> -----Original Message----- > From: Jonathan Cameron > Sent: Saturday, July 18, 2020 6:00 AM > To: linux-mm@xxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; x86@xxxxxxxxxx > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>; Bjorn Helgaas > <bhelgaas@xxxxxxxxxx>; linux-pci@xxxxxxxxxxxxxxx; martin@xxxxxxxxxx; Ingo > Molnar <mingo@xxxxxxxxxx>; linux-ia64@xxxxxxxxxxxxxxx; Tony Luck > <tony.luck@xxxxxxxxx>; Fenghua Yu <fenghua.yu@xxxxxxxxx>; Thomas > Gleixner <tglx@xxxxxxxxxxxxx>; Linuxarm <linuxarm@xxxxxxxxxx>; Dan > Williams <dan.j.williams@xxxxxxxxx>; Song Bao Hua (Barry Song) > <song.bao.hua@xxxxxxxxxxxxx>; Jonathan Cameron > <jonathan.cameron@xxxxxxxxxx> > Subject: [PATCH v2 5/6] ACPI: Remove side effect of partly creating a node in > acpi_get_node > > acpi_get_node calls acpi_get_pxm to evaluate the _PXM AML method for > entries found in DSDT/SSDT. ACPI 6.3 sec 6.2.14 states > "_PXM evaluates to an integer that identifies a device as belonging to > a Proximity Domain defined in the System Resource Affinity Table (SRAT)." > > Hence a _PXM method should not result in creation of a new NUMA node. > Before this patch, _PXM could result in partial instantiation of > NUMA node, missing elements such as zone lists. A call to devm_kzalloc > for example results in a null pointer dereference. > > This patch therefore replaces the acpi_map_pxm_to_node with a call > to pxm_to_node. > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Reviewed-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx> > --- > drivers/acpi/numa/srat.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c > index 8ef44ee0d76b..697a5c9e2eb5 100644 > --- a/drivers/acpi/numa/srat.c > +++ b/drivers/acpi/numa/srat.c > @@ -444,6 +444,6 @@ int acpi_get_node(acpi_handle handle) > > pxm = acpi_get_pxm(handle); > > - return acpi_map_pxm_to_node(pxm); > + return pxm_to_node(pxm); > } > EXPORT_SYMBOL(acpi_get_node); > -- > 2.19.1
