Bug 162545 - wrong dwarf register numbers generated
wrong dwarf register numbers generated
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: binutils (Show other bugs)
x86_64 Linux
medium Severity medium
: ---
: ---
Assigned To: Jakub Jelinek
Depends On:
Blocks: 156322
  Show dependency treegraph
Reported: 2005-07-06 00:02 EDT by Ulrich Drepper
Modified: 2007-11-30 17:07 EST (History)
0 users

See Also:
Fixed In Version: RHSA-2005-673
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2005-10-05 08:44:47 EDT
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)

  None (edit)
Description Ulrich Drepper 2005-07-06 00:02:50 EDT
Description of problem:
The assembler currently generated incorrect dwarf register numbers if symbolic
register names are used in cfi instructions.  This is on x86-64 only.  I expect
that ISVs will start using unwind info now since it is much more efficient then
old methods for thread cancellation.  And C++ unwinding needs the info in any
case and if exceptions need to be thrown throughasm code the ISVs hopefully will
use the cfi instructions and symbolic register names.

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

How reproducible:

Steps to Reproduce:
1.use .cfi_register(rbx)
Actual results:
dwarf2 output shows rdx used

Expected results:
rbx in dwarf2 info

Additional info:
This bug has the potential to cause long standing problems in ISV applications
if the ISV starts using cfi instructions.  The patch is harmless and tested in FC4.
Comment 1 Jakub Jelinek 2005-07-06 05:57:59 EDT
The patch is http://sources.redhat.com/ml/binutils/2005-05/msg00243.html
The incorrectly numbered registers are rdx (ought to be 1, but gas emits 3),
rbx (should be 3 instead of 1), rsi (should be 4 instead of 5) and rdi (should be
5 instead of 4).

In glibc sources this problem occurs in 4 places:
./sysdeps/unix/sysv/linux/x86_64/setcontext.S:  cfi_def_cfa(%rdi, 0)
./sysdeps/unix/sysv/linux/x86_64/setcontext.S:  cfi_offset(%rbx,oRBX)
./sysdeps/x86_64/__longjmp.S:   cfi_def_cfa(%rdi, 0)
./sysdeps/x86_64/__longjmp.S:   cfi_offset(%rbx,JB_RBX*8)
Comment 5 Red Hat Bugzilla 2005-10-05 08:44:47 EDT
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.


Note You need to log in before you can comment on or make changes to this bug.