elf: Allow core dump-related fields to be overridden

Allow some core dump-related fields to be overridden.  This allows
core dumps to work correctly for x32.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>

1 files changed, 20 insertions, 4 deletions

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index bcb884e2d613..43ba478c3386 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1390,6 +1390,22 @@ static void do_thread_regset_writeback(struct task_struct *task,
                 regset->writeback(task, regset, 1);
 }
 
+#ifndef PR_REG_SIZE
+#define PR_REG_SIZE(S) sizeof(S)
+#endif
+
+#ifndef PRSTATUS_SIZE
+#define PRSTATUS_SIZE(S) sizeof(S)
+#endif
+
+#ifndef PR_REG_PTR
+#define PR_REG_PTR(S) (&((S)->pr_reg))
+#endif
+
+#ifndef SET_PR_FPVALID
+#define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
+#endif
+
 static int fill_thread_core_info(struct elf_thread_core_info *t,
                                  const struct user_regset_view *view,
                                  long signr, size_t *total)
@@ -1404,11 +1420,11 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
          */
         fill_prstatus(&t->prstatus, t->task, signr);
         (void) view->regsets[0].get(t->task, &view->regsets[0],
-                                    0, sizeof(t->prstatus.pr_reg),
-                                    &t->prstatus.pr_reg, NULL);
+                                    0, PR_REG_SIZE(t->prstatus.pr_reg),
+                                    PR_REG_PTR(&t->prstatus), NULL);
 
         fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
-                  sizeof(t->prstatus), &t->prstatus);
+                  PRSTATUS_SIZE(t->prstatus), &t->prstatus);
         *total += notesize(&t->notes[0]);
 
         do_thread_regset_writeback(t->task, &view->regsets[0]);
@@ -1438,7 +1454,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
                                                   regset->core_note_type,
                                                   size, data);
                                 else {
-                                        t->prstatus.pr_fpvalid = 1;
+                                        SET_PR_FPVALID(&t->prstatus, 1);
                                         fill_note(&t->notes[i], "CORE",
                                                   NT_PRFPREG, size, data);
                                 }