[v4,07/10] Use <startup.h> in __libc_init_secure
Commit Message
From: "H.J. Lu" <hjl.tools@gmail.com>
Since __libc_init_secure is called before ARCH_SETUP_TLS, it must use
"int $0x80" for system calls in i386 static PIE. Add startup_getuid,
startup_geteuid, startup_getgid and startup_getegid to <startup.h>.
Update __libc_init_secure to use them.
---
elf/enbl-secure.c | 6 +++---
sysdeps/generic/startup.h | 26 +++++++++++++++++++++++
sysdeps/unix/sysv/linux/i386/startup.h | 29 ++++++++++++++++++++++++--
3 files changed, 56 insertions(+), 5 deletions(-)
Comments
On 18/01/2021 13:25, Szabolcs Nagy via Libc-alpha wrote:
> From: "H.J. Lu" <hjl.tools@gmail.com>
>
> Since __libc_init_secure is called before ARCH_SETUP_TLS, it must use
> "int $0x80" for system calls in i386 static PIE. Add startup_getuid,
> startup_geteuid, startup_getgid and startup_getegid to <startup.h>.
> Update __libc_init_secure to use them.
LGTM, thanks.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> elf/enbl-secure.c | 6 +++---
> sysdeps/generic/startup.h | 26 +++++++++++++++++++++++
> sysdeps/unix/sysv/linux/i386/startup.h | 29 ++++++++++++++++++++++++--
> 3 files changed, 56 insertions(+), 5 deletions(-)
>
> diff --git a/elf/enbl-secure.c b/elf/enbl-secure.c
> index ffd7938605..9e47526bd3 100644
> --- a/elf/enbl-secure.c
> +++ b/elf/enbl-secure.c
> @@ -23,7 +23,7 @@
> #if BUILD_PIE_DEFAULT
> # pragma GCC visibility push(hidden)
> #endif
> -#include <unistd.h>
> +#include <startup.h>
> #include <libc-internal.h>
>
> /* If nonzero __libc_enable_secure is already set. */
> @@ -35,6 +35,6 @@ void
> __libc_init_secure (void)
> {
> if (__libc_enable_secure_decided == 0)
> - __libc_enable_secure = (__geteuid () != __getuid ()
> - || __getegid () != __getgid ());
> + __libc_enable_secure = (startup_geteuid () != startup_getuid ()
> + || startup_getegid () != startup_getgid ());
> }
Ok.
> diff --git a/sysdeps/generic/startup.h b/sysdeps/generic/startup.h
> index 56c899a65e..04f20cde47 100644
> --- a/sysdeps/generic/startup.h
> +++ b/sysdeps/generic/startup.h
> @@ -19,5 +19,31 @@
> /* Targets should override this file if the default definitions below
> will not work correctly very early before TLS is initialized. */
>
> +#include <unistd.h>
> +
> /* Use macro instead of inline function to avoid including <stdio.h>. */
> #define _startup_fatal(message) __libc_fatal ((message))
> +
> +static inline uid_t
> +startup_getuid (void)
> +{
> + return __getuid ();
> +}
> +
> +static inline uid_t
> +startup_geteuid (void)
> +{
> + return __geteuid ();
> +}
> +
> +static inline gid_t
> +startup_getgid (void)
> +{
> + return __getgid ();
> +}
> +
> +static inline gid_t
> +startup_getegid (void)
> +{
> + return __getegid ();
> +}
Ok.
