Fix SPARC64 handling of R_SPARC_H34 (bug 24231).

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.

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

diff --git a/ChangeLog b/ChangeLog
index 312ef3b..de10cb5 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+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.
+
 2019-02-18  Florian Weimer  <fweimer@redhat.com>
 
        * resolv/compat-gethnamaddr.c (Dprintf): Remove definition.

diff --git a/sysdeps/sparc/sparc64/dl-machine.h b/sysdeps/sparc/sparc64/dl-machine.h
index 2fb207d..1493089 100644 (file)
--- 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: