Merge tag 'nolibc.2023.04.04a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull nolibc updates from Paul McKenney:

 - Add support for loongarch

 - Fix stack-protector issues

 - Support additional integral types and signal-related macros

 - Add support for stdin, stdout, and stderr

 - Add getuid() and geteuid()

 - Allow S_I* macros to be overridden by program

 - Defer to linux/fcntl.h and linux/stat.h to avoid duplicate
   definitions

 - Many improvements to the selftests

* tag 'nolibc.2023.04.04a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (22 commits)
  tools/nolibc: x86_64: add stackprotector support
  tools/nolibc: i386: add stackprotector support
  tools/nolibc: tests: add test for -fstack-protector
  tools/nolibc: tests: fold in no-stack-protector cflags
  tools/nolibc: add support for stack protector
  tools/nolibc: tests: constify test_names
  tools/nolibc: add helpers for wait() signal exits
  tools/nolibc: add definitions for standard fds
  selftests/nolibc: Adjust indentation for Makefile
  selftests/nolibc: Add support for LoongArch
  tools/nolibc: Add support for LoongArch
  tools/nolibc: Add statx() and make stat() rely on statx() if necessary
  tools/nolibc: Include linux/fcntl.h and remove duplicate code
  tools/nolibc: check for S_I* macros before defining them
  selftests/nolibc: skip the chroot_root and link_dir tests when not privileged
  tools/nolibc: add getuid() and geteuid()
  tools/nolibc: add tests for the integer limits in stdint.h
  tools/nolibc: enlarge column width of tests
  tools/nolibc: add integer types and integer limit macros
  tools/nolibc: add stdint.h
  ...

tools/include/nolibc/.gitignore

+sysroot

tools/include/nolibc/Makefile

@@ -25,8 +25,8 @@ endif
 
 nolibc_arch := $(patsubst arm64,aarch64,$(ARCH))
 arch_file := arch-$(nolibc_arch).h
-all_files := ctype.h errno.h nolibc.h signal.h std.h stdio.h stdlib.h string.h \
-             sys.h time.h types.h unistd.h
+all_files := ctype.h errno.h nolibc.h signal.h stackprotector.h std.h stdint.h \
+             stdio.h stdlib.h string.h sys.h time.h types.h unistd.h
 
 # install all headers needed to support a bare-metal compiler
 all: headers

tools/include/nolibc/arch-i386.h

@@ -181,6 +181,8 @@ 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:
@@ -188,9 +190,12 @@ const unsigned long *_auxv __attribute__((weak));
  * 2) The deepest stack frame should be set to zero
  *
  */
-void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
+void __attribute__((weak,noreturn,optimize("omit-frame-pointer"),no_stack_protector)) _start(void)
 {
 	__asm__ volatile (
+#ifdef NOLIBC_STACKPROTECTOR
+		"call __stack_chk_init\n"   // initialize stack protector
+#endif
 		"pop %eax\n"                // argc   (first arg, %eax)
 		"mov %esp, %ebx\n"          // argv[] (second arg, %ebx)
 		"lea 4(%ebx,%eax,4),%ecx\n" // then a NULL then envp (third arg, %ecx)

tools/include/nolibc/arch-x86_64.h

@@ -181,6 +181,8 @@ struct sys_stat_struct {
 char **environ __attribute__((weak));
 const unsigned long *_auxv __attribute__((weak));
 
+#define __ARCH_SUPPORTS_STACK_PROTECTOR
+
 /* startup code */
 /*
  * x86-64 System V ABI mandates:
@@ -191,6 +193,9 @@ const unsigned long *_auxv __attribute__((weak));
 void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
 {
 	__asm__ volatile (
+#ifdef NOLIBC_STACKPROTECTOR
+		"call __stack_chk_init\n"   // initialize stack protector
+#endif
 		"pop %rdi\n"                // argc   (first arg, %rdi)
 		"mov %rsp, %rsi\n"          // argv[] (second arg, %rsi)
 		"lea 8(%rsi,%rdi,8),%rdx\n" // then a NULL then envp (third arg, %rdx)

tools/include/nolibc/arch.h

@@ -29,6 +29,8 @@
 #include "arch-riscv.h"
 #elif defined(__s390x__)
 #include "arch-s390.h"
+#elif defined(__loongarch__)
+#include "arch-loongarch.h"
 #endif
 
