Use kinfo_getvmmap on FreeBSD to enumerate memory regions.

Use kinfo_getvmmap from libutil on FreeBSD to enumerate memory
regions in a running process instead of /proc/<pid>/map.  FreeBSD systems
do not mount procfs by default, but kinfo_getvmmap uses a sysctl that
is always available.

Skip memory regions for devices as well as regions an application has
requested to not be dumped via the MAP_NOCORE flag to mmap or
MADV_NOCORE advice to madvise.

gdb/ChangeLog:

	* configure.ac: AC_CHECK_LIB(util, kinfo_getvmmap).
	* configure: Regenerate.
	* config.in: Regenerate.
	* fbsd-nat.c [!HAVE_KINFO_GETVMMAP] (fbsd_read_mapping): Don't
        define.
	(fbsd_find_memory_regions): Use kinfo_getvmmap to
	enumerate memory regions if present.
This commit is contained in:
John Baldwin 2015-02-17 19:15:45 -05:00
parent 773eacf5b0
commit 25268153a1
5 changed files with 141 additions and 0 deletions

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@ -1,3 +1,13 @@
2015-03-13 John Baldwin <jhb@FreeBSD.org>
* configure.ac: AC_SEARCH_LIBS(kinfo_getvmmap, util).
* config.in: Regenerate.
* configure: Regenerate.
* fbsd-nat.c [!HAVE_KINFO_GETVMMAP] (fbsd_read_mapping): Don't
define.
(fbsd_find_memory_regions): Use kinfo_getvmmap to
enumerate memory regions if present.
2015-03-13 John Baldwin <jhb@FreeBSD.org>
* amd64fbsd-tdep.c (amd64fbsd_sigtramp_p): Style fixes.

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@ -213,6 +213,9 @@
/* Define to 1 if you have the <inttypes.h> header file. */
#undef HAVE_INTTYPES_H
/* Define to 1 if your system has the kinfo_getvmmap function. */
#undef HAVE_KINFO_GETVMMAP
/* Define if you have <langinfo.h> and nl_langinfo(CODESET). */
#undef HAVE_LANGINFO_CODESET

60
gdb/configure vendored
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@ -7159,6 +7159,66 @@ if test "$ac_res" != no; then :
fi
# On FreeBSD we may need libutil for kinfo_getvmmap (used by fbsd-nat.c).
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing kinfo_getvmmap" >&5
$as_echo_n "checking for library containing kinfo_getvmmap... " >&6; }
if test "${ac_cv_search_kinfo_getvmmap+set}" = set; then :
$as_echo_n "(cached) " >&6
else
ac_func_search_save_LIBS=$LIBS
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
/* Override any GCC internal prototype to avoid an error.
Use char because int might match the return type of a GCC
builtin and then its argument prototype would still apply. */
#ifdef __cplusplus
extern "C"
#endif
char kinfo_getvmmap ();
int
main ()
{
return kinfo_getvmmap ();
;
return 0;
}
_ACEOF
for ac_lib in '' util; do
if test -z "$ac_lib"; then
ac_res="none required"
else
ac_res=-l$ac_lib
LIBS="-l$ac_lib $ac_func_search_save_LIBS"
fi
if ac_fn_c_try_link "$LINENO"; then :
ac_cv_search_kinfo_getvmmap=$ac_res
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext
if test "${ac_cv_search_kinfo_getvmmap+set}" = set; then :
break
fi
done
if test "${ac_cv_search_kinfo_getvmmap+set}" = set; then :
else
ac_cv_search_kinfo_getvmmap=no
fi
rm conftest.$ac_ext
LIBS=$ac_func_search_save_LIBS
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_kinfo_getvmmap" >&5
$as_echo "$ac_cv_search_kinfo_getvmmap" >&6; }
ac_res=$ac_cv_search_kinfo_getvmmap
if test "$ac_res" != no; then :
test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
$as_echo "#define HAVE_KINFO_GETVMMAP 1" >>confdefs.h
fi

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@ -537,6 +537,11 @@ AM_ZLIB
# On HP/UX we may need libxpdl for dlgetmodinfo (used by solib-pa64.c).
AC_SEARCH_LIBS(dlgetmodinfo, [dl xpdl])
# On FreeBSD we may need libutil for kinfo_getvmmap (used by fbsd-nat.c).
AC_SEARCH_LIBS(kinfo_getvmmap, util,
[AC_DEFINE(HAVE_KINFO_GETVMMAP, 1,
[Define to 1 if your system has the kinfo_getvmmap function. ])])
AM_ICONV
# GDB may fork/exec the iconv program to get the list of supported character

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@ -26,6 +26,10 @@
#include <sys/types.h>
#include <sys/procfs.h>
#include <sys/sysctl.h>
#ifdef HAVE_KINFO_GETVMMAP
#include <sys/user.h>
#include <libutil.h>
#endif
#include "elf-bfd.h"
#include "fbsd-nat.h"
@ -62,6 +66,64 @@ fbsd_pid_to_exec_file (struct target_ops *self, int pid)
return NULL;
}
#ifdef HAVE_KINFO_GETVMMAP
/* Iterate over all the memory regions in the current inferior,
calling FUNC for each memory region. OBFD is passed as the last
argument to FUNC. */
int
fbsd_find_memory_regions (struct target_ops *self,
find_memory_region_ftype func, void *obfd)
{
pid_t pid = ptid_get_pid (inferior_ptid);
struct kinfo_vmentry *vmentl, *kve;
uint64_t size;
struct cleanup *cleanup;
int i, nitems;
vmentl = kinfo_getvmmap (pid, &nitems);
if (vmentl == NULL)
perror_with_name (_("Couldn't fetch VM map entries."));
cleanup = make_cleanup (free, vmentl);
for (i = 0; i < nitems; i++)
{
kve = &vmentl[i];
/* Skip unreadable segments and those where MAP_NOCORE has been set. */
if (!(kve->kve_protection & KVME_PROT_READ)
|| kve->kve_flags & KVME_FLAG_NOCOREDUMP)
continue;
/* Skip segments with an invalid type. */
if (kve->kve_type != KVME_TYPE_DEFAULT
&& kve->kve_type != KVME_TYPE_VNODE
&& kve->kve_type != KVME_TYPE_SWAP
&& kve->kve_type != KVME_TYPE_PHYS)
continue;
size = kve->kve_end - kve->kve_start;
if (info_verbose)
{
fprintf_filtered (gdb_stdout,
"Save segment, %ld bytes at %s (%c%c%c)\n",
(long) size,
paddress (target_gdbarch (), kve->kve_start),
kve->kve_protection & KVME_PROT_READ ? 'r' : '-',
kve->kve_protection & KVME_PROT_WRITE ? 'w' : '-',
kve->kve_protection & KVME_PROT_EXEC ? 'x' : '-');
}
/* Invoke the callback function to create the corefile segment.
Pass MODIFIED as true, we do not know the real modification state. */
func (kve->kve_start, size, kve->kve_protection & KVME_PROT_READ,
kve->kve_protection & KVME_PROT_WRITE,
kve->kve_protection & KVME_PROT_EXEC, 1, obfd);
}
do_cleanups (cleanup);
return 0;
}
#else
static int
fbsd_read_mapping (FILE *mapfile, unsigned long *start, unsigned long *end,
char *protection)
@ -137,3 +199,4 @@ fbsd_find_memory_regions (struct target_ops *self,
do_cleanups (cleanup);
return 0;
}
#endif