x32 write_linux_prstatus

x32 uses an elf_gregset64_t in the prstatus struct, which aligns the
struct to eight bytes.  This means four bytes of padding at the end of
the struct.

	* amd64-linux-tdep.c: Include elf-bfd.h.
	(amd64_x32_write_linux_prstatus): New function.
	(amd64_x32_linux_init_abi): Use it.
	* linux-tdep.c (linux_collect_regset_section_cb): Allocate an
	extra four bytes for regset buffer.
	* gdbarch.sh (elfcore_write_linux_prstatus): Remove const from info.
	* gdbarch.c: Regenerate.
	* gdbarch.h: Regenerate.

5 files changed, 27 insertions, 6 deletions

diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c
index c545cd0..cdde600 100644
--- a/gdb/amd64-linux-tdep.c
+++ b/gdb/amd64-linux-tdep.c
@@ -28,6 +28,7 @@
 #include "gdbtypes.h"
 #include "reggroups.h"
 #include "regset.h"
+#include "elf-bfd.h"            /* for elfcore_write_* */
 #include "parser-defs.h"
 #include "user-regs.h"
 #include "amd64-linux-tdep.h"
@@ -1646,6 +1647,25 @@ amd64_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
       &amd64_linux_xstateregset, "XSAVE extended state", cb_data);
 }
 
+/* The standard elfcore_write_linux_prstatus32 isn't quite correct
+   for x32, which needs an extra 4 bytes of padding at the end of
+   the note.  */
+
+static char *
+amd64_x32_write_linux_prstatus (bfd *obfd,
+				char *buf,
+				int *bufsize,
+				struct elf_internal_linux_prstatus *prstatus)
+{
+  /* Tack pr_fpvalid to end of pr_regs.  */
+  bfd_put_32 (obfd, prstatus->pr_fpvalid,
+	      (char *) prstatus->pr_reg + prstatus->pr_reg_size);
+  prstatus->pr_reg_size += 4;
+  /* pr_fpvalid becomes padding.  */
+  prstatus->pr_fpvalid = 0;
+  return elfcore_write_linux_prstatus32 (obfd, buf, bufsize, prstatus);
+}
+
 /* The instruction sequences used in x86_64 machines for a
    disabled is-enabled probe.  */
 
@@ -2075,7 +2095,7 @@ amd64_x32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   /* x32's layout is not compatible with the 32-bit layout.  */
   set_gdbarch_elfcore_write_linux_prstatus
-    (gdbarch, gdb_deprecated_elfcore_write_linux_prstatus);
+    (gdbarch, amd64_x32_write_linux_prstatus);
 
   amd64_x32_init_abi (info, gdbarch);
 
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index fe0acbc..58f8ce5 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -3481,7 +3481,7 @@ gdbarch_elfcore_write_linux_prstatus_p (struct gdbarch *gdbarch)
 }
 
 char *
-gdbarch_elfcore_write_linux_prstatus (struct gdbarch *gdbarch, bfd *obfd, char *note_data, int *note_size, const struct elf_internal_linux_prstatus *info)
+gdbarch_elfcore_write_linux_prstatus (struct gdbarch *gdbarch, bfd *obfd, char *note_data, int *note_size, struct elf_internal_linux_prstatus *info)
 {
   gdb_assert (gdbarch != NULL);
   gdb_assert (gdbarch->elfcore_write_linux_prstatus != NULL);
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 5e00b32..7e6e8ca 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -833,8 +833,8 @@ extern void set_gdbarch_elfcore_write_linux_prpsinfo (struct gdbarch *gdbarch, g
 
 extern int gdbarch_elfcore_write_linux_prstatus_p (struct gdbarch *gdbarch);
 
-typedef char * (gdbarch_elfcore_write_linux_prstatus_ftype) (bfd *obfd, char *note_data, int *note_size, const struct elf_internal_linux_prstatus *info);
-extern char * gdbarch_elfcore_write_linux_prstatus (struct gdbarch *gdbarch, bfd *obfd, char *note_data, int *note_size, const struct elf_internal_linux_prstatus *info);
+typedef char * (gdbarch_elfcore_write_linux_prstatus_ftype) (bfd *obfd, char *note_data, int *note_size, struct elf_internal_linux_prstatus *info);
+extern char * gdbarch_elfcore_write_linux_prstatus (struct gdbarch *gdbarch, bfd *obfd, char *note_data, int *note_size, struct elf_internal_linux_prstatus *info);
 extern void set_gdbarch_elfcore_write_linux_prstatus (struct gdbarch *gdbarch, gdbarch_elfcore_write_linux_prstatus_ftype *elfcore_write_linux_prstatus);
 
 /* Find core file memory regions */
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 71e3e8c..c10ac6a 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -703,7 +703,7 @@ M:char *:make_corefile_notes:bfd *obfd, int *note_size:obfd, note_size
 # as we call the Linux generic routines in bfd to write notes by
 # default.
 F:char *:elfcore_write_linux_prpsinfo:bfd *obfd, char *note_data, int *note_size, const struct elf_internal_linux_prpsinfo *info:obfd, note_data, note_size, info
-F:char *:elfcore_write_linux_prstatus:bfd *obfd, char *note_data, int *note_size, const struct elf_internal_linux_prstatus *info:obfd, note_data, note_size, info
+F:char *:elfcore_write_linux_prstatus:bfd *obfd, char *note_data, int *note_size, struct elf_internal_linux_prstatus *info:obfd, note_data, note_size, info
 
 # Find core file memory regions
 M:int:find_memory_regions:find_memory_region_ftype func, void *data:func, data
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index d432c47..a49a0f0 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -1574,7 +1574,8 @@ linux_collect_regset_section_cb (const char *sect_name, int size,
 
   gdb_assert (regset && regset->collect_regset);
 
-  buf = (char *) xmalloc (size);
+  /* Extra 4 bytes for use by amd64_x32_write_linux_prstatus.  */
+  buf = (char *) xmalloc (size + 4);
   regset->collect_regset (regset, data->regcache, -1, buf, size);
 
   /* PRSTATUS still needs to be treated specially.  */