@ static __always_inline __must_check bool refcount_inc_not_zero(refcount_t *r)
> return refcount_add_not_zero(1, r);
> }
>
> -#endif /* __ASSEMBLY__ */
> -
> #endif
> diff --git a/arch/x86/kernel/macros.S b/arch/x86/kernel/macros.S
> deleted file mode 100644
> index 161c950..0000000
> --- a/arch/x86/kernel/macros.S
> +++ /dev/null
> @@ -1,16 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -
> -/*
> - * This file includes headers whose assembly part includes macros which are
> - * commonly used. The macros are precompiled into assmebly file which is later
> - * assembled together with each compiled file.
> - */
> -
> -#include <linux/compiler.h>
> -#include <asm/refcount.h>
> -#include <asm/alternative-asm.h>
> -#include <asm/bug.h>
> -#include <asm/paravirt.h>
> -#include <asm/asm.h>
> -#include <asm/cpufeature.h>
> -#include <asm/jump_label.h>
> diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
> index cdafa5e..20561a6 100644
> --- a/include/asm-generic/bug.h
> +++ b/include/asm-generic/bug.h
> @@ -17,8 +17,10 @@
> #ifndef __ASSEMBLY__
> #include <linux/kernel.h>
>
> -struct bug_entry {
> +#ifdef CONFIG_BUG
> +
> #ifdef CONFIG_GENERIC_BUG
> +struct bug_entry {
> #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
> unsigned long bug_addr;
> #else
> @@ -33,10 +35,8 @@ struct bug_entry {
> unsigned short line;
> #endif
> unsigned short flags;
> -#endif /* CONFIG_GENERIC_BUG */
> };
> -
> -#ifdef CONFIG_BUG
> +#endif /* CONFIG_GENERIC_BUG */
>
> /*
> * Don't use BUG() or BUG_ON() unless there's really no way out; one
> diff --git a/include/linux/compiler.h b/include/linux/compiler.h
> index 06396c1..fc5004a 100644
> --- a/include/linux/compiler.h
> +++ b/include/linux/compiler.h
> @@ -99,13 +99,22 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
> * unique, to convince GCC not to merge duplicate inline asm statements.
> */
> #define annotate_reachable() ({ \
> - asm volatile("ANNOTATE_REACHABLE counter=%c0" \
> - : : "i" (__COUNTER__)); \
> + asm volatile("%c0:\n\t" \
> + ".pushsection .discard.reachable\n\t" \
> + ".long %c0b - .\n\t" \
> + ".popsection\n\t" : : "i" (__COUNTER__)); \
> })
> #define annotate_unreachable() ({ \
> - asm volatile("ANNOTATE_UNREACHABLE counter=%c0" \
> - : : "i" (__COUNTER__)); \
> + asm volatile("%c0:\n\t" \
> + ".pushsection .discard.unreachable\n\t" \
> + ".long %c0b - .\n\t" \
> + ".popsection\n\t" : : "i" (__COUNTER__)); \
> })
> +#define ASM_UNREACHABLE \
> + "999:\n\t" \
> + ".pushsection .discard.unreachable\n\t" \
> + ".long 999b - .\n\t" \
> + ".popsection\n\t"
> #else
> #define annotate_reachable()
> #define annotate_unreachable()
> @@ -293,45 +302,6 @@ static inline void *offset_to_ptr(const int *off)
> return (void *)((unsigned long)off + *off);
> }
>
> -#else /* __ASSEMBLY__ */
> -
> -#ifdef __KERNEL__
> -#ifndef LINKER_SCRIPT
> -
> -#ifdef CONFIG_STACK_VALIDATION
> -.macro ANNOTATE_UNREACHABLE counter:req
> -\counter:
> - .pushsection .discard.unreachable
> - .long \counter\()b -.
> - .popsection
> -.endm
> -
> -.macro ANNOTATE_REACHABLE counter:req
> -\counter:
> - .pushsection .discard.reachable
> - .long \counter\()b -.
> - .popsection
> -.endm
> -
> -.macro ASM_UNREACHABLE
> -999:
> - .pushsection .discard.unreachable
> - .long 999b - .
> - .popsection
> -.endm
> -#else /* CONFIG_STACK_VALIDATION */
> -.macro ANNOTATE_UNREACHABLE counter:req
> -.endm
> -
> -.macro ANNOTATE_REACHABLE counter:req
> -.endm
> -
> -.macro ASM_UNREACHABLE
> -.endm
> -#endif /* CONFIG_STACK_VALIDATION */
> -
> -#endif /* LINKER_SCRIPT */
> -#endif /* __KERNEL__ */
> #endif /* __ASSEMBLY__ */
>
> /* Compile time object size, -1 for unknown */
> diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
> index bb01555..3d09844 100644
> --- a/scripts/Kbuild.include
> +++ b/scripts/Kbuild.include
> @@ -115,9 +115,7 @@ __cc-option = $(call try-run,\
>
> # Do not attempt to build with gcc plugins during cc-option tests.
> # (And this uses delayed resolution so the flags will be up to date.)
> -# In addition, do not include the asm macros which are built later.
> -CC_OPTION_FILTERED = $(GCC_PLUGINS_CFLAGS) $(ASM_MACRO_FLAGS)
> -CC_OPTION_CFLAGS = $(filter-out $(CC_OPTION_FILTERED),$(KBUILD_CFLAGS))
> +CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
>
> # cc-option
> # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
> diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile
> index a5b4af4..42c5d50 100644
> --- a/scripts/mod/Makefile
> +++ b/scripts/mod/Makefile
> @@ -4,8 +4,6 @@ OBJECT_FILES_NON_STANDARD := y
> hostprogs-y := modpost mk_elfconfig
> always := $(hostprogs-y) empty.o
>
> -CFLAGS_REMOVE_empty.o := $(ASM_MACRO_FLAGS)
> -
> modpost-objs := modpost.o file2alias.o sumversion.o
>
> devicetable-offsets-file := devicetable-offsets.h
> --
> 2.7.4
>