[glibc/nsz/bug27072] elf: Make the tunable struct definition internal only

[glibc/nsz/bug27072] elf: Make the tunable struct definition internal only

[Szabolcs Nagy]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=54f2ce33f2ca2a30066bf0d43fb733b46aeda10c

commit 54f2ce33f2ca2a30066bf0d43fb733b46aeda10c
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Wed Jan 6 17:19:24 2021 +0000

    elf: Make the tunable struct definition internal only
    
    The representation of the tunables including type information and
    the tunable list structure are only used in the implementation not
    in the tunables api that is exposed to usage within glibc.
    
    This patch moves the representation related definitions into the
    existing dl-tunable-types.h and uses that only for implementation.
    
    The tunable callback and related types are moved to dl-tunables.h
    because they are part of the tunables api.
    
    This reduces the details exposed in the tunables api so the internals
    are easier to change.
    
    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

Diff:
---
 elf/dl-tunable-types.h   | 42 ++++++++++++++++++++++++++++++++----------
 elf/dl-tunables.h        | 35 ++++++++---------------------------
 scripts/gen-tunables.awk |  4 +++-
 3 files changed, 43 insertions(+), 38 deletions(-)

diff --git a/elf/dl-tunable-types.h b/elf/dl-tunable-types.h
index 8f6a383dcc..05d4958e1c 100644
--- a/elf/dl-tunable-types.h
+++ b/elf/dl-tunable-types.h
@@ -1,4 +1,4 @@
-/* Tunable type information.
+/* Internal representation of tunables.
 
    Copyright (C) 2016-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
@@ -18,8 +18,14 @@
    <https://www.gnu.org/licenses/>.  */
 
 #ifndef _TUNABLE_TYPES_H_
-# define _TUNABLE_TYPES_H_
+#define _TUNABLE_TYPES_H_
+
+/* Note: This header is included in the generated dl-tunables-list.h and
+   only used internally in the tunables implementation in dl-tunables.c.  */
+
+#include <stdbool.h>
 #include <stddef.h>
+#include <stdint.h>
 
 typedef enum
 {
@@ -36,14 +42,6 @@ typedef struct
   int64_t max;
 } tunable_type_t;
 
-typedef union
-{
-  int64_t numval;
-  const char *strval;
-} tunable_val_t;
-
-typedef void (*tunable_callback_t) (tunable_val_t *);
-
 /* Security level for tunables.  This decides what to do with individual
    tunables for AT_SECURE binaries.  */
 typedef enum
@@ -58,5 +56,29 @@ typedef enum
   TUNABLE_SECLEVEL_NONE = 2,
 } tunable_seclevel_t;
 
+/* A tunable.  */
+struct _tunable
+{
+  const char *name;			/* Internal name of the tunable.  */
+  tunable_type_t type;			/* Data type of the tunable.  */
+  tunable_val_t val;			/* The value.  */
+  bool initialized;			/* Flag to indicate that the tunable is
+					   initialized.  */
+  tunable_seclevel_t security_level;	/* Specify the security level for the
+					   tunable with respect to AT_SECURE
+					   programs.  See description of
+					   tunable_seclevel_t to see a
+					   description of the values.
+
+					   Note that even if the tunable is
+					   read, it may not get used by the
+					   target module if the value is
+					   considered unsafe.  */
+  /* Compatibility elements.  */
+  const char *env_alias;		/* The compatibility environment
+					   variable name.  */
+};
+
+typedef struct _tunable tunable_t;
 
 #endif
diff --git a/elf/dl-tunables.h b/elf/dl-tunables.h
index 518342a300..1773c7e254 100644
--- a/elf/dl-tunables.h
+++ b/elf/dl-tunables.h
@@ -21,8 +21,6 @@
 #ifndef _TUNABLES_H_
 #define _TUNABLES_H_
 
-#include <stdbool.h>
-
 #if !HAVE_TUNABLES
 static inline void
 __always_inline
@@ -31,34 +29,17 @@ __tunables_init (char **unused __attribute__ ((unused)))
   /* This is optimized out if tunables are not enabled.  */
 }
 #else
-
+# include <stdbool.h>
 # include <stddef.h>
-# include "dl-tunable-types.h"
+# include <stdint.h>
 
-/* A tunable.  */
-struct _tunable
+typedef union
 {
-  const char *name;			/* Internal name of the tunable.  */
-  tunable_type_t type;			/* Data type of the tunable.  */
-  tunable_val_t val;			/* The value.  */
-  bool initialized;			/* Flag to indicate that the tunable is
-					   initialized.  */
-  tunable_seclevel_t security_level;	/* Specify the security level for the
-					   tunable with respect to AT_SECURE
-					   programs.  See description of
-					   tunable_seclevel_t to see a
-					   description of the values.
-
-					   Note that even if the tunable is
-					   read, it may not get used by the
-					   target module if the value is
-					   considered unsafe.  */
-  /* Compatibility elements.  */
-  const char *env_alias;		/* The compatibility environment
-					   variable name.  */
-};
-
-typedef struct _tunable tunable_t;
+  int64_t numval;
+  const char *strval;
+} tunable_val_t;
+
+typedef void (*tunable_callback_t) (tunable_val_t *);
 
 /* Full name for a tunable is top_ns.tunable_ns.id.  */
 # define TUNABLE_NAME_S(top,ns,id) #top "." #ns "." #id
diff --git a/scripts/gen-tunables.awk b/scripts/gen-tunables.awk
index 622199061a..cda12ef62e 100644
--- a/scripts/gen-tunables.awk
+++ b/scripts/gen-tunables.awk
@@ -156,8 +156,10 @@ END {
   }
   print "} tunable_id_t;\n"
 
-  # Finally, the tunable list.
   print "\n#ifdef TUNABLES_INTERNAL"
+  # Internal definitions.
+  print "# include \"dl-tunable-types.h\""
+  # Finally, the tunable list.
   print "static tunable_t tunable_list[] attribute_relro = {"
   for (tnm in types) {
     split (tnm, indices, SUBSEP);

[glibc/nsz/bug27072] elf: Make the tunable struct definition internal only

[Szabolcs Nagy]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=e0ed9fdf7ed022cd77c59cac1f944e6c6c4bbbaf

commit e0ed9fdf7ed022cd77c59cac1f944e6c6c4bbbaf
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Wed Jan 6 17:19:24 2021 +0000

    elf: Make the tunable struct definition internal only
    
    The representation of the tunables including type information and
    the tunable list structure are only used in the implementation not
    in the tunables api that is exposed to usage within glibc.
    
    This patch moves the representation related definitions into the
    existing dl-tunable-types.h and uses that only for implementation.
    
    The tunable callback and related types are moved to dl-tunables.h
    because they are part of the tunables api.
    
    This reduces the details exposed in the tunables api so the internals
    are easier to change.
    
    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

Diff:
---
 elf/dl-tunable-types.h   | 42 ++++++++++++++++++++++++++++++++----------
 elf/dl-tunables.h        | 35 ++++++++---------------------------
 scripts/gen-tunables.awk |  4 +++-
 3 files changed, 43 insertions(+), 38 deletions(-)

diff --git a/elf/dl-tunable-types.h b/elf/dl-tunable-types.h
index 8f6a383dcc..05d4958e1c 100644
--- a/elf/dl-tunable-types.h
+++ b/elf/dl-tunable-types.h
@@ -1,4 +1,4 @@
-/* Tunable type information.
+/* Internal representation of tunables.
 
    Copyright (C) 2016-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
@@ -18,8 +18,14 @@
    <https://www.gnu.org/licenses/>.  */
 
 #ifndef _TUNABLE_TYPES_H_
-# define _TUNABLE_TYPES_H_
+#define _TUNABLE_TYPES_H_
+
+/* Note: This header is included in the generated dl-tunables-list.h and
+   only used internally in the tunables implementation in dl-tunables.c.  */
+
+#include <stdbool.h>
 #include <stddef.h>
+#include <stdint.h>
 
 typedef enum
 {
@@ -36,14 +42,6 @@ typedef struct
   int64_t max;
 } tunable_type_t;
 
-typedef union
-{
-  int64_t numval;
-  const char *strval;
-} tunable_val_t;
-
-typedef void (*tunable_callback_t) (tunable_val_t *);
-
 /* Security level for tunables.  This decides what to do with individual
    tunables for AT_SECURE binaries.  */
 typedef enum
@@ -58,5 +56,29 @@ typedef enum
   TUNABLE_SECLEVEL_NONE = 2,
 } tunable_seclevel_t;
 
