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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-11-26 21:42:40 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-11-26 21:42:40 +0300 |
commit | 1d87200446f1d10dfe9672ca8edb027a82612f8c (patch) | |
tree | 45cc71ff8e4d1bcde9b07ce8203277f2b8982941 /include/linux/linkage.h | |
parent | 5c4a1c090d8676d8b84e2ac40671602be44afdfc (diff) | |
parent | f01ec4fca8207e31b59a010c3de679c833f3a877 (diff) | |
download | linux-1d87200446f1d10dfe9672ca8edb027a82612f8c.tar.xz |
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
"The main changes in this cycle were:
- Cross-arch changes to move the linker sections for NOTES and
EXCEPTION_TABLE into the RO_DATA area, where they belong on most
architectures. (Kees Cook)
- Switch the x86 linker fill byte from x90 (NOP) to 0xcc (INT3), to
trap jumps into the middle of those padding areas instead of
sliding execution. (Kees Cook)
- A thorough cleanup of symbol definitions within x86 assembler code.
The rather randomly named macros got streamlined around a
(hopefully) straightforward naming scheme:
SYM_START(name, linkage, align...)
SYM_END(name, sym_type)
SYM_FUNC_START(name)
SYM_FUNC_END(name)
SYM_CODE_START(name)
SYM_CODE_END(name)
SYM_DATA_START(name)
SYM_DATA_END(name)
etc - with about three times of these basic primitives with some
label, local symbol or attribute variant, expressed via postfixes.
No change in functionality intended. (Jiri Slaby)
- Misc other changes, cleanups and smaller fixes"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits)
x86/entry/64: Remove pointless jump in paranoid_exit
x86/entry/32: Remove unused resume_userspace label
x86/build/vdso: Remove meaningless CFLAGS_REMOVE_*.o
m68k: Convert missed RODATA to RO_DATA
x86/vmlinux: Use INT3 instead of NOP for linker fill bytes
x86/mm: Report actual image regions in /proc/iomem
x86/mm: Report which part of kernel image is freed
x86/mm: Remove redundant address-of operators on addresses
xtensa: Move EXCEPTION_TABLE to RO_DATA segment
powerpc: Move EXCEPTION_TABLE to RO_DATA segment
parisc: Move EXCEPTION_TABLE to RO_DATA segment
microblaze: Move EXCEPTION_TABLE to RO_DATA segment
ia64: Move EXCEPTION_TABLE to RO_DATA segment
h8300: Move EXCEPTION_TABLE to RO_DATA segment
c6x: Move EXCEPTION_TABLE to RO_DATA segment
arm64: Move EXCEPTION_TABLE to RO_DATA segment
alpha: Move EXCEPTION_TABLE to RO_DATA segment
x86/vmlinux: Move EXCEPTION_TABLE to RO_DATA segment
x86/vmlinux: Actually use _etext for the end of the text segment
vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
...
Diffstat (limited to 'include/linux/linkage.h')
-rw-r--r-- | include/linux/linkage.h | 249 |
1 files changed, 241 insertions, 8 deletions
diff --git a/include/linux/linkage.h b/include/linux/linkage.h index 7e020782ade2..9280209d1f62 100644 --- a/include/linux/linkage.h +++ b/include/linux/linkage.h @@ -75,32 +75,61 @@ #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 CONFIG_X86 #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 /* CONFIG_X86 */ #endif /* LINKER_SCRIPT */ +#ifndef CONFIG_X86 #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 +139,215 @@ * 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 +#endif /* CONFIG_X86 */ + +/* === 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 */ |