Fix getting tunable values on big-endian (BZ #21109)

The code to set value passed a tunable_val_t, which when cast to
int32_t on big-endian gives the wrong value.  Instead, use
tunable_val_t.numval instead, which can then be safely cast into
int32_t.

2 files changed, 4 insertions, 2 deletions

diff --git a/elf/dl-tunable-types.h b/elf/dl-tunable-types.h
index a986f0b593..37a4e8021f 100644
--- a/elf/dl-tunable-types.h
+++ b/elf/dl-tunable-types.h
@@ -21,8 +21,6 @@
 # define _TUNABLE_TYPES_H_
 #include <stddef.h>
 
-typedef void (*tunable_callback_t) (void *);
-
 typedef enum
 {
   TUNABLE_TYPE_INT_32,
@@ -43,6 +41,8 @@ typedef union
   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
diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
index a8d53d6a31..e42aa67003 100644
--- a/elf/dl-tunables.c
+++ b/elf/dl-tunables.c
@@ -455,6 +455,8 @@ __tunable_set_val (tunable_id_t id, void *valp, tunable_callback_t callback)
   if (cur->strval == NULL)
     return;
 
+  /* Caller does not need the value, just call the callback with our tunable
+     value.  */
   if (valp == NULL)
     goto cb;