[PATCH] attributes: fix memEQs shared #14072
Comments
From @rurbanThis is a bug report for perl from rurban@cpanel.net, attributes: fix memEQs shared This bug blocks sv_grow and future string comparison improvements. Flags: Site configuration information for perl 5.21.4: Configured by rurban at Mon Sep 1 04:59:49 CDT 2014. Summary of my perl5 (revision 5 version 21 subversion 4) configuration: Locally applied patches: @INC for perl 5.21.4: Environment for perl 5.21.4: |
From @rurban0001-attributes-fix-memEQs-shared.patchFrom 776476c29f4b1a645837d5e6193c1c42710d0c2d Mon Sep 17 00:00:00 2001
From: Reini Urban <rurban@x-ray.at>
Date: Thu, 4 Sep 2014 09:49:15 -0500
Subject: [PATCH] attributes: fix memEQs shared
Do not access memory buffers shorter than 6, and also check for
longer buffers starting with "shared". This bug caused an ASAN error with
my sv_grow performance improvement on short strings (commit 880c169,
reverted with 3c239be),
and went undetected because the shortest strings are 10 byte long.
---
ext/attributes/attributes.xs | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git ext/attributes/attributes.xs ext/attributes/attributes.xs
index dbb644d..2238050 100644
--- ext/attributes/attributes.xs
+++ ext/attributes/attributes.xs
@@ -97,11 +97,11 @@ modify_SV_attributes(pTHX_ SV *sv, SV **retlist, SV **attrlist, int numattrs)
}
break;
default:
- if (memEQs(name, 6, "shared")) {
- if (negated)
- Perl_croak(aTHX_ "A variable may not be unshared");
- SvSHARE(sv);
- continue;
+ if (len == 6 && memEQs(name, 6, "shared")) {
+ if (negated)
+ Perl_croak(aTHX_ "A variable may not be unshared");
+ SvSHARE(sv);
+ continue;
}
break;
}
--
2.1.0
|
From @doughera88On Thu, Sep 04, 2014 at 07:57:21AM -0700, rurban @ cpanel . net wrote:
Thanks for the quick and accurate diagnosis and fix. I've applied Thanks, -- |
|
The RT System itself - Status changed from 'new' to 'open' |
From @rurbanOn 09/04/2014 11:47 AM, Andy Dougherty via RT wrote:
I see. Thanks! In a subsequent patch I want to change min. SvLEN to wordsize (4|8) with Should be much faster I hope. It was much faster in my tests because we |
From @bulk88On Thu Sep 04 09:47:40 2014, doughera wrote:
gdd36996 isnt a known commit -- |
From @TuxOn Mon, 8 Sep 2014 06:33:34 -0700, "bulk88 via RT"
Drop the leading g $ git show dd36996 Correct usage of memEQs in attributes.xs [perl #122701] Reported and diagnosed by Reini Urban <rurban@cpanel.net>. The call to -- |
From @rurbanOn 09/08/2014 08:33 AM, bulk88 via RT wrote:
It is known. The first char specifies the version control software (g for git, s for $ git describe |
|
@cpansprout - Status changed from 'open' to 'resolved' |
Migrated from rt.perl.org#122701 (status was 'resolved')
Searchable as RT122701$
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