Commit 818924d1 authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Paul E. McKenney
Browse files

tools/nolibc: add autodetection for stackprotector support 



The stackprotector support in nolibc should be enabled iff it is also
enabled in the compiler.
Use the preprocessor defines added by gcc and clang if stackprotector
support is enable to automatically do so in nolibc.

This completely removes the need for any user-visible API.

To avoid inlining the lengthy preprocessor check into every user
introduce a new header compiler.h that abstracts the logic away.

As the define NOLIBC_STACKPROTECTOR is now not user-relevant anymore
prefix it with an underscore.

Suggested-by: default avatarWilly Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230520133237.GA27501@1wt.eu/


Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent e21a2eef

tools/include/nolibc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ endif 
nolibc_arch := $(patsubst arm64,aarch64,$(ARCH))

arch_file := arch-$(nolibc_arch).h

all_files := \

		compiler.h \

		ctype.h \

		errno.h \

		nolibc.h \

tools/include/nolibc/arch-aarch64.h

+3 −3
Original line number Diff line number Diff line
@@ -7,6 +7,8 @@ 
#ifndef _NOLIBC_ARCH_AARCH64_H

#define _NOLIBC_ARCH_AARCH64_H



#include "compiler.h"



/* The struct returned by the newfstatat() syscall. Differs slightly from the

 * x86_64's stat one by field ordering, so be careful.

 */
@@ -172,13 +174,11 @@ struct sys_stat_struct { 
char **environ __attribute__((weak));

const unsigned long *_auxv __attribute__((weak));



#define __ARCH_SUPPORTS_STACK_PROTECTOR



/* startup code */

void __attribute__((weak,noreturn,optimize("omit-frame-pointer"),no_stack_protector)) _start(void)

{

	__asm__ volatile (

#ifdef NOLIBC_STACKPROTECTOR

#ifdef _NOLIBC_STACKPROTECTOR

		"bl __stack_chk_init\n"   /* initialize stack protector                     */

#endif

		"ldr x0, [sp]\n"     /* argc (x0) was in the stack                          */

tools/include/nolibc/arch-arm.h

+3 −3
Original line number Diff line number Diff line
@@ -7,6 +7,8 @@ 
#ifndef _NOLIBC_ARCH_ARM_H

#define _NOLIBC_ARCH_ARM_H



#include "compiler.h"



/* The struct returned by the stat() syscall, 32-bit only, the syscall returns

 * exactly 56 bytes (stops before the unused array). In big endian, the format

 * differs as devices are returned as short only.
@@ -199,13 +201,11 @@ struct sys_stat_struct { 
char **environ __attribute__((weak));

const unsigned long *_auxv __attribute__((weak));



#define __ARCH_SUPPORTS_STACK_PROTECTOR



/* startup code */

void __attribute__((weak,noreturn,optimize("omit-frame-pointer"),no_stack_protector)) _start(void)

{

	__asm__ volatile (

#ifdef NOLIBC_STACKPROTECTOR

#ifdef _NOLIBC_STACKPROTECTOR

		"bl __stack_chk_init\n"       /* initialize stack protector                          */

#endif

		"pop {%r0}\n"                 /* argc was in the stack                               */

tools/include/nolibc/arch-i386.h

+3 −3
Original line number Diff line number Diff line
@@ -7,6 +7,8 @@ 
#ifndef _NOLIBC_ARCH_I386_H

#define _NOLIBC_ARCH_I386_H



#include "compiler.h"



/* The struct returned by the stat() syscall, 32-bit only, the syscall returns

 * exactly 56 bytes (stops before the unused array).

 */
@@ -181,8 +183,6 @@ struct sys_stat_struct { 
char **environ __attribute__((weak));

const unsigned long *_auxv __attribute__((weak));



#define __ARCH_SUPPORTS_STACK_PROTECTOR



/* startup code */

/*

 * i386 System V ABI mandates:
@@ -193,7 +193,7 @@ const unsigned long *_auxv __attribute__((weak)); 
void __attribute__((weak,noreturn,optimize("omit-frame-pointer"),no_stack_protector)) _start(void)

{

	__asm__ volatile (

#ifdef NOLIBC_STACKPROTECTOR

#ifdef _NOLIBC_STACKPROTECTOR

		"call __stack_chk_init\n"   /* initialize stack protector                    */

#endif

		"pop %eax\n"                /* argc   (first arg, %eax)                      */

tools/include/nolibc/arch-loongarch.h

+3 −3
Original line number Diff line number Diff line
@@ -7,6 +7,8 @@ 
#ifndef _NOLIBC_ARCH_LOONGARCH_H

#define _NOLIBC_ARCH_LOONGARCH_H



#include "compiler.h"



/* Syscalls for LoongArch :

 *   - stack is 16-byte aligned

 *   - syscall number is passed in a7
@@ -149,8 +151,6 @@ 
char **environ __attribute__((weak));

const unsigned long *_auxv __attribute__((weak));



#define __ARCH_SUPPORTS_STACK_PROTECTOR



#if __loongarch_grlen == 32

#define LONGLOG      "2"

#define SZREG        "4"
@@ -175,7 +175,7 @@ const unsigned long *_auxv __attribute__((weak)); 
void __attribute__((weak,noreturn,optimize("omit-frame-pointer"),no_stack_protector)) _start(void)

{

	__asm__ volatile (

#ifdef NOLIBC_STACKPROTECTOR

#ifdef _NOLIBC_STACKPROTECTOR

		"bl __stack_chk_init\n"               /* initialize stack protector                          */

#endif

		REG_L        " $a0, $sp, 0\n"         /* argc (a0) was in the stack                          */