Fix SPARC64 handling of R_SPARC_H34 (bug 24231)

[Joseph Myers]

Building glibc with -Wextra shows a -Wimplicit-fallthrough warning for
SPARC64 that appears to be a real bug in glibc.  The dynamic linker
handling of R_SPARC_H34 falls through to that of R_SPARC_H44, which in
the case of this code is nonsensical (it means the value computed for
R_SPARC_H34 gets overwritten by one computed with the different logic
for R_SPARC_H44).  Thus, this patch adds the missing break there.
Note: I do not have a testcase to demonstrate this bug.

Tested with build-many-glibcs.py.

2019-02-18  Joseph Myers  <joseph@codesourcery.com>

	[BZ #24231]
	* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_rela): Add break
	after R_SPARC_H34 case.

diff --git a/sysdeps/sparc/sparc64/dl-machine.h b/sysdeps/sparc/sparc64/dl-machine.h
index 2fb207dc2d..14930890e3 100644
--- a/sysdeps/sparc/sparc64/dl-machine.h
+++ b/sysdeps/sparc/sparc64/dl-machine.h
@@ -573,6 +573,7 @@ elf_machine_rela (struct link_map *map, const Elf64_Rela *reloc,
       *(unsigned int *) reloc_addr =
 	((*(unsigned int *)reloc_addr & 0xffc00000) |
 	 ((value >> 12) & 0x3fffff));
+      break;
 
       /* MEDMID code model relocs */
     case R_SPARC_H44:

-- 
Joseph S. Myers
joseph@codesourcery.com