 #endif /* _NOLIBC_ARCH_H */

tools/include/nolibc/nolibc.h

@@ -104,6 +104,7 @@
 #include "string.h"
 #include "time.h"
 #include "unistd.h"
+#include "stackprotector.h"
 
 /* Used by programs to avoid std includes */
 #define NOLIBC

tools/include/nolibc/stackprotector.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * Stack protector support for NOLIBC
+ * Copyright (C) 2023 Thomas Weißschuh <linux@weissschuh.net>
+ */
+
+#ifndef _NOLIBC_STACKPROTECTOR_H
+#define _NOLIBC_STACKPROTECTOR_H
+
+#include "arch.h"
+
+#if defined(NOLIBC_STACKPROTECTOR)
+
+#if !defined(__ARCH_SUPPORTS_STACK_PROTECTOR)
+#error "nolibc does not support stack protectors on this arch"
+#endif
+
+#include "sys.h"
+#include "stdlib.h"
+
+/* The functions in this header are using raw syscall macros to avoid
+ * triggering stack protector errors themselves
+ */
+
+__attribute__((weak,noreturn,section(".text.nolibc_stack_chk")))
+void __stack_chk_fail(void)
+{
+	pid_t pid;
+	my_syscall3(__NR_write, STDERR_FILENO, "!!Stack smashing detected!!\n", 28);
+	pid = my_syscall0(__NR_getpid);
+	my_syscall2(__NR_kill, pid, SIGABRT);
+	for (;;);
+}
+
+__attribute__((weak,noreturn,section(".text.nolibc_stack_chk")))
+void __stack_chk_fail_local(void)
+{
+	__stack_chk_fail();
+}
+
+__attribute__((weak,section(".data.nolibc_stack_chk")))
+uintptr_t __stack_chk_guard;
+
+__attribute__((weak,no_stack_protector,section(".text.nolibc_stack_chk")))
+void __stack_chk_init(void)
+{
+	my_syscall3(__NR_getrandom, &__stack_chk_guard, sizeof(__stack_chk_guard), 0);
+	/* a bit more randomness in case getrandom() fails */
+	__stack_chk_guard ^= (uintptr_t) &__stack_chk_guard;
+}
+#endif // defined(NOLIBC_STACKPROTECTOR)
+
+#endif // _NOLIBC_STACKPROTECTOR_H

tools/include/nolibc/std.h

@@ -18,20 +18,7 @@
 #define NULL ((void *)0)
 #endif
 
-/* stdint types */
-typedef unsigned char       uint8_t;
-typedef   signed char        int8_t;
-typedef unsigned short     uint16_t;
-typedef   signed short      int16_t;
-typedef unsigned int       uint32_t;
-typedef   signed int        int32_t;
-typedef unsigned long long uint64_t;
-typedef   signed long long  int64_t;
-typedef unsigned long        size_t;
-typedef   signed long       ssize_t;
-typedef unsigned long     uintptr_t;
-typedef   signed long      intptr_t;
-typedef   signed long     ptrdiff_t;
+#include "stdint.h"
 
 /* those are commonly provided by sys/types.h */
 typedef unsigned int          dev_t;

