I agree, it should be allocated on the stack, like it is most everywhere else. >-----Original Message----- >From: linux-acpi-owner@xxxxxxxxxxxxxxx [mailto:linux-acpi- >owner@xxxxxxxxxxxxxxx] On Behalf Of Pavel Machek >Sent: Tuesday, November 25, 2008 3:05 AM >To: kernel list; ACPI mailing list; Brown, Len >Subject: acpi_evaluate_integer broken by design > > >Now I know why I had strange "scheduling in atomic" problems: >acpi_evaluate_integer() does malloc(..., irqs_disabled() ? GFP_ATOMIC >: GFP_KERNEL)... which is (of course) broken. > >There's no way to reliably tell if we need GFP_ATOMIC or not from >code, this one for example fails to detect spinlocks held. > >Fortunately, allocation seems small enough to be done on stack. > >Signed-off-by: Pavel Machek <pavel@xxxxxxx> > >diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c >index e827be3..f844941 100644 >--- a/drivers/acpi/utils.c >+++ b/drivers/acpi/utils.c >@@ -259,34 +259,26 @@ acpi_evaluate_integer(acpi_handle handle > struct acpi_object_list *arguments, unsigned long long >*data) > { > acpi_status status = AE_OK; >- union acpi_object *element; >+ union acpi_object element; > struct acpi_buffer buffer = { 0, NULL }; > >- > if (!data) > return AE_BAD_PARAMETER; > >- element = kzalloc(sizeof(union acpi_object), irqs_disabled() ? >GFP_ATOMIC: GFP_KERNEL); >- if (!element) >- return AE_NO_MEMORY; >- > buffer.length = sizeof(union acpi_object); >- buffer.pointer = element; >+ buffer.pointer = &element; > status = acpi_evaluate_object(handle, pathname, arguments, &buffer); > if (ACPI_FAILURE(status)) { > acpi_util_eval_error(handle, pathname, status); >- kfree(element); > return status; > } > >- if (element->type != ACPI_TYPE_INTEGER) { >+ if (element.type != ACPI_TYPE_INTEGER) { > acpi_util_eval_error(handle, pathname, AE_BAD_DATA); >- kfree(element); > return AE_BAD_DATA; > } > >- *data = element->integer.value; >- kfree(element); >+ *data = element.integer.value; > > ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data)); > > > > >-- >(english) http://www.livejournal.com/~pavelmachek >(cesky, pictures) >http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html >-- >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 -- 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
