[binutils-gdb] Release bfd_alloc memory in bfd_check_format_matches
Alan Modra
amodra@sourceware.org
Sat Jan 4 08:55:00 GMT 2020
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ea933f17c3c6b9fa1daf8d03baa34f7bec855d6c
commit ea933f17c3c6b9fa1daf8d03baa34f7bec855d6c
Author: Alan Modra <amodra@gmail.com>
Date: Thu Jan 2 17:39:32 2020 +1030
Release bfd_alloc memory in bfd_check_format_matches
It's a little tricky. We can release any memory back when we have a
match failure, but after a match success which we might want to
preserve for later use the high water mark must change to that of the
matched bfd.
* format.c (bfd_check_format_matches): Add preserve_match.
Save initial bfd state in "preserve", matched bfd state in
"preserve_match". Save just the first match. Release
bfd_alloc memory. Restore and finish preserved state as
appropriate on all function exit paths.
Diff:
---
bfd/ChangeLog | 8 ++++++++
bfd/format.c | 50 +++++++++++++++++++++++++++++++++++++-------------
2 files changed, 45 insertions(+), 13 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 8291a98..148de79 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,13 @@
2020-01-04 Alan Modra <amodra@gmail.com>
+ * format.c (bfd_check_format_matches): Add preserve_match.
+ Save initial bfd state in "preserve", matched bfd state in
+ "preserve_match". Save just the first match. Release
+ bfd_alloc memory. Restore and finish preserved state as
+ appropriate on all function exit paths.
+
+2020-01-04 Alan Modra <amodra@gmail.com>
+
* mmo.c (mmo_mkobject): Allocate tdata with bfd_zalloc.
2020-01-04 Alan Modra <amodra@gmail.com>
diff --git a/bfd/format.c b/bfd/format.c
index 5c30431..e53955e 100644
--- a/bfd/format.c
+++ b/bfd/format.c
@@ -219,7 +219,7 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
int match_count, best_count, best_match;
int ar_match_index;
unsigned int initial_section_id = _bfd_section_id;
- struct bfd_preserve preserve;
+ struct bfd_preserve preserve, preserve_match;
if (matching != NULL)
*matching = NULL;
@@ -247,7 +247,10 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
/* Presume the answer is yes. */
abfd->format = format;
save_targ = abfd->xvec;
- preserve.marker = NULL;
+
+ preserve_match.marker = NULL;
+ if (!bfd_preserve_save (abfd, &preserve))
+ goto err_ret;
/* If the target type was explicitly specified, just check that target. */
if (!abfd->target_defaulted)
@@ -289,6 +292,7 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
for (target = bfd_target_vector; *target != NULL; target++)
{
const bfd_target *temp;
+ void **high_water;
/* The binary target matches anything, so don't return it when
searching. Don't match the plugin target if we have another
@@ -306,6 +310,14 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
have sections attached, which will confuse the next
_bfd_check_format call. */
bfd_reinit (abfd, initial_section_id);
+ /* Free bfd_alloc memory too. If we have matched and preserved
+ a target then the high water mark is that much higher. */
+ if (preserve_match.marker)
+ high_water = &preserve_match.marker;
+ else
+ high_water = &preserve.marker;
+ bfd_release (abfd, *high_water);
+ *high_water = bfd_alloc (abfd, 1);
/* Change BFD's target temporarily. */
abfd->xvec = *target;
@@ -332,10 +344,6 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
match_priority = (*target)->match_priority;
#endif
- match_targ = temp;
- if (preserve.marker != NULL)
- bfd_preserve_finish (abfd, &preserve);
-
if (abfd->format != bfd_archive
|| (bfd_has_map (abfd)
&& bfd_get_error () != bfd_error_wrong_object_format))
@@ -374,8 +382,12 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
ar_match_index++;
}
- if (!bfd_preserve_save (abfd, &preserve))
- goto err_ret;
+ if (preserve_match.marker == NULL)
+ {
+ match_targ = temp;
+ if (!bfd_preserve_save (abfd, &preserve_match))
+ goto err_ret;
+ }
}
else if (bfd_get_error () != bfd_error_wrong_format)
goto err_ret;
@@ -448,18 +460,23 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
really shouldn't iterate on live bfd's. Note that saving the
whole bfd and restoring it would be even worse; the first thing
you notice is that the cached bfd file position gets out of sync. */
- if (preserve.marker != NULL)
- bfd_preserve_restore (abfd, &preserve);
+ if (preserve_match.marker != NULL)
+ bfd_preserve_restore (abfd, &preserve_match);
if (match_count == 1)
{
abfd->xvec = right_targ;
/* If we come out of the loop knowing that the last target that
matched is the one we want, then ABFD should still be in a usable
- state (except possibly for XVEC). */
+ state (except possibly for XVEC). This is not just an
+ optimisation. In the case of plugins a match against the
+ plugin target can result in the bfd being changed such that
+ it no longer matches the plugin target, nor will it match
+ RIGHT_TARG again. */
if (match_targ != right_targ)
{
bfd_reinit (abfd, initial_section_id);
+ bfd_release (abfd, preserve.marker);
if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
goto err_ret;
match_targ = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
@@ -477,6 +494,9 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
if (matching_vector)
free (matching_vector);
+ if (preserve_match.marker != NULL)
+ bfd_preserve_finish (abfd, &preserve_match);
+ bfd_preserve_finish (abfd, &preserve);
/* File position has moved, BTW. */
return TRUE;
@@ -491,8 +511,9 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
abfd->format = bfd_unknown;
if (matching_vector)
free (matching_vector);
- if (preserve.marker != NULL)
- bfd_preserve_restore (abfd, &preserve);
+ if (preserve_match.marker != NULL)
+ bfd_preserve_finish (abfd, &preserve_match);
+ bfd_preserve_restore (abfd, &preserve);
return FALSE;
}
@@ -515,6 +536,9 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
}
else if (matching_vector)
free (matching_vector);
+ if (preserve_match.marker != NULL)
+ bfd_preserve_finish (abfd, &preserve_match);
+ bfd_preserve_restore (abfd, &preserve);
return FALSE;
}
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