Accepting request 751829 from devel:tools:compiler

- Fix assertion failure 'refd != NULL' in write_die [swo#24169].
  * dwz-fix-refd-NULL-assertion-in-write_die.patch
- Fix assertion failure 'off == cu_size' in recompute_abbrevs
  [swo#24764].
  * dwz-fix-assertion-off-cu_size-in-recompute_abbrevs.patch

OBS-URL: https://build.opensuse.org/request/show/751829
OBS-URL: https://build.opensuse.org/package/show/openSUSE:Factory/dwz?expand=0&rev=10
This commit is contained in:
Dominique Leuenberger 2019-12-07 14:11:41 +00:00 committed by Git OBS Bridge
commit 2e58eea1ec
4 changed files with 210 additions and 0 deletions

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@ -0,0 +1,138 @@
Fix assertion 'off == cu_size' in recompute_abbrevs
[ Backport of master commit 331eabd. ]
With an executable from PR25024, we manage to reproduce PR24764:
...
$ dwz -l0 clang-offload-bundler-10.0.0-0.20190817snap5.fc30.x86_64.debug
dwz: dwz.c:9920: recompute_abbrevs: Assertion `off == cu_size' failed.
Aborted (core dumped)
...
The problem is that the cu_size as computed during recompute_abbrevs is not
the same as was computed before during compute_abbrevs.
I tracked down the first DIE in the CU that has a different size, at 0xdf615:
...
<5><df615>: Abbrev Number: 65 (DW_TAG_formal_parameter)
<df616> DW_AT_type : <0xe33be>
<df618> DW_AT_artificial : 1
...
Using a debug patch, we can track the size of the DIE during compute_abbrevs:
...
init_new_die_offsets: intracusize: 2
init_new_die_offsets: start die_size: 0
init_new_die_offsets: add DIE code size to die_size: 1
init_new_die_offsets: add nr_refs * intracusize to die_size: 3
update_new_die_offsets: die_size: 3
update_new_die_offsets: die_size: 3
finalize_new_die_offsets: die_size: 3
...
and recompute_abbrevs:
...
init_new_die_offsets: intracusize: 3
init_new_die_offsets: start die_size: 0
init_new_die_offsets: add DIE code size to die_size: 1
init_new_die_offsets: add nr_refs * intracusize to die_size: 4
update_new_die_offsets: die_size: 4
update_new_die_offsets: die_size: 4
update_new_die_offsets: die_size: 4
finalize_new_die_offsets: die_size: 4
...
The difference starts in init_new_die_offsets, when adding intracusize, which
is different for compute_abbrevs and recompute_abbrevs (2 vs. 3).
The code in recompute_abbrevs that calculates intracusize for the relevant
init_new_die_offsets call is:
...
/* Need to be conservatively high estimate, as update_new_die_offsets
relies on the offsets always decreasing. cu_size at this point is
the size we will end up with in the end, but if cu_size is
sufficiently close (from bottom) to some uleb128 boundary (say
16384), init_new_die_offsets might return off above that boundary
and then update_new_die_offsets might fail its assertions on
reference to DIEs that crossed the uleb128 boundary. */
intracusize = size_of_uleb128 (2 * cu_size);
off = init_new_die_offsets (cu->cu_die, headersz, intracusize);
...
where the '2 * cu_size' is the result of commit d16aa5e "Fix up
recompute_abbrevs if cu_size is close below an uleb128 boundary and
init_new_die_offsets would return offset above that uleb128 boundary":
...
- intracusize = size_of_uleb128 (cu_size);
+ intracusize = size_of_uleb128 (2 * cu_size);
...
Reverting commit d16aa5e gets us an intracusize of 2 in recompute_abbrevs, and
fixes the assert. However, doing so reintroduces the assertion that was fixed
by the commit (at least, provided commit a4668e1 "Fix assertion failure in
create_import_tree" is also reverted):
...
$ dwz -l0 inkview.debug
dwz: dwz.c:8527: update_new_die_offsets: Assertion \
`die->u.p2.die_intracu_udata_size >= intracu_udata_size' failed.
Aborted (core dumped)
...
Fix the 'off == cu_size' assert (without introducing the regression for
inkview.debug) by:
- saving the intracusize used for the call to init_new_die_offsets in
compute_abbrevs, and
- reusing the saved intracusize for the call to init_new_die_offsets in
recompute_abbrevs.
Also tested with clang and CheckerOptionHandlingAnalyzerPlugin.so, for which
this PR also triggered.
2019-11-27 Tom de Vries <tdevries@suse.de>
PR dwz/24764
* dwz.c (struct dw_cu): Add initial_intracusize field.
(compute_abbrevs): Initalize initial_intracusize.
(recompute_abbrevs): Use initial_intracusize.
---
dwz.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/dwz.c b/dwz.c
index 7c7b401..928fefa 100644
--- a/dwz.c
+++ b/dwz.c
@@ -674,6 +674,9 @@ struct dw_cu
unsigned int cu_chunk;
/* Form chosen for intra-cu references. */
enum dwarf_form cu_intracu_form;
+ /* Intracusize argument to init_new_die_offsets. Set in compute_abbrevs,
+ used in recompute_abbrevs. */
+ unsigned int initial_intracusize;
};
/* Internal representation of a debugging information entry (DIE).
@@ -8405,6 +8408,7 @@ compute_abbrevs (DSO *dso)
intracusize = i;
}
while (1);
+ cu->initial_intracusize = intracusize;
off = init_new_die_offsets (cu->cu_die, headersz, intracusize);
do
{
@@ -9555,14 +9559,7 @@ recompute_abbrevs (dw_cu_ref cu, unsigned int cu_size)
}
else
{
- /* Need to be conservatively high estimate, as update_new_die_offsets
- relies on the offsets always decreasing. cu_size at this point is
- the size we will end up with in the end, but if cu_size is
- sufficiently close (from bottom) to some uleb128 boundary (say
- 16384), init_new_die_offsets might return off above that boundary
- and then update_new_die_offsets might fail its assertions on
- reference to DIEs that crossed the uleb128 boundary. */
- intracusize = size_of_uleb128 (2 * cu_size);
+ intracusize = cu->initial_intracusize;
off = init_new_die_offsets (cu->cu_die, headersz, intracusize);
do

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@ -0,0 +1,55 @@
Fix 'refd != NULL' assertion in write_die
[ Backport of master commits 6959430 and 7cc8aae. ]
When running dwz on a file that contains invalid DW_FORM_ref_addr attributes
(which has been observed to be generated by a google go compiler) we run
either into an assert:
...
$ dwz multidictionary
dwz: dwz.c:9461: write_die: Assertion `refd != NULL' failed.
Aborted (core dumped)
...
or a segmentation fault in case of low-mem mode:
...
$ dwz -l0 multidictionary
Segmentation fault (core dumped)
...
Fix this by erroring out instead:
...
$ dwz multidictionary
dwz: Couldn't find DIE at DW_FORM_ref_addr offset 0x97
...
2019-02-05 Tom de Vries <tdevries@suse.de>
PR dwz/24169
* dwz.c (write_die): Error out on invalid DW_FORM_ref_addr.
---
dwz.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/dwz.c b/dwz.c
index 928fefa..c7db337 100644
--- a/dwz.c
+++ b/dwz.c
@@ -28,6 +28,7 @@
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
+#include <inttypes.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
@@ -9124,6 +9125,9 @@ write_die (unsigned char *ptr, dw_cu_ref cu, dw_die_ref die,
? ptr_size : 4);
inptr += refcu->cu_version == 2 ? ptr_size : 4;
refd = off_htab_lookup (NULL, value);
+ if (refd == NULL || refd->die_tag == 0)
+ error (1, 0, "Couldn't find DIE at DW_FORM_ref_addr offset"
+ " 0x%" PRIx64, value);
assert (refd != NULL);
refdt = refd;
while (refdt->die_toplevel == 0)

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@ -1,3 +1,16 @@
-------------------------------------------------------------------
Thu Nov 28 12:56:34 UTC 2019 - Tom de Vries <tdevries@suse.com>
- Fix assertion failure 'refd != NULL' in write_die [swo#24169].
* dwz-fix-refd-NULL-assertion-in-write_die.patch
-------------------------------------------------------------------
Wed Nov 27 18:50:07 UTC 2019 - Tom de Vries <tdevries@suse.com>
- Fix assertion failure 'off == cu_size' in recompute_abbrevs
[swo#24764].
* dwz-fix-assertion-off-cu_size-in-recompute_abbrevs.patch
-------------------------------------------------------------------
Tue Nov 5 09:55:50 UTC 2019 - Tom de Vries <tdevries@suse.com>

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@ -75,6 +75,8 @@ NoSource: 0
Patch1: dwz-update-version-copyright-message.patch
Patch2: dwz-fix-die-no-multifile-propagation.patch
Patch3: dwz-fix-assertion-off-cu_size-in-recompute_abbrevs.patch
Patch4: dwz-fix-refd-NULL-assertion-in-write_die.patch
%if %{build_main}
%description
@ -105,6 +107,8 @@ This package contains the testsuite results from DWZ.
%setup -q -n dwz
%patch1 -p1
%patch2 -p1
%patch3 -p1
%patch4 -p1
%build
make %{?_smp_mflags} CFLAGS="%{optflags}"