[PATCH 0/2] Small stack protector bits

[PATCH 0/2] Small stack protector bits

[Daniel Palmer]

Reworking my "static pie" series and going back
through comments from Willy and Thomas...

First patch was suggested by Willy as a preemptive
clean up task before the series. So here it is.

Second one is an issue only appeared with relocation
(because you shouldn't access global data before relocation)
but seems sensible to do.

Daniel Palmer (2):
  tools/nolibc: Rename __no_stack_protector to
    __nolibc_no_stack_protector
  tools/nolibc: Don't use stack protector before setting it up

 tools/include/nolibc/arch-arm.h       | 2 +-
 tools/include/nolibc/arch-arm64.h     | 2 +-
 tools/include/nolibc/arch-loongarch.h | 2 +-
 tools/include/nolibc/arch-m68k.h      | 2 +-
 tools/include/nolibc/arch-mips.h      | 2 +-
 tools/include/nolibc/arch-powerpc.h   | 8 ++++----
 tools/include/nolibc/arch-riscv.h     | 2 +-
 tools/include/nolibc/arch-s390.h      | 2 +-
 tools/include/nolibc/arch-sh.h        | 2 +-
 tools/include/nolibc/arch-sparc.h     | 2 +-
 tools/include/nolibc/arch-x86.h       | 4 ++--
 tools/include/nolibc/compiler.h       | 4 ++--
 tools/include/nolibc/crt.h            | 2 +-
 tools/include/nolibc/stackprotector.h | 2 +-
 14 files changed, 19 insertions(+), 19 deletions(-)

-- 
2.53.0

[PATCH 1/2] tools/nolibc: Rename __no_stack_protector to __nolibc_no_stack_protector

[Daniel Palmer]

To avoid polluting the namespace rename __no_stack_protector to
__nolibc_no_stack_protector so its now within the nolibc umbrella.

Suggested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Daniel Palmer <daniel@thingy.jp>
---
 tools/include/nolibc/arch-arm.h       | 2 +-
 tools/include/nolibc/arch-arm64.h     | 2 +-
 tools/include/nolibc/arch-loongarch.h | 2 +-
 tools/include/nolibc/arch-m68k.h      | 2 +-
 tools/include/nolibc/arch-mips.h      | 2 +-
 tools/include/nolibc/arch-powerpc.h   | 8 ++++----
 tools/include/nolibc/arch-riscv.h     | 2 +-
 tools/include/nolibc/arch-s390.h      | 2 +-
 tools/include/nolibc/arch-sh.h        | 2 +-
 tools/include/nolibc/arch-sparc.h     | 2 +-
 tools/include/nolibc/arch-x86.h       | 4 ++--
 tools/include/nolibc/compiler.h       | 4 ++--
 tools/include/nolibc/stackprotector.h | 2 +-
 13 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/tools/include/nolibc/arch-arm.h b/tools/include/nolibc/arch-arm.h
index a4d3a777a051..72a2b28170e2 100644
--- a/tools/include/nolibc/arch-arm.h
+++ b/tools/include/nolibc/arch-arm.h
@@ -186,7 +186,7 @@
 
 #ifndef NOLIBC_NO_RUNTIME
 /* startup code */
-void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start(void)
 {
 	__asm__ volatile (
 		"mov r0, sp\n"          /* save stack pointer to %r0, as arg1 of _start_c */
diff --git a/tools/include/nolibc/arch-arm64.h b/tools/include/nolibc/arch-arm64.h
index 28b3c7536ad6..814bcc13b4b2 100644
--- a/tools/include/nolibc/arch-arm64.h
+++ b/tools/include/nolibc/arch-arm64.h
@@ -143,7 +143,7 @@
 
 #ifndef NOLIBC_NO_RUNTIME
 /* startup code */
-void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start(void)
 {
 	__asm__ volatile (
 		"mov x0, sp\n"          /* save stack pointer to x0, as arg1 of _start_c */
diff --git a/tools/include/nolibc/arch-loongarch.h b/tools/include/nolibc/arch-loongarch.h
index 86fb34bbf185..3abed96a15e8 100644
--- a/tools/include/nolibc/arch-loongarch.h
+++ b/tools/include/nolibc/arch-loongarch.h
@@ -144,7 +144,7 @@
 
