Bug 28509 - gcc-2.96-75 miscompiles rpm
gcc-2.96-75 miscompiles rpm
Product: Red Hat Linux
Classification: Retired
Component: gcc (Show other bugs)
alpha Linux
medium Severity medium
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Assigned To: Jakub Jelinek
David Lawrence
Depends On:
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Reported: 2001-02-20 17:00 EST by Jeff Johnson
Modified: 2007-04-18 12:31 EDT (History)
2 users (show)

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Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Last Closed: 2001-02-22 04:38:28 EST
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RHEL 7.3 requirements from Atomic Host:
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Attachments (Terms of Use)
Debugging patch to display miscompilation. (1.26 KB, patch)
2001-02-20 17:03 EST, Jeff Johnson
no flags Details | Diff

  None (edit)
Description Jeff Johnson 2001-02-20 17:00:26 EST
From Bugzilla Helper:
User-Agent: Mozilla/4.75 [en] (X11; U; Linux 2.2.16-24 alpha)

gcc-2.96-75 (and most versions since Red Hat 7.0) has been miscompiling

Reproducible: Always
Steps to Reproduce:
1. Apply patch to rpm-4.0.2-7x.src.rpm, build and install
2. Attempt to do "rpm --checksig signed package here"
3. Examine debugging output., the short in lead.signature_type has several
values, mostly wrong.
Comment 1 Jeff Johnson 2001-02-20 17:03:07 EST
Created attachment 10580 [details]
Debugging patch to display miscompilation.
Comment 2 Jakub Jelinek 2001-02-20 17:48:35 EST
I get with both -O2 and -O0 build:
*** readLead: signature_type 5
*** rpmCheckSig, after readLead: lead.signature_type 5
*** rpmCheckSig, before rpmReadSignature: l->signature_type 25441
*** rpmReadSignature: sigType 25441
error: /mnt/redhat/comps/dist/7.0.x/i386/openssh-2.3.0p1-4.i386.rpm: rpmReadSignature failed
What is the expected output and why you think it is actually
a miscompilation?
I'll read it carefully tomorrow.
Comment 3 Jakub Jelinek 2001-02-21 12:34:21 EST
I had to #undef ALPHA_LOSSAGE because otherwise the fault is in rpm source -
with ALPHA_LOSSAGE defined you rpmLead into one rpmlead structure and read from
a malloced one which was never initialized.
I've managed to minimize this into small testcase, am checking CVS gcc ATM.
Comment 4 Jakub Jelinek 2001-02-22 04:38:24 EST
Fixed by
2000-08-11  Richard Henderson  <rth@cygnus.com>

        * combine.c (simplify_shift_const): Obey SHIFT_COUNT_TRUNCATED.
which will be included in gcc-2.96-76.
(and you please remove ALPHA_LOSSAGE next time you build rpm).

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