tools/include/nolibc/stdint.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * Standard definitions and types for NOLIBC
+ * Copyright (C) 2023 Vincent Dagonneau <v@vda.io>
+ */
+
+#ifndef _NOLIBC_STDINT_H
+#define _NOLIBC_STDINT_H
+
+typedef unsigned char       uint8_t;
+typedef   signed char        int8_t;
+typedef unsigned short     uint16_t;
+typedef   signed short      int16_t;
+typedef unsigned int       uint32_t;
+typedef   signed int        int32_t;
+typedef unsigned long long uint64_t;
+typedef   signed long long  int64_t;
+typedef unsigned long        size_t;
+typedef   signed long       ssize_t;
+typedef unsigned long     uintptr_t;
+typedef   signed long      intptr_t;
+typedef   signed long     ptrdiff_t;
+
+typedef   int8_t       int_least8_t;
+typedef  uint8_t      uint_least8_t;
+typedef  int16_t      int_least16_t;
+typedef uint16_t     uint_least16_t;
+typedef  int32_t      int_least32_t;
+typedef uint32_t     uint_least32_t;
+typedef  int64_t      int_least64_t;
+typedef uint64_t     uint_least64_t;
+
+typedef   int8_t        int_fast8_t;
+typedef  uint8_t       uint_fast8_t;
+typedef  ssize_t       int_fast16_t;
+typedef   size_t      uint_fast16_t;
+typedef  ssize_t       int_fast32_t;
+typedef   size_t      uint_fast32_t;
+typedef  ssize_t       int_fast64_t;
+typedef   size_t      uint_fast64_t;
+
+typedef  int64_t           intmax_t;
+typedef uint64_t          uintmax_t;
+
+/* limits of integral types */
+
+#define        INT8_MIN  (-128)
+#define       INT16_MIN  (-32767-1)
+#define       INT32_MIN  (-2147483647-1)
+#define       INT64_MIN  (-9223372036854775807LL-1)
+
+#define        INT8_MAX  (127)
+#define       INT16_MAX  (32767)
+#define       INT32_MAX  (2147483647)
+#define       INT64_MAX  (9223372036854775807LL)
+
+#define       UINT8_MAX  (255)
+#define      UINT16_MAX  (65535)
+#define      UINT32_MAX  (4294967295U)
+#define      UINT64_MAX  (18446744073709551615ULL)
+
+#define  INT_LEAST8_MIN  INT8_MIN
+#define INT_LEAST16_MIN  INT16_MIN
+#define INT_LEAST32_MIN  INT32_MIN
+#define INT_LEAST64_MIN  INT64_MIN
+
+#define  INT_LEAST8_MAX  INT8_MAX
+#define INT_LEAST16_MAX  INT16_MAX
+#define INT_LEAST32_MAX  INT32_MAX
+#define INT_LEAST64_MAX  INT64_MAX
+
+#define  UINT_LEAST8_MAX UINT8_MAX
+#define UINT_LEAST16_MAX UINT16_MAX
+#define UINT_LEAST32_MAX UINT32_MAX
+#define UINT_LEAST64_MAX UINT64_MAX
+
+#define SIZE_MAX         ((size_t)(__LONG_MAX__) * 2 + 1)
+#define INTPTR_MIN       (-__LONG_MAX__ - 1)
+#define INTPTR_MAX       __LONG_MAX__
+#define PTRDIFF_MIN      INTPTR_MIN
+#define PTRDIFF_MAX      INTPTR_MAX
+#define UINTPTR_MAX      SIZE_MAX
+
+#define  INT_FAST8_MIN   INT8_MIN
+#define INT_FAST16_MIN   INTPTR_MIN
+#define INT_FAST32_MIN   INTPTR_MIN
+#define INT_FAST64_MIN   INTPTR_MIN
+
+#define  INT_FAST8_MAX   INT8_MAX
+#define INT_FAST16_MAX   INTPTR_MAX
+#define INT_FAST32_MAX   INTPTR_MAX
+#define INT_FAST64_MAX   INTPTR_MAX
+
+#define  UINT_FAST8_MAX  UINT8_MAX
+#define UINT_FAST16_MAX  SIZE_MAX
+#define UINT_FAST32_MAX  SIZE_MAX
+#define UINT_FAST64_MAX  SIZE_MAX
+
+#endif /* _NOLIBC_STDINT_H */

tools/include/nolibc/sys.h

@@ -11,7 +11,6 @@
 #include "std.h"
 
 /* system includes */
-#include <asm/fcntl.h>   // for O_*
 #include <asm/unistd.h>
 #include <asm/signal.h>  // for SIGCHLD
 #include <asm/ioctls.h>
@@ -20,6 +19,8 @@
 #include <linux/loop.h>
 #include <linux/time.h>
 #include <linux/auxvec.h>
+#include <linux/fcntl.h> // for O_* and AT_*
+#include <linux/stat.h>  // for statx()
 
 #include "arch.h"
 #include "errno.h"
@@ -410,6 +411,27 @@ int getdents64(int fd, struct linux_dirent64 *dirp, int count)
 }
 
 
+/*
+ * uid_t geteuid(void);
+ */
+
+static __attribute__((unused))
+uid_t sys_geteuid(void)
+{
+#ifdef __NR_geteuid32
+	return my_syscall0(__NR_geteuid32);
+#else
+	return my_syscall0(__NR_geteuid);
+#endif
+}
+
+static __attribute__((unused))
+uid_t geteuid(void)
+{
+	return sys_geteuid();
+}
+
+
 /*
  * pid_t getpgid(pid_t pid);
  */
@@ -544,6 +566,27 @@ int gettimeofday(struct timeval *tv, struct timezone *tz)
 }
 
