[PATCH 2/2] [nto] Improve ABI sniffing.

Aleksandar Ristovski
2015-10-20T18:11:31Z

Use qnx specific notes to figure out the OS.

gdb/ChangeLog:
* gdb/nto-tdep.c (QNX_NOTE_NAME, QNX_INFO_SECT_NAME): New defines.
(nto_sniff_abi_note_section): New function.
(nto_elf_osabi_sniffer): Use new function to recognize nto specific
binary.
---
gdb/nto-tdep.c | 46 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/gdb/nto-tdep.c b/gdb/nto-tdep.c
index e50d302..48826cb 100644
--- a/gdb/nto-tdep.c
+++ b/gdb/nto-tdep.c
@@ -32,6 +32,9 @@
#include "gdbcore.h"
#include "objfiles.h"

+#define QNX_NOTE_NAME "QNX"
+#define QNX_INFO_SECT_NAME "QNX_info"
+
#ifdef __CYGWIN__
#include <sys/cygwin.h>
#endif
@@ -332,12 +335,51 @@ nto_dummy_supply_regset (struct regcache *regcache, char *regs)
/* Do nothing. */
}

+static void
+nto_sniff_abi_note_section (bfd *abfd, asection *sect, void *obj)
+{
+ const char *sectname;
+ unsigned int sectsize;
+ char *note; // buffer holding the section contents
+ unsigned int namelen;
+ const char *name;
+
+ sectname = bfd_get_section_name (abfd, sect);
+ sectsize = bfd_section_size (abfd, sect);
+
+ /* TODO: limit the note size here, for now limit is 128 bytes
+ (enough to check the name and type). */
+ if (sectsize > 128)
+ sectsize = 128;
+
+ if (sectname && strstr (sectname, QNX_INFO_SECT_NAME) != NULL)
+ *(enum gdb_osabi *) obj = GDB_OSABI_QNXNTO;
+
+ if (sectname && strstr (sectname, "note") != NULL)
+ {
+ note = alloca (sectsize);
+ bfd_get_section_contents (abfd, sect, note, 0, sectsize);
+ namelen = (unsigned int) bfd_h_get_32 (abfd, note);
+ name = note + 12;
+
+ if (namelen > 0
+ && (0 == strcmp (name, QNX_NOTE_NAME)))
+ *(enum gdb_osabi *) obj = GDB_OSABI_QNXNTO;
+ }
+}
+
enum gdb_osabi
nto_elf_osabi_sniffer (bfd *abfd)
{
- if (nto_is_nto_target)
+ enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
+
+ bfd_map_over_sections (abfd,
+ nto_sniff_abi_note_section,
+ &osabi);
+
+ if (osabi == GDB_OSABI_UNKNOWN && nto_is_nto_target)
return nto_is_nto_target (abfd);
- return GDB_OSABI_UNKNOWN;
+ return osabi;
}

static const char *nto_thread_state_str[] =
--
1.9.1