> diff --git a/sysdeps/unix/sysv/linux/i386/startup.h b/sysdeps/unix/sysv/linux/i386/startup.h
> index 3eb4cc43a2..dee7a4f1d3 100644
> --- a/sysdeps/unix/sysv/linux/i386/startup.h
> +++ b/sysdeps/unix/sysv/linux/i386/startup.h
> @@ -17,11 +17,12 @@
> <https://www.gnu.org/licenses/>. */
>
> #if BUILD_PIE_DEFAULT
> -# include <abort-instr.h>
> -
> /* Can't use "call *%gs:SYSINFO_OFFSET" during statup in static PIE. */
> # define I386_USE_SYSENTER 0
>
> +# include <sysdep.h>
> +# include <abort-instr.h>
> +
> __attribute__ ((__noreturn__))
> static inline void
> _startup_fatal (const char *message __attribute__ ((unused)))
> @@ -31,6 +32,30 @@ _startup_fatal (const char *message __attribute__ ((unused)))
> ABORT_INSTRUCTION;
> __builtin_unreachable ();
> }
> +
> +static inline uid_t
> +startup_getuid (void)
> +{
> + return (uid_t) INTERNAL_SYSCALL_CALL (getuid32);
> +}
> +
> +static inline uid_t
> +startup_geteuid (void)
> +{
> + return (uid_t) INTERNAL_SYSCALL_CALL (geteuid32);
> +}
> +
> +static inline gid_t
> +startup_getgid (void)
> +{
> + return (gid_t) INTERNAL_SYSCALL_CALL (getgid32);
> +}
> +
> +static inline gid_t
> +startup_getegid (void)
> +{
> + return (gid_t) INTERNAL_SYSCALL_CALL (getegid32);
> +}
> #else
> # include_next <startup.h>
> #endif
>
Ok.
@@ -23,7 +23,7 @@
#if BUILD_PIE_DEFAULT
# pragma GCC visibility push(hidden)
#endif
-#include <unistd.h>
+#include <startup.h>
#include <libc-internal.h>
/* If nonzero __libc_enable_secure is already set. */
@@ -35,6 +35,6 @@ void
__libc_init_secure (void)
{
if (__libc_enable_secure_decided == 0)
- __libc_enable_secure = (__geteuid () != __getuid ()
- || __getegid () != __getgid ());
+ __libc_enable_secure = (startup_geteuid () != startup_getuid ()
+ || startup_getegid () != startup_getgid ());
}
@@ -19,5 +19,31 @@
/* Targets should override this file if the default definitions below
will not work correctly very early before TLS is initialized. */
+#include <unistd.h>
+
/* Use macro instead of inline function to avoid including <stdio.h>. */
#define _startup_fatal(message) __libc_fatal ((message))
+
+static inline uid_t
+startup_getuid (void)
+{
+ return __getuid ();
+}
+
+static inline uid_t
+startup_geteuid (void)
+{
+ return __geteuid ();
+}
+
+static inline gid_t
+startup_getgid (void)
+{
+ return __getgid ();
+}
+
+static inline gid_t
+startup_getegid (void)
+{
+ return __getegid ();
+}
@@ -17,11 +17,12 @@
<https://www.gnu.org/licenses/>. */
#if BUILD_PIE_DEFAULT
-# include <abort-instr.h>
-
/* Can't use "call *%gs:SYSINFO_OFFSET" during statup in static PIE. */
# define I386_USE_SYSENTER 0
+# include <sysdep.h>
+# include <abort-instr.h>
+
__attribute__ ((__noreturn__))
static inline void
_startup_fatal (const char *message __attribute__ ((unused)))
@@ -31,6 +32,30 @@ _startup_fatal (const char *message __attribute__ ((unused)))
ABORT_INSTRUCTION;
__builtin_unreachable ();
}
+
+static inline uid_t
+startup_getuid (void)
+{
+ return (uid_t) INTERNAL_SYSCALL_CALL (getuid32);
+}
+
+static inline uid_t
+startup_geteuid (void)
+{
+ return (uid_t) INTERNAL_SYSCALL_CALL (geteuid32);
+}
+
+static inline gid_t
+startup_getgid (void)
+{
+ return (gid_t) INTERNAL_SYSCALL_CALL (getgid32);
+}
+
+static inline gid_t
+startup_getegid (void)
+{
+ return (gid_t) INTERNAL_SYSCALL_CALL (getegid32);
+}
#else
# include_next <startup.h>
#endif