tools/nolibc: add option to disable runtime

In principle, it is possible to use nolibc for only some object files in
a program. In that case, the startup code in _start and _start_c is not
going to be used. Add the NOLIBC_NO_RUNTIME compile time option to
disable it entirely and also remove anything that depends on it.

Doing this avoids warnings from modpost for UML as the _start_c code
references the main function from the .init.text section while it is not
inside .init itself.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

diff --git a/tools/include/nolibc/arch-arm.h b/tools/include/nolibc/arch-arm.h
index 1f66e7e5a444b2506150f0b4f4f11f296902b2bc..251c4257902820f0e76f066ef570d5b2eae69a54 100644 (file)
--- a/tools/include/nolibc/arch-arm.h
+++ b/tools/include/nolibc/arch-arm.h
@@ -184,6 +184,7 @@
        _arg1;                                                                \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -193,5 +194,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_ARM_H */

diff --git a/tools/include/nolibc/arch-arm64.h b/tools/include/nolibc/arch-arm64.h
index 02a3f74c8ec841e67004a1a3187908966e20f1d4..080a55a7144eece01c5da4f39a82cd5ee8ab0b78 100644 (file)
--- a/tools/include/nolibc/arch-arm64.h
+++ b/tools/include/nolibc/arch-arm64.h
@@ -141,6 +141,7 @@
        _arg1;                                                                \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -150,4 +151,5 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 #endif /* _NOLIBC_ARCH_ARM64_H */

diff --git a/tools/include/nolibc/arch-loongarch.h b/tools/include/nolibc/arch-loongarch.h
index 5511705303ea908209d5a8be62722491c2987f82..c894176c3f89a47f852d053a86883d260d433383 100644 (file)
--- a/tools/include/nolibc/arch-loongarch.h
+++ b/tools/include/nolibc/arch-loongarch.h
@@ -142,6 +142,7 @@
        _arg1;                                                                \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -151,5 +152,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_LOONGARCH_H */

diff --git a/tools/include/nolibc/arch-m68k.h b/tools/include/nolibc/arch-m68k.h
index 6dac1845f2988acce33df11fee6ebc003f545a6d..2a4fbada5e79cd88fb0d782e9bffe9eaba3c5213 100644 (file)
--- a/tools/include/nolibc/arch-m68k.h
+++ b/tools/include/nolibc/arch-m68k.h
@@ -128,6 +128,7 @@
        _num;                                                                 \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 void _start(void);
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -137,5 +138,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_M68K_H */

diff --git a/tools/include/nolibc/arch-mips.h b/tools/include/nolibc/arch-mips.h
index 0cbac63b249adf80ecbf70ba074f9ea5d56d9278..a72506ceec6bd33a0a8e07568b7fecfb47b1fe8d 100644 (file)
--- a/tools/include/nolibc/arch-mips.h
+++ b/tools/include/nolibc/arch-mips.h
@@ -245,6 +245,7 @@
 
 #endif /* _ABIO32 */
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code, note that it's called __start on MIPS */
 void __start(void);
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector __start(void)
@@ -266,5 +267,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector __
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_MIPS_H */

diff --git a/tools/include/nolibc/arch-powerpc.h b/tools/include/nolibc/arch-powerpc.h
index 204564bbcd328ed51a804ecbbdb55d578dee132e..e0c7e0b81f7cd35086f4f8f0ff34c3e00487e991 100644 (file)
--- a/tools/include/nolibc/arch-powerpc.h
+++ b/tools/include/nolibc/arch-powerpc.h
@@ -183,6 +183,7 @@
 #endif
 #endif /* !__powerpc64__ */
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -215,5 +216,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 #endif
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_POWERPC_H */

diff --git a/tools/include/nolibc/arch-riscv.h b/tools/include/nolibc/arch-riscv.h
index 885383a86c38b186bb6eb269e670080b36c9d982..1c00cacf57e15f57d30e4649c09bd8ddd2636e4c 100644 (file)
--- a/tools/include/nolibc/arch-riscv.h
+++ b/tools/include/nolibc/arch-riscv.h
@@ -139,6 +139,7 @@
        _arg1;                                                                \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -152,5 +153,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_RISCV_H */

diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
index df4c3cc713accd45551e07e1f02d3638e49e300e..6237211385c0d8e55d822c52cdbf22fcd4d6691f 100644 (file)
--- a/tools/include/nolibc/arch-s390.h
+++ b/tools/include/nolibc/arch-s390.h
@@ -139,6 +139,7 @@
        _arg1;                                                          \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -155,6 +156,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 struct s390_mmap_arg_struct {
        unsigned long addr;

diff --git a/tools/include/nolibc/arch-sh.h b/tools/include/nolibc/arch-sh.h
index a96b8914607ed2b9cafc1276da7fb1cdcc55d294..7a421197d104d3dad8859d05b67deb9cbb24e51e 100644 (file)
--- a/tools/include/nolibc/arch-sh.h
+++ b/tools/include/nolibc/arch-sh.h
@@ -140,6 +140,7 @@
        _ret;                                                                 \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void _start_wrapper(void);
 void __attribute__((weak,noreturn)) __nolibc_entrypoint __no_stack_protector _start_wrapper(void)
@@ -158,5 +159,6 @@ void __attribute__((weak,noreturn)) __nolibc_entrypoint __no_stack_protector _st
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_SH_H */