+/* A tunable.  */
+struct _tunable
+{
+  const char *name;			/* Internal name of the tunable.  */
+  tunable_type_t type;			/* Data type of the tunable.  */
+  tunable_val_t val;			/* The value.  */
+  bool initialized;			/* Flag to indicate that the tunable is
+					   initialized.  */
+  tunable_seclevel_t security_level;	/* Specify the security level for the
+					   tunable with respect to AT_SECURE
+					   programs.  See description of
+					   tunable_seclevel_t to see a
+					   description of the values.
+
+					   Note that even if the tunable is
+					   read, it may not get used by the
+					   target module if the value is
+					   considered unsafe.  */
+  /* Compatibility elements.  */
+  const char *env_alias;		/* The compatibility environment
+					   variable name.  */
+};
+
+typedef struct _tunable tunable_t;
 
 #endif
diff --git a/elf/dl-tunables.h b/elf/dl-tunables.h
index dfa16c1977..971376ba8d 100644
--- a/elf/dl-tunables.h
+++ b/elf/dl-tunables.h
@@ -21,8 +21,6 @@
 #ifndef _TUNABLES_H_
 #define _TUNABLES_H_
 
-#include <stdbool.h>
-
 #if !HAVE_TUNABLES
 static inline void
 __always_inline
@@ -31,34 +29,17 @@ __tunables_init (char **unused __attribute__ ((unused)))
   /* This is optimized out if tunables are not enabled.  */
 }
 #else
-
+# include <stdbool.h>
 # include <stddef.h>
-# include "dl-tunable-types.h"
+# include <stdint.h>
 
-/* A tunable.  */
-struct _tunable
+typedef union
 {
-  const char *name;			/* Internal name of the tunable.  */
-  tunable_type_t type;			/* Data type of the tunable.  */
-  tunable_val_t val;			/* The value.  */
-  bool initialized;			/* Flag to indicate that the tunable is
-					   initialized.  */
-  tunable_seclevel_t security_level;	/* Specify the security level for the
-					   tunable with respect to AT_SECURE
-					   programs.  See description of
-					   tunable_seclevel_t to see a
-					   description of the values.
-
-					   Note that even if the tunable is
-					   read, it may not get used by the
-					   target module if the value is
-					   considered unsafe.  */
-  /* Compatibility elements.  */
-  const char *env_alias;		/* The compatibility environment
-					   variable name.  */
-};
-
-typedef struct _tunable tunable_t;
+  int64_t numval;
+  const char *strval;
+} tunable_val_t;
+
+typedef void (*tunable_callback_t) (tunable_val_t *);
 
 /* Full name for a tunable is top_ns.tunable_ns.id.  */
 # define TUNABLE_NAME_S(top,ns,id) #top "." #ns "." #id
diff --git a/scripts/gen-tunables.awk b/scripts/gen-tunables.awk
index 622199061a..cda12ef62e 100644
--- a/scripts/gen-tunables.awk
+++ b/scripts/gen-tunables.awk
@@ -156,8 +156,10 @@ END {
   }
   print "} tunable_id_t;\n"
 
-  # Finally, the tunable list.
   print "\n#ifdef TUNABLES_INTERNAL"
+  # Internal definitions.
+  print "# include \"dl-tunable-types.h\""
+  # Finally, the tunable list.
   print "static tunable_t tunable_list[] attribute_relro = {"
   for (tnm in types) {
     split (tnm, indices, SUBSEP);

[glibc/nsz/bug27072] elf: Make the tunable struct definition internal only

[Szabolcs Nagy]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=0d5328b83b67ab0d38bb41f231675d05ec495cae

commit 0d5328b83b67ab0d38bb41f231675d05ec495cae
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Wed Jan 6 17:19:24 2021 +0000

    elf: Make the tunable struct definition internal only
    
    The representation of the tunables including type information and
    the tunable list structure are only used in the implementation not
    in the tunables api that is exposed to usage within glibc.
    
    This patch moves the representation related definitions into the
    existing dl-tunable-types.h and uses that only for implementation.
    
    The tunable callback and related types are moved to dl-tunables.h
    because they are part of the tunables api.
    
    This reduces the details exposed in the tunables api so the internals
    are easier to change.
    
    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

Diff:
---
 elf/dl-tunable-types.h   | 42 ++++++++++++++++++++++++++++++++----------
 elf/dl-tunables.h        | 35 ++++++++---------------------------
 scripts/gen-tunables.awk |  4 +++-
 3 files changed, 43 insertions(+), 38 deletions(-)

diff --git a/elf/dl-tunable-types.h b/elf/dl-tunable-types.h
index 8f6a383dcc..05d4958e1c 100644
--- a/elf/dl-tunable-types.h
+++ b/elf/dl-tunable-types.h
@@ -1,4 +1,4 @@
-/* Tunable type information.
+/* Internal representation of tunables.
 
    Copyright (C) 2016-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
@@ -18,8 +18,14 @@
    <https://www.gnu.org/licenses/>.  */
 
 #ifndef _TUNABLE_TYPES_H_
-# define _TUNABLE_TYPES_H_
+#define _TUNABLE_TYPES_H_
+
+/* Note: This header is included in the generated dl-tunables-list.h and
+   only used internally in the tunables implementation in dl-tunables.c.  */
+
+#include <stdbool.h>
 #include <stddef.h>
+#include <stdint.h>
 
 typedef enum
 {
@@ -36,14 +42,6 @@ typedef struct
   int64_t max;
 } tunable_type_t;
 
-typedef union
-{
-  int64_t numval;
-  const char *strval;
-} tunable_val_t;
-
-typedef void (*tunable_callback_t) (tunable_val_t *);
-
 /* Security level for tunables.  This decides what to do with individual
    tunables for AT_SECURE binaries.  */
 typedef enum
@@ -58,5 +56,29 @@ typedef enum
   TUNABLE_SECLEVEL_NONE = 2,
 } tunable_seclevel_t;
 
+/* A tunable.  */
+struct _tunable
+{
+  const char *name;			/* Internal name of the tunable.  */
+  tunable_type_t type;			/* Data type of the tunable.  */
+  tunable_val_t val;			/* The value.  */
+  bool initialized;			/* Flag to indicate that the tunable is
+					   initialized.  */
+  tunable_seclevel_t security_level;	/* Specify the security level for the
+					   tunable with respect to AT_SECURE
+					   programs.  See description of
+					   tunable_seclevel_t to see a
+					   description of the values.
+
+					   Note that even if the tunable is
+					   read, it may not get used by the
+					   target module if the value is
+					   considered unsafe.  */
+  /* Compatibility elements.  */
+  const char *env_alias;		/* The compatibility environment
+					   variable name.  */
+};
+
+typedef struct _tunable tunable_t;
 
 #endif
diff --git a/elf/dl-tunables.h b/elf/dl-tunables.h
index dfa16c1977..971376ba8d 100644
--- a/elf/dl-tunables.h
+++ b/elf/dl-tunables.h
@@ -21,8 +21,6 @@
 #ifndef _TUNABLES_H_
 #define _TUNABLES_H_
 
-#include <stdbool.h>
-
 #if !HAVE_TUNABLES
 static inline void
 __always_inline
@@ -31,34 +29,17 @@ __tunables_init (char **unused __attribute__ ((unused)))
   /* This is optimized out if tunables are not enabled.  */
 }
 #else
-
+# include <stdbool.h>
 # include <stddef.h>
-# include "dl-tunable-types.h"
+# include <stdint.h>
 
-/* A tunable.  */
-struct _tunable
+typedef union
 {
-  const char *name;			/* Internal name of the tunable.  */
-  tunable_type_t type;			/* Data type of the tunable.  */
-  tunable_val_t val;			/* The value.  */
-  bool initialized;			/* Flag to indicate that the tunable is
-					   initialized.  */
-  tunable_seclevel_t security_level;	/* Specify the security level for the
-					   tunable with respect to AT_SECURE
-					   programs.  See description of
-					   tunable_seclevel_t to see a
-					   description of the values.
-
-					   Note that even if the tunable is
-					   read, it may not get used by the
-					   target module if the value is
-					   considered unsafe.  */
-  /* Compatibility elements.  */
-  const char *env_alias;		/* The compatibility environment
-					   variable name.  */
-};
-
-typedef struct _tunable tunable_t;
+  int64_t numval;
+  const char *strval;
+} tunable_val_t;
+
+typedef void (*tunable_callback_t) (tunable_val_t *);
 
 /* Full name for a tunable is top_ns.tunable_ns.id.  */
 # define TUNABLE_NAME_S(top,ns,id) #top "." #ns "." #id
diff --git a/scripts/gen-tunables.awk b/scripts/gen-tunables.awk
index 622199061a..cda12ef62e 100644
--- a/scripts/gen-tunables.awk
+++ b/scripts/gen-tunables.awk
@@ -156,8 +156,10 @@ END {
   }
   print "} tunable_id_t;\n"
 
-  # Finally, the tunable list.
   print "\n#ifdef TUNABLES_INTERNAL"
+  # Internal definitions.
+  print "# include \"dl-tunable-types.h\""
+  # Finally, the tunable list.
   print "static tunable_t tunable_list[] attribute_relro = {"
   for (tnm in types) {
     split (tnm, indices, SUBSEP);

[glibc/nsz/bug27072] elf: Make the tunable struct definition internal only

[Szabolcs Nagy]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=58d4e6b7948d34f948b7a04386f5ec6baa82b9ff

commit 58d4e6b7948d34f948b7a04386f5ec6baa82b9ff
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Wed Jan 6 17:19:24 2021 +0000

    elf: Make the tunable struct definition internal only
    
    The representation of the tunables including type information and
    the tunable list structure are only used in the implementation not
    in the tunables api that is exposed to usage within glibc.
    
    This patch moves the representation related definitions into the
    existing dl-tunable-types.h and uses that only for implementation.
    
    The tunable callback and related types are moved to dl-tunables.h
    because they are part of the tunables api.
    
    This reduces the details exposed in the tunables api so the internals
    are easier to change.
    
    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

Diff:
---
 elf/dl-tunable-types.h   | 42 ++++++++++++++++++++++++++++++++----------
 elf/dl-tunables.h        | 35 ++++++++---------------------------
 scripts/gen-tunables.awk |  4 +++-
 3 files changed, 43 insertions(+), 38 deletions(-)

diff --git a/elf/dl-tunable-types.h b/elf/dl-tunable-types.h
index 8f6a383dcc..05d4958e1c 100644
--- a/elf/dl-tunable-types.h
+++ b/elf/dl-tunable-types.h
@@ -1,4 +1,4 @@
-/* Tunable type information.
+/* Internal representation of tunables.
 
    Copyright (C) 2016-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
@@ -18,8 +18,14 @@
    <https://www.gnu.org/licenses/>.  */
 
 #ifndef _TUNABLE_TYPES_H_
-# define _TUNABLE_TYPES_H_
+#define _TUNABLE_TYPES_H_
+
+/* Note: This header is included in the generated dl-tunables-list.h and
+   only used internally in the tunables implementation in dl-tunables.c.  */
+
+#include <stdbool.h>
 #include <stddef.h>
+#include <stdint.h>
 
 typedef enum
 {
@@ -36,14 +42,6 @@ typedef struct
   int64_t max;
 } tunable_type_t;
 
-typedef union
-{
-  int64_t numval;
-  const char *strval;
-} tunable_val_t;
-
-typedef void (*tunable_callback_t) (tunable_val_t *);
-
 /* Security level for tunables.  This decides what to do with individual
    tunables for AT_SECURE binaries.  */
 typedef enum
@@ -58,5 +56,29 @@ typedef enum
   TUNABLE_SECLEVEL_NONE = 2,
 } tunable_seclevel_t;
 
+/* A tunable.  */
+struct _tunable
+{
+  const char *name;			/* Internal name of the tunable.  */
+  tunable_type_t type;			/* Data type of the tunable.  */
+  tunable_val_t val;			/* The value.  */
+  bool initialized;			/* Flag to indicate that the tunable is
+					   initialized.  */
+  tunable_seclevel_t security_level;	/* Specify the security level for the
+					   tunable with respect to AT_SECURE
+					   programs.  See description of
+					   tunable_seclevel_t to see a
+					   description of the values.
+
+					   Note that even if the tunable is
+					   read, it may not get used by the
+					   target module if the value is
+					   considered unsafe.  */
+  /* Compatibility elements.  */
+  const char *env_alias;		/* The compatibility environment
+					   variable name.  */
+};
+
+typedef struct _tunable tunable_t;
 
 #endif
diff --git a/elf/dl-tunables.h b/elf/dl-tunables.h
index dfa16c1977..971376ba8d 100644
--- a/elf/dl-tunables.h
+++ b/elf/dl-tunables.h
@@ -21,8 +21,6 @@
 #ifndef _TUNABLES_H_
 #define _TUNABLES_H_
 
-#include <stdbool.h>
-
 #if !HAVE_TUNABLES
 static inline void
 __always_inline
@@ -31,34 +29,17 @@ __tunables_init (char **unused __attribute__ ((unused)))
   /* This is optimized out if tunables are not enabled.  */
 }
 #else
-
+# include <stdbool.h>
 # include <stddef.h>
-# include "dl-tunable-types.h"
+# include <stdint.h>
 
-/* A tunable.  */
-struct _tunable
+typedef union
 {
-  const char *name;			/* Internal name of the tunable.  */
-  tunable_type_t type;			/* Data type of the tunable.  */
-  tunable_val_t val;			/* The value.  */
-  bool initialized;			/* Flag to indicate that the tunable is
-					   initialized.  */
-  tunable_seclevel_t security_level;	/* Specify the security level for the
-					   tunable with respect to AT_SECURE
-					   programs.  See description of
-					   tunable_seclevel_t to see a
-					   description of the values.
-
-					   Note that even if the tunable is
-					   read, it may not get used by the
-					   target module if the value is
-					   considered unsafe.  */
-  /* Compatibility elements.  */
-  const char *env_alias;		/* The compatibility environment
-					   variable name.  */
-};
-
-typedef struct _tunable tunable_t;
+  int64_t numval;
+  const char *strval;
+} tunable_val_t;
+
+typedef void (*tunable_callback_t) (tunable_val_t *);
 
 /* Full name for a tunable is top_ns.tunable_ns.id.  */
 # define TUNABLE_NAME_S(top,ns,id) #top "." #ns "." #id
diff --git a/scripts/gen-tunables.awk b/scripts/gen-tunables.awk
index 622199061a..cda12ef62e 100644
--- a/scripts/gen-tunables.awk
+++ b/scripts/gen-tunables.awk
@@ -156,8 +156,10 @@ END {
   }
   print "} tunable_id_t;\n"
 
-  # Finally, the tunable list.
   print "\n#ifdef TUNABLES_INTERNAL"
+  # Internal definitions.
+  print "# include \"dl-tunable-types.h\""
+  # Finally, the tunable list.
   print "static tunable_t tunable_list[] attribute_relro = {"
   for (tnm in types) {
     split (tnm, indices, SUBSEP);

[glibc/nsz/bug27072] elf: Make the tunable struct definition internal only

[Szabolcs Nagy]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=7b64c9aa6cd771ec569c51d50395147e4b22acc5

commit 7b64c9aa6cd771ec569c51d50395147e4b22acc5
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Wed Jan 6 17:19:24 2021 +0000

    elf: Make the tunable struct definition internal only
    
    The representation of the tunables including type information and
    the tunable list structure are only used in the implementation not
    in the tunables api that is exposed to usage within glibc.
    
    This patch moves the representation related definitions into the
    existing dl-tunable-types.h and uses that only for implementation.
    
    The tunable callback and related types are moved to dl-tunables.h
    because they are part of the tunables api.
    
    This reduces the details exposed in the tunables api so the internals
    are easier to change.

Diff:
---
 elf/dl-tunable-types.h   | 42 ++++++++++++++++++++++++++++++++----------
 elf/dl-tunables.h        | 35 ++++++++---------------------------
 scripts/gen-tunables.awk |  4 +++-
 3 files changed, 43 insertions(+), 38 deletions(-)

diff --git a/elf/dl-tunable-types.h b/elf/dl-tunable-types.h
index 8f6a383dcc..05d4958e1c 100644
--- a/elf/dl-tunable-types.h
+++ b/elf/dl-tunable-types.h
@@ -1,4 +1,4 @@
-/* Tunable type information.
+/* Internal representation of tunables.
 
    Copyright (C) 2016-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
@@ -18,8 +18,14 @@
    <https://www.gnu.org/licenses/>.  */
 
 #ifndef _TUNABLE_TYPES_H_
-# define _TUNABLE_TYPES_H_
+#define _TUNABLE_TYPES_H_
+
+/* Note: This header is included in the generated dl-tunables-list.h and
+   only used internally in the tunables implementation in dl-tunables.c.  */
+
+#include <stdbool.h>
 #include <stddef.h>
+#include <stdint.h>
 
 typedef enum
 {
@@ -36,14 +42,6 @@ typedef struct
   int64_t max;
 } tunable_type_t;
 
-typedef union
-{
-  int64_t numval;
-  const char *strval;
-} tunable_val_t;
-
-typedef void (*tunable_callback_t) (tunable_val_t *);
-
 /* Security level for tunables.  This decides what to do with individual
    tunables for AT_SECURE binaries.  */
 typedef enum
@@ -58,5 +56,29 @@ typedef enum
   TUNABLE_SECLEVEL_NONE = 2,
 } tunable_seclevel_t;
 
+/* A tunable.  */
+struct _tunable
+{
+  const char *name;			/* Internal name of the tunable.  */
+  tunable_type_t type;			/* Data type of the tunable.  */
+  tunable_val_t val;			/* The value.  */
+  bool initialized;			/* Flag to indicate that the tunable is
+					   initialized.  */
+  tunable_seclevel_t security_level;	/* Specify the security level for the
+					   tunable with respect to AT_SECURE
+					   programs.  See description of
+					   tunable_seclevel_t to see a
+					   description of the values.
+
+					   Note that even if the tunable is
+					   read, it may not get used by the
+					   target module if the value is
+					   considered unsafe.  */
+  /* Compatibility elements.  */
+  const char *env_alias;		/* The compatibility environment
+					   variable name.  */
+};
+
+typedef struct _tunable tunable_t;
 
 #endif
diff --git a/elf/dl-tunables.h b/elf/dl-tunables.h
index 518342a300..1773c7e254 100644
--- a/elf/dl-tunables.h
+++ b/elf/dl-tunables.h
@@ -21,8 +21,6 @@
 #ifndef _TUNABLES_H_
 #define _TUNABLES_H_
 
-#include <stdbool.h>
-
 #if !HAVE_TUNABLES
 static inline void
 __always_inline
@@ -31,34 +29,17 @@ __tunables_init (char **unused __attribute__ ((unused)))
   /* This is optimized out if tunables are not enabled.  */
 }
 #else
-
+# include <stdbool.h>
 # include <stddef.h>
-# include "dl-tunable-types.h"
+# include <stdint.h>
 
-/* A tunable.  */
-struct _tunable
+typedef union
 {
-  const char *name;			/* Internal name of the tunable.  */
-  tunable_type_t type;			/* Data type of the tunable.  */
-  tunable_val_t val;			/* The value.  */
-  bool initialized;			/* Flag to indicate that the tunable is
-					   initialized.  */
-  tunable_seclevel_t security_level;	/* Specify the security level for the
-					   tunable with respect to AT_SECURE
-					   programs.  See description of
-					   tunable_seclevel_t to see a
-					   description of the values.
-
-					   Note that even if the tunable is
-					   read, it may not get used by the
-					   target module if the value is
-					   considered unsafe.  */
-  /* Compatibility elements.  */
-  const char *env_alias;		/* The compatibility environment
-					   variable name.  */
-};
-
-typedef struct _tunable tunable_t;
+  int64_t numval;
+  const char *strval;
+} tunable_val_t;
+
+typedef void (*tunable_callback_t) (tunable_val_t *);
 
 /* Full name for a tunable is top_ns.tunable_ns.id.  */
 # define TUNABLE_NAME_S(top,ns,id) #top "." #ns "." #id
diff --git a/scripts/gen-tunables.awk b/scripts/gen-tunables.awk
index 622199061a..cda12ef62e 100644
--- a/scripts/gen-tunables.awk
+++ b/scripts/gen-tunables.awk
@@ -156,8 +156,10 @@ END {
   }
   print "} tunable_id_t;\n"
 
-  # Finally, the tunable list.
   print "\n#ifdef TUNABLES_INTERNAL"
+  # Internal definitions.
+  print "# include \"dl-tunable-types.h\""
+  # Finally, the tunable list.
   print "static tunable_t tunable_list[] attribute_relro = {"
   for (tnm in types) {
     split (tnm, indices, SUBSEP);