summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/fixmap.h
diff options
context:
space:
mode:
authorWilliam Grant <william.grant@canonical.com>2018-01-30 14:22:55 +0300
committerThomas Gleixner <tglx@linutronix.de>2018-01-30 17:30:35 +0300
commit55f49fcb879fbeebf2a8c1ac7c9e6d90df55f798 (patch)
tree809736850942a87b269772a1bb1a51b14dc13f60 /arch/x86/include/asm/fixmap.h
parent830c1e3d16b2c1733cd1ec9c8f4d47a398ae31bc (diff)
downloadlinux-55f49fcb879fbeebf2a8c1ac7c9e6d90df55f798.tar.xz
x86/mm: Fix overlap of i386 CPU_ENTRY_AREA with FIX_BTMAP
Since commit 92a0f81d8957 ("x86/cpu_entry_area: Move it out of the fixmap"), i386's CPU_ENTRY_AREA has been mapped to the memory area just below FIXADDR_START. But already immediately before FIXADDR_START is the FIX_BTMAP area, which means that early_ioremap can collide with the entry area. It's especially bad on PAE where FIX_BTMAP_BEGIN gets aligned to exactly match CPU_ENTRY_AREA_BASE, so the first early_ioremap slot clobbers the IDT and causes interrupts during early boot to reset the system. The overlap wasn't a problem before the CPU entry area was introduced, as the fixmap has classically been preceded by the pkmap or vmalloc areas, neither of which is used until early_ioremap is out of the picture. Relocate CPU_ENTRY_AREA to below FIX_BTMAP, not just below the permanent fixmap area. Fixes: commit 92a0f81d8957 ("x86/cpu_entry_area: Move it out of the fixmap") Signed-off-by: William Grant <william.grant@canonical.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/7041d181-a019-e8b9-4e4e-48215f841e2c@canonical.com
Diffstat (limited to 'arch/x86/include/asm/fixmap.h')
-rw-r--r--arch/x86/include/asm/fixmap.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index 64c4a30e0d39..e203169931c7 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -137,8 +137,10 @@ enum fixed_addresses {
extern void reserve_top_address(unsigned long reserve);
-#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
-#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
+#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
+#define FIXADDR_TOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_TOT_START (FIXADDR_TOP - FIXADDR_TOT_SIZE)
extern int fixmaps_set;