diff --git a/tools/include/nolibc/arch-sparc.h b/tools/include/nolibc/arch-sparc.h
index ca420d843e254b831ed74b968f1b53faeab1b13c..2ebb5686e10538c317cfb9f61ab39b446df34960 100644 (file)
--- a/tools/include/nolibc/arch-sparc.h
+++ b/tools/include/nolibc/arch-sparc.h
@@ -152,6 +152,7 @@
        _arg1;                                                                \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -169,6 +170,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 static pid_t getpid(void);
 

diff --git a/tools/include/nolibc/arch-x86.h b/tools/include/nolibc/arch-x86.h
index c8b0c3e624a5183c4379522735e1f6f53930bd43..f6c43ac5377bb21cc71726faa3f9e397c59a973a 100644 (file)
--- a/tools/include/nolibc/arch-x86.h
+++ b/tools/include/nolibc/arch-x86.h
@@ -157,6 +157,7 @@
        _eax;                                                   \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 /*
  * i386 System V ABI mandates:
@@ -176,6 +177,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #else /* !defined(__x86_64__) */
 
@@ -323,6 +325,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
        _ret;                                                                 \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 /*
  * x86-64 System V ABI mandates:
@@ -340,6 +343,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
        );
        __nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #define NOLIBC_ARCH_HAS_MEMMOVE
 void *memmove(void *dst, const void *src, size_t len);

diff --git a/tools/include/nolibc/crt.h b/tools/include/nolibc/crt.h
index 961cfe777c3564e705dfdd581de828b374d05b0b..d9262998dae94b884ad794d687fc5df62e71203d 100644 (file)
--- a/tools/include/nolibc/crt.h
+++ b/tools/include/nolibc/crt.h
@@ -7,6 +7,8 @@
 #ifndef _NOLIBC_CRT_H
 #define _NOLIBC_CRT_H
 
+#ifndef NOLIBC_NO_RUNTIME
+
 #include "compiler.h"
 
 char **environ __attribute__((weak));
@@ -88,4 +90,5 @@ void _start_c(long *sp)
        exit(exitcode);
 }
 
+#endif /* NOLIBC_NO_RUNTIME */
 #endif /* _NOLIBC_CRT_H */

diff --git a/tools/include/nolibc/stackprotector.h b/tools/include/nolibc/stackprotector.h
index c71a2c257177aac9dbf4541b2e104944efa2182c..7123aa056cb09c7013ee1ae5bac3e98a5d17c021 100644 (file)
--- a/tools/include/nolibc/stackprotector.h
+++ b/tools/include/nolibc/stackprotector.h
@@ -9,6 +9,7 @@
 
 #include "compiler.h"
 
+#ifndef NOLIBC_NO_RUNTIME
 #if defined(_NOLIBC_STACKPROTECTOR)
 
 #include "sys.h"
@@ -49,5 +50,6 @@ static __no_stack_protector void __stack_chk_init(void)
 #else /* !defined(_NOLIBC_STACKPROTECTOR) */
 static void __stack_chk_init(void) {}
 #endif /* defined(_NOLIBC_STACKPROTECTOR) */
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_STACKPROTECTOR_H */

diff --git a/tools/include/nolibc/stdlib.h b/tools/include/nolibc/stdlib.h
index 5fd99a480f821210212f08d814a4c09c2c804db8..f184e108ed0aa67ec99c4d9210e60388c9aaf748 100644 (file)
--- a/tools/include/nolibc/stdlib.h
+++ b/tools/include/nolibc/stdlib.h
@@ -100,6 +100,7 @@ void free(void *ptr)
        munmap(heap, heap->len);
 }
 
+#ifndef NOLIBC_NO_RUNTIME
 /* getenv() tries to find the environment variable named <name> in the
  * environment array pointed to by global variable "environ" which must be
  * declared as a char **, and must be terminated by a NULL (it is recommended
@@ -122,6 +123,7 @@ char *getenv(const char *name)
        }
        return NULL;
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 static __attribute__((unused))
 void *malloc(size_t len)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index c5564f57deec88b8aa70291fcf6f9ca4dbc1d03f..386ed80aead008ff258ded5450bde3d4041b94ed 100644 (file)
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -512,6 +512,7 @@ pid_t gettid(void)
        return sys_gettid();
 }
 
+#ifndef NOLIBC_NO_RUNTIME
 static unsigned long getauxval(unsigned long key);
 
 /*
@@ -523,7 +524,7 @@ int getpagesize(void)
 {
        return __sysret((int)getauxval(AT_PAGESZ) ?: -ENOENT);
 }
-
+#endif /* NOLIBC_NO_RUNTIME */
 
 /*
  * uid_t getuid(void);

diff --git a/tools/include/nolibc/sys/auxv.h b/tools/include/nolibc/sys/auxv.h
index c52463d6c18d7a38f40344c1817bef3a4a121e7a..0e98325e73475921c51a96c754254a37e1c41994 100644 (file)
--- a/tools/include/nolibc/sys/auxv.h
+++ b/tools/include/nolibc/sys/auxv.h
@@ -10,6 +10,8 @@
 #ifndef _NOLIBC_SYS_AUXV_H
 #define _NOLIBC_SYS_AUXV_H
 
+#ifndef NOLIBC_NO_RUNTIME
+
 #include "../crt.h"
 
 static __attribute__((unused))
@@ -38,4 +40,5 @@ unsigned long getauxval(unsigned long type)
        return ret;
 }
 
+#endif /* NOLIBC_NO_RUNTIME */
 #endif /* _NOLIBC_SYS_AUXV_H */