On Fri, Oct 11, 2019 at 1:53 PM Jiri Slaby <jslaby@xxxxxxx> wrote: > > Introduce new C macros for annotations of functions and data in > assembly. There is a long-standing mess in macros like ENTRY, END, > ENDPROC and similar. They are used in different manners and sometimes > incorrectly. > > So introduce macros with clear use to annotate assembly as follows: > > a) Support macros for the ones below > SYM_T_FUNC -- type used by assembler to mark functions > SYM_T_OBJECT -- type used by assembler to mark data > SYM_T_NONE -- type used by assembler to mark entries of unknown type > > They are defined as STT_FUNC, STT_OBJECT, and STT_NOTYPE > respectively. According to the gas manual, this is the most portable > way. I am not sure about other assemblers, so this can be switched > back to %function and %object if this turns into a problem. > Architectures can also override them by something like ", @function" > if they need. > > SYM_A_ALIGN, SYM_A_NONE -- align the symbol? > SYM_L_GLOBAL, SYM_L_WEAK, SYM_L_LOCAL -- linkage of symbols > > b) Mostly internal annotations, used by the ones below > SYM_ENTRY -- use only if you have to (for non-paired symbols) > SYM_START -- use only if you have to (for paired symbols) > SYM_END -- use only if you have to (for paired symbols) > > c) Annotations for code > SYM_INNER_LABEL_ALIGN -- only for labels in the middle of code > SYM_INNER_LABEL -- only for labels in the middle of code > > SYM_FUNC_START_LOCAL_ALIAS -- use where there are two local names for > one function > SYM_FUNC_START_ALIAS -- use where there are two global names for one > function > SYM_FUNC_END_ALIAS -- the end of LOCAL_ALIASed or ALIASed function > > SYM_FUNC_START -- use for global functions > SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment > SYM_FUNC_START_LOCAL -- use for local functions > SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o > alignment > SYM_FUNC_START_WEAK -- use for weak functions > SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment > SYM_FUNC_END -- the end of SYM_FUNC_START_LOCAL, SYM_FUNC_START, > SYM_FUNC_START_WEAK, ... > > For functions with special (non-C) calling conventions: > SYM_CODE_START -- use for non-C (special) functions > SYM_CODE_START_NOALIGN -- use for non-C (special) functions, w/o > alignment > SYM_CODE_START_LOCAL -- use for local non-C (special) functions > SYM_CODE_START_LOCAL_NOALIGN -- use for local non-C (special) > functions, w/o alignment > SYM_CODE_END -- the end of SYM_CODE_START_LOCAL or SYM_CODE_START > > d) For data > SYM_DATA_START -- global data symbol > SYM_DATA_START_LOCAL -- local data symbol > SYM_DATA_END -- the end of the SYM_DATA_START symbol > SYM_DATA_END_LABEL -- the labeled end of SYM_DATA_START symbol > SYM_DATA -- start+end wrapper around simple global data > SYM_DATA_LOCAL -- start+end wrapper around simple local data > > ========== > > The macros allow to pair starts and ends of functions and mark functions > correctly in the output ELF objects. > > All users of the old macros in x86 are converted to use these in further > patches. > > Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> > Cc: hpa@xxxxxxxxx > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: jpoimboe@xxxxxxxxxx > Cc: Juergen Gross <jgross@xxxxxxxx> > Cc: Len Brown <len.brown@xxxxxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: linux-pm@xxxxxxxxxxxxxxx > Cc: Borislav Petkov <bp@xxxxxxxxx> > Cc: mingo@xxxxxxxxxx > Cc: Pavel Machek <pavel@xxxxxx> > Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx > Cc: x86@xxxxxxxxxx Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> for all the changes in the series affecting the power management code maintained by me. Thanks! > --- > > Notes: > [v2] > * use SYM_ prefix and sane names > * add SYM_START and SYM_END and parametrize all the macros > > [v3] > * add SYM_DATA, SYM_DATA_LOCAL, and SYM_DATA_END_LABEL > > [v4] > * add _NOALIGN versions of some macros > * add _CODE_ derivates of _FUNC_ macros > > [v5] > * drop "SIMPLE" from