On 12/11/2014 03:05 PM, Mark Wielaard wrote:
While rebasing my work on top of Josh attrabbrev reading speedups
I noticed a typo/thinko in my form_val_len bound checking patch.
We should check against the die->cu->endp, not the abbrev endp.
In that case, I don't think you need endp as a parameter at all. Just
use cu->endp as needed, and prevent this mistake from ever happening.
Maybe you could also check valp >= cu->startp while you're at it, but
that's probably an ok invariant to just assume.
Also along these lines, the dbg parameter could just use cu->dbg as
needed. Saving parameters probably won't do much for performance in
this case, nor is changing to a pointer read likely to hurt. It does
help code clarity though, IMO.
Signed-off-by: Mark Wielaard <mjw(a)redhat.com>
---
libdw/ChangeLog | 6 ++++++
libdw/dwarf_child.c | 2 +-
libdw/dwarf_getattrs.c | 2 +-
3 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 69592a7..8b00970 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,9 @@
+2014-12-11 Mark Wielaard <mjw(a)redhat.com>
+
+ * dwarf_child.c (__libdw_find_attr): Call __libdw_form_val_len with
+ die->cu->endp, not the abbrev endp.
+ * dwarf_getattrs.c (dwarf_getattrs): Likewise.
+
2014-12-10 Josh Stone <jistone(a)redhat.com>
* libdwP.h (Dwarf_CU): Add startp and endp boundaries.
diff --git a/libdw/dwarf_child.c b/libdw/dwarf_child.c
index 2a5d379..46d010d 100644
--- a/libdw/dwarf_child.c
+++ b/libdw/dwarf_child.c
@@ -95,7 +95,7 @@ __libdw_find_attr (Dwarf_Die *die, unsigned int search_name,
if (attr_form != 0)
{
size_t len = __libdw_form_val_len (dbg, die->cu, attr_form, readp,
- endp);
+ die->cu->endp);
if (unlikely (len == (size_t) -1l))
{
diff --git a/libdw/dwarf_getattrs.c b/libdw/dwarf_getattrs.c
index 9ea70fc..f6453c7 100644
--- a/libdw/dwarf_getattrs.c
+++ b/libdw/dwarf_getattrs.c
@@ -107,7 +107,7 @@ dwarf_getattrs (Dwarf_Die *die, int (*callback) (Dwarf_Attribute *,
void *),
if (attr.form != 0)
{
size_t len = __libdw_form_val_len (dbg, die->cu, attr.form,
- die_addr, endp);
+ die_addr, die->cu->endp);
if (unlikely (len == (size_t) -1l))
/* Something wrong with the file. */