On Fri, Feb 22, 2013 at 4:30 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > On Friday, February 22, 2013 09:22:15 AM Thomas Gleixner wrote: >> On Fri, 22 Feb 2013, Rafael J. Wysocki wrote: >> > On Friday, February 22, 2013 02:40:58 AM Rafael J. Wysocki wrote: >> > > It looks like the hest_tab memory mapping is unmapped between acpi_hest_init() >> > > and aer_acpi_firmware_first(), but I have no idea what may be responsible for >> > > that. >> > > >> > > And the only relevant difference between now and before the commit above seems >> > > to be the change of the acpi_hest_init() ordering (which now is called earlier). >> > >> > We actually don't really need to do that thing so early, I think. It looks like >> > we only need to make it available early enough for the AER driver to be able to >> > use it, so I wonder if moving the acpi_hest_init() to a separate >> > subsys_initcall() will work around the problem. That is, something like the >> > patch below. >> >> Yes, that makes the machine boot. > > Although for a reason I didn't think about. > >> > But even if this helps, I will be wanting to understand what's up here. >> >> It's very simple. I have "acpi=off" on the command line. With that >> acpi_hest_init is never called, so hest_disable is not set ..... > > Well, that explains things (and means that acpi=off doesn't really get much > test coverage these days). > >> Brilliant stuff that. > > The appended patch should fix the breakage too, can you please verify? > > Rafael > > > --- > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > Subject: ACPI / APEI: Fix crash in apei_hest_parse() for acpi=off > > After commit 92ef2a2 (ACPI: Change the ordering of PCI root bridge > driver registrarion), acpi_hest_init() is never called for acpi=off > (acpi_disabled), so hest_disable is not set, but hest_tab is NULL, > which causes apei_hest_parse() to crash when it is called from > aer_acpi_firmware_first(). > > Fix that by making apei_hest_parse() check if hest_tab is not NULL > in addition to checking hest_disable. Also remove the now useless > acpi_disabled check from apei_hest_parse(). > > Reported-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > --- > drivers/acpi/apei/hest.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > Index: test/drivers/acpi/apei/hest.c > =================================================================== > --- test.orig/drivers/acpi/apei/hest.c > +++ test/drivers/acpi/apei/hest.c > @@ -89,7 +89,7 @@ int apei_hest_parse(apei_hest_func_t fun > struct acpi_hest_header *hest_hdr; > int i, rc, len; > > - if (hest_disable) > + if (hest_disable || !hest_tab) > return -EINVAL; > > hest_hdr = (struct acpi_hest_header *)(hest_tab + 1); > @@ -216,9 +216,6 @@ void __init acpi_hest_init(void) > return; > } > > - if (acpi_disabled) > - goto err; > - > status = acpi_get_table(ACPI_SIG_HEST, 0, > (struct acpi_table_header **)&hest_tab); > if (status == AE_NOT_FOUND) > Acked-by: Yinghai Lu <yinghai@xxxxxxxxxx> -- 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