data annotations > * switch NOALIGN and ALIGN variants of inner labels > * s/visibility/linkage/; s@SYM_V_@SYM_L_@ > * add Documentation > > [v6] > * fixed typos found by Randy Dunlap > * remove doubled INNER_LABEL macros, one pair was unused > > [v8] > * use lkml.kernel.org for links > * link the docs from index.rst (by Boris) > * fixed typos on the docs > > [v9] > * updated the docs as requested by Boris > > Documentation/asm-annotations.rst | 216 ++++++++++++++++++++++++++ > Documentation/index.rst | 8 + > arch/x86/include/asm/linkage.h | 10 +- > include/linux/linkage.h | 245 +++++++++++++++++++++++++++++- > 4 files changed, 468 insertions(+), 11 deletions(-) > create mode 100644 Documentation/asm-annotations.rst > > diff --git a/Documentation/asm-annotations.rst b/Documentation/asm-annotations.rst > new file mode 100644 > index 000000000000..29ccd6e61fe5 > --- /dev/null > +++ b/Documentation/asm-annotations.rst > @@ -0,0 +1,216 @@ > +Assembler Annotations > +===================== > + > +Copyright (c) 2017-2019 Jiri Slaby > + > +This document describes the new macros for annotation of data and code in > +assembly. In particular, it contains information about ``SYM_FUNC_START``, > +``SYM_FUNC_END``, ``SYM_CODE_START``, and similar. > + > +Rationale > +--------- > +Some code like entries, trampolines, or boot code needs to be written in > +assembly. The same as in C, such code is grouped into functions and > +accompanied with data. Standard assemblers do not force users into precisely > +marking these pieces as code, data, or even specifying their length. > +Nevertheless, assemblers provide developers with such annotations to aid > +debuggers throughout assembly. On top of that, developers also want to mark > +some functions as *global* in order to be visible outside of their translation > +units. > + > +Over time, the Linux kernel has adopted macros from various projects (like > +``binutils``) to facilitate such annotations. So for historic reasons, > +developers have been using ``ENTRY``, ``END``, ``ENDPROC``, and other > +annotations in assembly. Due to the lack of their documentation, the macros > +are used in rather wrong contexts at some locations. Clearly, ``ENTRY`` was > +intended to denote the beginning of global symbols (be it data or code). > +``END`` used to mark the end of data or end of special functions with > +*non-standard* calling convention. In contrast, ``ENDPROC`` should annotate > +only ends of *standard* functions. > + > +When these macros are used correctly, they help assemblers generate a nice > +object with both sizes and types set correctly. For example, the result of > +``arch/x86/lib/putuser.S``:: > + > + Num: Value Size Type Bind Vis Ndx Name > + 25: 0000000000000000 33 FUNC GLOBAL DEFAULT 1 __put_user_1 > + 29: 0000000000000030 37 FUNC GLOBAL DEFAULT 1 __put_user_2 > + 32: 0000000000000060 36 FUNC GLOBAL DEFAULT 1 __put_user_4 > + 35: 0000000000000090 37 FUNC GLOBAL DEFAULT 1 __put_user_8 > + > +This is not only important for debugging purposes. When there are properly > +annotated objects like this, tools can be run on them to generate more useful > +information. In particular, on properly annotated objects, ``objtool`` can be > +run to check and fix the object if needed. Currently, ``objtool`` can report > +missing frame pointer setup/destruction in functions. It can also > +automatically generate annotations for :doc:`ORC unwinder <x86/orc-unwinder>` > +for most code. Both of these are especially important to support reliable > +stack traces which are in turn necessary for :doc:`Kernel live patching > +<livepatch/livepatch>`. > + > +Caveat and Discussion > +--------------------- > +As one might realize, there were only three macros previously. That is indeed > +insufficient to cover all the combinations of cases: > + > +* standard/non-standard function > +* code/data > +* global/local symbol > + > +There was a discussion_ and instead of extending the current ``ENTRY/END*`` > +macros, it was decided that