 #ifndef NOLIBC_NO_RUNTIME
 /* startup code */
-void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start(void)
 {
 	__asm__ volatile (
 		"move          $a0, $sp\n"         /* save stack pointer to $a0, as arg1 of _start_c */
diff --git a/tools/include/nolibc/arch-m68k.h b/tools/include/nolibc/arch-m68k.h
index 81d34c219a42..341f434a530c 100644
--- a/tools/include/nolibc/arch-m68k.h
+++ b/tools/include/nolibc/arch-m68k.h
@@ -130,7 +130,7 @@
 
 #ifndef NOLIBC_NO_RUNTIME
 void _start(void);
-void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start(void)
 {
 	__asm__ volatile (
 		"movel %sp, %sp@-\n"
diff --git a/tools/include/nolibc/arch-mips.h b/tools/include/nolibc/arch-mips.h
index bb9d580ea1b1..2b7a0bd3fc30 100644
--- a/tools/include/nolibc/arch-mips.h
+++ b/tools/include/nolibc/arch-mips.h
@@ -257,7 +257,7 @@
 #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)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector __start(void)
 {
 	__asm__ volatile (
 		"move  $a0, $sp\n"       /* save stack pointer to $a0, as arg1 of _start_c */
diff --git a/tools/include/nolibc/arch-powerpc.h b/tools/include/nolibc/arch-powerpc.h
index ef878868aa4a..111cda70f2cc 100644
--- a/tools/include/nolibc/arch-powerpc.h
+++ b/tools/include/nolibc/arch-powerpc.h
@@ -177,15 +177,15 @@
  * "omit-frame-pointer" fails with __attribute__((no_stack_protector)) but
  * works with __attribute__((__optimize__("-fno-stack-protector")))
  */
-#ifdef __no_stack_protector
-#undef __no_stack_protector
-#define __no_stack_protector __attribute__((__optimize__("-fno-stack-protector")))
+#ifdef __nolibc_no_stack_protector
+#undef __nolibc_no_stack_protector
+#define __nolibc_no_stack_protector __attribute__((__optimize__("-fno-stack-protector")))
 #endif
 #endif /* !__powerpc64__ */
 
 #ifndef NOLIBC_NO_RUNTIME
 /* startup code */
-void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start(void)
 {
 #ifdef __powerpc64__
 #if _CALL_ELF == 2
diff --git a/tools/include/nolibc/arch-riscv.h b/tools/include/nolibc/arch-riscv.h
index 386ebb9f5b08..1e84ed2e63b3 100644
--- a/tools/include/nolibc/arch-riscv.h
+++ b/tools/include/nolibc/arch-riscv.h
@@ -141,7 +141,7 @@
 
 #ifndef NOLIBC_NO_RUNTIME
 /* startup code */
-void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start(void)
 {
 	__asm__ volatile (
 		".option push\n"
diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
index 4e69123ae484..3f05c01aecc6 100644
--- a/tools/include/nolibc/arch-s390.h
+++ b/tools/include/nolibc/arch-s390.h
@@ -145,7 +145,7 @@
 
 #ifndef NOLIBC_NO_RUNTIME
 /* startup code */
-void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start(void)
 {
 	__asm__ volatile (
 		"lgr	%r2, %r15\n"          /* save stack pointer to %r2, as arg1 of _start_c */
diff --git a/tools/include/nolibc/arch-sh.h b/tools/include/nolibc/arch-sh.h
index b5a64ceeec97..a32378fd621f 100644
--- a/tools/include/nolibc/arch-sh.h
+++ b/tools/include/nolibc/arch-sh.h
@@ -143,7 +143,7 @@
 #ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void _start_wrapper(void);
-void __attribute__((weak,noreturn)) __nolibc_entrypoint __no_stack_protector _start_wrapper(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start_wrapper(void)
 {
 	__asm__ volatile (
 		".global _start\n"           /* The C function will have a prologue,         */
diff --git a/tools/include/nolibc/arch-sparc.h b/tools/include/nolibc/arch-sparc.h
index 240539d069a8..ddae9bc10dfe 100644
--- a/tools/include/nolibc/arch-sparc.h
+++ b/tools/include/nolibc/arch-sparc.h
@@ -154,7 +154,7 @@
 
