On Wed, Apr 26, 2017 at 7:13 AM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > On Tue, Apr 25, 2017 at 10:15 PM, Zheng, Lv <lv.zheng@xxxxxxxxx> wrote: >> Hi, >> >>> From: Dan Williams [mailto:dan.j.williams@xxxxxxxxx] >>> Subject: Re: [RFC PATCH] ACPICA: Tables: Fix regression introduced by a too early mechanism enabling >>> >>> On Tue, Apr 25, 2017 at 6:49 PM, Lv Zheng <lv.zheng@xxxxxxxxx> wrote: >>> > In the Linux kernel side, acpi_get_table() hasn't been fully balanced by >>> > acpi_put_table() invocations. So it is not a good timing to report errors. >>> > The strict balanced validation count check should only be enabled after >>> > confirming that all kernel side invocations are safe. >>> >>> We've been living with this bug for 7 years, let's just go fix all >>> acpi_get_table() invocations to make sure they have a corresponding >>> acpi_put_table(). >> >> We knew that, you should have already seen a series internally or >> externally from me achieving this. >> It's done several years ago. But it takes long time to make the >> ACPICA part upstreamed. >> >> Now my plan is: >> 1. introduce the APIs but allow old usage models in order not to >> change old ACPICA behavior and its users. >> 2. fix all users >> 3. disallow old usage models. >> It's just my mistake to leak the final stage approach to the ACPICA >> upstream from my local repo. >> Now we can try to jump to the final step, but as far as I know, >> not only Linux, ACPICA itself also contains several broken cases. >> >> Bottom line of Linux kernel is we shouldn't break any running system. >> So IMO, we will need this commit during this special period. >> >> I didn't say the final step is wrong or is not required. >> We can do both in parallel. >> >> So could you please help to confirm if it's working. >> And I would like to suggest linux to take this first step fix along >> with other final step fixes during this period. > > I just think "this period" is very short and we can skip the band-aid > and go straight to auditing the 48 call sites of acpi_get_table. Moreover, I don't think this workaround is a workable approach because it leaves the ACPI_ERROR() in place to continue to spam the logs. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