brand new macros should be introduced instead:: > + > + So how about using macro names that actually show the purpose, instead > + of importing all the crappy, historic, essentially randomly chosen > + debug symbol macro names from the binutils and older kernels? > + > +.. _discussion: https://lkml.kernel.org/r/20170217104757.28588-1-jslaby@xxxxxxx > + > +Macros Description > +------------------ > + > +The new macros are prefixed with the ``SYM_`` prefix and can be divided into > +three main groups: > + > +1. ``SYM_FUNC_*`` -- to annotate C-like functions. This means functions with > + standard C calling conventions, i.e. the stack contains a return address at > + the predefined place and a return from the function can happen in a > + standard way. When frame pointers are enabled, save/restore of frame > + pointer shall happen at the start/end of a function, respectively, too. > + > + Checking tools like ``objtool`` should ensure such marked functions conform > + to these rules. The tools can also easily annotate these functions with > + debugging information (like *ORC data*) automatically. > + > +2. ``SYM_CODE_*`` -- special functions called with special stack. Be it > + interrupt handlers with special stack content, trampolines, or startup > + functions. > + > + Checking tools mostly ignore checking of these functions. But some debug > + information still can be generated automatically. For correct debug data, > + this code needs hints like ``UNWIND_HINT_REGS`` provided by developers. > + > +3. ``SYM_DATA*`` -- obviously data belonging to ``.data`` sections and not to > + ``.text``. Data do not contain instructions, so they have to be treated > + specially by the tools: they should not treat the bytes as instructions, > + nor assign any debug information to them. > + > +Instruction Macros > +~~~~~~~~~~~~~~~~~~ > +This section covers ``SYM_FUNC_*`` and ``SYM_CODE_*`` enumerated above. > + > +* ``SYM_FUNC_START`` and ``SYM_FUNC_START_LOCAL`` are supposed to be **the > + most frequent markings**. They are used for functions with standard calling > + conventions -- global and local. Like in C, they both align the functions to > + architecture specific ``__ALIGN`` bytes. There are also ``_NOALIGN`` variants > + for special cases where developers do not want this implicit alignment. > + > + ``SYM_FUNC_START_WEAK`` and ``SYM_FUNC_START_WEAK_NOALIGN`` markings are > + also offered as an assembler counterpart to the *weak* attribute known from > + C. > + > + All of these **shall** be coupled with ``SYM_FUNC_END``. First, it marks > + the sequence of instructions as a function and computes its size to the > + generated object file. Second, it also eases checking and processing such > + object files as the tools can trivially find exact function boundaries. > + > + So in most cases, developers should write something like in the following > + example, having some asm instructions in between the macros, of course:: > + > + SYM_FUNC_START(function_hook) > + ... asm insns ... > + SYM_FUNC_END(function_hook) > + > + In fact, this kind of annotation corresponds to the now deprecated ``ENTRY`` > + and ``ENDPROC`` macros. > + > +* ``SYM_FUNC_START_ALIAS`` and ``SYM_FUNC_START_LOCAL_ALIAS`` serve for those > + who decided to have two or more names for one function. The typical use is:: > + > + SYM_FUNC_START_ALIAS(__memset) > + SYM_FUNC_START(memset) > + ... asm insns ... > + SYM_FUNC_END(memset) > + SYM_FUNC_END_ALIAS(__memset) > + > + In this example, one can call ``__memset`` or ``memset`` with the same > + result, except the debug information for the instructions is generated to > + the object file only once -- for the non-``ALIAS`` case. > + > +* ``SYM_CODE_START`` and ``SYM_CODE_START_LOCAL`` should be used only in > + special cases -- if you know what you are doing. This is used exclusively > + for interrupt handlers and similar where the calling convention is not the C > + one. ``_NOALIGN`` variants exist too. The use is the same as for the ``FUNC`` > + category above:: > + > + SYM_CODE_START_LOCAL(bad_put_user) > + ... asm insns ... > + SYM_CODE_END(bad_put_user) > + > + Again, every ``SYM_CODE_START*`` **shall** be coupled by ``SYM_CODE_END``. > + > + To some extent, this category corresponds to deprecated ``ENTRY`` and > + ``END``. Except ``END`` had several other meanings too. > + > +* ``SYM_INNER_LABEL*`` is used to denote a label inside some > + ``SYM_{CODE,FUNC}_START`` and ``SYM_{CODE,FUNC}_END``. They are very similar > + to C labels, except they can be made global. An example of use:: > + > + SYM_CODE_START(ftrace_caller) > + /* save_mcount_regs fills in first two parameters */ > + ... > + > + SYM_INNER_LABEL(ftrace_caller_op_ptr, SYM_L_GLOBAL) > + /* Load the ftrace_ops into the 3rd parameter */ > + ... > + > + SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) > + call ftrace_stub > + ... > + retq > + SYM_CODE_END(ftrace_caller) > + > +Data Macros > +~~~~~~~~~~~ > +Similar to instructions, there is a couple of macros to describe data in the > +assembly. > + > +* ``SYM_DATA_START`` and ``SYM_DATA_START_LOCAL`` mark the start of some data > + and shall be used in conjunction with either ``SYM_DATA_END``, or > + ``SYM_DATA_END_LABEL``. The latter adds also a label to the end, so that > + people can use ``lstack`` and (local) ``lstack_end`` in the following > + example:: > + > + SYM_DATA_START_LOCAL(lstack) > + .skip 4096 > + SYM_DATA_END_LABEL(lstack, SYM_L_LOCAL, lstack_end) > + > +* ``SYM_DATA`` and ``SYM_DATA_LOCAL`` are variants for simple, mostly one-line > + data:: > + > + SYM_DATA(HEAP, .long rm_heap) > + SYM_DATA(heap_end, .long rm_stack) > + > + In the end, they expand to ``SYM_DATA_START`` with ``SYM_DATA_END`` > + internally. > + > +Support Macros > +~~~~~~~~~~~~~~ > +All the above reduce themselves to some invocation of ``SYM_START``, > +``SYM_END``, or ``SYM_ENTRY`` at last. Normally, developers should avoid using > +these. > + > +Further, in the above examples, one could see ``SYM_L_LOCAL``. There are also > +``SYM_L_GLOBAL`` and ``SYM_L_WEAK``. All are intended to denote linkage of a > +symbol marked by them. They are used either in ``_LABEL`` variants of the > +earlier macros, or in ``SYM_START``. > + > + > +Overriding Macros > +~~~~~~~~~~~~~~~~~ > +Architecture can also override any of the macros in their own > +``asm/linkage.h``, including macros specifying the type of a symbol > +(``SYM_T_FUNC``, ``SYM_T_OBJECT``, and ``SYM_T_NONE``). As every macro > +described in this file is surrounded by ``#ifdef`` + ``#endif``, it is enough > +to define the macros differently in the aforementioned architecture-dependent > +header. > diff --git a/Documentation/index.rst b/Documentation/index.rst > index b843e313d2f2..2ceab197246f 100644 > --- a/Documentation/index.rst > +++ b/Documentation/index.rst > @@ -135,6 +135,14 @@ needed). > mic/index > scheduler/index > > +Architecture-agnostic documentation > +----------------------------------- > + > +.. toctree:: > + :maxdepth: 2 > + > + asm-annotations > + > Architecture-specific documentation > ----------------------------------- > > diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h > index 14caa9d9fb7f..e07188e8d763 100644 > --- a/arch/x86/include/asm/linkage.h > +++ b/arch/x86/include/asm/linkage.h > @@ -13,9 +13,13 @@ > > #ifdef __ASSEMBLY__ > > -#define GLOBAL(name) \ > - .globl name; \ > - name: > +/* > + * GLOBAL is DEPRECATED > + * > + * use SYM_DATA_START, SYM_FUNC_START, SYM_INNER_LABEL, SYM_CODE_START, or > + * similar > + */ > +#define GLOBAL(name) SYM_ENTRY(name, SYM_L_GLOBAL, SYM_A_NONE) > > #if defined(CONFIG_X86_64) || defined(CONFIG_X86_ALIGNMENT_16) > #define __ALIGN .p2align 4, 0x90 > diff --git a/include/linux/linkage.h b/include/linux/linkage.h > index 7e020782ade2..f3ae8f3dea2c 100644 > --- a/include/linux/linkage.h > +++ b/include/linux/linkage.h > @@ -75,32 +75,58 @@ > > #ifdef __ASSEMBLY__ > > +/* SYM_T_FUNC -- type used by assembler to mark functions */ > +#ifndef SYM_T_FUNC > +#define SYM_T_FUNC