From ef32e9b6a325d1d013b30d898b4dff94082902cd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Wed, 7 Aug 2024 23:51:41 +0200
Subject: [PATCH] tools/nolibc: move entrypoint specifics to compiler.h
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The specific attributes for the _start entrypoint are duplicated for
each architecture.
Deduplicate it into a dedicated #define into compiler.h.
For clang compatibility, the epilogue will also need to be adapted, so
move that one, too.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-5-c20f2f5fc7c2@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
tools/include/nolibc/arch-aarch64.h | 4 ++--
tools/include/nolibc/arch-arm.h | 4 ++--
tools/include/nolibc/arch-i386.h | 4 ++--
tools/include/nolibc/arch-loongarch.h | 4 ++--
tools/include/nolibc/arch-mips.h | 4 ++--
tools/include/nolibc/arch-powerpc.h | 4 ++--
tools/include/nolibc/arch-riscv.h | 4 ++--
tools/include/nolibc/arch-s390.h | 4 ++--
tools/include/nolibc/arch-x86_64.h | 4 ++--
tools/include/nolibc/compiler.h | 3 +++
10 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/tools/include/nolibc/arch-aarch64.h b/tools/include/nolibc/arch-aarch64.h
index b23ac1f04035..06fdef7b291a 100644
--- a/tools/include/nolibc/arch-aarch64.h
+++ b/tools/include/nolibc/arch-aarch64.h
@@ -142,13 +142,13 @@
})
/* startup code */
-void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
{
__asm__ volatile (
"mov x0, sp\n" /* save stack pointer to x0, as arg1 of _start_c */
"and sp, x0, -16\n" /* sp must be 16-byte aligned in the callee */
"bl _start_c\n" /* transfer to c runtime */
);
- __builtin_unreachable();
+ __nolibc_entrypoint_epilogue();
}
#endif /* _NOLIBC_ARCH_AARCH64_H */
diff --git a/tools/include/nolibc/arch-arm.h b/tools/include/nolibc/arch-arm.h
index d1c19d973e55..6180ff99ab43 100644
--- a/tools/include/nolibc/arch-arm.h
+++ b/tools/include/nolibc/arch-arm.h
@@ -185,7 +185,7 @@
})
/* startup code */
-void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
{
__asm__ volatile (
"mov r0, sp\n" /* save stack pointer to %r0, as arg1 of _start_c */
@@ -193,7 +193,7 @@ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_
"mov sp, ip\n"
"bl _start_c\n" /* transfer to c runtime */
);
- __builtin_unreachable();
+ __nolibc_entrypoint_epilogue();
}
#endif /* _NOLIBC_ARCH_ARM_H */
diff --git a/tools/include/nolibc/arch-i386.h b/tools/include/nolibc/arch-i386.h
index 28c26a00a762..ff5afc35bbd8 100644
--- a/tools/include/nolibc/arch-i386.h
+++ b/tools/include/nolibc/arch-i386.h
@@ -162,7 +162,7 @@
* 2) The deepest stack frame should be set to zero
*
*/
-void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
{
__asm__ volatile (
"xor %ebp, %ebp\n" /* zero the stack frame */
@@ -174,7 +174,7 @@ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_
"call _start_c\n" /* transfer to c runtime */
"hlt\n" /* ensure it does not return */
);
- __builtin_unreachable();
+ __nolibc_entrypoint_epilogue();
}
#endif /* _NOLIBC_ARCH_I386_H */
diff --git a/tools/include/nolibc/arch-loongarch.h b/tools/include/nolibc/arch-loongarch.h
index 3f8ef8f86c0f..fb519545959e 100644
--- a/tools/include/nolibc/arch-loongarch.h
+++ b/tools/include/nolibc/arch-loongarch.h
@@ -149,14 +149,14 @@
#endif
/* startup code */
-void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
{
__asm__ volatile (
"move $a0, $sp\n" /* save stack pointer to $a0, as arg1 of _start_c */
LONG_BSTRINS " $sp, $zero, 3, 0\n" /* $sp must be 16-byte aligned */
"bl _start_c\n" /* transfer to c runtime */
);
- __builtin_unreachable();
+ __nolibc_entrypoint_epilogue();
}
#endif /* _NOLIBC_ARCH_LOONGARCH_H */
diff --git a/tools/include/nolibc/arch-mips.h b/tools/include/nolibc/arch-mips.h
