diff options
Diffstat (limited to 'include/asm-generic/vmlinux.lds.h')
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 81 |
1 files changed, 49 insertions, 32 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 8a9a2e732a65..a464ff6c1a61 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -87,39 +87,56 @@ #define ALIGN_FUNCTION() . = ALIGN(CONFIG_FUNCTION_ALIGNMENT) /* - * LD_DEAD_CODE_DATA_ELIMINATION option enables -fdata-sections, which - * generates .data.identifier sections, which need to be pulled in with - * .data. We don't want to pull in .data..other sections, which Linux - * has defined. Same for text and bss. + * Support -ffunction-sections by matching .text and .text.*, + * but exclude '.text..*', .text.startup[.*], and .text.exit[.*]. * - * With LTO_CLANG, the linker also splits sections by default, so we need - * these macros to combine the sections during the final link. + * .text.startup and .text.startup.* are matched later by INIT_TEXT, and + * .text.exit and .text.exit.* are matched later by EXIT_TEXT, so they must be + * explicitly excluded here. * - * With AUTOFDO_CLANG and PROPELLER_CLANG, by default, the linker splits - * text sections and regroups functions into subsections. + * Other .text.* sections that are typically grouped separately, such as + * .text.unlikely or .text.hot, must be matched explicitly before using + * TEXT_MAIN. * - * RODATA_MAIN is not used because existing code already defines .rodata.x - * sections to be brought in with rodata. + * NOTE: builds *with* and *without* -ffunction-sections are both supported by + * this single macro. Even with -ffunction-sections, there may be some objects + * NOT compiled with the flag due to the use of a specific Makefile override + * like cflags-y or AUTOFDO_PROFILE_foo.o. So this single catchall rule is + * needed to support mixed object builds. + * + * One implication is that functions named startup(), exit(), split(), + * unlikely(), hot(), and unknown() are not allowed in the kernel due to the + * ambiguity of their section names with -ffunction-sections. For example, + * .text.startup could be __attribute__((constructor)) code in a *non* + * ffunction-sections object, which should be placed in .init.text; or it could + * be an actual function named startup() in an ffunction-sections object, which + * should be placed in .text. The build will detect and complain about any such + * ambiguously named functions. + */ +#define TEXT_MAIN \ + .text \ + .text.[_0-9A-Za-df-rt-z]* \ + .text.s[_0-9A-Za-su-z]* .text.s .text.s.* \ + .text.st[_0-9A-Zb-z]* .text.st .text.st.* \ + .text.sta[_0-9A-Za-qs-z]* .text.sta .text.sta.* \ + .text.star[_0-9A-Za-su-z]* .text.star .text.star.* \ + .text.start[_0-9A-Za-tv-z]* .text.start .text.start.* \ + .text.startu[_0-9A-Za-oq-z]* .text.startu .text.startu.* \ + .text.startup[_0-9A-Za-z]* \ + .text.e[_0-9A-Za-wy-z]* .text.e .text.e.* \ + .text.ex[_0-9A-Za-hj-z]* .text.ex .text.ex.* \ + .text.exi[_0-9A-Za-su-z]* .text.exi .text.exi.* \ + .text.exit[_0-9A-Za-z]* + +/* + * Support -fdata-sections by matching .data, .data.*, and others, + * but exclude '.data..*'. */ -#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG) || \ -defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) -#define TEXT_MAIN .text .text.[0-9a-zA-Z_]* -#else -#define TEXT_MAIN .text -#endif -#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG) #define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data.rel.* .data..L* .data..compoundliteral* .data.$__unnamed_* .data.$L* #define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]* #define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* .rodata..L* #define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..L* .bss..compoundliteral* #define SBSS_MAIN .sbss .sbss.[0-9a-zA-Z_]* -#else -#define DATA_MAIN .data .data.rel .data.rel.local -#define SDATA_MAIN .sdata -#define RODATA_MAIN .rodata -#define BSS_MAIN .bss -#define SBSS_MAIN .sbss -#endif /* * GCC 4.5 and later have a 32 bytes section alignment for structures. @@ -581,9 +598,8 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) * during second ld run in second ld pass when generating System.map * * TEXT_MAIN here will match symbols with a fixed pattern (for example, - * .text.hot or .text.unlikely) if dead code elimination or - * function-section is enabled. Match these symbols first before - * TEXT_MAIN to ensure they are grouped together. + * .text.hot or .text.unlikely). Match those before TEXT_MAIN to ensure + * they get grouped together. * * Also placing .text.hot section at the beginning of a page, this * would help the TLB performance. @@ -729,16 +745,16 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) #define INIT_TEXT \ *(.init.text .init.text.*) \ - *(.text.startup) + *(.text.startup .text.startup.*) #define EXIT_DATA \ *(.exit.data .exit.data.*) \ *(.fini_array .fini_array.*) \ - *(.dtors .dtors.*) \ + *(.dtors .dtors.*) #define EXIT_TEXT \ *(.exit.text) \ - *(.text.exit) \ + *(.text.exit .text.exit.*) #define EXIT_CALL \ *(.exitcall.exit) @@ -832,7 +848,7 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) /* Required sections not related to debugging. */ #define ELF_DETAILS \ - .modinfo : { *(.modinfo) } \ + .modinfo : { *(.modinfo) . = ALIGN(8); } \ .comment 0 : { *(.comment) } \ .symtab 0 : { *(.symtab) } \ .strtab 0 : { *(.strtab) } \ @@ -955,7 +971,8 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) #define RUNTIME_CONST_VARIABLES \ RUNTIME_CONST(shift, d_hash_shift) \ - RUNTIME_CONST(ptr, dentry_hashtable) + RUNTIME_CONST(ptr, dentry_hashtable) \ + RUNTIME_CONST(ptr, __dentry_cache) /* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */ #define KUNIT_TABLE() \ |