 #ifndef NOLIBC_NO_RUNTIME
 /* startup code */
-void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start(void)
 {
 	__asm__ volatile (
 		/*
diff --git a/tools/include/nolibc/arch-x86.h b/tools/include/nolibc/arch-x86.h
index 769ba01a8629..db5ccba772d0 100644
--- a/tools/include/nolibc/arch-x86.h
+++ b/tools/include/nolibc/arch-x86.h
@@ -165,7 +165,7 @@
  * 2) The deepest stack frame should be set to zero
  *
  */
-void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start(void)
 {
 	__asm__ volatile (
 		"xor  %ebp, %ebp\n"       /* zero the stack frame                                */
@@ -333,7 +333,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
  * 2) The deepest stack frame should be zero (the %rbp).
  *
  */
-void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
+void __attribute__((weak, noreturn)) __nolibc_entrypoint __nolibc_no_stack_protector _start(void)
 {
 	__asm__ volatile (
 		"xor  %ebp, %ebp\n"       /* zero the stack frame                            */
diff --git a/tools/include/nolibc/compiler.h b/tools/include/nolibc/compiler.h
index b56570bf9f69..f2d7a81d0d7c 100644
--- a/tools/include/nolibc/compiler.h
+++ b/tools/include/nolibc/compiler.h
@@ -36,9 +36,9 @@
 #endif /* defined(__SSP__) ... */
 
 #if __nolibc_has_attribute(no_stack_protector)
-#  define __no_stack_protector __attribute__((no_stack_protector))
+#  define __nolibc_no_stack_protector __attribute__((no_stack_protector))
 #else
-#  define __no_stack_protector __attribute__((__optimize__("-fno-stack-protector")))
+#  define __nolibc_no_stack_protector __attribute__((__optimize__("-fno-stack-protector")))
 #endif /* __nolibc_has_attribute(no_stack_protector) */
 
 #if __nolibc_has_attribute(__fallthrough__)
diff --git a/tools/include/nolibc/stackprotector.h b/tools/include/nolibc/stackprotector.h
index ae8b1d3a374d..e11c20c75465 100644
--- a/tools/include/nolibc/stackprotector.h
+++ b/tools/include/nolibc/stackprotector.h
@@ -40,7 +40,7 @@ void __stack_chk_fail_local(void)
 __attribute__((weak,used,section(".data.nolibc_stack_chk")))
 uintptr_t __stack_chk_guard;
 
-static __no_stack_protector void __stack_chk_init(void)
+static __nolibc_no_stack_protector void __stack_chk_init(void)
 {
 	__nolibc_syscall3(__NR_getrandom, &__stack_chk_guard, sizeof(__stack_chk_guard), 0);
 	/* a bit more randomness in case getrandom() fails, ensure the guard is never 0 */
-- 
2.53.0

[PATCH 2/2] tools/nolibc: Don't use stack protector before setting it up

[Daniel Palmer]

The stack protector is configured in _start_c() so we shouldn't
use it before then.

Add __nolibc_no_stack_protector to _start_c() to avoid the compiler
generating stack protector code for _start_c() and thus using it
before its configured.

Signed-off-by: Daniel Palmer <daniel@thingy.jp>
---
 tools/include/nolibc/crt.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/include/nolibc/crt.h b/tools/include/nolibc/crt.h
index d8ce91fd2e3b..0fe0a066d15a 100644
--- a/tools/include/nolibc/crt.h
+++ b/tools/include/nolibc/crt.h
@@ -47,7 +47,7 @@ char *__nolibc_program_invocation_short_name(char *long_name)
 #endif /* NOLIBC_IGNORE_ERRNO */
 
 void _start_c(long *sp);
-__attribute__((weak,used)) __nolibc_no_sanitize_undefined
+__attribute__((weak, used)) __nolibc_no_sanitize_undefined __nolibc_no_stack_protector
 void _start_c(long *sp)
 {
 	long argc;
-- 
2.53.0

Re: [PATCH 1/2] tools/nolibc: Rename __no_stack_protector to __nolibc_no_stack_protector

[Thomas Weißschuh]

On 2026-04-25 20:13:14+0900, Daniel Palmer wrote:
> To avoid polluting the namespace rename __no_stack_protector to
> __nolibc_no_stack_protector so its now within the nolibc umbrella.

Both patches applied, thanks!
 
> Suggested-by: Willy Tarreau <w@1wt.eu>
> Signed-off-by: Daniel Palmer <daniel@thingy.jp>

(...)