On 11/17/2010 03:17 PM, Magnus Glantz wrote: > On 11/17/2010 11:36 AM, nodata wrote: >> On 17/11/10 10:20, drago01 wrote: >>> On Wed, Nov 17, 2010 at 10:17 AM, nodata<lsof@xxxxxxxxxxxx> wrote: >>>> On 17/11/10 08:57, Hans de Goede wrote: >>>>> Hi all, >>>>> >>>>> For those who do not know it yet, recent Fedora glibc updates include >>>>> an optimized memcpy (which gets used on some processors) which breaks the >>>>> 64 bit adobe flash plugin. >>>>> >>>>> The problem has been analyzed and is known, as well as a fix for it, see: >>>>> https://bugzilla.redhat.com/show_bug.cgi?id=638477 >>>>> >>>>> The problem still exists however. The glibc developers say that this is >>>>> not a glibc bug, but a flash plugin bug. And technically they are 100% >>>>> correct, and the adobe flash plugin is a buggy .... (no surprise there). >>>>> To be specific the flash plugin is doing overlapping memcpy-s which is >>>>> clearly not how memcpy is supposed to be used. But the way the flash >>>>> plugin does overlapping memcpy's happens to work fine as long as one as >>>>> the c library does the memcpy-s in forward direction. And the new memcpy >>>>> implementation does the memcpy in backward direction. >>>>> >>>>> The glibc developers being technically 100% correct is not helping our >>>>> end users in this case though. So we (The Fedora project) need to come up >>>>> with a solution to help our end users, many of whom want to use the adobe >>>>> flash plugin. >>>>> >>>>> This solution could be reverting the problem causing glibc change, or >>>>> maybe changing it to do forward memcpy's while still using the new SSE >>>>> instructions, or something more specific to the flash plugin, as long >>>>> as it will automatically fix things with a yum upgrade without requiring >>>>> any further user intervention. >>>>> >>>>> I would also like to point out that if this were to happen in Ubuntu >>>>> which we sometimes look at jealously for getting more attention / users >>>>> then us, the glibc change would likely be reverted immediately, as that >>>>> is the right thing to do from an end user pov. >>>>> >>>>> I've filed a ticket for FESCo to look into this, as I believe this >>>>> makes us look really bad, and the glibc maintainers do not seem to be >>>>> willing to fix it without some sort of intervention: >>>>> https://fedorahosted.org/fesco/ticket/501 >>>>> >>>>> Regards, >>>>> >>>>> Hans >>>> Is someone talking to Adobe about this? >>> Yes, see https://bugs.adobe.com/jira/browse/FP-5739 >> Adobe benefits from Flash in Linux. So it seems sensible to: >> >> 1. Get Adobe to commit to a fix soon WITH A $DATE >> 2. Agree to patch the change until $DATE >> 3. Adobe updates Flash, we revert the patch, everyone is happy > I've e-mailed a with Shu Wang at Adobe (who is the assigned contact for > this issue) about a date when they can have this fixed. > You've got the e-mail thread regarding this below: So we should be able simply to patch glibc, right? Can't see any reason not to. Andrew. -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
