Thread (6 messages) 6 messages, 3 authors, 2018-11-27

[PATCH 2/2] arm64: acpi: Prepare for longer MADTs

From: Lorenzo Pieralisi <hidden>
Date: 2018-11-01 11:31:46
Also in: linux-acpi, lkml

On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
The BAD_MADT_GICC_ENTRY check is a little too strict because
it rejects MADT entries that don't match the currently known
lengths. We should remove this restriction to avoid problems
if the table length changes. Future code which might depend on
additional fields should be written to validate those fields
before using them, rather than trying to globally check
known MADT version lengths.

Signed-off-by: Jeremy Linton <redacted>
---
 arch/arm64/include/asm/acpi.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
Hi Jeremy,

I assume there is no [PATCH 1/2] (to make sure I have not missed
anything).
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 709208dfdc8b..4d0946bd485a 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -22,12 +22,12 @@
 #include <asm/tlbflush.h>
 
 /* Macros for consistency checks of the GICC subtable of MADT */
-#define ACPI_MADT_GICC_LENGTH	\
-	(acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
+#define ACPI_MADT_GICC_MIN_LENGTH   ACPI_OFFSET(  \
+	struct acpi_madt_generic_interrupt, efficiency_class)
I would add a comment explaining why the efficiency_class offset
corresponds to the min length, I will do it myself before sending it
upstream.

I will take this patch and send it to Will/Catalin with ARM64 ACPI
material for v4.21.

Thanks,
Lorenzo
 
 #define BAD_MADT_GICC_ENTRY(entry, end)					\
-	(!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH ||	\
-	(unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end))
+	(!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \
+	(unsigned long)(entry) + (entry)->header.length > (end))
 
 /* Basic configuration for ACPI */
 #ifdef	CONFIG_ACPI
-- 
2.14.3
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help