STT_FUNC > +#endif > + > +/* SYM_T_OBJECT -- type used by assembler to mark data */ > +#ifndef SYM_T_OBJECT > +#define SYM_T_OBJECT STT_OBJECT > +#endif > + > +/* SYM_T_NONE -- type used by assembler to mark entries of unknown type */ > +#ifndef SYM_T_NONE > +#define SYM_T_NONE STT_NOTYPE > +#endif > + > +/* SYM_A_* -- align the symbol? */ > +#define SYM_A_ALIGN ALIGN > +#define SYM_A_NONE /* nothing */ > + > +/* SYM_L_* -- linkage of symbols */ > +#define SYM_L_GLOBAL(name) .globl name > +#define SYM_L_WEAK(name) .weak name > +#define SYM_L_LOCAL(name) /* nothing */ > + > #ifndef LINKER_SCRIPT > #define ALIGN __ALIGN > #define ALIGN_STR __ALIGN_STR > > +/* === DEPRECATED annotations === */ > + > #ifndef GLOBAL > +/* deprecated, use SYM_DATA*, SYM_ENTRY, or similar */ > #define GLOBAL(name) \ > .globl name ASM_NL \ > name: > #endif > > #ifndef ENTRY > +/* deprecated, use SYM_FUNC_START */ > #define ENTRY(name) \ > - .globl name ASM_NL \ > - ALIGN ASM_NL \ > - name: > + SYM_FUNC_START(name) > #endif > #endif /* LINKER_SCRIPT */ > > #ifndef WEAK > +/* deprecated, use SYM_FUNC_START_WEAK* */ > #define WEAK(name) \ > - .weak name ASM_NL \ > - ALIGN ASM_NL \ > - name: > + SYM_FUNC_START_WEAK(name) > #endif > > #ifndef END > +/* deprecated, use SYM_FUNC_END, SYM_DATA_END, or SYM_END */ > #define END(name) \ > .size name, .-name > #endif > @@ -110,11 +136,214 @@ > * static analysis tools such as stack depth analyzer. > */ > #ifndef ENDPROC > +/* deprecated, use SYM_FUNC_END */ > #define ENDPROC(name) \ > - .type name, @function ASM_NL \ > - END(name) > + SYM_FUNC_END(name) > +#endif > + > +/* === generic annotations === */ > + > +/* SYM_ENTRY -- use only if you have to for non-paired symbols */ > +#ifndef SYM_ENTRY > +#define SYM_ENTRY(name, linkage, align...) \ > + linkage(name) ASM_NL \ > + align ASM_NL \ > + name: > +#endif > + > +/* SYM_START -- use only if you have to */ > +#ifndef SYM_START > +#define SYM_START(name, linkage, align...) \ > + SYM_ENTRY(name, linkage, align) > +#endif > + > +/* SYM_END -- use only if you have to */ > +#ifndef SYM_END > +#define SYM_END(name, sym_type) \ > + .type name sym_type ASM_NL \ > + .size name, .-name > +#endif > + > +/* === code annotations === */ > + > +/* > + * FUNC -- C-like functions (proper stack frame etc.) > + * CODE -- non-C code (e.g. irq handlers with different, special stack etc.) > + * > + * Objtool validates stack for FUNC, but not for CODE. > + * Objtool generates debug info for both FUNC & CODE, but needs special > + * annotations for each CODE's start (to describe the actual stack frame). > + * > + * ALIAS -- does not generate debug info -- the aliased function will > + */ > + > +/* SYM_INNER_LABEL_ALIGN -- only for labels in the middle of code */ > +#ifndef SYM_INNER_LABEL_ALIGN > +#define SYM_INNER_LABEL_ALIGN(name, linkage) \ > + .type name SYM_T_NONE ASM_NL \ > + SYM_ENTRY(name, linkage, SYM_A_ALIGN) > +#endif > + > +/* SYM_INNER_LABEL -- only for labels in the middle of code */ > +#ifndef SYM_INNER_LABEL > +#define SYM_INNER_LABEL(name, linkage) \ > + .type name SYM_T_NONE ASM_NL \ > + SYM_ENTRY(name, linkage, SYM_A_NONE) > +#endif > + > +/* > + * SYM_FUNC_START_LOCAL_ALIAS -- use where there are two local names for one > + * function > + */ > +#ifndef SYM_FUNC_START_LOCAL_ALIAS > +#define SYM_FUNC_START_LOCAL_ALIAS(name) \ > + SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) > +#endif > + > +/* > + * SYM_FUNC_START_ALIAS -- use where there are two global names for one > + * function > + */ > +#ifndef SYM_FUNC_START_ALIAS > +#define SYM_FUNC_START_ALIAS(name) \ > + SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) > +#endif > + > +/* SYM_FUNC_START -- use for global functions */ > +#ifndef SYM_FUNC_START > +/* > + * The same as SYM_FUNC_START_ALIAS, but we will need to distinguish these two > + * later. > + */ > +#define SYM_FUNC_START(name) \ > + SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) > +#endif > + > +/* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */ > +#ifndef SYM_FUNC_START_NOALIGN > +#define SYM_FUNC_START_NOALIGN(name) \ > + SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) > +#endif > + > +/* SYM_FUNC_START_LOCAL -- use for local functions */ > +#ifndef SYM_FUNC_START_LOCAL > +/* the same as SYM_FUNC_START_LOCAL_ALIAS, see comment near SYM_FUNC_START */ > +#define SYM_FUNC_START_LOCAL(name) \ > + SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) > #endif > > +/* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */ > +#ifndef SYM_FUNC_START_LOCAL_NOALIGN > +#define SYM_FUNC_START_LOCAL_NOALIGN(name) \ > + SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) > #endif > > +/* SYM_FUNC_START_WEAK -- use for weak functions */ > +#ifndef SYM_FUNC_START_WEAK > +#define SYM_FUNC_START_WEAK(name) \ > + SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN) > #endif > + > +/* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */ > +#ifndef SYM_FUNC_START_WEAK_NOALIGN > +#define SYM_FUNC_START_WEAK_NOALIGN(name) \ > + SYM_START(name, SYM_L_WEAK, SYM_A_NONE) > +#endif > + > +/* SYM_FUNC_END_ALIAS -- the end of LOCAL_ALIASed or ALIASed function */ > +#ifndef SYM_FUNC_END_ALIAS > +#define SYM_FUNC_END_ALIAS(name) \ > + SYM_END(name, SYM_T_FUNC) > +#endif > + > +/* > + * SYM_FUNC_END -- the end of SYM_FUNC_START_LOCAL, SYM_FUNC_START, > + * SYM_FUNC_START_WEAK, ... > + */ > +#ifndef SYM_FUNC_END > +/* the same as SYM_FUNC_END_ALIAS, see comment near SYM_FUNC_START */ > +#define SYM_FUNC_END(name) \ > + SYM_END(name, SYM_T_FUNC) > +#endif > + > +/* SYM_CODE_START -- use for non-C (special) functions */ > +#ifndef SYM_CODE_START > +#define SYM_CODE_START(name) \ > + SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) > +#endif > + > +/* SYM_CODE_START_NOALIGN -- use for non-C (special) functions, w/o alignment */ > +#ifndef SYM_CODE_START_NOALIGN > +#define SYM_CODE_START_NOALIGN(name) \ > + SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) > +#endif > + > +/* SYM_CODE_START_LOCAL -- use for local non-C (special) functions */ > +#ifndef SYM_CODE_START_LOCAL > +#define SYM_CODE_START_LOCAL(name) \ > + SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) > +#endif > + > +/* > + * SYM_CODE_START_LOCAL_NOALIGN -- use for local non-C (special) functions, > + * w/o alignment > + */ > +#ifndef SYM_CODE_START_LOCAL_NOALIGN > +#define SYM_CODE_START_LOCAL_NOALIGN(name) \ > + SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) > +#endif > + > +/* SYM_CODE_END -- the end of SYM_CODE_START_LOCAL, SYM_CODE_START, ... */ > +#ifndef SYM_CODE_END > +#define SYM_CODE_END(name) \ > + SYM_END(name, SYM_T_NONE) > +#endif > + > +/* === data annotations === */ > + > +/* SYM_DATA_START -- global data symbol */ > +#ifndef SYM_DATA_START > +#define SYM_DATA_START(name) \ > + SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) > +#endif > + > +/* SYM_DATA_START -- local data symbol */ > +#ifndef SYM_DATA_START_LOCAL > +#define SYM_DATA_START_LOCAL(name) \ > + SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) > +#endif > + > +/* SYM_DATA_END -- the end of SYM_DATA_START symbol */ > +#ifndef SYM_DATA_END > +#define SYM_DATA_END(name) \ > + SYM_END(name, SYM_T_OBJECT) > +#endif > + > +/* SYM_DATA_END_LABEL -- the labeled end of SYM_DATA_START symbol */ > +#ifndef SYM_DATA_END_LABEL > +#define SYM_DATA_END_LABEL(name, linkage, label) \ > + linkage(label) ASM_NL \ > + .type label SYM_T_OBJECT ASM_NL \ > + label: \ > + SYM_END(name, SYM_T_OBJECT) > +#endif > + > +/* SYM_DATA -- start+end wrapper around simple global data */ > +#ifndef SYM_DATA > +#define SYM_DATA(name, data...) \ > + SYM_DATA_START(name) ASM_NL \ > + data ASM_NL \ > + SYM_DATA_END(name) > +#endif > + > +/* SYM_DATA_LOCAL -- start+end wrapper around simple local data */ > +#ifndef SYM_DATA_LOCAL > +#define SYM_DATA_LOCAL(name, data...) \ > + SYM_DATA_START_LOCAL(name) ASM_NL \ > + data ASM_NL \ > + SYM_DATA_END(name) > +#endif > + > +#endif /* __ASSEMBLY__ */ > + > +#endif /* _LINUX_LINKAGE_H */ > -- > 2.23.0 >
