Bug 589918

Summary: bad dwarf cfi data in ypserv binary
Product: Red Hat Enterprise Linux 6 Reporter: Mark Wielaard <mjw>
Component: ypservAssignee: Karel Klíč <kklic>
Status: CLOSED CURRENTRELEASE QA Contact: Ales Zelinka <azelinka>
Severity: medium Docs Contact:
Priority: low    
Version: 6.0CC: azelinka, rvokal
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: ypserv-2.19-18.el6 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2010-11-10 22:24:42 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Attachments:
Description Flags
python script to check for bad cfi in a binary none

Description Mark Wielaard 2010-05-07 10:03:13 UTC
Description of problem:

An old version of gcc generated bad dwarf cfi expressions. This would not impact the functioning of the package itself, but might make debugging the binary with gdb, or tracing with systemtap less practical. This isn't a very high priority. But if the package can be rebuild with a current toolchain, gcc-4.4.3-19.el6 or later, that would solve this issue. Background information: http://gcc.gnu.org/ml/gcc-patches/2010-04/msg01422.html This only affects a very small number of packages (and only the i686 binaries).

Version-Release number of selected component (if applicable):

ypserv-2.19-17.el6.i686 (/usr/lib/yp/yphelper, /usr/lib/yp/makedbm)

The attached check_cfi.py script (thanks to Petr Machata) can be used to check the output of readelf --debug-dump=frames to see whether the faulty dwarf cfi expressions are present in the binary. There should be no output, currently the output is:

readelf --debug-dump=frames /usr/lib/yp/yphelper | tail -n +3 | python check_cfi
.py
['00000000', '00000014', '00000000', 'CIE']
   DW_CFA_def_cfa: r4 (esp) ofs 4
   DW_CFA_offset: r8 (eip) at cfa-4
   DW_CFA_nop
   DW_CFA_nop
['000000ac', '00000040', '000000b0', 'FDE', 'cie=00000000', 'pc=08049550..08049e
48']
   DW_CFA_advance_loc: 4 to 08049554
>  DW_CFA_def_cfa: r1 (ecx) ofs 0
   DW_CFA_advance_loc: 9 to 0804955d
   DW_CFA_expression: r5 (ebp) (DW_OP_breg5: 0)
   DW_CFA_advance_loc: 17 to 0804956e
   DW_CFA_expression: r3 (ebx) (DW_OP_breg5: -12)
   DW_CFA_expression: r6 (esi) (DW_OP_breg5: -8)
   DW_CFA_expression: r7 (edi) (DW_OP_breg5: -4)
   DW_CFA_advance_loc: 1 to 0804956f
>  DW_CFA_def_cfa_expression (DW_OP_breg5: -16; DW_OP_deref)
   DW_CFA_advance_loc1: 206 to 0804963d
   DW_CFA_remember_state
>  DW_CFA_def_cfa_register: r1 (ecx)
   DW_CFA_advance_loc: 1 to 0804963e
   DW_CFA_restore: r3 (ebx)
   DW_CFA_advance_loc: 1 to 0804963f
   DW_CFA_restore: r6 (esi)
   DW_CFA_advance_loc: 1 to 08049640
   DW_CFA_restore: r7 (edi)
   DW_CFA_advance_loc: 1 to 08049641
   DW_CFA_restore: r5 (ebp)
   DW_CFA_advance_loc: 3 to 08049644
   DW_CFA_def_cfa: r4 (esp) ofs 4
   DW_CFA_advance_loc: 4 to 08049648
   DW_CFA_restore_state
error in instr #16, DW_CFA_def_cfa_register


readelf --debug-dump=frames /usr/lib/yp/makedbm | tail -n +3 | python check_cfi.py
['00000000', '00000014', '00000000', 'CIE']
   DW_CFA_def_cfa: r4 (esp) ofs 4
   DW_CFA_offset: r8 (eip) at cfa-4
   DW_CFA_nop
   DW_CFA_nop
['00000060', '00000044', '00000064', 'FDE', 'cie=00000000', 'pc=08048dc0..08049ff2']
   DW_CFA_advance_loc: 4 to 08048dc4
>  DW_CFA_def_cfa: r1 (ecx) ofs 0
   DW_CFA_advance_loc: 9 to 08048dcd
   DW_CFA_expression: r5 (ebp) (DW_OP_breg5: 0)
   DW_CFA_advance_loc: 5 to 08048dd2
   DW_CFA_expression: r6 (esi) (DW_OP_breg5: -8)
   DW_CFA_expression: r7 (edi) (DW_OP_breg5: -4)
   DW_CFA_advance_loc: 12 to 08048dde
   DW_CFA_expression: r3 (ebx) (DW_OP_breg5: -12)
   DW_CFA_advance_loc: 1 to 08048ddf
>  DW_CFA_def_cfa_expression (DW_OP_breg5: -16; DW_OP_deref)
   DW_CFA_advance_loc2: 640 to 0804905f
   DW_CFA_remember_state
>  DW_CFA_def_cfa_register: r1 (ecx)
   DW_CFA_advance_loc: 1 to 08049060
   DW_CFA_restore: r3 (ebx)
   DW_CFA_advance_loc: 1 to 08049061
   DW_CFA_restore: r6 (esi)
   DW_CFA_advance_loc: 1 to 08049062
   DW_CFA_restore: r7 (edi)
   DW_CFA_advance_loc: 1 to 08049063
   DW_CFA_restore: r5 (ebp)
   DW_CFA_advance_loc: 3 to 08049066
   DW_CFA_def_cfa: r4 (esp) ofs 4
   DW_CFA_advance_loc: 1 to 08049067
   DW_CFA_restore_state
   DW_CFA_nop
   DW_CFA_nop
error in instr #17, DW_CFA_def_cfa_register

Comment 1 Mark Wielaard 2010-05-07 10:25:33 UTC
Created attachment 412294 [details]
python script to check for bad cfi in a binary

Comment 3 RHEL Program Management 2010-05-07 11:31:03 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux major release.  Product Management has requested further
review of this request by Red Hat Engineering, for potential inclusion in a Red
Hat Enterprise Linux Major release.  This request is not yet committed for
inclusion.

Comment 6 releng-rhel@redhat.com 2010-11-10 22:24:42 UTC
Red Hat Enterprise Linux 6.0 is now available and should resolve
the problem described in this bug report. This report is therefore being closed
with a resolution of CURRENTRELEASE. You may reopen this bug report if the
solution does not work for you.