From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     linux-kernel@vger.kernel.org
Cc:     gwml@vger.gnuweeb.org, kernel-team@meta.com, w@lwt.eu,
        Willy Tarreau <w@1wt.eu>,
        "Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH nolibc 07/14] tools/nolibc: add getuid() and geteuid()
Date:   Mon, 20 Mar 2023 18:11:30 -0700
Message-Id: <20230321011137.51837-7-paulmck@kernel.org>
In-Reply-To: <6a3206d0-e5cd-4990-9604-444a24a8207c@paulmck-laptop>
References: <6a3206d0-e5cd-4990-9604-444a24a8207c@paulmck-laptop>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Willy Tarreau <w@1wt.eu>

This can be useful to avoid attempting some privileged operations,
starting from the nolibc-test tool that gets two failures when not
privileged.

We call getuid32() and geteuid32() when they are defined, and fall
back to getuid() and geteuid() otherwise.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/include/nolibc/sys.h | 42 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index b5f8cd35c03b..115579e7f1db 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -410,6 +410,27 @@ 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 +565,27 @@ 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);
  */
-- 
2.40.0.rc2