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) -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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