index a2ee77ed2fbb..1791a8ce58da 100644
--- a/tools/include/nolibc/arch-mips.h
+++ b/tools/include/nolibc/arch-mips.h
@@ -179,7 +179,7 @@
})
/* startup code, note that it's called __start on MIPS */
-void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector __start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector __start(void)
{
__asm__ volatile (
".set push\n"
@@ -200,7 +200,7 @@ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_
" nop\n" /* delayed slot */
".set pop\n"
);
- __builtin_unreachable();
+ __nolibc_entrypoint_epilogue();
}
#endif /* _NOLIBC_ARCH_MIPS_H */
diff --git a/tools/include/nolibc/arch-powerpc.h b/tools/include/nolibc/arch-powerpc.h
index 41ebd394b90c..ee2fdb8d601d 100644
--- a/tools/include/nolibc/arch-powerpc.h
+++ b/tools/include/nolibc/arch-powerpc.h
@@ -184,7 +184,7 @@
#endif /* !__powerpc64__ */
/* startup code */
-void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
{
#ifdef __powerpc64__
#if _CALL_ELF == 2
@@ -215,7 +215,7 @@ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_
"bl _start_c\n" /* transfer to c runtime */
);
#endif
- __builtin_unreachable();
+ __nolibc_entrypoint_epilogue();
}
#endif /* _NOLIBC_ARCH_POWERPC_H */
diff --git a/tools/include/nolibc/arch-riscv.h b/tools/include/nolibc/arch-riscv.h
index 1927c643c739..8827bf936212 100644
--- a/tools/include/nolibc/arch-riscv.h
+++ b/tools/include/nolibc/arch-riscv.h
@@ -140,7 +140,7 @@
})
/* startup code */
-void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
{
__asm__ volatile (
".option push\n"
@@ -151,7 +151,7 @@ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_
"andi sp, a0, -16\n" /* sp must be 16-byte aligned */
"call _start_c\n" /* transfer to c runtime */
);
- __builtin_unreachable();
+ __nolibc_entrypoint_epilogue();
}
#endif /* _NOLIBC_ARCH_RISCV_H */
diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
index 5d60fd43f883..2ec13d8b9a2d 100644
--- a/tools/include/nolibc/arch-s390.h
+++ b/tools/include/nolibc/arch-s390.h
@@ -139,7 +139,7 @@
})
/* startup code */
-void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
{
__asm__ volatile (
"lgr %r2, %r15\n" /* save stack pointer to %r2, as arg1 of _start_c */
@@ -147,7 +147,7 @@ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_
"xc 0(8,%r15), 0(%r15)\n" /* clear backchain */
"brasl %r14, _start_c\n" /* transfer to c runtime */
);
- __builtin_unreachable();
+ __nolibc_entrypoint_epilogue();
}
struct s390_mmap_arg_struct {
diff --git a/tools/include/nolibc/arch-x86_64.h b/tools/include/nolibc/arch-x86_64.h
index 68609f421934..65252c005a30 100644
--- a/tools/include/nolibc/arch-x86_64.h
+++ b/tools/include/nolibc/arch-x86_64.h
@@ -161,7 +161,7 @@
* 2) The deepest stack frame should be zero (the %rbp).
*
*/
-void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
{
__asm__ volatile (
"xor %ebp, %ebp\n" /* zero the stack frame */
@@ -170,7 +170,7 @@ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_
"call _start_c\n" /* transfer to c runtime */
"hlt\n" /* ensure it does not return */
);
- __builtin_unreachable();
+ __nolibc_entrypoint_epilogue();
}
#define NOLIBC_ARCH_HAS_MEMMOVE
diff --git a/tools/include/nolibc/compiler.h b/tools/include/nolibc/compiler.h
index 1730d0454a55..3a1d5b8d4fb9 100644
--- a/tools/include/nolibc/compiler.h
+++ b/tools/include/nolibc/compiler.h
@@ -12,6 +12,9 @@
# define __nolibc_has_attribute(attr) 0
#endif
+#define __nolibc_entrypoint __attribute__((optimize("Os", "omit-frame-pointer")))
+#define __nolibc_entrypoint_epilogue() __builtin_unreachable()
+
#if defined(__SSP__) || defined(__SSP_STRONG__) || defined(__SSP_ALL__) || defined(__SSP_EXPLICIT__)
#define _NOLIBC_STACKPROTECTOR
--
2.30.9