 
+/*
+ * uid_t getuid(void);
+ */
+
+static __attribute__((unused))
+uid_t sys_getuid(void)
+{
+#ifdef __NR_getuid32
+	return my_syscall0(__NR_getuid32);
+#else
+	return my_syscall0(__NR_getuid);
+#endif
+}
+
+static __attribute__((unused))
+uid_t getuid(void)
+{
+	return sys_getuid();
+}
+
+
 /*
  * int ioctl(int fd, unsigned long req, void *value);
  */
@@ -1048,12 +1091,66 @@ pid_t setsid(void)
 	return ret;
 }
 
+#if defined(__NR_statx)
+/*
+ * int statx(int fd, const char *path, int flags, unsigned int mask, struct statx *buf);
+ */
+
+static __attribute__((unused))
+int sys_statx(int fd, const char *path, int flags, unsigned int mask, struct statx *buf)
+{
+	return my_syscall5(__NR_statx, fd, path, flags, mask, buf);
+}
+
+static __attribute__((unused))
+int statx(int fd, const char *path, int flags, unsigned int mask, struct statx *buf)
+{
+	int ret = sys_statx(fd, path, flags, mask, buf);
+
+	if (ret < 0) {
+		SET_ERRNO(-ret);
+		ret = -1;
+	}
+	return ret;
+}
+#endif
 
 /*
  * int stat(const char *path, struct stat *buf);
  * Warning: the struct stat's layout is arch-dependent.
  */
 
+#if defined(__NR_statx) && !defined(__NR_newfstatat) && !defined(__NR_stat)
+/*
+ * Maybe we can just use statx() when available for all architectures?
+ */
+static __attribute__((unused))
+int sys_stat(const char *path, struct stat *buf)
+{
+	struct statx statx;
+	long ret;
+
+	ret = sys_statx(AT_FDCWD, path, AT_NO_AUTOMOUNT, STATX_BASIC_STATS, &statx);
+	buf->st_dev     = ((statx.stx_dev_minor & 0xff)
+			  | (statx.stx_dev_major << 8)
+			  | ((statx.stx_dev_minor & ~0xff) << 12));
+	buf->st_ino     = statx.stx_ino;
+	buf->st_mode    = statx.stx_mode;
+	buf->st_nlink   = statx.stx_nlink;
+	buf->st_uid     = statx.stx_uid;
+	buf->st_gid     = statx.stx_gid;
+	buf->st_rdev    = ((statx.stx_rdev_minor & 0xff)
+			  | (statx.stx_rdev_major << 8)
+			  | ((statx.stx_rdev_minor & ~0xff) << 12));
+	buf->st_size    = statx.stx_size;
+	buf->st_blksize = statx.stx_blksize;
+	buf->st_blocks  = statx.stx_blocks;
+	buf->st_atime   = statx.stx_atime.tv_sec;
+	buf->st_mtime   = statx.stx_mtime.tv_sec;
+	buf->st_ctime   = statx.stx_ctime.tv_sec;
+	return ret;
+}
+#else
 static __attribute__((unused))
 int sys_stat(const char *path, struct stat *buf)
 {
@@ -1083,6 +1180,7 @@ int sys_stat(const char *path, struct stat *buf)
 	buf->st_ctime   = stat.st_ctime;
 	return ret;
 }
+#endif
 
 static __attribute__((unused))
 int stat(const char *path, struct stat *buf)

tools/include/nolibc/types.h

@@ -9,6 +9,7 @@
 
 #include "std.h"
 #include <linux/time.h>
+#include <linux/stat.h>
 
 
 /* Only the generic macros and types may be defined here. The arch-specific
@@ -16,7 +17,11 @@
  * the layout of sys_stat_struct must not be defined here.
  */
 
-/* stat flags (WARNING, octal here) */
+/* stat flags (WARNING, octal here). We need to check for an existing
+ * definition because linux/stat.h may omit to define those if it finds
+ * that any glibc header was already included.
+ */
+#if !defined(S_IFMT)
 #define S_IFDIR        0040000
 #define S_IFCHR        0020000
 #define S_IFBLK        0060000
@@ -34,6 +39,22 @@
 #define S_ISLNK(mode)  (((mode) & S_IFMT) == S_IFLNK)
 #define S_ISSOCK(mode) (((mode) & S_IFMT) == S_IFSOCK)
 
+#define S_IRWXU 00700
+#define S_IRUSR 00400
+#define S_IWUSR 00200
+#define S_IXUSR 00100
+
+#define S_IRWXG 00070
+#define S_IRGRP 00040
+#define S_IWGRP 00020
+#define S_IXGRP 00010
+
+#define S_IRWXO 00007
+#define S_IROTH 00004
+#define S_IWOTH 00002
+#define S_IXOTH 00001
+#endif
+
 /* dirent types */
 #define DT_UNKNOWN     0x0
 #define DT_FIFO        0x1
@@ -60,11 +81,6 @@
 #define MAXPATHLEN     (PATH_MAX)
 #endif
 
-/* Special FD used by all the *at functions */
-#ifndef AT_FDCWD
-#define AT_FDCWD       (-100)
-#endif
-
 /* whence values for lseek() */
 #define SEEK_SET       0
 #define SEEK_CUR       1
@@ -81,6 +97,8 @@
 /* Macros used on waitpid()'s return status */
 #define WEXITSTATUS(status) (((status) & 0xff00) >> 8)
 #define WIFEXITED(status)   (((status) & 0x7f) == 0)
+#define WTERMSIG(status)    ((status) & 0x7f)
+#define WIFSIGNALED(status) ((status) - 1 < 0xff)
 
 /* waitpid() flags */
 #define WNOHANG      1

tools/include/nolibc/unistd.h

@@ -13,6 +13,11 @@
 #include "sys.h"
 
 
+#define STDIN_FILENO  0
+#define STDOUT_FILENO 1
+#define STDERR_FILENO 2
+
+
 static __attribute__((unused))
 int msleep(unsigned int msecs)
 {

tools/testing/selftests/nolibc/Makefile

 # SPDX-License-Identifier: GPL-2.0
 # Makefile for nolibc tests
 include ../../../scripts/Makefile.include
+# We need this for the "cc-option" macro.
+include ../../../build/Build.include
 
 # we're in ".../tools/testing/selftests/nolibc"
 ifeq ($(srctree),)
@@ -21,6 +23,7 @@ IMAGE_arm     = arch/arm/boot/zImage
 IMAGE_mips       = vmlinuz
 IMAGE_riscv      = arch/riscv/boot/Image
 IMAGE_s390       = arch/s390/boot/bzImage
+IMAGE_loongarch  = arch/loongarch/boot/vmlinuz.efi
 IMAGE            = $(IMAGE_$(ARCH))
 IMAGE_NAME       = $(notdir $(IMAGE))
 
@@ -33,6 +36,7 @@ DEFCONFIG_arm     = multi_v7_defconfig
 DEFCONFIG_mips       = malta_defconfig
 DEFCONFIG_riscv      = defconfig
 DEFCONFIG_s390       = defconfig
+DEFCONFIG_loongarch  = defconfig
 DEFCONFIG            = $(DEFCONFIG_$(ARCH))
 
 # optional tests to run (default = all)
@@ -47,6 +51,7 @@ QEMU_ARCH_arm     = arm
 QEMU_ARCH_mips       = mipsel  # works with malta_defconfig
 QEMU_ARCH_riscv      = riscv64
 QEMU_ARCH_s390       = s390x
+QEMU_ARCH_loongarch  = loongarch64
 QEMU_ARCH            = $(QEMU_ARCH_$(ARCH))
 
 # QEMU_ARGS : some arch-specific args to pass to qemu
@@ -58,6 +63,7 @@ QEMU_ARGS_arm     = -M virt -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_mips       = -M malta -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_riscv      = -M virt -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_s390       = -M s390-ccw-virtio -m 1G -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
+QEMU_ARGS_loongarch  = -M virt -append "console=ttyS0,115200 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS            = $(QEMU_ARGS_$(ARCH))
 
 # OUTPUT is only set when run from the main makefile, otherwise
@@ -70,8 +76,16 @@ else
 Q=@
 endif
 
+CFLAGS_STACKPROTECTOR = -DNOLIBC_STACKPROTECTOR \
+			$(call cc-option,-mstack-protector-guard=global) \
+			$(call cc-option,-fstack-protector-all)
+CFLAGS_STKP_i386 = $(CFLAGS_STACKPROTECTOR)
+CFLAGS_STKP_x86_64 = $(CFLAGS_STACKPROTECTOR)
+CFLAGS_STKP_x86 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_s390 = -m64
-CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables $(CFLAGS_$(ARCH))
+CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables \
+		$(call cc-option,-fno-stack-protector) \
+		$(CFLAGS_STKP_$(ARCH)) $(CFLAGS_$(ARCH))
 LDFLAGS := -s
 
 help: