diff --git a/ChangeLog b/ChangeLog
index 0862ad09bd..e2caa3ee61 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2017-03-18  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #21261]
+	* sysdeps/unix/sysv/linux/sparc/bits/setjmp.h
+	[__WORDSIZE == 64 && !_ASM] (__sparc64_jmp_buf): Use reserved
+	names for all fields.
+	* sysdeps/sparc/sparc64/jmpbuf-unwind.h (_JMPBUF_UNWINDS): Update
+	for jmp_buf field renaming.
+	(_JMPBUF_UNWINDS_ADJ): Likewise.
+
 	* conform/conformtest.pl: Handle xfail[cond]- in header mentioned
 	with allow-header.
 
diff --git a/sysdeps/sparc/sparc64/jmpbuf-unwind.h b/sysdeps/sparc/sparc64/jmpbuf-unwind.h
index d84a5ea410..eb2e2e2fb4 100644
--- a/sysdeps/sparc/sparc64/jmpbuf-unwind.h
+++ b/sysdeps/sparc/sparc64/jmpbuf-unwind.h
@@ -22,15 +22,16 @@
 
 /* Test if longjmp to JMPBUF would unwind the frame
    containing a local variable at ADDRESS.  */
-#define _JMPBUF_UNWINDS(jmpbuf, address, demangle)			\
-  ((unsigned long int) (address) < (jmpbuf)->uc_mcontext.mc_gregs[MC_O6] + 2047)
+#define _JMPBUF_UNWINDS(jmpbuf, address, demangle)	\
+  ((unsigned long int) (address)			\
+   < (jmpbuf)->__uc_mcontext.__mc_gregs[MC_O6] + 2047)
 
 #define _JMPBUF_CFA_UNWINDS_ADJ(_jmpbuf, _context, _adj) \
   _JMPBUF_UNWINDS_ADJ (_jmpbuf, (void *) _Unwind_GetCFA (_context), _adj)
 
 #define _JMPBUF_UNWINDS_ADJ(_jmpbuf, _address, _adj) \
   ((uintptr_t) (_address) - (_adj) \
-   < (uintptr_t) (_jmpbuf)[0].uc_mcontext.mc_gregs[MC_O6] + 2047 - (_adj))
+   < (uintptr_t) (_jmpbuf)[0].__uc_mcontext.__mc_gregs[MC_O6] + 2047 - (_adj))
 
 /* We use the normal lobngjmp for unwinding.  */
 #define __libc_unwind_longjmp(buf, val) __libc_longjmp (buf, val)
diff --git a/sysdeps/unix/sysv/linux/sparc/bits/setjmp.h b/sysdeps/unix/sysv/linux/sparc/bits/setjmp.h
index e43bc72a6b..5e92e829d5 100644
--- a/sysdeps/unix/sysv/linux/sparc/bits/setjmp.h
+++ b/sysdeps/unix/sysv/linux/sparc/bits/setjmp.h
@@ -29,30 +29,30 @@
 #ifndef _ASM
 typedef struct __sparc64_jmp_buf
   {
-    struct __sparc64_jmp_buf	*uc_link;
-    unsigned long		uc_flags;
-    unsigned long		uc_sigmask;
+    struct __sparc64_jmp_buf	*__uc_link;
+    unsigned long		__uc_flags;
+    unsigned long		__uc_sigmask;
     struct __sparc64_jmp_buf_mcontext
       {
-	unsigned long		mc_gregs[19];
-	unsigned long		mc_fp;
-	unsigned long		mc_i7;
+	unsigned long		__mc_gregs[19];
+	unsigned long		__mc_fp;
+	unsigned long		__mc_i7;
 	struct __sparc64_jmp_buf_fpu
 	  {
 	    union
 	      {
-		unsigned int	sregs[32];
-		unsigned long	dregs[32];
-		long double	qregs[16];
-	      }			mcfpu_fpregs;
-	    unsigned long	mcfpu_fprs;
-	    unsigned long	mcfpu_gsr;
-	    void		*mcfpu_fq;
-	    unsigned char	mcfpu_qcnt;
-	    unsigned char	mcfpu_qentsz;
-	    unsigned char	mcfpu_enab;
-	  }			mc_fpregs;
-      }				uc_mcontext;
+		unsigned int	__sregs[32];
+		unsigned long	__dregs[32];
+		long double	__qregs[16];
+	      }			__mcfpu_fpregs;
+	    unsigned long	__mcfpu_fprs;
+	    unsigned long	__mcfpu_gsr;
+	    void		*__mcfpu_fq;
+	    unsigned char	__mcfpu_qcnt;
+	    unsigned char	__mcfpu_qentsz;
+	    unsigned char	__mcfpu_enab;
+	  }			__mc_fpregs;
+      }				__uc_mcontext;
   } __jmp_buf[1];
 #endif